A MODEL OF SYNCHRONIZATION OF MOTOR ACTS TO A STIMULUS SEQUENCE .1. TIMING AND ERROR CORRECTIONS
A MODEL OF SYNCHRONIZATION OF MOTOR ACTS TO A STIMULUS SEQUENCE .1. TIMING AND ERROR CORRECTIONS
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DOI：
10.1007/bf00203239
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发表时间：
1994-03-01
影响因子：
1.9
通讯作者：
MATES, J
中科院分区：
文献类型：
--
作者：
MATES, J
提出了一个闭环定时模型，该模型考虑了在需要与一系列刺激同步产生一系列运动动作的任务中观察到的几种现象。与之前的模型相反，该模型区分了主体中枢神经系统可用的变量（内部变量）和外部可测量的变量，并包括几个生理上合理的内部变量。该模型假定存在(a)产生参考间隔的内部计时器，该参考间隔在电机控制单元中用于下一个电机命令的定时；(b)一种内在的（主观的）同步性，它依赖于一些关于已经执行的动作开始的后验（反馈）信息。假设了一种双向纠错机制：(1)周期（反向频率）纠错——在任务开始时根据刺激间间隔(s)设定参考间隔（周期），然后根据其持续时间与实际持续时间(s)的差异进行纠错；(2)相位校正——内部同步误差（即刺激的内部表征的中央时间可用性与反应的某些反馈方面之间的时间间隔）直接在运动控制单元中进行校正。客观测量的反应和刺激的系统异步是由信息转导的内部延迟决定的。最后，该模型用于预测受试者在同步任务的其他实验设置中的表现。
A closed-loop timing model is proposed that accounts for several phenomena observed in tasks which require production of a sequence of motor acts in synchrony with a sequence of stimuli. In contrast to the previous models, variables available to the central nervous system of a subject (internal variables) and externally measurable variables are distinguished, and several physiologically justifiable internal variables are included. The model assumes the existence of (a) an internal time-keeper producing a reference interval that is used in a motor-control unit for timing of the next motor command; (b) an intrinsic (subjective) synchrony that relies on some a posteriori (feedback) information about the already executed onset of the motor act. A two-way error-corrective mechanism is hypothesized: (1) period (inverted frequency) corrections - the reference interval (period) is set at the beginning of the task according to the interstimulus-onset interval (s) and later corrected for differences between its duration and the actual duration of s; (2) phase corrections - internal synchronization errors (i.e., time gaps between the central temporal availability of internal representations of stimuli and of some feedback aspect of responses) are corrected for directly in the motor-control unit. Objectively measured systematic asynchrony of responses and stimuli is determined by the internal delays in information transduction. Finally, the model is used for making predictions of a subject's performance in some other experimental settings of the synchronization task.