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  5. 中年群体时间感知加速的心理与生理机制研究综述

中年群体时间感知加速的心理与生理机制研究综述

深度研究匿名用户发表于 2025年12月23日 18:270阅读
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1. 中年群体时间感知加速的现象特征与测量方法

1.1 现象的普遍性与主观描述

中年群体普遍存在一种“时间飞逝”的主观体验，即随着年龄增长，感觉时间流逝的速度越来越快。这种现象在日常生活中表现为多种特征，例如，过去某个时期的记忆变得模糊，许多事件似乎都压缩在了一起，难以清晰分辨具体的发生时间点。重要的生活节点，如生日、节假日或周年纪念日，感觉上间隔时间显著缩短，仿佛“一眨眼就过去了”。这种主观感受并非个例，而是跨文化背景的普遍现象，多数人认为随着年龄增长，时间似乎过得更快 12。

这种“时间加速”的感知体现在日常生活的方方面面。例如，与年轻时相比，中年人可能会觉得一周、一个月甚至一年过得非常快，日常例行公事占据了大部分时间，而那些具有里程碑意义的事件却显得稀疏且迅速闪过。记忆研究表明，人们对过去五年时间流逝的判断与能够回忆起的有意义事件数量相关。当受试者回忆起至少四个重要事件时，激活记忆会减缓时间流逝的感知；而回忆起较少事件时，反而会加速时间的感知 3。这提示我们，记忆内容的丰富程度在一定程度上影响着主观时间体验。

尽管这种主观体验在不同文化背景下具有共性，但在具体表达和影响程度上可能存在差异。例如，在强调长期规划和积累的文化中，对时间流逝的敏感性可能更高，因为时间被视为一种宝贵的、有限的资源。社会情绪选择理论也指出，当人们感知到生命时间有限时，会优先考虑情绪调节相关的目标，而非知识获取，这可能导致对时间流逝的敏感性增强 45。这种对未来时间有限性的感知，在某种程度上与中年群体普遍的“时间飞逝”感相呼应，构成了一种跨文化背景下的心理共性。

1.2 客观实验中的量化验证

除了主观描述，时间感知加速的现象也在客观实验中得到了量化验证。研究者通常采用时间估计任务来评估不同年龄群体的时程判断能力，常见的任务包括时间二分任务（time bisection）、时间复制任务（time reproduction）和时间生产任务（time production）等67。在这些任务中，参与者需要对给定时间间隔进行估计、复现或生成，通过比较其主观估计与实际物理时间之间的差异来量化时间感知偏差。

多项研究表明，随着年龄增长，人们在这些任务中的表现会出现显著变化。例如，一项针对20至85岁成年人进行的综合性研究发现，显性时间处理的精确性会随着年龄的增长而降低6。具体来说，年龄较大的参与者在时间二分任务中表现出更平坦的心理测量曲线（psychometric curve）和更高的最小可觉差（just noticeable difference, JND）指标，这表明他们对时间间隔的辨别能力下降，感知精度降低6。

另一项研究发现，中年和老年群体在时间估计任务中普遍倾向于感知时间加速。例如，一项对20至80岁人群的研究显示，老年组倾向于高估未被占据的时间间隔8。在时间复制任务中，老年人在复制时间间隔时可能出现更大的时间估计偏差79。有研究指出，在时间复制任务中，随着年龄增长，时间判断的精确性有所下降，并可能伴随对时间间隔的显著高估或低估7。

表1总结了不同时间估计任务中年龄对时间感知的影响：

任务类型描述年龄增长后的普遍趋势引用
时间二分任务判断一个比较刺激的时间间隔是更接近两个标准刺激中的哪一个精确性降低，心理测量曲线更平坦，最小可觉差增大6
时间复制任务观察一个时间间隔后，尝试以相同长度复现该时间间隔精确性降低，时间估计偏差增大79
时间生产任务按照要求生成指定长度的时间间隔（如“请拍手5秒钟”）复杂性较高，可能受注意力等多种因素影响，结果不如复制任务一致7

这些客观实验数据与中年群体“时间飞逝”的主观体验相互印证，共同揭示了时间感知随年龄增长而加速的普遍现象。同时，有研究指出，尽管显性时间处理（explicit timing）随年龄增长而衰退，但隐性时间处理（implicit timing），即无意识的时间加工，可能在成年期保持相对稳定，不受年龄影响6。这意味着，虽然中年人可能更难精确判断时间长度，但他们对时间信息的自动加工能力可能依然保持较好水平。

2. 心理层面的解释机制

2.1 社会情绪选择理论的视角

社会情绪选择理论（Socioemotional Selectivity Theory, SST）为理解中年群体时间感知加速提供了一个有力的心理学框架。该理论的核心观点认为，个体对未来时间有限性的感知，深刻地影响着其社会动机和目标优先级 4。具体而言，当人们感知到生命时间是开放的、无限的（如青少年和成年早期），他们倾向于优先追求与知识获取、未来导向和视野拓展相关的目标。然而，当中年及以后，个体开始感知到未来时间有限时，其动机重心会发生转变，情感目标（如情绪调节、亲密关系维护、自我实现等）将取代知识获取目标，成为优先考虑项 41011。

这种“时间有限性”的感知，直接导致了对时间流逝敏感性的增强。中年人通常已经完成了职业生涯的初步积累，家庭关系趋于稳定，但同时也面临着衰老和死亡的现实挑战，这使得他们对剩余生命时间的珍视程度显著提高 12。时间不再被视为取之不尽的资源，而是有限且日益减少的宝贵财富。这种内在的心理转变，使得中年人更加关注当下体验的质量和情绪的积极性，而非简单地积累信息或追求长远但抽象的目标 10。

当情绪调节成为主要目标时，人们倾向于投入到能够立即带来情感满足的活动中，并维护已有的亲密关系，而不是扩展新的社交圈或学习新知识 4。这种选择可能导致日常生活中重复性、程式化的活动增多，而新颖、刺激的体验相对减少。新异体验的减少，反过来又会影响记忆编码的密度，使得日子在回顾时显得更加“平淡无奇”，从而加剧了“时间过得快”的主观感受。例如，有研究发现，当个体感知到未来时间延长时，他们表现出更少的抑郁症状和更高的生活满意度，这间接证明了时间感知与情绪状态的密切关联 5。

因此，社会情绪选择理论认为，中年阶段对未来时间有限性的感知，促使个体将重心从未来导向的知识获取转向当下导向的情绪调节。这种动机优先级的转变，使得中年人对时间的流逝更加敏感和在意，从而更容易产生“时间加速”的主观体验。这种心理机制并非基于生理的直接变化，而是源于对生命进程的认知评估和情绪需求的变化。

2.2 记忆编码密度与时间判断

中年群体时间感知加速的另一个重要心理机制是记忆编码密度的变化，这与日常生活中新异体验的减少密切相关。时间感知与记忆之间存在深刻的联系：人们对持续时间的判断通常依赖于对所发生事件的记忆编码和提取 13。当记忆中包含的事件或信息越密集、越独特，主观上感知到的时间就越长；反之，当记忆事件稀疏、重复性高时，时间则显得短暂。

在中年阶段，个体往往面临着生活模式趋于稳定和重复的状况。职业生涯进入成熟期，日常工作内容可能变得程式化；家庭生活也可能形成了固定的模式，新奇的经历和刺激减少。这种缺乏新异体验的生活状态，直接导致了记忆中“时间标记”（time markers）的减少。时间标记是指那些独特、显著或情感上重要的事件，它们在记忆中形成了锚点，有助于我们感知和回顾时间的流逝。例如，一次独特的旅行、一个重要的里程碑事件、或是一段新学会的技能，都能在记忆中留下深刻的印记，成为时间感的参照点。

然而，当日常活动变得重复和可预测时，如每天通勤、完成相似的工作任务、进行例行的家务等，这些事件在记忆中形成的编码密度就会降低。记忆不再充满鲜明的时间标记，而是由大量相似甚至相同的经历组成，导致在回顾时难以区分不同事件的发生顺序或具体日期。这种记忆编码的“模糊化”或“压缩”，使得人们在事后回溯时，感觉一段客观上较长的时间段（例如过去的一年）似乎很快就过去了，因为其中缺乏足够多的独特事件来“填充”这段时间 14。

具体来说，这种机制可以从两个方面理解：

  1. 新异性缺失与记忆密度降低：新异刺激或情境更容易吸引注意力，促使大脑进行更深入的加工和编码，形成更丰富、更持久的记忆表征 1516。中年人由于生活趋于稳定，新异体验减少，这使得大脑在编码日常事件时，信息处理的强度和广度下降。记忆中的“帧率”降低，导致回顾时，时间就像被快进了一样。
  2. 重复性活动与记忆稀释：大量重复性活动的记忆会相互干扰，使得个体难以区分不同时间点发生的相似事件。例如，每周重复的工作会议或家务劳动，在记忆中可能只会形成一个模糊的整体印象，而不是一系列独立的、可区分的事件。这种记忆的稀释效应，减少了可供提取的独特记忆点，使得主观时间感被压缩。

因此，中年阶段生活模式的程式化导致新异体验减少，进而降低了记忆编码的密度，减少了可提取的“时间标记”。这种记忆层面的变化，使得人们在回顾过去时，感觉时间流逝得更快，从而强化了“时间飞逝”的主观感受。

2.3 注意力分配模式的变化

中年群体时间感知加速的另一个重要心理因素是注意力分配模式的改变。随着工作和生活复杂性的提升，中年人往往需要处理更多的信息和任务，导致注意力资源被分散，这会影响对时间流逝的持续监测，从而产生“时间跳过”或加速的感知。时间感知并非一个独立的认知过程，它与注意力紧密相关。当个体将注意力集中于任务本身而非时间的流逝时，通常会低估时间间隔，即感觉时间过得更快 1718。

在中年阶段，职业发展往往达到高峰，伴随着更高的管理责任、更多的项目协调以及更复杂的决策过程。同时，家庭责任也可能加重，例如抚养子女、照顾年迈的父母等。这些多重任务要求个体频繁地在不同认知活动之间切换，导致注意力资源被高度瓜分和碎片化。

多任务处理情境下的时间感知研究表明，当人们同时执行多个任务时，用于监测时间流逝的注意力资源会减少，从而导致对时间的主观估计缩短 1920。例如，在一项使用双任务范式（dual-task paradigm）的实验中，参与者需要同时进行一个时间估计任务和一个非时间性任务。结果发现，非时间性任务（如追踪任务或随机数生成任务）显著干扰了时间估计，使得主观时间判断变得更短、更易变、更不准确 2122。当注意力资源被转移到非时间性任务上时，用于“内部时钟”的加工能力就会减弱，导致时钟节律累积的“滴答声”减少，从而使时间显得过得更快。

具体来说，这种注意力碎片化对时间感知的影响体现在以下几个方面：

  1. 注意力资源竞争：时间感知需要消耗一定的注意力资源，类似于一个“内部计时器”需要持续运行并累积时间信号。当大脑同时处理多项任务时，这些任务会与时间感知过程竞争有限的注意力资源。中年人频繁切换任务，使得注意力难以长时间聚焦于单一任务或时间流逝本身，导致时间信号累积不完整或中断，从而产生时间加速的错觉 23。
  2. 分心效应：外部干扰或任务切换本身就是一种分心。研究发现，即使是任务不相关的刺激，也可能分散注意力并影响时间感知。例如，在听觉分心实验中，与任务无关的声音刺激会增加时间估计的偏差，尤其在年龄增长后，这种分心效应更为显著 24。中年人生活和工作环境中的信息过载（如不断涌入的通知、会议等）也构成持续的分心，进一步加剧了注意力资源的损耗。
  3. 认知负荷：多任务处理通常伴随着较高的认知负荷。当认知负荷增加时，大脑用于处理时间信息的容量会减少。有研究指出，执行需要更高抑制控制的执行功能任务时，会与时间任务产生双向干扰，且这种干扰在中年及老年群体中表现更强 23。这意味着，中年人需要付出更多的认知努力来抑制无关信息、管理任务切换，这些努力会“挤占”用于时间感知的资源。

因此，中年阶段工作与生活复杂性的提升，导致多任务处理成为常态，注意力资源被高度分散和碎片化。这种注意力分配模式的变化，使得个体难以持续监测时间的流逝，减少了“内部时钟”的有效运行，从而导致主观上感觉时间过得更快，仿佛被“跳过”了一般。

3. 生理层面的神经与认知基础

3.1 时间感知的核心神经结构

时间感知并非单一脑区的功能，而是由多个脑区协同作用的复杂过程。在中年群体中，时间感知加速的生理基础可能与特定神经结构，尤其是默认模式网络（Default Mode Network, DMN）和海马体的功能及连接变化密切相关。这两个脑区在自我相关的时间叙事构建和事件时间序列编码中扮演着关键角色。

默认模式网络（DMN）在自我相关时间叙事中的作用

默认模式网络是一组在个体处于清醒休息状态、不执行具体任务时表现出高度同步活动的大脑区域，主要包括内侧前额叶皮层、后扣带皮层、楔前叶、角回以及内侧颞叶等 25。DMN被认为与自我参照处理、情景记忆检索、未来规划和心智游走（mind-wandering）等高级认知功能密切相关。在时间感知中，DMN尤其参与构建自我相关的、跨越时间的情景叙事。例如，当人们回忆过去或展望未来时，DMN的活动显著增强，它有助于将离散的事件整合到连贯的时间线和个人叙事中 26。这种对个人经历进行时间排序和整合的能力，是形成连续时间感的基础。有研究表明，DMN区域能够整合长达30秒或更长时间的叙事信息，即使在海马受损的患者中，某些DMN区域仍能维持这种长时程信息整合能力 25。

海马体在时间序列编码中的作用

海马体是颞叶内侧的一个关键结构，在情景记忆的形成和巩固中发挥着核心作用，尤其擅长编码事件发生的时间序列和上下文信息 2728。近年来的研究发现，海马体中存在“时间细胞”（time cells），这些神经元在特定时间间隔内按顺序放电，从而形成对时间进程的神经表征 293031。这些时间细胞不仅能编码纯粹的时间流逝，还能编码与特定情境或事件相关的上下文时间信息 2931。例如，在记忆任务中，海马体通过其内部连接，对事件的顺序和时间上下文进行精确编码，帮助我们记住“什么事件在何时以何种顺序发生” 28。海马体与DMN的协同作用，使得个体能够将这些时间序列信息整合到更广泛的个人叙事和经验框架中。

DMN与海马体的协同及其对时间感知的扭曲

DMN与海马体之间存在紧密的结构和功能连接，这种协同作用对于构建连贯的时空感知至关重要。DMN中的某些节点，如前海马体（anterior hippocampus），与DMN的其他区域连接紧密 2632。这种连接与情景记忆的加工及个人叙事相关。当这种连接发生改变时，个体的时空感知可能会受到显著影响。

一项关于裸盖菇素（psilocybin，一种致幻剂）对大脑影响的研究揭示了DMN与海马体连接减弱与时空感知扭曲之间的关联。研究发现，单剂量裸盖菇素能显著扰乱大脑的功能连接，特别是在DMN中，并且会引起空间-时间感知扭曲和自我消融的主观体验 32。裸盖菇素导致的功能连接变化在DMN中最为显著，且这种变化与前海马体连接，进一步支持了DMN-海马体连接在构建时空自我感中的重要性 32。持续性地，裸盖菇素还导致了前海马体与默认模式网络之间连接的持续下降，这种连接的减少可能与致幻剂的神经可塑性和治疗效果有关 32。此外，其他研究也强调了DMN在颞叶癫痫患者中代谢连接异常，包括双侧海马体和DMN其他区域的连接减弱，这可能与患者认知功能障碍有关 33。

因此，DMN与海马体在构建和维护个体时间感知方面发挥着核心作用。DMN负责整合自我相关的宏观时间叙事，而海马体则精确编码离散事件的时间序列。中年时期，这些关键神经结构的潜在变化，特别是它们之间连接的效率或稳定性下降，可能导致时间信息编码和整合的效率降低，从而在生理层面促成了“时间加速”的主观体验。

3.2 神经递质系统的年龄相关变化

中年群体时间感知加速的生理基础与大脑神经递质系统的年龄相关变化密切相关，特别是多巴胺（Dopamine）和胆碱能（Cholinergic）系统的衰退。这两种神经递质在调节内部时钟速率、记忆巩固和时间信息处理中扮演着关键角色。

多巴胺系统与内部时钟速率

多巴胺是纹状体区域（striatum）中含量最丰富的神经递质，被广泛认为是调节内部时钟（internal clock）速率的关键因素。内部时钟模型假设大脑中存在一个基于神经振荡器或脉冲发生器的计时机制，而多巴胺通过调节这些脉冲的产生速率来影响时间感知 34。有研究表明，较高或较低的多巴胺水平都可能导致时间感知的改变 34。

然而，多巴胺与时间感知之间的关系是复杂的，并且可能在不同时间尺度和任务类型中表现出不同的作用。有证据表明，随着年龄增长，纹状体中的多巴胺能系统会发生显著变化。例如，非人灵长类动物的研究发现，与帕金森病相关的多巴胺神经元退化标志物（包括蛋白酶体/溶酶体功能受损、氧化/硝化损伤以及炎症）都随年龄增长而增加，特别是在对帕金森病最易感的腹侧黑质多巴胺神经元中更为明显 35。这表明，在衰老过程中，多巴胺系统的功能会逐渐下降。

多巴胺水平的下降可能导致内部时钟速率的减慢。当内部时钟走得比实际时间慢时，个体需要积累更多的“内部滴答声”才能达到预设的时间长度，这会使外部世界的时间感觉上过得更快 34。例如，一项研究发现，对帕金森病患者（其多巴胺系统受损）进行左旋多巴（L-dopa）治疗（一种多巴胺前体药物）可以改变其时间感知，这进一步支持了多巴胺在时间感知中的作用 36。虽然有研究指出，单剂量左旋多巴会延长年轻人和老年人的时间生产（time production），但这并不意味着衰老对时间生产的影响是多巴胺介导的，因为左旋多巴对时间感知的影响与年龄的影响是独立的 37。这表明，年龄相关的多巴胺变化对时间感知的具体影响可能比简单地调节内部时钟速率更为复杂。

胆碱能系统与记忆巩固和时间处理

胆碱能系统，特别是与记忆巩固和注意功能相关的乙酰胆碱，在时间感知中也扮演着重要角色。海马体和新皮层中的胆碱能系统在衰老过程中表现出化学和生理异常，并与减缓认知处理和记忆痕迹的持续性有关 38。随着年龄增长，胆碱能系统同样会发生衰退。例如，研究发现衰老小鼠的内侧隔/对角带（MS/DB）复合体中的胆碱能神经元数量减少，这与停止时间（stop times）的习得呈负相关，提示胆碱能功能在时间处理中的重要性 39。

乙酰胆碱不仅影响记忆，也可能间接影响时间感知的精确性。良好的记忆巩固有助于形成清晰的时间标记，进而影响对时间长度的判断。当胆碱能系统功能下降，导致记忆编码和检索效率降低时，个体可能更难对事件进行精确的时间排序，这也会加剧“时间飞逝”的主观体验。一项关于持续时间记忆（duration memory）的研究发现，纹状体内M1型胆碱能受体的阻断，而非多巴胺D1或谷氨酸NMDA受体的阻断，会抑制持续时间记忆的巩固 40。这表明胆碱能系统在特定时间间隔的记忆形成中具有直接作用。

显式与隐式时间处理的年龄差异

Turgeon等人（2016）的综述指出，正常衰老通常伴随着注意力和记忆损伤导致噪声增加和时间不确定性升高，以及中央计时机制（可能由多巴胺-谷氨酸相互作用支持）的准确性和精确性下降 34。这提示我们，年龄相关的神经递质变化可能导致时间处理能力的普遍下降。

然而，时间处理能力（timing abilities）可以分为显式时间处理和隐式时间处理。显式时间处理是指有意识地对时间间隔进行判断和估计（如时间复制任务），而隐式时间处理是指在不自觉的情况下对时间信息进行加工（如运动技能学习中的时序控制）。有研究表明，显式时间处理的精度会随着年龄增长而降低，尤其是在毫秒到分钟级别的时间估计任务中表现出更大的可变性和偏差 34。例如，在要求受试者心理计数2分钟间隔的实验中，50岁以上群体对2分钟间隔的平均低估达到24.6%（即平均只数了86.6秒），远低于30岁以下群体的114.9秒 41。这直接支持了中年及老年群体对时间间隔的显著低估，从而感知时间过得更快。

综上所述，中年阶段多巴胺和胆碱能系统随年龄增长的衰退，可能通过减缓内部时钟速率、降低记忆巩固效率和削弱时间信息处理的准确性，共同导致时间感知加速。虽然多巴胺对时间感知的影响机制复杂，但其整体下降趋势与中年人“时间飞逝”的主观体验在生理层面上存在关联。

3.3 感觉运动时间处理能力的衰退

中年群体时间感知加速的生理层面解释还涉及感觉运动时间处理能力的普遍衰退。随着年龄增长，个体在听觉和视觉系统对时间信息的精细分辨能力上会表现出显著的下降，这包括毫秒级的时间间隔分辨和秒级的时间估计任务中的精确度降低。这种衰退并非仅限于简单的感官输入，而是涉及到更复杂的神经处理过程。

