Department of System Neuroscience, Division of Cerebral Integration, National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa, 240-0193, Japan.
Center for Information and Neural Networks (CiNet), Advanced ICT Research Institute, National Institute of Information and Communications Technology (NICT), Osaka, 565-0781, Japan.
Neuropsychologia. 2022 Feb 10;166:108145. doi: 10.1016/j.neuropsychologia.2022.108145. Epub 2022 Jan 8.
Time duration, an essential feature of the physical world, is perceived and cognitively interpreted subjectively. While this perception is deeply connected with arousal and interoceptive signals, the underlying neural mechanisms remain elusive. As the insula is critical for integrating information from the external world with the organism's inner state, we hypothesized that it might have a central role in the perception of time duration and contribute to its estimation accuracy. We conducted a functional magnetic resonance imaging study with 27 healthy participants performing temporal duration and pitch bisection tasks that used the same stimuli. By comparison with two referents with short and long duration in the time range of 1 s (close to the heart rate period), or low and high pitch, participants had to decide whether target stimuli were closer in duration or pitch to the referent stimuli. The temporal bisection point between short and long duration perception was obtained through a psychometric response curve analysis for each participant. The deviation between the bisection point and the average of reference stimuli durations was used as a marker of duration accuracy. Duration discrimination-specific activation, contrasted to pitch discrimination, was found in the dorsomedial prefrontal cortex, bilateral cerebellum, and right anterior insular cortex (AIC), extending to the inferior frontal gyrus (IFG), inferior parietal lobule, and frontal pole. The activity in the right AIC and IFG was positively correlated with the accuracy of duration discrimination. The right AIC is known to be related to the reproduction of duration, whereas the right IFG is involved in categorical decisions. Thus, the comparison between the referent durations reproduced in the AIC and the target duration may occur in the right IFG. We conclude that the right AIC and IFG contribute to the accurate perception of temporal duration.
时间持续是物理世界的一个基本特征，它是主观感知和认知解释的。虽然这种感知与唤醒和内感受信号密切相关，但潜在的神经机制仍然难以捉摸。由于脑岛对于整合来自外部世界的信息与生物体内部状态至关重要，我们假设它可能在时间持续感知中发挥核心作用，并有助于提高其估计准确性。我们进行了一项功能磁共振成像研究，共有 27 名健康参与者参与，他们执行了时间持续和音高二分任务，使用了相同的刺激。与在 1 秒时间范围内（接近心率周期）的短和长持续时间或低和高音高的两个参照刺激相比，参与者必须判断目标刺激在持续时间或音高上更接近参照刺激。通过对每个参与者的心理响应曲线分析，获得了短持续时间和长持续时间感知之间的二分点。二分点与参照刺激持续时间平均值之间的偏差被用作持续时间准确性的标记。与音高辨别相比，发现了与时间辨别特异性激活相关的背内侧前额叶皮层、双侧小脑和右侧前脑岛（AIC），扩展到额下回（IFG）、下顶叶和额极。右侧 AIC 和 IFG 的活动与持续时间辨别准确性呈正相关。已知右侧 AIC 与持续时间的再现有关，而右侧 IFG 则与分类决策有关。因此，在 AIC 中再现的参照持续时间与目标持续时间之间的比较可能发生在右侧 IFG 中。我们的结论是，右侧 AIC 和 IFG 有助于准确感知时间持续。
