Matsuda Shunichi, Matsumoto Hideyuki, Furubayashi Toshiaki, Hanajima Ritsuko, Tsuji Shoji, Ugawa Yoshikazu, Terao Yasuo
Department of Neurology, The University of Tokyo, Tokyo, Japan.
Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
PLoS One. 2015 Feb 23;10(2):e0118592. doi: 10.1371/journal.pone.0118592. eCollection 2015.
The '3-second rule' has been proposed based on miscellaneous observations that a time period of around 3 seconds constitutes the fundamental unit of time related to the neuro-cognitive machinery in normal humans. The aim of paper was to investigate the temporal processing in patients with spinocerebellar ataxia type 6 (SCA6) and SCA31, pure cerebellar types of spinocerebellar degeneration, using a synchronized tapping task. Seventeen SCA patients (11 SCA6, 6 SCA31) and 17 normal age-matched volunteers participated. The task required subjects to tap a keyboard in synchrony with sequences of auditory stimuli presented at fixed interstimulus intervals (ISIs) between 200 and 4800 ms. In this task, the subjects required non-motor components to estimate the time of forthcoming tone in addition to motor components to tap. Normal subjects synchronized their taps to the presented tones at shorter ISIs, whereas as the ISI became longer, the normal subjects displayed greater latency between the tone and the tapping (transition zone). After the transition zone, normal subjects pressed the button delayed relative to the tone. On the other hand, SCA patients could not synchronize their tapping with the tone even at shorter ISIs, although they pressed the button delayed relative to the tone earlier than normal subjects did. The earliest time of delayed tapping appearance after the transition zone was 4800 ms in normal subjects but 1800 ms in SCA patients. The span of temporal integration in SCA patients is shortened compared to that in normal subjects. This could represent non-motor cerebellar dysfunction in SCA patients.
基于各种观察结果提出了“3秒规则”，即大约3秒的时间段构成了与正常人类神经认知机制相关的基本时间单位。本文的目的是使用同步敲击任务研究6型脊髓小脑共济失调（SCA6）和31型脊髓小脑共济失调（SCA31）患者（均为单纯小脑型脊髓小脑变性）的时间处理情况。17名SCA患者（11名SCA6患者，6名SCA31患者）和17名年龄匹配的正常志愿者参与了研究。该任务要求受试者根据以200至4800毫秒的固定刺激间隔（ISI）呈现的一系列听觉刺激同步敲击键盘。在这项任务中，受试者除了需要敲击的运动成分外，还需要非运动成分来估计即将到来的音调的时间。正常受试者在较短的ISI时将敲击与呈现的音调同步，而随着ISI变长，正常受试者在音调与敲击之间表现出更大的延迟（过渡区）。在过渡区之后，正常受试者相对于音调延迟按下按钮。另一方面，SCA患者即使在较短的ISI时也无法将敲击与音调同步，尽管他们比正常受试者更早相对于音调延迟按下按钮。正常受试者在过渡区后延迟敲击出现的最早时间为4800毫秒，而SCA患者为1800毫秒。与正常受试者相比，SCA患者的时间整合跨度缩短。这可能代表SCA患者存在非运动性小脑功能障碍。