听觉时间分辨力的下降

听觉系统对时间信息的处理能力是感知节奏、理解言语以及进行时间判断的基础。研究表明，中年和老年群体在听觉时间分辨力方面普遍存在下降。例如，在瞬时相位同步稳定性（Wavelet Phase Synchronization Stability, WPSS）研究中发现，听觉晚期反应（Auditory Late Responses, ALRs）的相位同步稳定性与听觉努力度相关，且这种神经同步性会受到年龄和听力损失的影响42。这意味着，即使在听力正常的范围内，中老年人处理听觉信息所需的神经努力可能增加，间接影响时间信息的有效编码。

更具体地，Fostick和Babkoff（2013）的研究发现，年龄与听觉时间分辨任务的表现呈显著负相关，如二分时序判断（dichotic temporal-order judgment）、频谱时序判断（spectral temporal-order judgment）和间隙检测（gap detection）等。这些任务要求参与者在毫秒级的时间尺度上区分声音事件的顺序或存在时间空隙。研究结果强调，这种年龄相关的下降是听觉时间领域的特异性衰退，而非普遍的听觉感知能力下降，即使在控制了听觉敏感性和认知能力后，这一趋势依然存在43。

此外，对节律和节拍的神经处理也受到年龄的影响。Sauvé等人（2022）使用脑电图（EEG）记录了年轻人和老年人对节律模式的反应，发现尽管老年人的听力损失明显，但他们对节律模式的神经活动仍然保留。然而，不同频率下的幅度分布存在年龄效应：与年轻人相比，老年人在对应于节律中单个事件发生速率的频率上显示出相对较大的幅度，而在较低的、与更高层次节拍分组相关的频率上，神经活动相对减少。这可能与老年人对声音起始的N1-P2电位普遍增大有关，表明他们可能通过皮层感觉机制补偿年龄相关听力损失，但这种补偿可能伴随着对更高级时间分组处理能力的减弱44。

视觉时间分辨力的下降

与听觉类似，视觉系统对时间信息的处理能力也会随年龄衰退。例如，研究发现中年人对视听刺激的整合能力显著减弱。Yang和Ren（2017）的研究表明，中年人对单模态听觉和视觉刺激以及视听双模态刺激的反应时间均显著慢于年轻人，且视听整合的起始时间明显延迟（中年人360毫秒 vs. 年轻人260毫秒），整合强度也更弱（中年人峰值3.97% vs. 年轻人峰值11.86%），这提示信息处理速度的年龄相关下降45。

在视听同步判断任务中，Chan等人（2017）的研究也发现，老年人对视听刺激相对时间知觉的改变，即使在刺激水平上调整以平衡可检测性。虽然两组在预测同步判断的感官信息起始时间上没有差异，但老年人为了维持相似的判断表现，使用了与年轻人不同的神经资源，这可能反映了他们处理时序信息的效率下降46。

神经相位同步性与时间感知衰退

“Ageing Impacts Basic Auditory and Timing Processes”等研究深入探讨了神经相位同步性在时间感知中的作用。神经相位同步性指的是不同脑区或神经元群体之间电活动节律的协调一致性，它被认为是实现高效信息传递和整合的基础。在时间处理中，精确的神经相位同步有助于大脑准确编码和解码时间信息。

研究表明，随着年龄增长，神经系统，特别是听觉皮层中的相位同步性可能减弱。这种减弱导致神经元对重复性刺激的响应变得不那么精确和同步，从而影响对快速变化的时间模式（如节奏、语音语调）的编码。例如，在节律同步敲击任务中，研究发现，认知功能正常的个体也表现出与年龄相关的节律同步一致性下降，尤其是在同步音乐节拍时，这与注意力与工作记忆的初始衰退有关47。帕金森病患者由于多巴胺系统功能障碍，在超秒级时间复制任务中表现出运动时间缺陷，提示了基底神经节在时间处理中的关键作用，以及神经递质失衡对运动时间控制的影响4849。尽管这些研究主要针对运动时间或疾病状态，但它们共同揭示了神经生理基础在维持时间感知精确性方面的重要性。

总之，中年群体在毫秒级（如节奏感知）和秒级（如时间复制任务）的时间间隔分辨和估计中表现出精度下降。这种感觉运动时间处理能力的衰退，部分归因于神经相位同步性的减弱以及信息处理速度的普遍放缓。这些生理变化共同构成了中年人“时间飞逝”主观体验的神经基础。

4. 外部环境与生活方式的调节作用

4.1 数字时代的信息过载效应

数字时代的到来，以其高频信息刺激和碎片化的呈现方式，对中年群体的时间感知产生了显著的调节作用，尤其强化了“时间加速”的主观体验。信息过载（information overload）是指信息量或强度超出个体认知处理能力的状况 50。在当前高度互联的社会中，人们持续暴露于海量的、不确定且复杂的信息中，特别是在社交媒体和多媒体平台上，这种现象尤为突出 51。

短视频、多屏互动等碎片化信息输入模式，是数字时代信息过载的典型表现。这些内容往往以极快的速度呈现，持续吸引用户的注意力，但同时也显著缩短了注意力驻留时间。例如，一项研究发现，年轻人对社交媒体的高度关注可能增加信息过载的感知 51。虽然这项研究主要针对年轻人，但其揭示的机制，即高频、碎片化的信息输入如何影响认知负荷和注意力分配，同样适用于中年群体。

信息过载的一个直接后果是认知负荷的增加。当大脑需要处理超出其容量的信息时，会耗费更多的认知资源，导致处理效率下降，并可能引发混乱、决策延迟、批判性思维减弱以及焦虑和压力等负面情绪 50。

具体到中年群体，数字时代的信息过载效应可以通过以下几个方面影响其时间感知：

  1. 注意力碎片化加剧：社交媒体、短视频平台以及各种即时通讯工具不断推送通知和更新，要求用户频繁切换注意力，导致注意力的持续性和深度受到严重影响。这种注意力碎片化使得中年人更难以专注于单一任务，从而削弱了对时间流逝的持续感知和内部时钟的正常运作，进而产生时间加速的主观感受。有研究指出，过度依赖数字设备（如智能手机和谷歌）与注意力缺陷多动障碍（ADHD）和记忆力丧失的加剧有关，这被称为“数字痴呆” 52。记忆力受损和注意力不集中会直接影响时间信息的编码和回顾，加剧时间感知的扭曲。
  2. “数字失忆症”与记忆密度下降：过度依赖搜索引擎和数字设备来存储和检索信息，可能导致大脑“卸载”了部分外围信息，从而减少了自身记忆编码的密度 52。如前所述，记忆编码密度是影响时间判断的关键因素。当大脑不再主动记忆大量细节，而是依赖外部设备时，个人经历中的“时间标记”会减少，使得回顾时过去的时间段显得更加空泛和短暂，进一步强化了时间加速感。
  3. 时间扭曲与“成瘾”行为：社交媒体的过度使用甚至可能导致时间扭曲。一项研究发现，有社交媒体“成瘾”风险的个体在从事非社交媒体任务时，会表现出显著的时间高估偏差，即感觉时间过得更慢（与正常情况下的时间低估相反）53。然而，另一项研究则指出，社交媒体成瘾者在超秒级时间二分任务中表现出显著的时间高估和时间敏感性降低 54。这表明，虽然具体表现可能因任务类型和成瘾程度而异，但社交媒体的过度使用确实与时间感知异常密切相关。这种异常的时间感知，尤其是对时间消耗的错误估计，使得个体难以准确评估自己在数字活动上花费的时间，从而可能无意中花费更多时间，进一步加剧了信息过载。
  4. 无意识的屏幕时间消耗：人们往往低估自己使用屏幕的时间。一项研究发现在封锁期间，参与者系统性地低估了他们使用智能手机的时间，平均每天低估约71分钟，并且这种低估在不活跃的参与者中更为显著 55。这种对屏幕时间的无意识消耗，意味着个体在大量接收碎片化信息的同时，并未察觉到时间的真实流逝，这无疑会加剧“时间飞逝”的主观体验。

综上所述，数字时代高频、碎片化的信息刺激通过加剧注意力碎片化、影响记忆编码密度以及可能导致时间感知的扭曲，共同强化了中年群体“时间加速”的主观体验。应对这种效应，需要个体有意识地管理信息摄入，减少屏幕时间，并培养专注力，以更好地掌控自己的时间感知。

4.2 日常活动模式的结构化程度

日常活动模式的结构化程度对中年群体的时间感知具有显著影响。中年阶段，个体的工作和家庭生活往往趋于程式化和规律化，导致新异体验减少，缺乏独特的时间标记，从而引发主观时间感的压缩，即感觉时间过得更快。

程式化生活与新异体验的减少

随着年龄的增长，尤其是进入中年，许多人的生活模式会变得相对稳定和可预测。在职业上，可能已经达到了一定的职位，工作内容趋于熟练和重复，创新和挑战性任务的比例相对减少。在家庭方面，子女可能已进入青少年或成年阶段，家庭生活模式也趋于固定，如固定的作息、固定的社交圈、固定的娱乐方式等。这种高度结构化、重复性的生活模式，虽然带来了稳定和可控感，但也大幅减少了新异的、令人兴奋的体验。

新异性在时间感知中扮演着关键角色。心理学研究表明，新异事件更容易吸引注意力，并被大脑进行更深入的编码和记忆 5657。这些独特的新异事件在记忆中形成鲜明的“时间标记”或“锚点”，使得个体在回顾过去时，能够清晰地辨别不同时间段的特征和差异。例如，一次特别的旅行、一次重要的职业突破、一段新兴趣的开始，都能成为时间流程中的显著参照物。

然而，当中年人的日常活动变得高度重复和缺乏新异性时，记忆中可供提取的独特时间标记便会减少。每一天、每一周、每一年似乎都与之前相似，缺乏显著的记忆点来区分。这种“记忆稀释”效应导致在回顾时，一段客观上较长的时间（例如过去五年）由于缺乏鲜明事件的填充，感觉就像被压缩了一样，显得过得很快。这种现象与记忆编码密度理论相符，即记忆中事件密度越高，主观时间感越长；反之则越短。

规律性活动与时间感知的调节

尽管程式化活动普遍导致时间感知加速，但某些规律性活动，特别是那些需要高度专注和精确时间判断的技能型活动，可能对时间感知产生积极的调节作用。例如，研究发现，像Aikido或Quadrato Motor Training这样的专注型运动训练，可以与更长的时间产出和更高的协调效率相关联。这表明，参与需要精细时间判断和高度专注的活动，例如某些爱好、体育锻炼或认知训练，可能会在一定程度上抵消或调节因生活程式化带来的时间加速感。

此外，身体努力（physical effort）和认知努力（cognitive effort）也会影响时间感知。例如，剧烈运动可以扭曲时间感知，使得最大努力下的时间感觉更短 58。而在需要较高认知资源的活动中，如倒着走路（一种需要注意力的运动任务）或同时进行视觉工作记忆任务，也会导致时间过高估计 59。这意味着，如果中年人的程式化工作和生活依然伴随着高强度的认知或身体负荷，这种负荷可能会进一步加剧时间感知上的扭曲或加速感，使其更难以准确评估时间。

生活方式与时间感知的关联

研究表明，生活方式与生物年龄的加速密切相关，例如久坐、睡眠不足等不良行为模式会加速生物老化过程 。这种生物老化的加速可能间接影响神经时间处理能力，从而影响时间感知。中年人如果长期处于久坐不动、缺乏新刺激、睡眠不规律的状态，不仅会加速生理衰退，也会进一步削弱大脑对时间信息的有效编码和处理能力。

综上所述，中年阶段日常活动模式的程式化和新异体验的减少，是导致主观时间压缩和“时间飞逝”感的重要心理因素。缺乏独特的时间标记使得记忆密度降低，从而在回顾时感觉时间过得更快。尽管规律性、需要专注的活动可能在特定任务中提升时间感知精度，但整体而言，高度结构化的生活模式在中年群体中更容易导致时间感知的加速。

4.3 生物老化与时间感知的关联

中年群体时间感知加速的现象，除了受到心理和社会环境因素的影响外，还与个体生理层面的生物老化过程密切相关。生物老化（biological aging）是一个复杂的、多因素过程，反映了细胞和分子损伤的累积，导致生理功能逐渐下降和疾病风险增加。不同于实际年龄（chronological age），生物年龄能够更准确地反映个体的生理健康状况。研究表明，加速的生物年龄，可以通过多种生活方式因素影响，进而间接影响神经时间处理能力，从而加剧时间感知的加速。

生物年龄与表观遗传时钟

生物年龄的评估方法多样，其中表观遗传时钟（epigenetic clock）是一种新兴且被广泛认可的衡量指标。表观遗传时钟主要通过测量DNA甲基化模式的变化来估计个体的生物学衰老速度。DNA甲基化是一种表观遗传修饰，它不会改变DNA序列本身，但会影响基因的表达，并在衰老过程中表现出特定的、可预测的模式变化 60。加速的表观遗传时钟意味着个体的生物年龄快于其实际年龄，这通常与更高的疾病发病率和更短的寿命相关联。

生活方式对生物老化的影响

中年阶段，个体所采取的特定行为模式，如久坐不动、睡眠不足和不健康的饮食习惯，已被证实能够加速生物老化。这些行为模式通过多种生理途径对细胞和分子层面产生负面影响：

  1. 久坐行为：长时间的久坐与多种慢性疾病风险增加和生物老化加速有关。例如，久坐的生活方式还与心血管疾病、代谢综合征等风险增加有关，这些疾病状态本身也会影响认知功能，包括时间处理能力。一项针对老年人的研究发现，在旨在减少久坐行为的干预措施中，参与者普遍认为久坐行为已根深蒂固于日常习惯中，且与积极的强化作用相关联 61。
  2. 睡眠不足：慢性睡眠不足是现代社会普遍存在的健康问题，已被证明对生物老化具有显著影响。睡眠剥夺会扰乱昼夜节律、增加氧化应激、影响激素分泌（如皮质醇和生长激素），从而加速细胞和组织的老化过程。有研究表明，长时间的清醒状态会影响时间估计的准确性，且老年人在长时间清醒状态下的时间估计误差显著大于年轻人，这提示睡眠和昼夜节律对时间感知有重要影响 62。
  3. 其他行为模式：除了久坐和睡眠不足，不健康的饮食、缺乏体育锻炼、吸烟、过量饮酒等不良生活习惯，同样会通过增加炎症、氧化应激和代谢紊乱，加速生物老化。多项研究发现，社会、物理和政治环境因素，如空气质量、社会经济不平等和性别不平等，都与加速衰老密切相关 63。相反，心理健康状态，如积极的情绪和生活满意度，则与健康的衰老过程相关联，预示着更长的健康寿命和更低的衰老相关疾病风险 64。

生物老化与神经时间处理能力的关联

加速的生物老化，无论是通过表观遗传时钟还是其他生理指标反映，都可能间接影响大脑的结构和功能，进而影响神经时间处理能力。

  • 神经系统结构与功能的变化：生物老化会导致大脑体积的缩小（特别是灰质和白质），神经元连接的减少，以及神经递质系统（如多巴胺和胆碱能系统）功能的衰退。这些变化会降低大脑处理信息的速度和效率，影响认知灵活性和注意力控制。由于时间感知与注意力、记忆和执行功能等认知过程密切相关，大脑这些结构和功能的衰退必然会影响时间感知的精确性。例如，有研究表明，衰老与视觉和听觉时间处理能力的下降直接相关 65。
  • 内部时钟的调节障碍：内部时钟的精确运作依赖于大脑中一系列神经回路和神经递质的协同作用。生物老化可能导致这些回路的稳定性下降和神经递质的失衡，从而影响内部时钟的节律和速率。当内部时钟不能精确计时时，个体对外部时间流逝的感知就会出现偏差，例如感觉时间过得更快。一项研究发现，老年人在长时间的清醒状态下，对时间流逝的估计误差显著大于年轻人，这可能与昼夜节律和睡眠压力对内部时钟的影响有关 62。
  • 认知储备的耗竭：生物老化也会影响个体的认知储备。认知储备是指大脑在面对病理或衰老变化时，通过更有效的大脑网络或策略来维持认知功能的能力。痴呆症等神经退行性疾病与时间感知的显著改变相关，这提示了大脑健康状态对时间感知的重要性。对痴呆症患者时间感知的研究表明，与健康老年人相比，痴呆症患者的时间感知存在差异，这可能与认知功能受损有关 66。

综上所述，久坐、睡眠不足等不良生活习惯通过加速生物老化（反映在表观遗传时钟等指标上），间接导致大脑结构和功能（包括神经递质系统、内部时钟机制）的衰退，从而影响神经时间处理能力，最终表现为中年群体时间感知加速的主观体验。因此，改善生活方式，减缓生物老化过程，对于维持健康的时间感知具有重要意义。

5. 心理与生理机制的交互作用

5.1 情绪状态的调节效应

情绪状态对时间感知具有显著的调节作用，特别是在中年群体中，负性情绪如抑郁、孤独等，可能通过对注意力分配和记忆编码的双重调节，进一步放大或复杂化“时间加速”的主观体验。理解情绪如何影响时间感知，对于全面认识中年人时间飞逝感至关重要。

抑郁与孤独对时间感知的复杂影响

在抑郁状态下，时间感知往往会表现出“时间变慢”的特征。研究发现，抑郁症患者倾向于感觉时间过得比实际更慢 67。例如，一项研究指出，抑郁症患者在时间二分任务中，感知到的信号持续时间更短，即低估了探针持续时间，这提示内部时钟可能变慢 67。这种“时间膨胀”（time dilation）的现象，可能与抑郁症患者注意力内化、专注于自身负性情绪以及缺乏外部刺激有关，导致内部时钟脉冲累积减慢。此外，抑郁症状与未来时间视角（PFT）之间存在负相关，即抑郁程度越高，个体对未来时间的感知越有限 568。而感知未来时间有限又与时间流逝敏感性增强有关，这种复杂关系表明情绪在时间感知中扮演了多重角色。参考文献69指出，在抑郁状态下，主观时间感知从最初的膨胀（约1秒持续时间）到工作记忆中随后的加速（约30秒持续时间）。

然而，这与中年人普遍体验的“时间变快”似乎构成了一种矛盾。这种矛盾可能源于情绪对注意力分配和记忆编码的双重调节机制：

  1. 情绪对注意力分配的调节：

    • 抑郁状态下的时间变慢：抑郁症患者的注意力往往高度集中于内在的负性思维、反刍和自我批评，导致对外部事件的关注减少。当注意力主要投向内部状态而非外部刺激或任务时，用于追踪外部时间流逝的资源被剥夺，使得内部时钟产生更少的“滴答声”，从而感觉时间过慢 13。此外，抑郁可能导致认知处理速度的普遍减慢，进一步影响对时间的判断。
    • 中年负性情绪下的时间变快：在中年群体中，即使没有达到临床抑郁诊断标准，常见的焦虑、压力、孤独感也可能导致注意力分散和碎片化。例如，高度孤独的个体在社交情境下会延长亚秒级时间，而在超秒级时间判断中则会缩短时间 70。这提示，负性情绪可能导致对特定情境（如社交互动）的注意力高度集中或回避，进而扭曲时间感知。当工作和生活压力导致持续的注意力分散或多任务处理时，对时间流逝的监测功能减弱，从而产生时间加速的感知。

  2. 情绪对记忆编码的调节：

    • 负性情绪与记忆偏差：情绪状态会影响记忆的编码和检索过程。例如，高唤醒度的负性情绪（如厌恶或恐惧）会增强事件记忆，导致回忆时主观时间过长（回顾性时间判断）71。然而，在预期性时间判断任务中，当情绪相关的记忆编码优先于时间估计时，反而可能导致时间被低估 71。这意味着，情绪事件本身可能在记忆中留下深刻印记，使得这些事件持续的时间在回顾时被高估。
    • 孤独与记忆密度：孤独感通常伴随着社交互动的减少和日常活动的单调化，这会降低记忆编码的密度，使得日子缺乏独特的时间标记。如前所述，记忆密度降低会导致主观时间的压缩，加剧时间加速感。研究也证实，孤独感是未来时间视角与抑郁症状之间的重要中介因素，即孤独感越强，对未来时间的感知越有限，抑郁症状也越严重 68。

情绪与时间感知的交互作用实例

在实际情境中，情绪与时间感知的复杂交互作用在患有精神疾病的患者中表现得更为明显。例如，在COVID-19大流行期间的一项纵向研究发现，锁定期间的主观时间流逝（SFT）发生显著改变，且这种改变与抑郁、失眠和自杀意念密切相关 72。有自杀企图史的患者在初始锁定期间表现出较低的SFT水平，且SFT与自杀意念之间的关系受到抑郁的影响。这表明，在极端压力和情绪困扰下，个体的心理状态可能显著改变其时间感知，而这种改变反过来又可能加剧负性情绪。

此外，一项研究探讨了焦虑和抑郁在静息状态和活动状态下对时间感知的影响，发现冲动性、抑郁和焦虑水平是静息状态运动强度的强预测因子，且临床患者和健康对照组在运动强度变化、时间生产比率改变和症状减轻之间的路径不同 73。这进一步强调了情绪障碍与时间感知之间存在复杂的双向关系。

综上所述，情绪状态通过影响注意力分配和记忆编码，显著调节着个体对时间的感知。中年群体中普遍存在的压力、焦虑和孤独感等负性情绪，可能通过碎片化注意力、降低记忆密度等途径，强化“时间加速”的主观体验。同时，像抑郁症等更严重的情绪障碍，则可能导致时间感知出现“时间变慢”的矛盾现象，这提示我们需要更细致地分析情绪的类型、强度以及其对不同认知过程的影响，以全面理解其在时间感知加速中的调节作用。

