Univ Paul Valéry Montpellier 3, Montpellier, France.
Department of Neuroscience, University of Padova, Padova, Italy.
PLoS One. 2022 Mar 16;17(3):e0264999. doi: 10.1371/journal.pone.0264999. eCollection 2022.
This study aimed to test two common explanations for the general finding of age-related changes in the performance of timing tasks within the millisecond-to-second range intervals. The first explanation is that older adults have a real difficulty in temporal processing as compared to younger adults. The second explanation is that older adults perform poorly on timing tasks because of their reduced cognitive control functions. These explanations have been mostly contrasted in explicit timing tasks that overtly require participants to process interval durations. Fewer studies have instead focused on implicit timing tasks, where no explicit instructions to process time are provided. Moreover, the investigation of both explicit and implicit timing in older adults has been restricted so far to healthy older participants. Here, a large sample (N = 85) comprising not only healthy but also pathological older adults completed explicit (time bisection) and implicit (foreperiod) timing tasks within a single session. Participants' age and cognitive decline, measured with the Mini-Mental State Examination (MMSE), were used as continuous variables to explain performance on explicit and implicit timing tasks. Results for the explicit timing task showed a flatter psychometric curve with increasing age or decreasing MMSE scores, pointing to a deficit at the level of cognitive control functions rather than of temporal processing. By contrast, for the implicit timing task, a decrease in the MMSE scores was associated with a reduced foreperiod effect, an index of implicit time processing. Overall, these findings extend previous studies on explicit and implicit timing in healthy aged samples by dissociating between age and cognitive decline (in the normal-to-pathological continuum) in older adults.
本研究旨在检验毫秒至秒范围内时间任务表现随年龄变化的一般发现的两种常见解释。第一种解释是，与年轻人相比，老年人在时间处理方面确实存在困难。第二种解释是，老年人在时间任务上表现不佳是因为他们的认知控制功能下降。这些解释主要在需要参与者明确处理时间间隔的显性计时任务中进行对比。相反，较少的研究关注隐性计时任务，在这些任务中没有提供明确的处理时间的指令。此外，到目前为止，对老年人的显性和隐性计时的研究仅限于健康的老年人参与者。在这里，一个由 85 名参与者组成的大样本（包括健康和患病的老年人）在一次会议中完成了显性（时间二分法）和隐性（预备期）计时任务。参与者的年龄和认知能力下降（用简易精神状态检查（MMSE）测量）被用作连续变量，以解释显性和隐性计时任务的表现。显性计时任务的结果显示，随着年龄的增长或 MMSE 分数的降低，心理测量曲线变得更加平坦，这表明认知控制功能存在缺陷，而不是时间处理存在缺陷。相比之下，对于隐性计时任务，MMSE 分数的下降与预备期效应的减少有关，预备期效应是隐性时间处理的指标。总的来说，这些发现通过在老年人的正常至病理连续体中分离年龄和认知能力下降（在健康老年人样本中的显性和隐性计时研究中），扩展了之前关于显性和隐性计时的研究。