5.2 认知储备的保护作用

认知储备（Cognitive Reserve, CR）是指个体大脑在面对年龄增长或病理损伤时，通过更有效的大脑网络或认知策略来维持认知功能的能力。中年群体通过体育锻炼和认知训练等方式积累和增强认知储备，可以在一定程度上延缓时间感知能力的衰退，甚至改善某些认知功能，进而对“时间加速”的主观体验起到保护作用。

体育锻炼对时间感知衰退的延缓机制

规律的体育锻炼，特别是中等强度的有氧运动和抗阻训练，被广泛认为是增强认知功能、延缓认知衰老的重要干预措施 74。其对时间感知的保护作用主要体现在以下几个方面：

  1. 增强海马神经可塑性：海马体在记忆编码和时间序列处理中发挥着核心作用。体育锻炼，尤其是长期的有氧运动，已被证实能够促进海马区的神经发生（neurogenesis）、突触可塑性（synaptic plasticity）以及脑源性神经营养因子（BDNF）的表达 757677。BDNF是一种重要的神经营养因子，能够支持神经元的生长、分化和存活，并增强突触连接的强度和效率。例如，游泳运动就被发现能够通过增加海马区的BDNF表达来增强大脑可塑性，并改善认知功能 777879。这种神经可塑性的增强意味着海马体能够更有效地编码和整合时间信息，从而减缓因衰老导致的时间处理能力下降。
  2. 改善神经递质系统功能：规律运动有助于维持和改善多巴胺和胆碱能系统等神经递质的平衡和功能。健康的神经递质系统是内部时钟稳定运行和时间信息精确处理的基础。通过运动，可能优化内部时钟的速率，减缓时间感知的加速。
  3. 提升注意力和执行功能：体育锻炼能够改善认知功能，包括注意力、工作记忆和执行功能 74。这些认知能力是精确时间感知的重要组成部分。例如，更好的注意力控制可以减少注意力分散对时间感知的干扰，而更强的执行功能则有助于更有效地分配认知资源进行时间估计任务。有研究指出，有氧运动可以显著改善整体认知功能和执行功能 74。
  4. 减轻氧化应激和炎症：体育锻炼具有抗炎和抗氧化的作用，可以减少大脑中的氧化应激和慢性炎症反应。这些生理过程是导致神经元损伤和认知功能下降的重要因素。通过减轻这些负面影响，体育锻炼有助于保护大脑结构和功能，从而间接维护时间处理能力 7578。

认知训练对时间感知衰退的延缓机制

认知训练，尤其是针对执行功能、处理速度和记忆的训练，也能够提升认知储备，对时间感知具有保护作用：

  1. 直接训练时间感知能力：一些认知训练程序可能直接包含时间估计任务，通过反复练习来提高个体对时间间隔的辨别和估计能力。这有助于校准“内部时钟”，提高时间判断的精确性。
  2. 增强认知控制和处理速度：认知训练，如记忆、推理和处理速度训练，可以增强大脑的认知效率，提高信息处理速度。在多项研究中，认知训练已被证实能够改善老年人的全球认知功能 80。例如，虚拟现实（VR）运动认知训练已被证明能有效提升认知障碍老年人的全球认知功能，并降低身体虚弱程度 80。针对轻度认知障碍老年人的VR训练也被发现能改善认知功能 81。这种处理速度的提高有助于更有效地编码和提取时间标记，从而减缓主观时间的加速感。
  3. 改善注意力分配模式：认知训练可以提升个体对注意力的控制能力，使其能够更有效地分配认知资源，减少注意力碎片化。当注意力能够更集中地用于监测时间流逝时，时间感知的准确性就会提高。一项研究发现，同时进行认知和有氧运动训练的干预措施显著改善了健康老年人在双任务行走测试中的认知表现 82。另一项针对认知障碍老年人的研究显示，双任务抗阻训练比单一抗阻训练更能改善认知功能 83。这表明结合认知训练能够更好地提升认知能力，包括注意力分配。
  4. 认知储备的积累：通过持续的认知挑战和学习新技能，个体可以积累更丰富的认知储备。这种储备使得大脑在面对衰老导致的神经元损失或功能下降时，能够更好地代偿，维持时间感知等认知功能的相对稳定。结构化的多领域生活方式干预（包括认知活动和身体活动）在提高全球认知功能方面优于自我引导的干预 84。

内感受与衰老交互作用的理论框架

内感受（Interoception）是指大脑对身体内部生理状态的感知和整合。它与情绪、自我意识以及时间感知之间存在密切联系。内感受系统通过监测心率、呼吸、体温等内部信号，为大脑提供身体状态的实时反馈。这些内部信号可以作为一种“内部时钟”的输入，影响个体对时间流逝的感知。

内感受在时间感知中的作用机制复杂，一方面，内感受信号可能作为内部时钟的节律来源，影响时间估计的准确性。另一方面，内感受的精确性也与情绪状态和认知功能密切相关。衰老过程会导致内感受的精确性下降，这可能进一步影响时间感知的准确性。例如，有研究表明，右侧脑岛（insula）在区分持续时间方面具有特定作用，但似乎不参与情绪相关的颞叶扭曲 85。脑岛是大脑中一个重要的内感受区域，其功能受损可能影响时间感知。

在衰老过程中，内感受能力的下降可能导致身体内部信号的“噪声”增加或敏感性降低，使得大脑对内部时钟的节律难以精确感知和利用。这可能导致内部时钟运行不稳，从而影响时间感知的准确性。体育锻炼和认知训练通过改善生理健康、增强神经可塑性和认知功能，间接或直接地提升内感受的精确性，从而可能减缓时间感知能力的衰退。例如，一些运动（如瑜伽、太极）被认为能够提升身体觉知和内感受能力，这可能有助于改善时间感知。

综上所述，体育锻炼和认知训练通过多重机制，包括增强海马神经可塑性、改善神经递质功能、提升注意力和执行功能，以及减轻炎症和氧化应激，来积累和保护认知储备。这些积极的生理和认知改变共同作用，有助于延缓中年群体时间感知能力的衰退，从而在心理和生理层面缓解“时间飞逝”的主观体验。

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参考文献

1Subjective acceleration of time experience in everyday life across adulthood.PubMed

Dennis John, Frieder R Lang
Dev Psychol. 2015 Dec;51(12):1824-1839. doi: 10.1037/dev0000059. Epub 2015 Sep 28.
Most people believe that time seems to pass more quickly as they age. Building on assumptions of socioemotional selectivity theory, we investigated whether awareness that one's future lifetime is limited is associated with one's experience of time during everyday activities across adulthood in 3 studies. In the first 2 studies (Study 1: N = 608; Study 2: N = 398), participants completed a web-based version of the day reconstruction method. In Study 3 (N = 392) participants took part in a newly developed tomorrow construction method, a web-based experimental method for assessing everyday life plans. Results confirmed that older adults' subjective interpretation of everyday episodes is that these episodes pass more quickly compared with younger adults. The subjective acceleration of time experience in old age was more pronounced during productive activities than during regenerative-consumptive activities. The age differences were partly related to limited time remaining in life. In addition, subjective acceleration of time experience was associated with positive evaluations of everyday activities. Findings suggest that subjective acceleration of time in older adults' daily lives reflects an adaptation to limitations in time remaining in life. (PsycINFO Database Record

2On the perception of time.PubMed

F Thomas Bruss, Ludger Rüschendorf
Gerontology. 2010;56(4):361-70. doi: 10.1159/000272315. Epub 2009 Dec 29.
In this article, we review scientific work and present new results on the perception of time, that is, on the feeling of time as perceived by individuals. The phenomenon of time being felt passing faster with growing age is well known, and there are numerous interesting studies to shed light on the question why this is so. Many of these are based on studies in psychology and social sciences. Others range from symptoms of the ageing process to related symptoms of decreasing memory capacities. Again other explanations, quite different in nature from the preceding ones, involve event intensities in the life of individuals. The relative decrease of interesting new events as one grows older is seen as an important factor contributing to the feeling that time is thinned out. The last type of possible explanations can be made more explicit in a mathematical model. Quantitative conclusions about the rate of decrease of the feeling of time can be drawn, and, interestingly, without restrictive assumptions. It is shown that under this model the feeling of time is thinned out at least logarithmically. Numerical constants will depend on specific hypotheses which we discuss but the lower-bound logarithmic character of the thinning-out phenomenon does not depend much on these. The presented model can be generalized in several ways. In particular we prove that there are, a priori, no logical incompatibilities in a model leading to the very same distribution of time perception for individuals with completely different pace and style of life. Our model is built to explain long-time perception. No claim is made that the feeling of time being thinned out is omnipresent for very individual. However, this is typically the case and we explain why.

3Time passes too fast? Then recall the past! - Evidence for a reminiscence heuristic in passage of time judgments.PubMed

Ferdinand Kosak, Christof Kuhbandner, Sven Hilbert
Acta Psychol (Amst). 2019 Feb;193:197-202. doi: 10.1016/j.actpsy.2019.01.003. Epub 2019 Jan 17.
Memory-based approaches suggest that retrospective judgments concerning the passage of lifetime are based on available meaningful experiences. However, an open question is whether passage of time judgments reflect the objective amount of important experiences or rather the amount of memories that are currently activated in the moment of judging. To examine this issue, we asked 473 participants to judge the passage of the last five years either before or after recalling as many important autobiographical events as possible from the last five years. Activating memories before the judgment slowed the experienced passage of time, but only if participants recalled at least four memories. For participants recalling less than four memories, the opposite effect was found: few activated memories had even an accelerating effect. Interestingly, the experienced speed of time did not continuously decrease with a rising number of memories activated: Below and above the threshold of four memories, passage of time judgments were unrelated to the number of activated memories. These results indicate that passage of time judgments are based on currently activated memories, suggesting that the common phenomenon of time flying reflects the effect of a reminiscence heuristic.

4Taking time seriously. A theory of socioemotional selectivity.PubMed

L L Carstensen, D M Isaacowitz, S T Charles
Am Psychol. 1999 Mar;54(3):165-81. doi: 10.1037//0003-066x.54.3.165.
Socioemotional selectivity theory claims that the perception of time plays a fundamental role in the selection and pursuit of social goals. According to the theory, social motives fall into 1 of 2 general categories--those related to the acquisition of knowledge and those related to the regulation of emotion. When time is perceived as open-ended, knowledge-related goals are prioritized. In contrast, when time is perceived as limited, emotional goals assume primacy. The inextricable association between time left in life and chronological age ensures age-related differences in social goals. Nonetheless, the authors show that the perception of time is malleable, and social goals change in both younger and older people when time constraints are imposed. The authors argue that time perception is integral to human motivation and suggest potential implications for multiple subdisciplines and research interests in social, developmental, cultural, cognitive, and clinical psychology.

5Longitudinal associations between perception of future time and subjective well-being among middle-aged and older people in China: the moderating roles of individual health and socioeconomic status.PubMed

Shiyu Lu
Qual Life Res. 2022 Oct;31(10):3009-3018. doi: 10.1007/s11136-022-03163-6. Epub 2022 Jun 1.
PURPOSE: This study examined the longitudinal association between perception of future time (PFT) and subjective well-being among middle- and old-aged people in China, and investigated the moderating roles of individual health resources and socioeconomic status (SES) in the association between PFT and subjective well-being. METHODS: Data for this study drew from a final sample of 10,644 respondents aged 45 years and above from four waves (2011-2018) of the China Health and Retirement Longitudinal Study (CHARLS). Subjective well-being was measured by depressive symptoms and life satisfaction. Multilevel linear modelling (MLM) was applied to analyse the main effects of PFT on depressive symptoms and life satisfaction over time and the moderating effects of individual health resources and SES. RESULTS: After controlling for the covariates, perceived future time as extended was associated with fewer depressive symptoms (β = - 0.85, p < 0.001) and higher levels of life satisfaction (β = 0.07, p < 0.001). Significant moderating effects of individual health resources (self-rated health, functional limitations and chronic diseases) and SES (urban-rural hukou) were found in associations between PFT and depressive symptoms. CONCLUSION: Perceived future time as extended was associated with better subjective well-being. These associations differed in relation to different individual health resources and SES. This study extends understanding of Socioemotional Selectivity Theory and helps identify vulnerable people when they feel near to death.

6Explicit and implicit timing across the adult lifespan.PubMed

Antonino Visalli, Mariagrazia Capizzi, Giovanna Mioni
Psychol Aging. 2025 Mar;40(2):137-146. doi: 10.1037/pag0000866. Epub 2024 Nov 25.
The study of whether temporal processing in the millisecond-to-seconds range changes with age is an active and debated research field. Here, we adopted a lifespan approach in which younger to older participants performed both explicit and implicit timing tasks (time bisection and foreperiod tasks, respectively) in a single session. Three hundred seven participants (age range: 20-85 years) took part in the study. Participants performed two timing tasks to test explicit and implicit time processing. Age was used as a continuous predictor to elucidate whether explicit and implicit temporal processing change with increasing age. The results from the explicit timing task showed reduced precision with age, as indexed by a flatter psychometric curve and greater just noticeable difference metrics. By contrast, implicit processing of time was not significantly affected by age, as evinced by a comparable foreperiod effect across age. These findings provide first adult lifespan evidence that only explicit, but not implicit, timing is sensitive to age-related changes. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

7[Alterations of time judgement with age].PubMed

Richard Mahlberg, Tom Bschor
Psychiatr Prax. 2007 Apr;34(3):117-21. doi: 10.1055/s-2006-951972.
OBJECTIVE: Time perception can be divided into two processes: time experience and time judgement. Although there have been frequent reports of changes in these two processes with increasing age, none of these changes has been demonstrated using objective measures. METHODS: We evaluated time judgement by employing time estimation, time production, and time reproduction tasks in 33 healthy subjects of all age groups. In addition, we used the Trail-Making Test to measure attentional performance. RESULTS: For both time estimation and time reproduction, we found positive correlations between length of time interval and age (overestimation). After we calculated partial correlations controlling for the results of the Trail-Making Test, the age-related changes we initially observed in the time estimation task disappeared, but the age-related changes seen in the time reproduction task remained significant. CONCLUSIONS: Considering the Scalar Timing Theory and the Attentional Gate Theory, our findings indicated that age-related effects on time estimation may be due to attentional factors. In contrast, the age-related changes seen in the time reproduction task may be due to disturbances in working memory function.

8Subjective time estimation in relation to age, health, and interhemispheric brain asymmetry.PubMed

A M Polyukhov
Z Gerontol. 1989 Mar-Apr;22(2):79-84.
The subjective estimation of time was studied in the population sample of 256 subjects aged 20 to 80 years. Among the elderly, a group of patients with cerebral atherosclerosis and a group of apparently healthy persons were selected. The study also involved 48 patients with remaining manifestations of right- and left-sided stroke. The unoccupied time interval and the interval occupied with performance of verbal tasks were estimated. In both cases, interval durations were 45 s. There was an underestimation of the unoccupied interval in the young group and it was overestimated by the elderly group. With the performance of verbal tasks, the age differences were insignificant. Occupied interval vs unoccupied interval was underestimated to a greater degree. No sex differences were noted. Time estimation in cerebral atherosclerosis without focal disturbances was analogous to the pattern being observed in aging. In left-sided stroke, underestimation of time and estimation accuracy exceeded similar indices in other groups. The relationship was established of the subjective time estimation with non-verbal intellect and several characteristics of brain asymmetry, but not with handedness.

9The effect of aging and emotions on time processing.PubMed

Pasquale La Malva, Giulia Prete, Adolfo Di Crosta, et al.
Aging Clin Exp Res. 2023 Nov;35(11):2783-2795. doi: 10.1007/s40520-023-02563-z. Epub 2023 Sep 23.
BACKGROUND: Time perception is an automatic process that can be influenced by intrinsic and extrinsic factors. AIMS: This study aimed to investigate the effect of age and emotions on the ability to keep track of short suprasecond intervals. METHODS: Younger adults (N = 108, age range: 18-35) and older adults (N = 51, age range: 65-87) were asked to reproduce, bisect, or double the duration of facial stimuli randomly presented for 1500, 3000, and 4500 ms. The experiment included facial stimuli with positive, negative, or neutral expressions. RESULTS: The participants across age correctly reproduced intervals but overestimated and underestimated them when asked to bisect and double the intervals, respectively. Overall, when faces were presented with a positive or negative expression, an overestimation of time intervals emerged compared to faces with neutral expressions. Emotions had a greater effect on older adults, who showed a greater overestimation of positive facial expressions and an underestimation of sad, but not angry, facial expressions. DISCUSSION: The results provide evidence that time perception is influenced by age and emotions, with older adults showing a greater effect of emotions on time processing. CONCLUSION: The study suggests an interaction among time processing, age, and emotions, highlighting an automatic relationship among these domains, often considered independent.

10Time counts: future time perspective, goals, and social relationships.PubMed

Frieder R Lang, Laura L Carstensen
Psychol Aging. 2002 Mar;17(1):125-139. doi: 10.1037/0882-7974.17.1.125.
On the basis of postulates derived from socioemotional selectivity theory, the authors explored the extent to which future time perspective (FTP) is related to social motivation, and to the composition and perceived quality of personal networks. Four hundred eighty German participants with ages ranging from 20 to 90 years took part in the study. In 2 card-sort tasks, participants indicated their partner preference and goal priority. Participants also completed questionnaires on personal networks and social satisfaction. Older people, as a group, perceived their future time as more limited than younger people. Individuals who perceived future time as being limited prioritized emotionally meaningful goals (e.g., generativity, emotion regulation), whereas individuals who perceived their futures as open-ended prioritized instrumental or knowledge-related goals. Priority of goal domains was found to be differently associated with the size, composition, and perceived quality of personal networks depending on FTP. Prioritizing emotion-regulatory goals was associated with greater social satisfaction and less perceived strain with others when participants perceived their future as limited. Findings underscore the importance of FTP in the self-regulation of social relationships and the subjective experience associated with them.

11Socioemotional selectivity theory, aging, and health: the increasingly delicate balance between regulating emotions and making tough choices.PubMed

Corinna E Löckenhoff, Laura L Carstensen
J Pers. 2004 Dec;72(6):1395-424. doi: 10.1111/j.1467-6494.2004.00301.x.
After providing an introductory overview of socioemotional selectivity theory, we review empirical evidence for its basic postulates and consider the implications of the predicted cognitive and behavioral changes for physical health. The main assertion of socioemotional selectivity theory is that when boundaries on time are perceived, present-oriented goals related to emotional meaning are prioritized over future-oriented goals aimed at acquiring information and expanding horizons. Such motivational changes, which are strongly correlated with chronological age, systematically influence social preferences, social network composition, emotion regulation, and cognitive processing. On the one hand, there is considerable reason to believe that such changes are good for well-being and social adjustment. On the other hand, the very same motivational changes may limit health-related information-seeking and influence attention, memory, and decision-making such that positive material is favored over negative information. Grounding our arguments in socioemotional selectivity theory, we consider possible ways to tailor contexts such that disadvantages are avoided.

12Socioemotional Selectivity Theory: The Role of Perceived Endings in Human Motivation.PubMed

Laura L Carstensen
Gerontologist. 2021 Nov 15;61(8):1188-1196. doi: 10.1093/geront/gnab116.
Socioemotional selectivity theory (SST) is a theory of life-span development grounded in the uniquely human ability to monitor time. SST maintains that the approach of endings-whether due to aging or other endings such as geographic relocations and severe illness-elicits motivational changes in which emotionally meaningful goals are prioritized over exploration. Research guided by SST has informed preferences, social networks, and emotional experience and led to the discovery of the positivity effect in cognitive processing. This article, based on my 2015 Robert W. Kleemeier Award Lecture, describes the development of SST and its related program of empirical research.

13Temporal cognition: Connecting subjective time to perception, attention, and memory.PubMed

William J Matthews, Warren H Meck
Psychol Bull. 2016 Aug;142(8):865-907. doi: 10.1037/bul0000045. Epub 2016 May 19.
Time is a universal psychological dimension, but time perception has often been studied and discussed in relative isolation. Increasingly, researchers are searching for unifying principles and integrated models that link time perception to other domains. In this review, we survey the links between temporal cognition and other psychological processes. Specifically, we describe how subjective duration is affected by nontemporal stimulus properties (perception), the allocation of processing resources (attention), and past experience with the stimulus (memory). We show that many of these connections instantiate a "processing principle," according to which perceived time is positively related to perceptual vividity and the ease of extracting information from the stimulus. This empirical generalization generates testable predictions and provides a starting-point for integrated theoretical frameworks. By outlining some of the links between temporal cognition and other domains, and by providing a unifying principle for understanding these effects, we hope to encourage time-perception researchers to situate their work within broader theoretical frameworks, and that researchers from other fields will be inspired to apply their insights, techniques, and theorizing to improve our understanding of the representation and judgment of time. (PsycINFO Database Record

14Time perception, attention, and memory: a selective review.PubMed

Richard A Block, Ronald P Gruber
Acta Psychol (Amst). 2014 Jun;149:129-33. doi: 10.1016/j.actpsy.2013.11.003. Epub 2013 Dec 21.
This article provides a selective review of time perception research, mainly focusing on the authors' research. Aspects of psychological time include simultaneity, successiveness, temporal order, and duration judgments. In contrast to findings at interstimulus intervals or durations less than 3.0-5.0 s, there is little evidence for an "across-senses" effect of perceptual modality (visual vs. auditory) at longer intervals or durations. In addition, the flow of time (events) is a pervasive perceptual illusion, and we review evidence on that. Some temporal information is encoded All rights reserved. relatively automatically into memory: People can judge time-related attributes such as recency, frequency, temporal order, and duration of events. Duration judgments in prospective and retrospective paradigms reveal differences between them, as well as variables that moderate the processes involved. An attentional-gate model is needed to account for prospective judgments, and a contextual-change model is needed to account for retrospective judgments.

15Linear vector models of time perception account for saccade and stimulus novelty interactions.PubMed

Amirhossein Ghaderi, Matthias Niemeier, John Douglas Crawford
Heliyon. 2022 Mar 1;8(3):e09036. doi: 10.1016/j.heliyon.2022.e09036. eCollection 2022 Mar.
Various models (e.g., scalar, state-dependent network, and vector models) have been proposed to explain the global aspects of time perception, but they have not been tested against specific visual phenomena like perisaccadic time compression and novel stimulus time dilation. Here, in two separate experiments (N = 31), we tested how the perceived duration of a novel stimulus is influenced by 1) a simultaneous saccade, in combination with 2) a prior series of repeated stimuli in human participants. This yielded a novel behavioral interaction: pre-saccadic stimulus repetition neutralizes perisaccadic time compression. We then tested these results against simulations of the above models. Our data yielded low correlations against scalar model simulations, high but non-specific correlations for our feedforward neural network, and correlations that were both high and specific for a vector model based on identity of objective and subjective time. These results demonstrate the power of global time perception models in explaining disparate empirical phenomena and suggest that subjective time has a similar essence to time's physical vector.

16Attention and the subjective expansion of time.PubMed

Peter Ulric Tse, James Intriligator, Josée Rivest, et al.
Percept Psychophys. 2004 Oct;66(7):1171-89. doi: 10.3758/bf03196844.
During brief, dangerous events, such as car accidents and robberies, many people report that events seem to pass in slow motion, as if time had slowed down. We have measured a similar, although less dramatic, effect in response to unexpected, nonthreatening events. We attribute the subjective expansion of time to the engagement of attention and its influence on the amount of perceptual information processed. We term the effect time's subjective expansion (TSE) and examine here the objective temporal dynamics of these distortions. When a series of stimuli are shown in succession, the low-probability oddball stimulus in the series tends to last subjectively longer than the high-probability stimulus even when they last the same objective duration. In particular, (1) there is a latency of at least 120 msec between stimulus onset and the onset of TSE, which may be preceded by subjective temporal contraction; (2) there is a peak in TSE at which subjective time is particularly distorted at a latency of 225 msec after stimulus onset; and (3) the temporal dynamics of TSE are approximately the same in the visual and the auditory domains. Two control experiments (in which the methods of magnitude estimation and stimulus reproduction were used) replicated the temporal dynamics of TSE revealed by the method of constant stimuli, although the initial peak was not apparent with these methods. In addition, a third, control experiment (in which the method of single stimuli was used) showed that TSE in the visual domain can occur because of semantic novelty, rather than image novelty per se. Overall, the results support the view that attentional orienting underlies distortions in perceived duration.

17Distracted to a fault: Attention, actions, and time perception.PubMed

Katharina A Schwarz, Lisa Weller
Atten Percept Psychophys. 2023 Feb;85(2):301-314. doi: 10.3758/s13414-022-02632-x. Epub 2022 Dec 15.
In the last years, it has become general consensus that actions change our time perception. Performing an action to elicit a specific event seems to lead to a systematic underestimation of the interval between action and effect, a phenomenon termed temporal (or previously intentional) binding. Temporal binding has been closely associated with sense of agency, our perceived control over our actions and our environment, and because of its robust behavioral effects has indeed been widely utilized as an implicit correlate of sense of agency. The most robust and clear temporal binding effects are typically found via Libet clock paradigms. In the present study, we investigate a crucial methodological confound in these paradigms that provides an alternative explanation for temporal binding effects: a redirection of attentional resources in two-event sequences (as in classical operant conditions) versus singular events (as in classical baseline conditions). Our results indicate that binding effects in Libet clock paradigms may be based to a large degree on such attentional processes, irrespective of intention or action-effect sequences. Thus, these findings challenge many of the previously drawn conclusions and interpretations with regard to actions and time perception.

18Passage of time judgements.PubMed

J H Wearden
Conscious Cogn. 2015 Dec 15;38:165-71. doi: 10.1016/j.concog.2015.06.005. Epub 2015 Jun 23.
The article discusses passage of time judgements (POTJs), judgements about how fast time seems to pass in some situation or during some event. It is argued that POTJs should be distinguished from duration judgements, and that the relation between the two remains to be identified. The article discusses (a) POTJs in laboratory situations and in the real world, (b) "feel judgements", the statement that a duration "feels longer" than a person knows it to be, (c) distortions of passage of time in emergency situations, (d) passage of time and ageing, and (e) determinants of POTJs, particularly the roles of information-processing/attention and arousal.

19Error modulates categorization of subsecond durations in multitasking contexts.PubMed

Maryam Rafiezadeh, Anahita Tashk, Fatemeh Mafi, et al.
Psychol Res. 2024 Jun;88(4):1253-1271. doi: 10.1007/s00426-024-01945-w. Epub 2024 Mar 16.
Monitoring errors consumes limited cognitive resources and can disrupt subsequent task performance in multitasking scenarios. However, there is a dearth of empirical evidence concerning this interference with prospective estimation of time. In this study, we sought to investigate this issue through a serial multitasking experiment, employing a temporal bisection task as the primary task. We introduced two task contexts by implementing two different concurrent tasks. In one context, participants were tasked with discriminating the size difference between two visual items, while in the other context, they were required to judge the temporal order of similar visual items. The primary task remained the same for the entire experiment. Psychophysical metrics, including subjective bias (determined by the bisection point) and temporal sensitivity (measured by the Weber ratio), in addition to reaction time, remained unaltered in the primary task regardless of the perceptual context exerted by the concurrent tasks. However, commission of error in the concurrent tasks (i.e., non-specific errors) led to a right-ward shift in the bisection point, indicating underestimation of time after errors. Applying a drift-diffusion framework for temporal decision making, we observed alterations in the starting point and drift rate parameters, supporting the error-induced underestimation of time. The error-induced effects were all diminished with increasing a delay between the primary and concurrent task, indicating an adaptive response to errors at a trial level. Furthermore, the error-induced shift in the bisection point was diminished in the second half of the experiment, probably because of a decline in error significance and subsequent monitoring response. These findings indicate that non-specific errors impact the prospective estimation of time in multitasking scenarios, yet their effects can be alleviated through both local and global reallocation of cognitive resources from error processing to time processing.

20A unified neurocomputational model of prospective and retrospective timing.PubMed

Joost de Jong, Aaron R Voelker, Terrence C Stewart, et al.
Psychol Rev. 2025 Jul;132(4):781-827. doi: 10.1037/rev0000519. Epub 2025 Jan 6.
Time is a central dimension against which perception, action, and cognition play out. From anticipating when future events will happen to recalling how long ago previous events occurred, humans and animals are exquisitely sensitive to temporal structure. Empirical evidence seems to suggest that estimating time prospectively (i.e., in passing) is qualitatively different from estimating time in retrospect (i.e., after the event is over). Indeed, computational models that attempt to explain both prospective and retrospective timing assume a fundamental separation of their underlying processes. We, in contrast, propose a new neurocomputational model of timing, the unified temporal coding (UTC) model that unifies prospective and retrospective timing through common principles. The UTC model assumes that both stimulus and timing information are represented inside the same rolling window of input history. As a consequence, the UTC model explains a wide range of phenomena typically covered by specialized models, such as conformity to and violations of the scalar property, one-shot learning of intervals, neural responses underlying timing, timing behavior under normal and distracting conditions, common capacity limits in timing and working memory, and how timing depends on attention. Strikingly, by assuming that prospective and retrospective timing rely on the same principles and are implemented in the same neural network, a simple attentional gain mechanism can resolve the apparently paradoxical effect of cognitive load on prospective and retrospective timing. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

21The role of practice and automaticity in temporal and nontemporal dual-task performance.PubMed

S W Brown, E D Bennett
Psychol Res. 2002 Feb;66(1):80-9. doi: 10.1007/s004260100076.
Research on time and attention shows that a nontemporal task may interfere with a concurrent timing task by making time judgments shorter, more variable, and/or more inaccurate compared to timing-only conditions. Brown (1998, Psychological Research, 61, 71-81) counteracted the interference effect by giving subjects automaticity training on a nontemporal task to reduce the amount of processing resources the task required. Such practice attenuated interference in timing. Two new experiments were designed to replicate and extend the previous findings. Subjects generated a series of 5-s temporal productions under single-task (timing only) and dual-task (timing plus nontemporal task) conditions. The nontemporal tasks were pursuit rotor tracking (Experiment 1), and mirror-reversed reading (Experiment 2). We employed a pretest-practice-posttest paradigm, with the practice sessions devoted to performance of the nontemporal task. Pretest-posttest comparisons showed that practice reduced interference in timing in both experiments. Dual-task probe trials were given during the practice sessions to trace the time course of the improvement in timing. The results showed that interference in timing was reduced with even small amounts of practice. The findings support the idea that timing is very sensitive to changes in the allocation of attentional resources.

22Timing and executive function: bidirectional interference between concurrent temporal production and randomization tasks.PubMed

Scott W Brown
Mem Cognit. 2006 Oct;34(7):1464-71. doi: 10.3758/bf03195911.
A review of interference effects in concurrent temporal/nontemporal dual-task studies suggests that prospective timing may be related to executive cognitive functions. Executive processes play a supervisory role in behavior by controlling attention, coordinating information, and scheduling actions. In the present research, a timing task was paired with an established executive task in a dual-task paradigm. The timing task required subjects t o generate a series o f 5-sec temporal productions,and the executive task was random number generation. These tasks were performed both separately and concurrently. Comparisons of single-task and dual-task conditions showed that (1) the randomization task interfered with timing by making temporal productions more variable and longer and (2) concurrent timing disrupted randomization performance by making responses less random. This pattern of bidirectional interference supports the idea that timing relies on the same attentional resources used by other executive-level tasks.

23Executive attentional resources in timing: Effects of inhibitory control and cognitive aging.PubMed

Scott W Brown, Tammy M Johnson, Mary E Sohl, et al.
J Exp Psychol Hum Percept Perform. 2015 Aug;41(4):1063-83. doi: 10.1037/xhp0000078. Epub 2015 May 25.
This research is based on an executive resource theory of timing, which postulates that time perception relies on specialized attentional resources that support executive cognitive functions. In 4 experiments, older and younger participants performed a timing task and an executive task emphasizing inhibitory control under both single-task and dual-task conditions. The timing task in each experiment was serial temporal production. The executive tasks, representing different types of inhibitory control, were the flanker task (Experiment 1), the number-letter task (Experiment 2), the go/no-go task (Experiment 3), and the antisaccade task (Experiment 4). The results showed (a) a pattern of bidirectional interference in each experiment, in that the concurrent inhibition tasks interfered with timing performance and concurrent timing interfered with inhibition performance, (b) the older participants demonstrated a stronger bidirectional interference effect relative to younger participants in 3 experiments, and (c) weaker versions of the inhibition tasks produced weaker interference effects. These findings support the idea that temporal processing relies on executive attentional resources.

24Auditory distraction, time perception, and the role of age: ERP evidence from a large cohort study.PubMed

Stephan Getzmann, Stefan Arnau, Patrick D Gajewski, et al.
Neurobiol Aging. 2024 Dec;144:114-126. doi: 10.1016/j.neurobiolaging.2024.09.012. Epub 2024 Sep 20.
Cognitive aging is typically associated with a higher susceptibility to distraction by concurrent, but task-irrelevant stimuli. Here, we studied the cognitive sub-processes involved in a sample of 484 healthy adults aged 20-70 years from the Dortmund Vital Study (Clinicaltrials.gov NCT05155397). Participants judged the duration of tone stimuli of a random sequence of long and short tones, having either a regular (standard) pitch or rare (deviant) pitch. Deviance-related ERPs were explored, reflecting neuro-cognitive correlates of pre-attentive deviance detection (MMN), attention allocation toward (P3a) and processing of (P3b) the deviance, and re-orienting toward the task-relevant stimulus feature (RON). Accuracy was reduced for deviant long tones, possibly due to withdrawing attention from processing the time information, making long stimuli appear shorter. This effect increased with age, and cluster-based permutation tests on the correlation of ERPs and age as well as linear mixed modeling indicated a decrease in MMN, an increase in P3a with long tones, and decreases in P3b and RON. This suggests a greater attentional orienting to the deviant stimulus feature and a reduced re-orienting to the task-relevant feature with increasing age.

25Temporal integration of narrative information in a hippocampal amnesic patient.PubMed

Xiaoye Zuo, Christopher J Honey, Morgan D Barense, et al.
Neuroimage. 2020 Jun;213:116658. doi: 10.1016/j.neuroimage.2020.116658. Epub 2020 Feb 19.
Default network regions appear to integrate information over time windows of 30 ​s or more during narrative listening. Does this long-timescale capability require the hippocampus? Amnesic behavior suggests that regions other than the hippocampus can independently support some online processing when input is continuous and semantically rich: amnesics can participate in conversations and tell stories spanning minutes, and when tested immediately on recently heard prose they are able to retain some information. We hypothesized that default network regions can integrate the semantically coherent information of a narrative across long time windows, even in the absence of an intact hippocampus. To test this prediction, we measured BOLD activity in the brain of a hippocampal amnesic patient (D.A.) and healthy control participants while they listened to a 7 min narrative. The narrative was played either in its intact form, or as a paragraph-scrambled version, which has been previously shown to interfere with the long-range temporal dependencies in default network activity. In the intact story condition, D.A.'s moment-by-moment BOLD activity spatial patterns were similar to those of controls in low-level auditory cortex as well as in some high-level default network regions (including lateral and medial posterior parietal cortex). Moreover, as in controls, D.A.'s response patterns in medial and lateral posterior parietal cortex were disrupted when paragraphs of the story were presented in a shuffled order, suggesting that activity in these areas did depend on information from 30 ​s or more in the past. Together, these results suggest that some default network cortical areas can integrate information across long timescales, even when the hippocampus is severely damaged.

26Narrative imagery: Emotional modulation in the default mode network.PubMed

Nicola Sambuco, Margaret M Bradley, Peter J Lang
Neuropsychologia. 2022 Jan 7;164:108087. doi: 10.1016/j.neuropsychologia.2021.108087. Epub 2021 Nov 14.
The default mode network (DMN) is activated when constructing and imagining narrative events, with functional brain activity in the medial-prefrontal cortex hypothesized to be modulated during emotional processing by adding value (or pleasure) to the episodic representation. However, since enhanced reactivity during emotional, compared to neutral, content is a more frequent finding in both the brain and body in physiological, neural, and behavioral measures, the current study directly assesses the effects of pleasure and emotion during narrative imagery in the DMN by using a within-subject design to first identify the DMN during resting state and then assess activation during pleasant, neutral, or unpleasant imagery. Replicating previous findings, enhanced functional activity in the medial prefrontal cortex was found when imagining pleasant, compared to unpleasant, events. On the other hand, emotion-related activation was found when imagining either pleasant or unpleasant, compared to neutral, events in other nodes of the DMN including the posterior cingulate cortex (PCC), angular gyrus, anterior hippocampus, lateral temporal cortex, temporal pole, dorsomedial prefrontal cortex (dmPFC), and ventrolateral prefrontal cortex (vlPFC). Pervasive emotional modulation in the DMN is consistent with the view that a primary function of event retrieval and construction is to remember, recreate, and imagine motivationally relevant events important for planning adaptive behavior.

27Cell assemblies, sequences and temporal coding in the hippocampus.PubMed

George Dragoi
Curr Opin Neurobiol. 2020 Oct;64:111-118. doi: 10.1016/j.conb.2020.03.003. Epub 2020 May 3.
Like social networks, neurons in the brain are organized in neuronal ensembles that constrain and at the same time enrich the role and temporal precision of activity of individual neurons. Changes in coordinated firing across cortical neurons as well as selective changes in timing and sequential order across neurons that are important for encoding of novel information have collectively been known as ensemble temporal coding. Here we review recent findings on the role of online and offline temporal coding within sequential cell assemblies from the rodent hippocampus thought be important for memory encoding and consolidation and for spatial navigation. We propose that temporal coding in the rodent hippocampus represented as plasticity in replay activity relies primarily on subtle and selective changes in coordinated firing within the microstructure of individual cell assembly organization during sleep.

28Hippocampal Representations of Event Structure and Temporal Context during Episodic Temporal Order Memory.PubMed

Chuqi Liu, Zhifang Ye, Chuansheng Chen, et al.
Cereb Cortex. 2022 Mar 30;32(7):1520-1534. doi: 10.1093/cercor/bhab304.
The hippocampus plays an important role in representing spatial locations and sequences and in transforming representations. How these representational structures and operations support memory for the temporal order of random items is still poorly understood. We addressed this question by leveraging the method of loci, a powerful mnemonic strategy for temporal order memory that particularly recruits hippocampus-dependent computations of spatial locations and associations. Applying representational similarity analysis to functional magnetic resonance imaging activation patterns revealed that hippocampal subfields contained representations of multiple features of sequence structure, including spatial locations, location distance, and sequence boundaries, as well as episodic-like temporal context. Critically, the hippocampal CA1 exhibited spatial transformation of representational patterns, showing lower pattern similarity for items in same locations than closely matched different locations during retrieval, whereas the CA23DG exhibited sequential transformation of representational patterns, showing lower pattern similarity for items in near locations than in far locations during encoding. These transformations enabled the encoding of multiple items in the same location and disambiguation of adjacent items. Our results suggest that the hippocampus can flexibly reconfigure multiplexed event structure representations to support accurate temporal order memory.

29Contextual and pure time coding for self and other in the hippocampus.PubMed

David B Omer, Liora Las, Nachum Ulanovsky
Nat Neurosci. 2023 Feb;26(2):285-294. doi: 10.1038/s41593-022-01226-y. Epub 2022 Dec 30.
Navigation and episodic memory depend critically on representing temporal sequences. Hippocampal 'time cells' form temporal sequences, but it is unknown whether they represent context-dependent experience or time per se. Here we report on time cells in bat hippocampal area CA1, which, surprisingly, formed two distinct populations. One population of time cells generated different temporal sequences when the bat hung at different locations, thus conjunctively encoding spatial context and time-'contextual time cells'. A second population exhibited similar preferred times across different spatial contexts, thus purely encoding elapsed time. When examining neural responses after the landing moment of another bat, in a social imitation task, we found time cells that encoded temporal sequences aligned to the other's landing. We propose that these diverse time codes may support the perception of interval timing, episodic memory and temporal coordination between self and others.

30Temporal and Rate Coding for Discrete Event Sequences in the Hippocampus.PubMed

Satoshi Terada, Yoshio Sakurai, Hiroyuki Nakahara, et al.
Neuron. 2017 Jun 21;94(6):1248-1262.e4. doi: 10.1016/j.neuron.2017.05.024. Epub 2017 Jun 9.
Although the hippocampus is critical to episodic memory, neuronal representations supporting this role, especially relating to nonspatial information, remain elusive. Here, we investigated rate and temporal coding of hippocampal CA1 neurons in rats performing a cue-combination task that requires the integration of sequentially provided sound and odor cues. The majority of CA1 neurons displayed sensory cue-, combination-, or choice-specific (simply, "event"-specific) elevated discharge activities, which were sustained throughout the event period. These event cells underwent transient theta phase precession at event onset, followed by sustained phase locking to the early theta phases. As a result of this unique single neuron behavior, the theta sequences of CA1 cell assemblies of the event sequences had discrete representations. These results help to update the conceptual framework for space encoding toward a more general model of episodic event representations in the hippocampus.

31Differential Emergence and Stability of Sensory and Temporal Representations in Context-Specific Hippocampal Sequences.PubMed

Jiannis Taxidis, Eftychios A Pnevmatikakis, Conor C Dorian, et al.
Neuron. 2020 Dec 9;108(5):984-998.e9. doi: 10.1016/j.neuron.2020.08.028. Epub 2020 Sep 18.
Hippocampal spiking sequences encode external stimuli and spatiotemporal intervals, linking sequential experiences in memory, but the dynamics controlling the emergence and stability of such diverse representations remain unclear. Using two-photon calcium imaging in CA1 while mice performed an olfactory working-memory task, we recorded stimulus-specific sequences of "odor-cells" encoding olfactory stimuli followed by "time-cells" encoding time points in the ensuing delay. Odor-cells were reliably activated and retained stable fields during changes in trial structure and across days. Time-cells exhibited sparse and dynamic fields that remapped in both cases. During task training, but not in untrained task exposure, time-cell ensembles increased in size, whereas odor-cell numbers remained stable. Over days, sequences drifted to new populations with cell activity progressively converging to a field and then diverging from it. Therefore, CA1 employs distinct regimes to encode external cues versus their variable temporal relationships, which may be necessary to construct maps of sequential experiences.

32Psilocybin desynchronizes the human brain.PubMed

Joshua S Siegel, Subha Subramanian, Demetrius Perry, et al.
Nature. 2024 Aug;632(8023):131-138. doi: 10.1038/s41586-024-07624-5. Epub 2024 Jul 17.
A single dose of psilocybin, a psychedelic that acutely causes distortions of space-time perception and ego dissolution, produces rapid and persistent therapeutic effects in human clinical trials. In animal models, psilocybin induces neuroplasticity in cortex and hippocampus. It remains unclear how human brain network changes relate to subjective and lasting effects of psychedelics. Here we tracked individual-specific brain changes with longitudinal precision functional mapping (roughly 18 magnetic resonance imaging visits per participant). Healthy adults were tracked before, during and for 3 weeks after high-dose psilocybin (25 mg) and methylphenidate (40 mg), and brought back for an additional psilocybin dose 6-12 months later. Psilocybin massively disrupted functional connectivity (FC) in cortex and subcortex, acutely causing more than threefold greater change than methylphenidate. These FC changes were driven by brain desynchronization across spatial scales (areal, global), which dissolved network distinctions by reducing correlations within and anticorrelations between networks. Psilocybin-driven FC changes were strongest in the default mode network, which is connected to the anterior hippocampus and is thought to create our sense of space, time and self. Individual differences in FC changes were strongly linked to the subjective psychedelic experience. Performing a perceptual task reduced psilocybin-driven FC changes. Psilocybin caused persistent decrease in FC between the anterior hippocampus and default mode network, lasting for weeks. Persistent reduction of hippocampal-default mode network connectivity may represent a neuroanatomical and mechanistic correlate of the proplasticity and therapeutic effects of psychedelics.

33Abnormal metabolic connectivity in default mode network of right temporal lobe epilepsy.PubMed

Xiaoyang Wang, Dandan Lin, Chunlei Zhao, et al.
Front Neurosci. 2023 Mar 23;17:1011283. doi: 10.3389/fnins.2023.1011283. eCollection 2023.
AIMS: Temporal lobe epilepsy (TLE) is a common neurological disorder associated with the dysfunction of the default mode network (DMN). Metabolic connectivity measured by 18F-fluorodeoxyglucose Positron Emission Computed Tomography (18F-FDG PET) has been widely used to assess cumulative energy consumption and provide valuable insights into the pathophysiology of TLE. However, the metabolic connectivity mechanism of DMN in TLE is far from fully elucidated. The present study investigated the metabolic connectivity mechanism of DMN in TLE using 18F-FDG PET. METHOD: Participants included 40 TLE patients and 41 health controls (HC) who were age- and gender-matched. A weighted undirected metabolic network of each group was constructed based on 14 primary volumes of interest (VOIs) in the DMN, in which Pearson's correlation coefficients between each pair-wise of the VOIs were calculated in an inter-subject manner. Graph theoretic analysis was then performed to analyze both global (global efficiency and the characteristic path length) and regional (nodal efficiency and degree centrality) network properties. RESULTS: Metabolic connectivity in DMN showed that regionally networks changed in the TLE group, including bilateral posterior cingulate gyrus, right inferior parietal gyrus, right angular gyrus, and left precuneus. Besides, significantly decreased ( < 0.05, FDR corrected) metabolic connections of DMN in the TLE group were revealed, containing bilateral hippocampus, bilateral posterior cingulate gyrus, bilateral angular gyrus, right medial of superior frontal gyrus, and left inferior parietal gyrus. CONCLUSION: Taken together, the present study demonstrated the abnormal metabolic connectivity in DMN of TLE, which might provide further insights into the understanding the dysfunction mechanism and promote the treatment for TLE patients.

34Cognitive Aging and Time Perception: Roles of Bayesian Optimization and Degeneracy.PubMed

Martine Turgeon, Cindy Lustig, Warren H Meck
Front Aging Neurosci. 2016 May 18;8:102. doi: 10.3389/fnagi.2016.00102. eCollection 2016.
This review outlines the basic psychological and neurobiological processes associated with age-related distortions in timing and time perception in the hundredths of milliseconds-to-minutes range. The difficulty in separating indirect effects of impairments in attention and memory from direct effects on timing mechanisms is addressed. The main premise is that normal aging is commonly associated with increased noise and temporal uncertainty as a result of impairments in attention and memory as well as the possible reduction in the accuracy and precision of a central timing mechanism supported by dopamine-glutamate interactions in cortico-striatal circuits. Pertinent to these findings, potential interventions that may reduce the likelihood of observing age-related declines in timing are discussed. Bayesian optimization models are able to account for the adaptive changes observed in time perception by assuming that older adults are more likely to base their temporal judgments on statistical inferences derived from multiple trials than on a single trial's clock reading, which is more susceptible to distortion. We propose that the timing functions assigned to the age-sensitive fronto-striatal network can be subserved by other neural networks typically associated with finely-tuned perceptuo-motor adjustments, through degeneracy principles (different structures serving a common function).

35Aging and Parkinson's disease: Different sides of the same coin?PubMed

Timothy J Collier, Nicholas M Kanaan, Jeffrey H Kordower
Mov Disord. 2017 Jul;32(7):983-990. doi: 10.1002/mds.27037. Epub 2017 May 18.
Despite abundant epidemiological evidence in support of aging as the primary risk factor for PD, biological correlates of a connection have been elusive. In this article, we address the following question: does aging represent biology accurately characterized as pre-PD? We present evidence from our work on midbrain dopamine neurons of aging nonhuman primates that demonstrates that markers of known correlates of dopamine neuron degeneration in PD, including impaired proteasome/lysosome function, oxidative/nitrative damage, and inflammation, all increase with advancing age and are exaggerated in the ventral tier substantia nigra dopamine neurons most vulnerable to degeneration in PD. Our findings support the view that aging-related changes in the dopamine system approach the biological threshold for parkinsonism, actively producing a vulnerable pre-parkinsonian state. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

36Investigating the perceived timing of sensory events triggering actions in patients with Parkinson's disease and the effects of dopaminergic therapy.PubMed

Yoshiko Yabe, Melvyn A Goodale, Penny A MacDonald
Cortex. 2019 Jun;115:309-323. doi: 10.1016/j.cortex.2019.02.009. Epub 2019 Feb 23.
Few studies have investigated if Parkinson's disease (PD), advancing age, or exogenous dopamine therapy affect the perceived timing of past events. Here we show a phenomenon of 'temporal repulsion' of a sensory event relative to an action decision in patients with PD. In these patients, the timing of a sensory event triggering an action was perceived to have occurred earlier in time than it really did. In other words, the event appeared to be pushed away in time from the performance of the action. This finding stands in sharp contrast to the 'temporal binding' we have observed here and elsewhere (Yabe et al., 2017; Yabe & Goodale, 2015) in young healthy participants for whom the perceived onset of a sensory event triggering an action is typically delayed, as if it were pulled towards the action in time. In elderly patients, sensory events were neither repulsed nor pulled toward the action decision event. Exogenous dopamine alleviated the temporal repulsion in PD patients and normalized the temporal binding in healthy elderly controls. In contrast, dopaminergic therapy worsened temporal binding in healthy young participants. We discuss this pattern of findings, relating temporal binding processes to dopaminergic and striatal mechanisms.

37Single-dose levodopa administration and aging independently disrupt time production.PubMed

Brian C Rakitin, Nikolaos Scarmeas, Tina Li, et al.
J Cogn Neurosci. 2006 Mar;18(3):376-87. doi: 10.1162/089892906775990615.
We tested the hypothesis that age-related time production deficits are dopamine-mediated. The experiment was conducted double-blind, and with random assignment of 32 healthy aged and 32 healthy young participants to either inert placebo or levodopa (200 mg) groups. The procedure included training participants to produce two target time intervals (6 and 17 sec) in separate blocks, drug/placebo administration, a 1-hr delay, and then delayed free-recall time production retesting without feedback. Participants also performed a speeded choice reaction time (RT) task, as a control for potential dopaminergic and aging effects on attention and psychomotor speed. Results indicate that during retesting, aged participants show duration-dependent timing errors that are larger than those shown by the young participants. Levodopa administration yielded lengthened time production of both target intervals. The aging and levodopa effects did not interact. Also, aging slowed RT and increased RT variability, but levodopa had no effect on the RT. These results suggest that at this dosage and under these specific conditions, timing is dopamine-mediated but the effect of aging on time production is not. Moreover, the levodopa timing effect cannot be attributed to the effects of dopaminergic function on psychomotor speed.

38Functional implications of changes in the senescent brain: a review.PubMed

C H Beck
Can J Neurol Sci. 1978 Nov;5(4):417-24. doi: 10.1017/s0317167100024203.
The morphological, chemical, and physiological changes in the brain accompanying old age are reviewed. The deterioration of the striatal and hypothalamic dopaminergic systems were implicated in the onset of age related Parkinsonian-like slowing of performance and altered affect. Cholinergic hippocampal and neocortical systems were chemically and physiologically abnormal in the aged. The implications for slowed cognitive processing and persistance of the memory trace are presented.

39Interval timing deficits and their neurobiological correlates in aging mice.PubMed

Ezgi Gür, Yalçın Akın Duyan, Sertan Arkan, et al.
Neurobiol Aging. 2020 Jun;90:33-42. doi: 10.1016/j.neurobiolaging.2020.02.021. Epub 2020 Mar 4.
Age-related neurobiological and cognitive alterations suggest that interval timing (as a related function) is also altered in aging, which can, in turn, disrupt timing-dependent functions. We investigated alterations in interval timing with aging and accompanying neurobiological changes. We tested 4-6, 10-12, and 18-20 month-old mice on the dual peak interval procedure. Results revealed a specific deficit in the termination of timed responses (stop-times). The decision processes contributed more to timing variability (vs. clock/memory process) in the aged mice. We observed age-dependent reductions in the number of dopaminergic neurons in the VTA and SNc, cholinergic neurons in the medial septum/diagonal band (MS/DB) complex, and density of dopaminergic axon terminals in the DLS/DMS. Negative correlations were found between the number of dopaminergic neurons in the VTA and stop times, and the number of cholinergic neurons in MS/DB complex and the acquisition of stop times. Our results point at age-dependent changes in the decisional components of interval timing and the role of dopaminergic and cholinergic functions in these behavioral alterations.

40Intra-dorsal striatal acetylcholine M1 but not dopaminergic D1 or glutamatergic NMDA receptor antagonists inhibit consolidation of duration memory in interval timing.PubMed

Masahiko Nishioka, Taisuke Kamada, Atsushi Nakata, et al.
Behav Brain Res. 2022 Feb 15;419:113669. doi: 10.1016/j.bbr.2021.113669. Epub 2021 Nov 17.
The striatal beat frequency model assumes that striatal medium spiny neurons encode duration via synaptic plasticity. Muscarinic 1 (M1) cholinergic receptors as well as dopamine and glutamate receptors are important for neural plasticity in the dorsal striatum. Therefore, we investigated the effect of inhibiting these receptors on the formation of duration memory. After sufficient training in a peak interval (PI)-20-s procedure, rats were administered a single or mixed infusion of a selective antagonist for the dopamine D1 receptor (SCH23390, 0.5 µg per side), N-methyl-D-aspartic acid (NMDA)-type glutamate receptor (D-AP5, 3 µg), or M1 receptor (pirenzepine, 10 µg) bilaterally in the dorsal striatum, immediately before initiating a PI-40 s session (shift session). The next day, the rats were tested for new duration memory (40 s) in a session in which no lever presses were reinforced (test session). In the shift session, the performance was comparable irrespective of the drug injected. However, in the test session, the mean peak time (an index of duration memory) of the M1 + NMDA co-blockade group, but not of the D1 + NMDA co-blockade group, was lower than that of the control group (Experiments 1 and 2). In Experiment 3, the effect of the co-blockade of M1 and NMDA receptors was replicated. Moreover, sole blockade of M1 receptors induced the same effect as M1 and NMDA blockade. These results suggest that in the dorsal striatum, the M1 receptor, but not the D1 or NMDA receptors, is involved in the consolidation of duration memory.

41Time perception and age.PubMed

Vanessa Fernanda Moreira Ferreira, Gabriel Pina Paiva, Natália Prando, et al.
Arq Neuropsiquiatr. 2016 Apr;74(4):299-302. doi: 10.1590/0004-282X20160025.
UNLABELLED: Our internal clock system is predominantly dopaminergic, but memory is predominantly cholinergic. Here, we examined the common sensibility encapsulated in the statement: "time goes faster as we get older". OBJECTIVE: To measure a 2 min time interval, counted mentally in subjects of different age groups. METHOD: 233 healthy subjects (129 women) were divided into three age groups: G1, 15-29 years; G2, 30-49 years; and G3, 50-89 years. Subjects were asked to close their eyes and mentally count the passing of 120 s. RESULTS: The elapsed times were: G1, mean = 114.9 ± 35 s; G2, mean = 96.0 ± 34.3 s; G3, mean = 86.6 ± 34.9 s. The ANOVA-Bonferroni multiple comparison test showed that G3 and G1 results were significantly different (P < 0.001). CONCLUSION: Mental calculations of 120 s were shortened by an average of 24.6% (28.3 s) in individuals over age 50 years compared to individuals under age 30 years.

42Neural correlates of listening effort related factors: influence of age and hearing impairment.PubMed

Corinna Bernarding, Daniel J Strauss, Ronny Hannemann, et al.
Brain Res Bull. 2013 Feb;91:21-30. doi: 10.1016/j.brainresbull.2012.11.005. Epub 2012 Nov 29.
In the last years, there has been a rising interest to find an objective method to estimate listening effort. Previously, we have shown that the wavelet phase synchronization stability (WPSS), gained from the instantaneous phase of auditory late responses (ALRs), could serve as a feasible measure for listening effort related factors. In the current study, we examined if the WPSS reflects the listening effort in young as well as middle-aged subjects and in persons with a different degree of hearing loss. To evoke ALR sequences, we generated syllabic paradigms with a different level of difficulty to evoke ALR sequences. We expected, due to the varying task demand, that the subjects require a measurable difference in the amount of effort to solve the paradigms. Additionally, a possible age and/or hearing loss related effect on the neural correlates of listening effort was investigated. The results indicate, that WPSS reflects the listening effort related factors needed to solve an auditory task. A further finding was that the reaction time data and the N1 wave amplitude information hardly yield any correlate of the invested listening effort. In addition, we noticed an age as well as hearing sensitivity related effect on the listening effort.

43Temporal and non-temporal processes in the elderly.PubMed

Leah Fostick, Harvey Babkoff
J Basic Clin Physiol Pharmacol. 2013;24(3):191-9. doi: 10.1515/jbcpp-2013-0049.
BACKGROUND: The present study examined whether the reported age-related decline in auditory temporal resolution is specific to the temporal domain or rather reflects a general decline in auditory perception, including the stimulus intensity domain. METHODS: The performance of 89 healthy participants aged between 21 and 82 years with normal hearing was tested on a variety of psychophysical tasks, where discrimination was based either on the temporal or on the intensity domains. Stimulus levels for all tasks were 40 dB SL (corrected for threshold). Participants were also tested on two cognitive tasks: Wechsler Adult Intelligence Scale, Third Edition, matrices and digit span. RESULTS: Findings indicate that age was significantly negatively correlated with performance on three of the temporal resolution tasks, namely, dichotic temporal-order judgment, spectral temporal-order judgment, and gap detection, but not on the intensity discrimination task, thus emphasizing the specificity of the age-related decline to the auditory temporal domain. CONCLUSIONS: The overall results suggest that age-related changes in auditory perception are specific to the temporal domain, even when controlling for hearing sensitivity and cognitive ability, and are not reflected in other aspects of non-temporal perception, such as intensity discrimination.

44Aging effects on neural processing of rhythm and meter.PubMed

Sarah A Sauvé, Emily L W Bolt, Sylvie Nozaradan, et al.
Front Aging Neurosci. 2022 Sep 1;14:848608. doi: 10.3389/fnagi.2022.848608. eCollection 2022.
When listening to musical rhythm, humans can perceive and move to beat-like metrical pulses. Recently, it has been hypothesized that meter perception is related to brain activity responding to the acoustic fluctuation of the rhythmic input, with selective enhancement of the brain response elicited at meter-related frequencies. In the current study, electroencephalography (EEG) was recorded while younger (<35) and older (>60) adults listened to rhythmic patterns presented at two different tempi while intermittently performing a tapping task. Despite significant hearing loss compared to younger adults, older adults showed preserved brain activity to the rhythms. However, age effects were observed in the distribution of amplitude across frequencies. Specifically, in contrast with younger adults, older adults showed relatively larger amplitude at the frequency corresponding to the rate of individual events making up the rhythms as compared to lower meter-related frequencies. This difference is compatible with larger N1-P2 potentials as generally observed in older adults in response to acoustic onsets, irrespective of meter perception. These larger low-level responses to sounds have been linked to processes by which age-related hearing loss would be compensated by cortical sensory mechanisms. Importantly, this low-level effect would be associated here with relatively reduced neural activity at lower frequencies corresponding to higher-level metrical grouping of the acoustic events, as compared to younger adults.

45Attenuated audiovisual integration in middle-aged adults in a discrimination task.PubMed

Weiping Yang, Yanna Ren
Cogn Process. 2018 Feb;19(1):41-45. doi: 10.1007/s10339-017-0838-1. Epub 2017 Sep 13.
Numerous studies have focused on the diversity of audiovisual integration between younger and older adults. However, consecutive trends in audiovisual integration throughout life are still unclear. In the present study, to clarify audiovisual integration characteristics in middle-aged adults, we instructed younger and middle-aged adults to conduct an auditory/visual stimuli discrimination experiment. Randomized streams of unimodal auditory (A), unimodal visual (V) or audiovisual stimuli were presented on the left or right hemispace of the central fixation point, and subjects were instructed to respond to the target stimuli rapidly and accurately. Our results demonstrated that the responses of middle-aged adults to all unimodal and bimodal stimuli were significantly slower than those of younger adults (p < 0.05). Audiovisual integration was markedly delayed (onset time 360 ms) and weaker (peak 3.97%) in middle-aged adults than in younger adults (onset time 260 ms, peak 11.86%). The results suggested that audiovisual integration was attenuated in middle-aged adults and further confirmed age-related decline in information processing.

46Spatio-temporal patterns of event-related potentials related to audiovisual synchrony judgments in older adults.PubMed

Yu Man Chan, Michael Julian Pianta, Stefan Bode, et al.
Neurobiol Aging. 2017 Jul;55:38-48. doi: 10.1016/j.neurobiolaging.2017.03.011. Epub 2017 Mar 18.
Older adults have altered perception of the relative timing between auditory and visual stimuli, even when stimuli are scaled to equate detectability. To help understand why, this study investigated the neural correlates of audiovisual synchrony judgments in older adults using electroencephalography (EEG). Fourteen younger (18-32 year old) and 16 older (61-74 year old) adults performed an audiovisual synchrony judgment task on flash-pip stimuli while EEG was recorded. All participants were assessed to have healthy vision and hearing for their age. Observers responded to whether audiovisual pairs were perceived as synchronous or asynchronous via a button press. The results showed that the onset of predictive sensory information for synchrony judgments was not different between groups. Channels over auditory areas contributed more to this predictive sensory information than visual areas. The spatial-temporal profile of the EEG activity also indicates that older adults used different resources to maintain a similar level of performance in audiovisual synchrony judgments compared with younger adults.

47Sensorimotor Impairment in Aging and Neurocognitive Disorders: Beat Synchronization and Adaptation to Tempo Changes.PubMed

Andres von Schnehen, Lise Hobeika, Marion Houot, et al.
J Alzheimers Dis. 2024;100(3):945-959. doi: 10.3233/JAD-231433.
BACKGROUND: Understanding the nature and extent of sensorimotor decline in aging individuals and those with neurocognitive disorders (NCD), such as Alzheimer's disease, is essential for designing effective music-based interventions. Our understanding of rhythmic functions remains incomplete, particularly in how aging and NCD affect sensorimotor synchronization and adaptation to tempo changes. OBJECTIVE: This study aimed to investigate how aging and NCD severity impact tapping to metronomes and music, with and without tempo changes. METHODS: Patients from a memory clinic participated in a tapping task, synchronizing with metronomic and musical sequences, some of which contained sudden tempo changes. After exclusions, 51 patients were included in the final analysis. RESULTS: Participants' Mini-Mental State Examination scores were associated with tapping consistency. Additionally, age negatively influenced consistency when synchronizing with a musical beat, whereas consistency remained stable across age when tapping with a metronome. CONCLUSIONS: The results indicate that the initial decline of attention and working memory with age may impact perception and synchronization to a musical beat, whereas progressive NCD-related cognitive decline results in more widespread sensorimotor decline, affecting tapping irrespective of audio type. These findings underline the importance of customizing rhythm-based interventions to the needs of older adults and individuals with NCD, taking into consideration their cognitive as well as their rhythmic aptitudes.

48Coupled temporal memories in Parkinson's disease: a dopamine-related dysfunction.PubMed

C Malapani, B Rakitin, R Levy, et al.
J Cogn Neurosci. 1998 May;10(3):316-31. doi: 10.1162/089892998562762.
Dysfunction of the basal ganglia and the brain nuclei interconnected with them leads to disturbances of movement and cognition, including disordered timing of movement and perceptual timing deficits. Patients with Parkinson's disease (PD) were studied in temporal reproduction tasks. We examined PD patients when brain dopamine (DA) transmission was impaired (OFF state) and when DA transmission was reestablished, at the time of maximal clinical benefit following administration of levodopa + apomorphine (ON state). Patients reproduced target times of 8 and 21 sec trained in blocked trials with the peak interval procedure, which were veridical in the ON state, comparable to normative performance by healthy young and aged controls (Experiment 1). In the OFF state, temporal reproduction was impaired in both accuracy and precision (variance). The 8-sec signal was reproduced as longer and the 21-sec signal was reproduced as shorter than they actually were (Experiment 1). This "migration" effect was dependent upon training of two different durations. When PD patients were trained on 21 sec only (Experiment 2), they showed a reproduction error in the long direction, opposite to the error produced under the dual training condition of Experiment 1. The results are discussed as a mutual attraction between temporal processing systems, in memory and clock stages, when dopaminergic regulation in the striatum is dysfunctional.

49Motor timing deficits in sequential movements in Parkinson disease are related to action planning: a motor imagery study.PubMed

Laura Avanzino, Elisa Pelosin, Davide Martino, et al.
PLoS One. 2013 Sep 23;8(9):e75454. doi: 10.1371/journal.pone.0075454. eCollection 2013.
Timing of sequential movements is altered in Parkinson disease (PD). Whether timing deficits in internally generated sequential movements in PD depends also on difficulties in motor planning, rather than merely on a defective ability to materially perform the planned movement is still undefined. To unveil this issue, we adopted a modified version of an established test for motor timing, i.e. the synchronization-continuation paradigm, by introducing a motor imagery task. Motor imagery is thought to involve mainly processes of movement preparation, with reduced involvement of end-stage movement execution-related processes. Fourteen patients with PD and twelve matched healthy volunteers were asked to tap in synchrony with a metronome cue (SYNC) and then, when the tone stopped, to keep tapping, trying to maintain the same rhythm (CONT-EXE) or to imagine tapping at the same rhythm, rather than actually performing it (CONT-MI). We tested both a sub-second and a supra-second inter-stimulus interval between the cues. Performance was recorded using a sensor-engineered glove and analyzed measuring the temporal error and the interval reproduction accuracy index. PD patients were less accurate than healthy subjects in the supra-second time reproduction task when performing both continuation tasks (CONT-MI and CONT-EXE), whereas no difference was detected in the synchronization task and on all tasks involving a sub-second interval. Our findings suggest that PD patients exhibit a selective deficit in motor timing for sequential movements that are separated by a supra-second interval and that this deficit may be explained by a defect of motor planning. Further, we propose that difficulties in motor planning are of a sufficient degree of severity in PD to affect also the motor performance in the supra-second time reproduction task.

50[Information overload syndrome: a bibliographic review].PubMed

L E Parra-Medina, F J Álvarez-Cervera
Rev Neurol. 2021 Nov 16;73(12):421-428. doi: 10.33588/rn.7312.2021113.
INTRODUCTION: We are living in the time of greatest dissemination of information in the history of the human race, and this excess of information has resulted in considering human attention as a scarce resource. Information overload is the situation in which the amount or intensity of information exceeds the individual's limited capacity for cognitive processing. OBJECTIVE: To describe the concept of information overload, its possible neurocognitive substrates, associated symptoms, causes, measures to avoid it, as well as its possible relationship with the internet and electronic devices. DEVELOPMENT: People respond differently to information overload, and this depends on individual factors as well as on the amount and characteristics of the informative stimulation. Some symptoms of information overload are: inefficient work, confusion, delay in making decisions, lack of critical evaluation of information, loss of control over information, refusal to receive communication, lack of general perspective, greater tolerance for error, anxiety, stress, etc. The limits of information processing capacity are probably conditioned by the limited metabolic energy that is distributed in the brain and remains constant regardless of the difficulty of the tasks. CONCLUSION: Attention is a limited cognitive function. In order to reduce the adverse effects of information overload, it is necessary to improve the personal management of our own cognitive resources and to understand their relationship with technology. Likewise, it is necessary to improve the handling of information through the organization, filtering and application of cognitive ergonomics design guidelines.

51Factors Predicting Information Overload During the COVID-19 Pandemic in the Digital Age: Longitudinal Study.PubMed

Hiroko Okada, Tsuyoshi Okuhara, Takahiro Kiuchi
Interact J Med Res. 2025 Oct 30;14:e67098. doi: 10.2196/67098.
BACKGROUND: The human capacity to process information is limited. During the COVID-19 pandemic, people were exposed to a large amount of uncertain and complex health information. This situation made some people experience perceived information overload, which made them unable to adopt appropriate preventive behaviors. OBJECTIVE: This study aimed to examine the individual characteristics, abilities, and attention to informational media that predict the perception of information overload during a pandemic. METHODS: We conducted a longitudinal study with 2 time points, August 2020 and August 2021, among residents of Japan under a COVID-19 emergency declaration. The sample had the same proportions for sex, age, and prefecture as the general Japanese population. We used a web-based survey to measure sociodemographic characteristics, health literacy (HL), attention to 6 different types of information channels, and participants' perception of information overload. Hierarchical multiple regression analysis was conducted with information overload as the objective variable. RESULTS: A total of 784 participants responded to the survey at both time points, with a follow-up rate of 78.4% (784/1000). Hierarchical multiple regression analysis showed that younger age (β=-0.084, 95% CI -0.142 to -0.013), male sex (β=-0.163, 95% CI -0.008 to -0.003), lower HL (β=-0.084, 95% CI -0.114 to -0.011), paying less attention to television news (β=-0.118, 95% CI -0.038 to -0.001), and paying greater attention to social media (β=0.089, 95% CI 0.000-0.027) significantly predicted information overload 1 year after exposure to information during the pandemic. CONCLUSIONS: Public health communicators should aim to provide concise and understandable information in consideration of a target population that is vulnerable to information overload during a pandemic. A high level of attention to social media may increase the perception of information overload. By contrast, HL may reduce the cognitive load in information processing. Providing an environment during normal periods that allows people to develop the skills to critically interpret health information will help them to prepare for future infodemics.

52Understanding Digital Dementia and Cognitive Impact in the Current Era of the Internet: A Review.PubMed

Zeeshan Ali, Jayaprakash Janarthanan, Prasanna Mohan
Cureus. 2024 Sep 23;16(9):e70029. doi: 10.7759/cureus.70029. eCollection 2024 Sep.
Dementia encompasses symptoms resulting from brain damage that impairs cognitive functions, surpassing natural aging effects. This condition affects emotional regulation, behavior, and motivation while preserving consciousness. Dr. Manfred Spitzer coined the term 'digital dementia,' highlighting the cognitive decline associated with excessive reliance on digital devices such as smartphones and Google, potentially exacerbating attention deficit hyperactivity disorder (ADHD) and memory loss. This condition mirrors terms like 'digital amnesia' and 'the Google Effect,' highlighting the brain's tendency to offload peripheral information, leading to panic and forgetfulness. Spitzer's book, focuses on gaming effects on children and has thus popularized the term. Teenagers are known to use electronic devices regularly, correlating with rising cognitive impairments. The advent of the internet's fifth generation (5G) has transformed technology use, impacting mental health treatments and clinical practices globally. Digital media's influence on the developing brain encompasses motor skills, language, and cognition. Excessive digital media use in young adults correlates with lower cognitive empathy, affecting interpersonal understanding and facial recognition. Studies link heavy reliance on web-based media to decreased white matter integrity, crucial for language skills. Adolescents may be more vulnerable to anxiety and unrealistic expectations due to digital media overuse. Digital media overuse impacts brain development, especially cognitive and inhibitory control, attention, memory, and reasoning, essential for adapting to dynamic environments. Early exposure to fast-paced media can impair motor skills, spatial awareness, problem-solving, and language learning. Neuroimaging studies reveal that environmental factors like screen usage affect brain networks controlling social-emotional behavior and executive functions. Overreliance on smartphones diminishes gray matter in key brain regions, affecting cognitive and emotional regulation. The internet generation, characterized by advancements such as Web 3.0, introduces artificial intelligence and semantic web technologies, reshaping digital content processing. The neurobiological basis of digital dementia involves changes in the brain structure and function, with excessive screen exposure linked to cognitive impairments. Neuroplasticity, or the brain's adaptability, plays a role in cognitive decline from digital media overuse. Early childhood and adolescent brain development stages exhibit significant plasticity, influencing cognitive trajectories. Addressing digital dementia requires strategies to reduce screen time, promote cognitive exercises, and enhance awareness. Parents should regulate children's screen usage, encourage digital detox periods, and substitute screen time with other activities. Cognitive training programs such as Cogmed (Neural Assembly Int AB, Stockholm, SWE) and CogniFit (San Francisco, CA, USA) can improve memory and attention in older adults. Promoting balanced technology use and educating on the risks of excessive digital media consumption is crucial for maintaining cognitive health in the digital age.

53Effect of Abstinence from Social Media on Time Perception: Differences between Low- and At-Risk for Social Media "Addiction" Groups.PubMed

Ofir Turel, Daniel R Cavagnaro
Psychiatr Q. 2019 Mar;90(1):217-227. doi: 10.1007/s11126-018-9614-3.
Time distortion is a hallmark feature of addictive behaviors including excessive technology use. It has clinically significant implications for diagnosis and treatment. Additional information on such distortions after prolonged abstinence from technology use is needed. We seek to examine differences in the effects of several days of abstinence on time-distortion in two groups: social media users who are at-risk and those who are at low risk for social media "addiction." To examine this, we employed a randomized, two group, pre (t1) - post (t2) design. Both groups completed survey tasks that cued social media use at t1 and at t2. Between t1 and t2, the treatment group (n = 294) abstained from social media use for up to one week (less if they "broke" and decided to resume use), and the control group (n = 121) did not. Results indicated that low-risk individuals in both the treatment and control groups presented downward time bias at t1; at-risk individuals presented non-significant upward bias. After abstinence, both low- and at- risk individuals in the treatment group presented upward time distortion. This effect did not take place in the control group; low-risk users still presented significant downward bias at t2. The post-abstinence increase in time distortion was significantly more pronounced in at-risk users. These differences between pre- and post-abstinence time distortion patterns in normal and at-risk-for-"addiction" social media users can be used for adjusting and interpreting self-reports related to addictive uses of technologies.

54Selective suprasecond timing deficit in social media addicts: Bisection task reveals overestimation and impaired sensitivity without subsecond effects.PubMed

Hongyu Zhou, Qingqing Li, Yuanyuan Tang, et al.
Iperception. 2025 Nov 21;16(6):20416695251391634. doi: 10.1177/20416695251391634. eCollection 2025 Nov-Dec.
The rise of social media has raised concerns about its addictive potential and impairments in mental health and cognitive functions, including distortions in time processing. Emerging evidence suggests social media addicts tend to misestimate the amount of time spent using social media, hinting at possible problems with their cognitive time-processing. This study aimed to investigate the impact of social media addiction on basic time perception using controlled experimental paradigms. Forty participants scoring ≥24 on the Bergen Social Media Addiction Scale with ≥5 hr daily usage were recruited, alongside 40 controls. After excluding individuals craving, fear of missing out for social media, or test anxiety during experiment, final samples included 36 addicts and 37 controls. Time reproduction (motor timing) and bisection (perceptual timing) tasks were administered, distinguishing subsecond (<1 s) and suprasecond (>1 s) intervals. Tasks used neutral gray stimuli to avoid social media cues and included pretask rest to control physiological arousal. Social media addicts exhibited significant deficits in suprasecond bisection task, demonstrated by lower subjective equality points (1,430.69 vs. 1,549.32 ms) and higher Weber ratios (0.41 vs. 0.29), indicating both time overestimation and reduced time sensitivity. No significant group differences were observed in reproduction tasks or in subsecond bisection task. These findings establish that social media addiction selectively impairs suprasecond perceptual timing, characterized by overestimation and diminished sensitivity. These findings establish a novel cognitive deficit linked to addictive social media use, with potential clinical implications for intervention strategies targeting distorted time processing.

55Discrepancies Between Self-reported and Objectively Measured Smartphone Screen Time: Before and During Lockdown.PubMed

Pedro B Júdice, Eduarda Sousa-Sá, António L Palmeira
J Prev (2022). 2023 Jun;44(3):291-307. doi: 10.1007/s10935-023-00724-4. Epub 2023 Jan 24.
Screen time shows higher health risks compared to other types of sedentary behaviors. A lockdown may simultaneously increase screen time, reduce physical activity (PA), and change time perception. Our goal was to compare self-reported against objectively measured smartphone screen time (SST) in a sample of active and inactive Portuguese adults before and during a social lockdown. This study was a cross-sectional analysis with 211 Portuguese adults (57.8% males), aged 25.2 ± 8.5 years, from two cohorts, one before the social lockdown and the other during the lockdown. SST was self-reported (SR-SST) and objectively measured using a smartphone (OM-SST). PA was self-reported. Linear regressions were performed to determine the association between SR-SST and OM-SST. A Bland and Altman analysis was used to assess agreement. Independent T-tests were performed for comparisons between cohorts and paired sample T-tests for comparisons within each cohort. The cohort assessed during the lockdown showed a higher SST than the cohort assessed before the lockdown (OM-SST; p < 0.001 and SR-SST; p = 0.009). Before the lockdown, there was no difference between SR-SST and OM-SST (p = 0.100). However, during the social lockdown, although the agreement between SR-SST and OM-SST was good (ICC = 0.72), participants systematically underestimated their SST by ~ 71 min/day (p < 0.001), and this underestimation was higher in inactive participants (~ 85 min/day) than in active individuals (~ 49 min/day). The general population needs to be aware of the benefits of limiting screen time, especially during periods of societal modifications, such as a generalized lockdown. There was a tendency to underestimate SST, meaning a lack of awareness of the actual time spent in this potentially deleterious behavior. This underestimation was more pronounced during the lockdown period and for the inactive participants, thus posing a greater health risk. The findings from this investigation entail relevant information for policy makers to delineate strategies for reducing population screen time from a preventive health perspective.

56Locus Coeruleus and Dopamine-Dependent Memory Consolidation.PubMed

Miwako Yamasaki, Tomonori Takeuchi
Neural Plast. 2017;2017:8602690. doi: 10.1155/2017/8602690. Epub 2017 Oct 16.
Most everyday memories including many episodic-like memories that we may form automatically in the hippocampus (HPC) are forgotten, while some of them are retained for a long time by a memory stabilization process, called initial memory consolidation. Specifically, the retention of everyday memory is enhanced, in humans and animals, when something novel happens shortly before or after the time of encoding. Converging evidence has indicated that dopamine (DA) signaling via D/D receptors in HPC is required for persistence of synaptic plasticity and memory, thereby playing an important role in the novelty-associated memory enhancement. In this review paper, we aim to provide an overview of the key findings related to D/D receptor-dependent persistence of synaptic plasticity and memory in HPC, especially focusing on the emerging evidence for a role of the locus coeruleus (LC) in DA-dependent memory consolidation. We then refer to candidate brain areas and circuits that might be responsible for detection and transmission of the environmental novelty signal and molecular and anatomical evidence for the LC-DA system. We also discuss molecular mechanisms that might mediate the environmental novelty-associated memory enhancement, including plasticity-related proteins that are involved in initial memory consolidation processes in HPC.

57Initial memory consolidation and the synaptic tagging and capture hypothesis.PubMed

Kosuke Okuda, Kristoffer Højgaard, Lucia Privitera, et al.
Eur J Neurosci. 2021 Oct;54(8):6826-6849. doi: 10.1111/ejn.14902. Epub 2020 Jul 25.
Everyday memories are retained automatically in the hippocampus and then decay very rapidly. Memory retention can be boosted when novel experiences occur shortly before or shortly after the time of memory encoding via a memory stabilization process called "initial memory consolidation." The dopamine release and new protein synthesis in the hippocampus during a novel experience are crucial for this novelty-induced memory boost. The mechanisms underlying initial memory consolidation are not well-understood, but the synaptic tagging and capture (STC) hypothesis provides a conceptual basis of synaptic plasticity events occurring during initial memory consolidation. In this review, we provide an overview of the STC hypothesis and its relevance to dopaminergic signalling, in order to explore the cellular and molecular mechanisms underlying initial memory consolidation in the hippocampus. We summarize electrophysiological STC processes based on the evidence from two-pathway experiments and a behavioural tagging hypothesis, which translates the STC hypothesis into a related behavioural hypothesis. We also discuss the function of two types of molecules, "synaptic tags" and "plasticity-related proteins," which have a crucial role in the STC process and initial memory consolidation. We describe candidate molecules for the roles of synaptic tag and plasticity-related proteins and interpret their candidacy based on evidence from two-pathway experiments ex vivo, behavioural tagging experiments in vivo and recent cutting-edge optical imaging experiments. Lastly, we discuss the direction of future studies to advance our understanding of molecular mechanisms underlying the STC process, which are critical for initial memory consolidation in the hippocampus.

58Time perception, pacing and exercise intensity: maximal exercise distorts the perception of time.PubMed

A M Edwards, A McCormick
Physiol Behav. 2017 Oct 15;180:98-102. doi: 10.1016/j.physbeh.2017.08.009. Epub 2017 Aug 15.
INTRODUCTION: Currently there are no data examining the impact of exercise on the perception of time, which is surprising as optimal competitive performance is dependent on accurate pacing using knowledge of time elapsed. METHODS: With institutional ethics approval, 12 recreationally active adult participants (f=7, m=5) undertook both 30s Wingate cycles and 20min (1200s) rowing ergometer bouts as short and long duration self-paced exercise trials, in each of three conditions on separate occasions: 1) light exertion: RPE 11, 2) heavy exertion: RPE 15, 3) maximal exertion: RPE 20. Participants were unaware of exercise duration and were required to verbally indicate when they perceived (subjective time) 1) 25%, 2) 50%, 3) 75% and 4) 100% of each bout's measured (chronological) time had elapsed. RESULTS: In response to the Wingate task, there was no difference between durations of subjective time at the 25%, nor at the 50% interval. However, at the 75% and 100% intervals, the estimate for the RPE 20 condition was shortest (P<0.01). In response to rowing, there were no differences at the 25% interval, but there was some evidence that the RPE 20 condition was perceived shorter at 50%. At 75% and 100%, the RPE 20 condition was perceived to be shorter than both RPE 15 (P=0.04) and RPE 11 (P=0.008) conditions. CONCLUSION: This study is the first to empirically demonstrate that exercise intensity distorts time perception, particularly during maximal exercise. Consequently external feedback of chronological time may be an important factor for athletes undertaking maximal effort tasks or competitions.

59The role of physical and cognitive effort on time perception.PubMed

Tommaso Bartolini, Irene Petrizzo, Roberto Arrighi, et al.
Sci Rep. 2025 Jul 15;15(1):25595. doi: 10.1038/s41598-025-07814-9.
Action and perception are intertwined, and time perception is not an exception to this general principle. In line with that, we have recently reported that the perceived duration of visual stimuli is extended while running. Here we tested the nature of this phenomenon by contrasting two possibilities: one related to physiological changes induced by physical effort (e.g. heart rate, temperature, arousal), and one related to cognitive alterations linked to motor control. To this aim we compared the direction and magnitude of the temporal bias induced by running to that prompted by other two conditions requiring much lower physical effort but both depleting cognitive resources. In these two conditions, participants either performed the timing task while walking backwards (an attentional motor task) or standing still with cognitive resources divided in a concurrent visual-working memory task. Both conditions yielded temporal overestimations virtually identical to that found while running, suggesting that physical activity could modulate temporal processing through the cognitive effort required to perform/control that specific motor routine. The results are informative for the scientific community investigating time perception in ecological sensorimotor contexts, suggesting the importance of considering the potential confounding role of cognitive factors related to motor execution.

60Reversible DNA methylation regulates seasonal photoperiodic time measurement.PubMed

Tyler J Stevenson, Brian J Prendergast
Proc Natl Acad Sci U S A. 2013 Oct 8;110(41):16651-6. doi: 10.1073/pnas.1310643110. Epub 2013 Sep 25.
In seasonally breeding vertebrates, changes in day length induce categorically distinct behavioral and reproductive phenotypes via thyroid hormone-dependent mechanisms. Winter photoperiods inhibit reproductive neuroendocrine function but cannot sustain this inhibition beyond 6 mo, ensuring vernal reproductive recrudescence. This genomic plasticity suggests a role for epigenetics in the establishment of seasonal reproductive phenotypes. Here, we report that DNA methylation of the proximal promoter for the type III deiodinase (dio3) gene in the hamster hypothalamus is reversible and critical for photoperiodic time measurement. Short photoperiods and winter-like melatonin inhibited hypothalamic DNA methyltransferase expression and reduced dio3 promoter DNA methylation, which up-regulated dio3 expression and induced gonadal regression. Hypermethylation attenuated reproductive responses to short photoperiods. Vernal refractoriness to short photoperiods reestablished summer-like methylation of the dio3 promoter, dio3 expression, and reproductive competence, revealing a dynamic and reversible mechanism of DNA methylation in the mammalian brain that plays a central role in physiological orientation in time.

61Older Adults' Perceptions of Sedentary Behavior: A Systematic Review and Thematic Synthesis of Qualitative Studies.PubMed

Sofie Compernolle, Katrien De Cocker, Greet Cardon, et al.
Gerontologist. 2020 Nov 23;60(8):572-582. doi: 10.1093/geront/gnz127.
BACKGROUND AND OBJECTIVES: Reducing sedentary behavior contributes to healthy aging. In order to develop sedentary behavior interventions, insight is needed into older adults' perceptions of (reducing) sedentary behavior. Therefore, this systematic review aims to synthesize qualitative evidence of older adults' perceptions towards (a) the concept of sedentary behavior, (b) barriers and facilitators of sedentary behavior, and (c) solutions and strategies to reduce sedentary behavior. RESEARCH DESIGN AND METHODS: A systematic search was conducted in four electronic databases. Inclusion criteria comprised qualitative and mixed-methods studies investigating the perceptions of older adults (mean age: ≥60 years) towards (reducing) sedentary behavior. Quality of the included studies was rated using the Critical Appraisal Skills Programme (CASP) Qualitative Checklist. Relevant data on older adults' perceptions were extracted and imported into NVivo. Two independent reviewers analyzed the data by means of thematic synthesis (line-by-line coding, constructing descriptive (sub)themes, developing analytical themes). RESULTS: Fifteen studies were included. Four analytical themes were developed to be considered when aiming to reduce sedentary behavior in older adults: the lack of knowledge on/awareness of sedentary behavior, the habitual nature of sedentary behavior, the importance of enjoyment and convenience, and the key role of aging. DISCUSSION AND IMPLICATIONS: The reduction of older adults' sedentary behavior will likely be challenging as sedentary behavior seems to be firmly incorporated into older adults' daily routines, and strongly linked with positive reinforcement. Both aspects deserve thoughtful attention by intervention developers and health care professionals who aim to promote healthy aging by reducing sedentary behavior.

62Impact of age, sleep pressure and circadian phase on time-of-day estimates.PubMed

Jakub Späti, Mirjam Münch, Katharina Blatter, et al.
Behav Brain Res. 2009 Jul 19;201(1):48-52. doi: 10.1016/j.bbr.2009.01.029. Epub 2009 Feb 4.
Orientation and self-location within the temporal fabric of the environment involves multiple organismic systems. While temporal self-location on the physiological level has been known for some time to be based on a 'biological clock' located within the hypothalamus, the mechanisms that participate in temporal position finding on the cognitive level are not yet fully understood. In order to probe the mechanisms that underlie this faculty, verbal estimates on time-of-day were collected at 3.75-h intervals from 16 young (7 males, 8 females; 20-31 years) and 16 older (8 males, 8 females; 57-74 years) subjects in a balanced crossover design during 40-h epochs of prolonged wakefulness and 40-h epochs of sleep satiation spent under constant routine conditions. An overestimation of clock time during prolonged wakefulness was found in both age-groups, with significantly larger errors for the older group (young: 0.5+/-0.2h; older: 1.5+/-0.2h, p<0.05). In both age-groups, estimation errors ran roughly parallel to the time course of core body temperature. However a significant interaction between time-of-day and age-group was observed (rANOVA, p<0.05): younger subjects exhibited similar estimation errors as the older subjects after 16 h of prior wakefulness, whereas the latter did not manifest decrements under high sleep pressure. Data collected under conditions of sleep satiation also displayed a diurnal oscillation in estimation errors and a general overestimation (young: 0.8+/-0.2h; older: 1.3+/-0.3h, p<0.05). Here however, the age-groups did not differ significantly nor was there an interactive effect between time-of-day and age-group. The effects of age, duration of wake time and circadian phase on temporal position finding are in line with predictions based on the idea that awareness about current position in time is derived from interval timing processes.

63The exposome of healthy and accelerated aging across 40 countries.PubMed

Hernan Hernandez, Hernando Santamaria-Garcia, Sebastian Moguilner, et al.
Nat Med. 2025 Sep;31(9):3089-3100. doi: 10.1038/s41591-025-03808-2. Epub 2025 Jul 14.
Protective and risk factors can drive healthy or accelerated aging, with distinct environments modulating their effects. The impact of the exposome-the combined physical and social exposures experienced throughout life-on accelerated aging remains unknown. We assessed delayed and accelerated aging in 161,981 participants from 40 countries (45.09% female; mean age, 67.06; s.d., 9.85) by measuring biobehavioral age gaps (BBAGs), defined as the difference between estimated age from protective and risk factors and chronological age, in cross-sectional and longitudinal designs. BBAGs predicted chronological age, followed by regional and exposomal factor analyses, linked to accelerated aging. Europe led in healthy aging, while Egypt and South Africa showed the greatest acceleration; Asia and Latin America fell in between (Cliff's delta (δd) = 0.15-0.52; all P < 0.0001). Accelerated aging was more evident in eastern and southern Europe; globally, it was also associated with lower income (δd = 0.48-0.56, P < 1 × 10). Exposomal factors of accelerated aging include physical (air quality), social (socioeconomic and gender inequality, migration) and sociopolitical (representation, party freedom, suffrage, elections and democracy) determinants (all Cohen's d (d) > 0.37, P < 0.0001). BBAGs predicted future functional (r (Pearson correlation) = -0.33, P < 1 × 10, d = 0.70) and cognitive declines (r = -0.22, P < 1 × 10, d = 0.44), and larger BBAGs (P < 0.0001, d = 1.55). Healthy and accelerated aging are influenced by physical, social and sociopolitical exposomes, with considerable disparities across nations.

64Mendelian randomization evidence for the causal effect of mental well-being on healthy aging.PubMed

Chao-Jie Ye, Dong Liu, Ming-Ling Chen, et al.
Nat Hum Behav. 2024 Sep;8(9):1798-1809. doi: 10.1038/s41562-024-01905-9. Epub 2024 Jun 17.
Mental well-being relates to multitudinous lifestyle behaviours and morbidities and underpins healthy aging. Thus far, causal evidence on whether and in what pattern mental well-being impacts healthy aging and the underlying mediating pathways is unknown. Applying genetic instruments of the well-being spectrum and its four dimensions including life satisfaction, positive affect, neuroticism and depressive symptoms (n = 80,852 to 2,370,390), we performed two-sample Mendelian randomization analyses to estimate the causal effect of mental well-being on the genetically independent phenotype of aging (aging-GIP), a robust and representative aging phenotype, and its components including resilience, self-rated health, healthspan, parental lifespan and longevity (n = 36,745 to 1,012,240). Analyses were adjusted for income, education and occupation. All the data were from the largest available genome-wide association studies in populations of European descent. Better mental well-being spectrum (each one Z-score higher) was causally associated with a higher aging-GIP (β [95% confidence interval (CI)] in different models ranging from 1.00 [0.82-1.18] to 1.07 [0.91-1.24] standard deviations (s.d.)) independent of socioeconomic indicators. Similar association patterns were seen for resilience (β [95% CI] ranging from 0.97 [0.82-1.12] to 1.04 [0.91-1.17] s.d.), self-rated health (0.61 [0.43-0.79] to 0.76 [0.59-0.93] points), healthspan (odds ratio [95% CI] ranging from 1.23 [1.02-1.48] to 1.35 [1.11-1.65]) and parental lifespan (1.77 [0.010-3.54] to 2.95 [1.13-4.76] years). Two-step Mendelian randomization mediation analyses identified 33 out of 106 candidates as mediators between the well-being spectrum and the aging-GIP: mainly lifestyles (for example, TV watching and smoking), behaviours (for example, medication use) and diseases (for example, heart failure, attention-deficit hyperactivity disorder, stroke, coronary atherosclerosis and ischaemic heart disease), each exhibiting a mediation proportion of >5%. These findings underscore the importance of mental well-being in promoting healthy aging and inform preventive targets for bridging aging disparities attributable to suboptimal mental health.

65The impact of early aging on visual perception of space and time.PubMed

Sara Incao, Carlo Mazzola, Alessandra Sciutti
Front Hum Neurosci. 2022 Nov 16;16:988644. doi: 10.3389/fnhum.2022.988644. eCollection 2022.
Visual perception of space and time has been shown to rely on context dependency, an inferential process by which the average magnitude of a series of stimuli previously experienced acts as a prior during perception. This article aims to investigate the presence and evolution of this phenomenon in early aging. Two groups of participants belonging to two different age ranges (Young Adults: average age 28.8 years old; Older Adults: average age 62.8 years old) participated in the study performing a discrimination and a reproduction task, both in a spatial and temporal conditions. In particular, they were asked to evaluate lengths in the spatial domain and interval durations in the temporal one. Early aging resulted to be associated to a general decline of the perceptual acuity, which is particularly evident in the temporal condition. The context dependency phenomenon was preserved also during aging, maintaining similar levels as those exhibited by the younger group in both space and time perception. However, the older group showed a greater variability in context dependency among participants, perhaps due to different strategies used to face a higher uncertainty in the perceptual process.

66Time perception among people living with and without dementia: A scoping review.PubMed

Natasha L Gallant, Chelsea L Russill, Natasha C Taylor, et al.
Dementia (London). 2024 Oct;23(7):1183-1211. doi: 10.1177/14713012241257299. Epub 2024 May 31.
Dementia often manifests with profound alterations in perception, but it is unclear if and to what extent time perception is altered among people living with dementia compared to those experiencing normal aging. Thus, this scoping review aimed to answer the following research questions: (1) What study designs, participants, time intervals, paradigms, tests, and scores have been employed and in which countries were these methods employed to study time perception in dementia? (2) In which ways do time perception differ across individuals living with and without dementia? (3) In which ways do time perception differ across individuals living with different types of dementia? After deduplication, title and abstract screening, and full-text review, a total of 12 studies were included in this scoping review. Findings generally indicated that people living with dementia perceive time differently than people living without dementia, and that some differences across dementia diagnoses may exist, but the body of literature on time perception in dementia was quite limited. Future research should focus on replicating findings while extending the research to look beyond the dementia versus non-dementia dichotomy as differences across dementia diagnoses may exist. Moreover, if people living with dementia (and, in particular, living with different dementia diagnoses) experience time differently from those experiencing normal aging, we need to begin to address these differences in dementia-friendly initiatives to improve well-being for this population.

67Time perception, depression and sadness.PubMed

Sandrine Gil, Sylvie Droit-Volet
Behav Processes. 2009 Feb;80(2):169-76. doi: 10.1016/j.beproc.2008.11.012. Epub 2008 Nov 25.
This study examined changes in time perception as a function of depressive symptoms, assessed for each participant with the Beck Depression Inventory (BDI). The participants performed a temporal bisection task in which they had to categorize a signal duration of between 400 and 1600 ms as either as short or long. The data showed that the bisection function was shifted toward the right, and that the point of subjective equality was higher in the depressive than in the non-depressive participants. Furthermore, the higher the depression score was, the shorter the signal duration was judged to be. In contrast, the sensitivity to time was similar in these two groups of participants. These results thus indicate that the probe durations were underestimated by the depressive participants. The sadness scores assessed by the Brief Mood Inventory Scale (BMIS) also suggest that the emotional state of sadness in the depressive participants goes some way to explaining their temporal performance. Statistical analyses and modeling of data support the idea according to which these results may be explained by a slowing down of the internal clock in the depressive participants.

68Future time perspective, loneliness, and depressive symptoms among middle-aged adults: A mediation model.PubMed

Yoav S Bergman, Dikla Segel-Karpas
J Affect Disord. 2018 Dec 1;241:173-175. doi: 10.1016/j.jad.2018.08.019. Epub 2018 Aug 8.
BACKGROUND: Recent studies have demonstrated the relevance of subjective time perceptions with regard to depressive symptoms among aging and older adults. Moreover, loneliness was found to bear a strong connection to such symptoms. However, little is known about the connection between the three constructs. Accordingly, the current research examines whether the connection between future time perspective and depressive symptoms is mediated by loneliness. METHODS: Data was collected from 1021 participants aged 50-67 (mean age = 57.89), who completed the Future Time Perspective Scale, a scale measuring loneliness, and the Center for Epidemiological Studies Depression Scale (CES-D), and provided relevant socio-demographic information. RESULTS: Future time perspective was negatively linked with both loneliness and depressive symptoms. Moreover, loneliness was a significant mediator for the connection between future time perspective and depressive symptoms. LIMITATIONS: The study focused on a specific age range, and employed a cross-sectional design. CONCLUSIONS: This study provides a view into the manner by which subjective perceptions of time are linked with depressive symptoms during the aging process, and highlights the clinical importance of such perceptions to depressive symptoms.

69Time dilation and acceleration in depression.PubMed

Lachlan Kent, George Van Doorn, Britt Klein
Acta Psychol (Amst). 2019 Mar;194:77-86. doi: 10.1016/j.actpsy.2019.02.003. Epub 2019 Feb 22.
BACKGROUND: A recent meta-analysis left open a significant question regarding altered time perception in depression: Why do depressed people overproduce short durations and under-produce longer durations if their present experience is that time flows slowly? Experience and judgement of time do not seem to accord with one another. ANALYSIS: By excluding two of the six studies on methodological grounds from a previous meta-analysis of medium-length interval productions, and re-analysing the remaining four studies, the present paper finds that subjective time accelerates from initial dilation within present experience (approximately 1 s duration) to subsequent acceleration within working memory (approximately 30 s duration) when depressed. PROPOSALS: It is proposed that depressive time dilation and acceleration refer to the default mode and central executive networks, respectively. The acceleration effect is suggested to occur due to mood congruency between long intervals, boredom, and depression. This mood congruency leads to the automatic recall of intrusive, negative, and non-specific autobiographical long-term memories used to judge intervals from previous experience. Acceleration in working memory then occurs according to the contextual change model of duration estimation. LIMITATIONS: The meta-analysis is limited to four studies only, but provides a potential link between time experience and judgement within the same explanatory model. CONCLUSIONS: Similarities between psychological time dilation/acceleration and physical time dilation/acceleration are discussed.

70Lonely individuals reveal proximal social avoidance and distal general approach motivation: Evidence from time perception in social and non-social contexts.PubMed

Chunlin Wu, Rui Guo, Youguo Chen, et al.
Br J Psychol. 2025 Jul 16. doi: 10.1111/bjop.70010.
Loneliness is a major public health issue, leading to serious physical and mental health problems. Research has shown that trait-like, chronically lonely individuals exhibit either avoidance or approach behaviour towards social connections. However, how social avoidance and approach motivation co-occur in trait-like, chronically lonely individuals remains unclear. We hypothesized that loneliness would first induce social avoidance and then approach motivation, given the inherent negative bias of loneliness and the general process model of threat and defence, which asserts that threat first activates avoidance motivation followed by approach motivation. To test this hypothesis, we used sub- and supra-second time bisection tasks in social and non-social contexts based on the motivational dimensional model of time perception. The results showed that high-loneliness (HL) and low-loneliness (LL) individuals had similar sub-second time estimates in non-social contexts. However, HL individuals lengthened time in the sub-second range in social contexts and shortened time in the supra-second range compared to LL individuals, regardless of social or non-social context. These findings suggest that HL individuals exhibit proximal social avoidance and distal general approach as a defence mechanism, which is consistent with the general process model of threat and defence and extends the evolutionary theory of loneliness.

71Relations between emotion, memory encoding, and time perception.PubMed

Laura W Johnson, Donald G MacKay
Cogn Emot. 2019 Mar;33(2):185-196. doi: 10.1080/02699931.2018.1435506. Epub 2018 Feb 7.
This study examined duration judgments for taboo and neutral words in prospective and retrospective timing tasks. In the prospective task, participants attended to time from the beginning and generated shorter duration estimates for taboo than neutral words and for words that they subsequently recalled in a surprise free recall task. These findings suggested that memory encoding took priority over estimating durations, directing attention away from time and causing better recall but shorter perceived durations for taboo than neutral words. However, in the retrospective task, participants only judged durations in a surprise test at the end, and their duration estimates were longer for taboo than neutral words. Present findings therefore suggest that the same emotion-linked memory encoding processes can cause underestimation of durations in prospective tasks but overestimation in retrospective tasks, as if emotion enhances recall of ongoing events but causes overestimation of the durations of those events in retrospect.

72Time perception and suicidal ideation during COVID-19 pandemic: A longitudinal study.PubMed

Sergio Sanz-Gómez, Jonathan Dubois, Adrián Alacreu-Crespo, et al.
J Affect Disord. 2025 Jan 15;369:1045-1052. doi: 10.1016/j.jad.2024.10.094. Epub 2024 Oct 22.
BACKGROUND: There are several reports of disruptions in time perception during lockdown periods throughout the COVID-19 pandemic. Our aim was to study the role of subjective flow of time (SFT) in the triggering of suicidal ideation in patients with a history of suicide attempt (SA), as compared with affective controls without such history (AC). METHODS: This study involved 296 psychiatric patients that were assessed five times between 2020 and 2021. We analyzed the SFT using a mixed logistic model and characterized SFT during significant periods of governmental restrictions. Multivariate logistic regressions were used to identify independent SFT characteristics. We evaluated the association between SFT and suicidal ideation, considering interactions with depression, insomnia, loneliness, and social support. RESULTS: The findings revealed a significant alteration in SFT, closely linked to the implementation and easing of governmental restrictions. During the initial lockdown, SA exhibited lower SFT levels compared to AC. Furthermore, the relationship between SFT and suicidal ideation was influenced by depression. In the interim period between lockdowns, SFT's impact on suicidal ideation was mediated by insomnia. DISCUSSION: Disturbances in SFT could be related to adaptability to lockdown conditions or may be a coping mechanism with depression, insomnia, suicidal ideation and overall psychological distress. Understanding the interplay of SFT with these factors provides crucial insights into the complex psychological mechanisms involved.

73Time perception at resting state and during active motion: The role of anxiety and depression.PubMed

Máté Kapitány-Fövény, Orsolya Bokk, Anna Kiss, et al.
J Psychiatr Res. 2022 Nov;155:186-193. doi: 10.1016/j.jpsychires.2022.08.023. Epub 2022 Aug 26.
BACKGROUND: Time perception and motion intensity are interrelated factors that may influence symptom expression and severity in case of various psychiatric conditions, including anxiety and depression. AIMS: The present study aimed to 1) explore the associations between the intensity of physical activity, time perception, impulsivity, anxiety and depressive symptoms, and to 2) investigate the extent to which resting state motion intensity can be used to identify the assessed psychiatric conditions. METHODS: 20 healthy controls and 20 psychiatric patients (with either anxiety or depression-related diagnoses) were included in the study and filled out a questionnaire consisting of validated anxiety, depression and impulsivity measures. Time perception was measured by a computerized time production task, whereas motion intensity was analyzed by a motion capture and analysis software. Respondents were randomly assigned to an experimental (with active motion task) and non-experimental group (resting state conditions). Both subgroups were repeatedly assessed, in order to explore changes in motion intensity, time perception and psychiatric symptom levels. RESULTS: Random forest regression analysis identified the level of impulsivity, depression and anxiety as the strongest predictors of resting state motion intensity, while a path analysis model indicated that controls and psychiatric patients show different pathways regarding the connection between motion intensity changes, time production ratio alterations and symptom reduction. CONCLUSIONS: Our study implies the importance of distinguishing between clinical and subclinical severity of psychiatric symptoms when considering the association between motion intensity, time perception, anxiety and depression. Potential transdiagnostic relevance of resting state motion intensity is also addressed.

74Effects of exercise interventions on cognitive functions in healthy populations: A systematic review and meta-analysis.PubMed

Minggang Zhang, Jiafeng Jia, Yang Yang, et al.
Ageing Res Rev. 2023 Dec;92:102116. doi: 10.1016/j.arr.2023.102116. Epub 2023 Nov 3.
Chronic exercise intervention is a non-pharmacological therapy suggested to improve cognitive function in various populations. However, few meta-analyses have assessed the cognitive benefits associated with all FITT-VP variables (exercise frequency, intensity, bout duration time, type, volume or total intervention length, and progression) in healthy populations by age. Thus, this meta-analysis assessed the effects of each FITT-VP variable on cognitive function in healthy children, adults, and older adults. This study followed PRISMA guidelines. After searching PubMed and the Web of Science, we included 54 randomized controlled trials to examined the effects of FITT-VP variables on five cognitive domains: global cognition, executive function, memory, attention, and information processing. Moderation analyses assessed the effects by age and by each exercise variables. Exercise benefitted overall cognition and all subcognitive domains. Aerobic and resistance exercise showed the greatest benefits on global cognition and executive function respectively, whereas mind-body exercise benefitted memory. Among all populations, older adults showed the greatest benefits of exercise on global cognition, executive function, and memory compared with controls. Additional studies are needed to assess the effects of exercise on attention and information processing. This meta-analysis offers new insights on the relationships between cognition and FITT-VP exercise variables in healthy populations.

75Exercise-mimetic AICAR transiently benefits brain function.PubMed

Davide Guerrieri, Henriette van Praag
Oncotarget. 2015 Jul 30;6(21):18293-313. doi: 10.18632/oncotarget.4715.
Exercise enhances learning and memory in animals and humans. The role of peripheral factors that may trigger the beneficial effects of running on brain function has been sparsely examined. In particular, it is unknown whether AMP-kinase (AMPK) activation in muscle can predict enhancement of brain plasticity. Here we compare the effects of running and administration of AMPK agonist 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR, 500 mg/kg), for 3, 7 or 14 days in one-month-old male C57BL/6J mice, on muscle AMPK signaling. At the time-points where we observed equivalent running- and AICAR-induced muscle pAMPK levels (7 and 14 days), cell proliferation, synaptic plasticity and gene expression, as well as markers of oxidative stress and inflammation in the dentate gyrus (DG) of the hippocampus and lateral entorhinal cortex (LEC) were evaluated. At the 7-day time-point, both regimens increased new DG cell number and brain-derived neurotrophic factor (BDNF) protein levels. Furthermore, microarray analysis of DG and LEC tissue showed a remarkable overlap between running and AICAR in the regulation of neuronal, mitochondrial and metabolism related gene classes. Interestingly, while similar outcomes for both treatments were stable over time in muscle, in the brain an inversion occurred at fourteen days. The compound no longer increased DG cell proliferation or neurotrophin levels, and upregulated expression of apoptotic genes and inflammatory cytokine interleukin-1β. Thus, an exercise mimetic that produces changes in muscle consistent with those of exercise does not have the same sustainable positive effects on the brain, indicating that only running consistently benefits brain function.

76Physical exercise prevents cognitive impairment by enhancing hippocampal neuroplasticity and mitochondrial function in doxorubicin-induced chemobrain.PubMed

Hye-Sang Park, Chang-Ju Kim, Hyo-Bum Kwak, et al.
Neuropharmacology. 2018 May 1;133:451-461. doi: 10.1016/j.neuropharm.2018.02.013.
Although chemotherapy increases the survival rate of patients with various cancers, such treatment can induce acute or long-term cognitive dysfunction a phenomenon known as post-chemotherapy cognitive impairment (PCCI) or "chemobrain." Exercise is known to positively affect brain function. Thus, the present study aimed to determine whether symptoms of chemobrain and disruptions in the neuroplasticity and functioning of hippocampal mitochondria can be prevented or relieved by exercise. Wistar rats were separated into the following groups: control, control plus exercise, chemobrain, and chemobrain plus exercise. For chemobrain induction, 2 mg/kg of doxorubicin (DOX) a widely utilized chemotherapeutic agent among patients with breast cancer was dissolved in saline and directly injected to the abdomen once every 4 weeks. The exercise groups were subjected to low-intensity treadmill, 6 days per week for 4 weeks. The Morris water maze and step-down avoidance tests were conducted to evaluate cognitive function, while neuroplasticity and mitochondrial function were assessed in the hippocampus and dentate gyrus. Decreased cognitive function were observed in the chemobrain group, along with decreases in levels of neurogenesis, brain derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB), Ca retention in hippocampus. Rats of the chemobrain group also exhibited an increase in apoptosis, HO emission and permeability transition pore by hippocampal mitochondria. However, exercise attenuated impairments in cognitive function, neuroplasticity, and mitochondrial function induced by DOX treatment. Therefore, the findings of the present study indicate that low-intensity exercise may assist in preventing cognitive dysfunction during or after chemotherapy in patients with various cancers, including breast cancer.

77Swimming exercise enhances brain plasticity in fish.PubMed

Daan Mes, Arjan P Palstra, Christiaan V Henkel, et al.
R Soc Open Sci. 2020 Jan 15;7(1):191640. doi: 10.1098/rsos.191640. eCollection 2020 Jan.
It is well-established that sustained exercise training can enhance brain plasticity and boost cognitive performance in mammals, but this phenomenon has not received much attention in fish. The aim of this study was to determine whether sustained swimming exercise can enhance brain plasticity in juvenile Atlantic salmon. Brain plasticity was assessed by both mapping the whole telencephalon transcriptome and conducting telencephalic region-specific microdissections on target genes. We found that 1772 transcripts were differentially expressed between the exercise and control groups. Gene ontology (GO) analysis identified 195 and 272 GO categories with a significant overrepresentation of up- or downregulated transcripts, respectively. A multitude of these GO categories was associated with neuronal excitability, neuronal signalling, cell proliferation and neurite outgrowth (i.e. cognition-related neuronal markers). Additionally, we found an increase in () after both three and eight weeks of exercise in the equivalent to the hippocampus in fish. Furthermore, the expression of the neural plasticity markers () and () were also increased due to exercise in the equivalent to the lateral septum in fish. In conclusion, this is the first time that swimming exercise has been directly linked to increased telencephalic neurogenesis and neural plasticity in a teleost, and our results pave the way for future studies on exercise-induced neuroplasticity in fish.

78Effects of exercise timing and intensity on neuroplasticity in a rat model of cerebral infarction.PubMed

Min-Keun Song, Eun-Jong Kim, Jung-Kook Kim, et al.
Brain Res Bull. 2020 Jul;160:50-55. doi: 10.1016/j.brainresbull.2020.04.002. Epub 2020 Apr 17.
Exercise therapy plays key roles in functional improvements during neurorehabilitation. However, it may be difficult for some people to properly perform exercise because mobility and endurance might be restricted by neurological deficits due to stroke. Additionally, there is little evidence detailing the biological mechanisms underlying the most effective swimming exercise protocols for neuroplasticity after stroke. Thus, the present study investigated the effects of swimming exercise on neuroplasticity in a cerebral infarction rat model according to the timing and intensity of exercise. A total of 45 male Sprague-Dawley rats (300 ± 50 g, 10 weeks old) were subjected to photothrombotic cerebral infarction and randomly divided into five groups: non-exercise (group A, n = 9); early submaximal (group B, n = 9); early maximal (group C, n = 9); late submaximal (group D, n = 9); and late maximal (group E, n = 9). Swimming exercise was performed five times a week for 4 weeks, and cognition was evaluated with the Morris water maze (MWM) test. Assessments of superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels and immunohistochemical analyses of brain-derived neurotrophic factor (BDNF) were conducted in the ipsilesional hippocampus region. After 4 weeks of exercise, the escape latency was shorter and velocity was greater in group B than in groups A, C, D, and E (p = 0.046, p < 0.001, respectively). Furthermore, SOD activity was higher and MDA levels were lower in group B than in groups A, C, D, and E (p = 0.004, p = 0.019). The immunohistochemistry results revealed that the greatest BDNF immunoreactivity was in group B. Taken together, these results indicate that early submaximal swimming exercise may be the most effective protocol for the recovery of neurological deficits in a rat model of cerebral infarction.

79Swimming exercise reverses chronic unpredictable mild stress-induced depression-like behaviors and alleviates neuroinflammation and collapsing response mediator protein-2-mediated neuroplasticity injury in adult male mice.PubMed

Yumeng Xie, Zuotian Wu, Limin Sun, et al.
Neuroreport. 2022 Apr 6;33(6):272-282. doi: 10.1097/WNR.0000000000001779.
OBJECTIVE: Impaired neuroplasticity and neuroinflammation are vital in the mechanisms of depression. Exercise alleviates depressive symptoms and ameliorates body functions. Swimming is one of the most common exercises; however, whether swimming alters depressive behaviors and the underlying mechanism has not been fully elucidated. METHODS: Male C57/BL6J mice were exposed to chronic unpredictable mild stress (CUMS) for 6 weeks and then were subjected to a 5-week swimming program. Behavioral test, including sucrose preference test (SPT), open field test (OFT), elevated plus-maze (EPM) test, and tail suspension test (TST), was conducted to assess the anxiety-like and depressive behaviors. Western blotting and immunofluorescence staining were carried out after tissue collection. RESULTS: This study showed that CUMS-induced depressive behaviors but swimming exercise increased sucrose preference in SPT, increased time and velocity in the center on OFT, decreased time in the closed arm, increased time in the open arm in EPM, and decreased immobility time in TST. We further found swimming exercise increased hippocampal collapsing response mediator protein-2 (CRMP2) expression and decreased p-CRMP2 expression in CUMS mice. CUMS inhibited the levels of α-tubulin and CRMP2, and the expression of ionized calcium-binding adaptor molecule 1 and caspase-1, whereas swimming reversed them in CUMS-exercised mice. CONCLUSION: Our study confirmed that swimming exercise reverses CUMS-induced depressive behaviors, and neuroinflammation and CRMP2-mediated neuroplasticity are involved, which may provide a new insight into the antidepression therapy of exercise.

80Effects of Virtual Reality Motor-Cognitive Training for Older People With Cognitive Frailty: Multicentered Randomized Controlled Trial.PubMed

Rick Yiu Cho Kwan, Justina Liu, Olive Suk Kan Sin, et al.
J Med Internet Res. 2024 Sep 11;26:e57809. doi: 10.2196/57809.
BACKGROUND: Cognitive frailty refers to a clinical syndrome in which physical frailty and mild cognitive impairment coexist. Motor-cognitive training and virtual reality (VR) have been used to launch various therapeutic modalities to promote health in older people. The literature advocates that motor-cognitive training and VR are effective in promoting the cognitive and physical function of older people. However, the effects on older people with cognitive frailty are unclear. OBJECTIVE: This study examined the effects of VR motor-cognitive training (VRMCT) on global cognitive function, physical frailty, walking speed, visual short-term memory, inhibition of cognitive interference, and executive function in older people with cognitive frailty. METHODS: This study used a multicentered, assessor-blinded, 2-parallel-group randomized controlled trial design. Participants were recruited face-to-face in 8 older adult community centers. Eligible participants were aged ≥60 years, were community dwelling, lived with cognitive frailty, had no dementia, and were not mobility restricted. In the intervention group, participants received VRMCT led by interventionists with 16 one-hour training sessions delivered twice per week for 8 weeks. In the control group, participants received the usual care provided by the older adult community centers that the investigators did not interfere with. The primary outcome was global cognitive function. The secondary outcomes included physical frailty, walking speed, verbal short-term memory, inhibition of cognitive interference, and executive function. Data were collected at baseline (T0) and the week after the intervention (T1). Generalized estimating equations were used to examine the group, time, and interaction (time × group) effects on the outcomes. RESULTS: In total, 293 eligible participants enrolled in the study. The mean age of the participants was 74.5 (SD 6.8) years. Most participants were female (229/293, 78.2%), had completed primary education (152/293, 52.1%), were married (167/293, 57.2%), lived with friends (127/293, 43.3%), and had no VR experience (232/293, 79.5%). In the intervention group, 81.6% (119/146) of participants attended >80% (13/16, 81%) of the total number of sessions. A negligible number of participants experienced VR sickness symptoms (1/146, 0.7% to 5/146, 3%). VRMCT was effective in promoting global cognitive function (interaction effect: P=.03), marginally promoting executive function (interaction effect: P=.07), and reducing frailty (interaction effect: P=.03). The effects were not statistically significant on other outcomes. CONCLUSIONS: VRMCT is effective in promoting cognitive functions and reducing physical frailty and is well tolerated and accepted by older people with cognitive frailty, as evidenced by its high attendance rate and negligible VR sickness symptoms. Further studies should examine the efficacy of the intervention components (eg, VR vs non-VR or dual task vs single task) on health outcomes, the effect of using technology on intervention adherence, and the long-term effects of the intervention on older people with cognitive frailty at the level of daily living. TRIAL REGISTRATION: ClinicalTrials.gov NCT04730817; https://clinicaltrials.gov/study/NCT04730817.

81Using virtual reality-based training to improve cognitive function, instrumental activities of daily living and neural efficiency in older adults with mild cognitive impairment.PubMed

Ying-Yi Liao, Han-Yun Tseng, Yi-Jia Lin, et al.
Eur J Phys Rehabil Med. 2020 Feb;56(1):47-57. doi: 10.23736/S1973-9087.19.05899-4. Epub 2019 Oct 15.
BACKGROUND: A combination of physical and cognitive training appears to be the effective intervention to improve cognitive function in older adults with mild cognitive impairment (MCI). Computing technology such as virtual reality (VR) may have the potential to assist rehabilitation in shaping brain health. However, little is known about the potential of VR-based physical and cognitive training designed as an intervention for cognition and brain activation in elderly patients with MCI. Moreover, whether a VR program designed around functional tasks can improve their instrumental activities of daily living (IADL) requires further investigation. AIM: This study investigated the effects of 12 weeks of VR-based physical and cognitive training on cognitive function, brain activation and IADL and compared the VR intervention with combined physical and cognitive training. DESIGN: A single-blinded randomized controlled trial. SETTING: Communities and day care centers in Taipei, Taiwan. POPULATION: Older adults with mild cognitive impairment. METHODS: Thirty-four community-dwelling older adults with MCI were randomized into either a VR-based physical and cognitive training (VR) group or a combined physical and cognitive training (CPC) group for 36 sessions over 12 weeks. Participants were assessed for their cognitive function (global cognition, executive function and verbal memory) and IADL at pre- and postintervention. Changes in prefrontal cortex activation during the global cognition test were also captured by functional near-infrared spectroscopy (NIRS) to identify the potential mediating pathway of the intervention. RESULTS: Both groups showed improved executive function and verbal memory (immediate recall). However, only the VR group showed significant improvements in global cognition (P<0.001), verbal memory (delayed recall, P=0.002), and IADL (P<0.001) after the intervention. The group × time interaction effects further demonstrated that IADL were more significantly improved with VR training than with CPC training (P=0.006). The hemodynamic data revealed decreased activation in prefrontal areas after training (P=0.0015), indicative of increased neural efficiency, in the VR-trained subjects. CONCLUSIONS: VR-based physical and cognitive training improves cognitive function, IADL and neural efficiency in older adults with MCI. CLINICAL REHABILITATION IMPACT: VR training could be implemented for older adults with MCI.

82Effects of simultaneous cognitive and aerobic exercise training on dual-task walking performance in healthy older adults: results from a pilot randomized controlled trial.PubMed

David A Raichlen, Pradyumna K Bharadwaj, Lauren A Nguyen, et al.
BMC Geriatr. 2020 Mar 2;20(1):83. doi: 10.1186/s12877-020-1484-5.
BACKGROUND: The ability to walk and perform cognitive tasks simultaneously is a key aspect of daily life. Performance declines in these dual-tasks may be associated with early signs of neurodegenerative disease and increased risk of falls. Thus, interventions to improve dual-task walking performance are of great interest for promoting healthy aging. Here, we present results of a pilot randomized controlled trial (RCT) to evaluate the effects of a simultaneous aerobic exercise and cognitive training intervention on dual-task walking performance in healthy older adults. METHODS: Community-dwelling, healthy older adults were recruited to participate in a 12-week RCT. Participants were randomized into one of four groups (n = 74): 1) cognitive training (COG), 2) aerobic exercise (EX), 3) combined aerobic exercise and cognitive training (EXCOG), and 4) video-watching control (CON). The COG and EXCOG groups both used a tablet-based cognitive training program that challenged aspects of executive cognitive function, memory, and processing speed. Performance on a dual-task walking test (DTWT; serial subtraction during two-minute walk) was assessed by researchers blinded to groupings before the intervention, and at 6 and 12 weeks. We included all participants randomized with baseline measurements in an intention to treat analysis using linear mixed effects models. RESULTS: We found a significant group by time interaction for cognitive performance on the DTWT (p = 0.039). Specifically, participants in the EXCOG, EX, and COG groups significantly improved on the cognitive aspect of the DTWT following the full 12-week intervention (p = 3.5e-7, p = 0.048, p = 0.048, respectively). The improvements in EXCOG were twice as large as in the other groups, and were significant at 6 weeks (p = 0.019). The CON group did not show a significant change in cognitive performance on the DTWT, and no group significantly altered dual-task gait measures following the intervention. CONCLUSIONS: A simultaneous aerobic exercise and cognitive training intervention significantly improved cognitive performance during a DTWT in healthy older adults. Despite no change in DTWT gait measures, significant improvements in cognitive performance indicate that further investigation in a larger RCT is warranted. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04120792, Retrospectively Registered 08 October 2019.

83Effects of dual-task resistance exercise on cognition, mood, depression, functional fitness, and activities of daily living in older adults with cognitive impairment: a single-blinded, randomized controlled trial.PubMed

Ji-Eun Baek, Sang-Jun Hyeon, May Kim, et al.
BMC Geriatr. 2024 Apr 24;24(1):369. doi: 10.1186/s12877-024-04942-1.
BACKGROUND: Regular exercise is emphasized for the improvement of functional capacity and independence of older adults. This study aimed to compare the effects of a dual-task resistance exercise program and resistance exercise on cognition, mood, depression, physical function, and activities of daily living (ADL) in older adults with cognitive impairment. METHODS: A total of 44 older adults participated in the study. Participants were randomly allocated to an experimental group (n = 22) performing a dual-task resistance exercise program for cognitive function improvement and a control group (n = 22) performing a resistance exercise program. Both groups performed the exercise for 40 min per session, three times a week, for 6 weeks (18 sessions). Cognition, mood, depression, functional fitness, and ADL were quantified before and after the intervention using the Mini-Mental State Examination (MMSE), profile of mood states (POMS), geriatric depression scale (GDS), senior fitness test (SFT), and Korean version of ADL, respectively. RESULTS: There was a significant time and group interaction on the MMSE (p = 0.044). There were no significant time and group interactions in the POMS, GDS, SFT, or ADL. Cognitive function (p < 0.001), mood (p < 0.001), depression (p < 0.001), functional fitness (p < 0.001), and ADL (p < 0.001) significantly improved after dual-task resistance exercise, and cognitive function (p < 0.001), mood (p < 0.001), depression (p < 0.001), functional fitness (p < 0.001), and ADL (p < 0.001) significantly improved after resistance exercise. CONCLUSIONS: Dual-task resistance exercise is more effective than resistance exercise in improving cognitive function in older adults with cognitive impairment. Both dual-task resistance exercise and resistance exercise improves mood, depression, functional fitness, and ADL after the intervention. We propose using dual-task resistance exercises for cognitive and physical health management in the older adults with cognitive impairment. TRIAL REGISTRATION: This study was registered with the Clinical Research Information Service (WHO International Clinical Trials Registry Platform) (Registration ID, KCT0005389; Registration date, 09/09/2020).

84Structured vs Self-Guided Multidomain Lifestyle Interventions for Global Cognitive Function: The US POINTER Randomized Clinical Trial.PubMed

Laura D Baker, Mark A Espeland, Rachel A Whitmer, et al.
JAMA. 2025 Aug 26;334(8):681-691. doi: 10.1001/jama.2025.12923.
IMPORTANCE: Identifying new interventions to slow and prevent cognitive decline associated with dementia is critical. Nonpharmacological interventions targeting modifiable risk factors are promising, relatively low-cost, accessible, and safe approaches. OBJECTIVE: To compare the effects of two 2-year lifestyle interventions on cognitive trajectory in older adults at risk of cognitive decline and dementia. DESIGN, SETTING, AND PARTICIPANTS: Single-blind, multicenter randomized clinical trial enrolling 2111 participants from May 2019 to March 2023 (final follow-up, May 14, 2025) at 5 clinical sites in the US. Participant inclusion criteria enriched risk of cognitive decline and included age 60 to 79 years, sedentary lifestyle, and suboptimal diet plus at least 2 additional criteria related to family history of memory impairment, cardiometabolic risk, race and ethnicity, older age, and sex. INTERVENTIONS: Participants were randomly assigned with equal probability to structured (n = 1056) or self-guided (n = 1055) interventions. Both interventions encouraged increased physical and cognitive activity, healthy diet, social engagement, and cardiovascular health monitoring, but differed in structure, intensity, and accountability. MAIN OUTCOMES AND MEASURES: The primary comparison was difference between intervention groups in annual rate of change in global cognitive function, assessed by a composite measure of executive function, episodic memory, and processing speed, over 2 years. RESULTS: Among the 2111 individuals enrolled (mean age, 68.2 [SD, 5.2] years; 1455 [68.9%] female), 89% completed the year 2 assessment. The mean global cognitive composite z score increased from baseline over time in both groups, with a mean rate of increase per year of 0.243 SD (95% CI, 0.227-0.258) for the structured intervention and 0.213 SD (95% CI, 0.198-0.229) for the self-guided intervention. The mean rate of increase per year was statistically significantly greater for the structured group than the self-guided group by 0.029 SD (95% CI, 0.008-0.050; P = .008). Based on prespecified secondary subgroup comparisons, the structured intervention benefit was consistent for APOE ε4 carriers and noncarriers (P = .95 for interaction) but appeared greater for adults with lower vs higher baseline cognition (P = .02 for interaction). Fewer ascertained adverse events were reported in the structured group (serious: 151; nonserious: 1091) vs the self-guided group (serious: 190; nonserious: 1225), with a positive COVID-19 test result being the most common adverse event overall and more frequent in the structured group. CONCLUSIONS AND RELEVANCE: Among older adults at risk of cognitive decline and dementia, a structured, higher-intensity intervention had a statistically significant greater benefit on global cognition compared with an unstructured, self-guided intervention. Further investigation of functional outcomes, biomarkers, and ongoing extended follow-up will help address clinical relevance and sustainability of the observed cognitive benefits. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03688126.

85Does the insula contribute to emotion-related distortion of time? A neuropsychological approach.PubMed

Nathalie Mella, Alexia Bourgeois, Fabienne Perren, et al.
Hum Brain Mapp. 2019 Apr 1;40(5):1470-1479. doi: 10.1002/hbm.24460. Epub 2018 Nov 2.
The literature points to a large distributed brain network involved in the estimation of time. Among these regions, the role of the insular cortex is still poorly understood. At the confluence of emotional, interoceptive, and environmental signals, this brain structure has been proposed to underlie awareness of the passage of time and emotion related time dilation. Yet, this assumption has not been tested so far. This study aimed at exploring how a lesion of the insula affects subjective duration, either in an emotional context or in a non-emotional context. Twenty-one patients with a stroke affecting the insula, either left or right, were studied for their perception of sub and supra second durations. A verbal estimation task and a temporal bisection task were used with either pure tones or neutral and emotional sounds lasting between 300 and 1500 ms and presented monaurally. Results revealed that patients with a right insular lesion, showed less temporal sensitivity than both control participants and patients with a left insular lesion. Unexpectedly, emotional effects were similar in patients and control participants. Altogether, these results suggest a specific role of the right insula in the discrimination of durations, but not in emotion related temporal distortion. In addition, an ear × emotion interaction in control participants suggests that temporal processing of positive and negative sounds may be lateralized in the brain.