MENTAL SUMMATION - THE TIMING OF VOLUNTARY INTENTIONS BY CORTICAL ACTIVITY
MENTAL SUMMATION - THE TIMING OF VOLUNTARY INTENTIONS BY CORTICAL ACTIVITY
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DOI：
10.1017/s0140525x00044952
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发表时间：
1985-12-01
影响因子：
29.3
通讯作者：
ECCLES, JC
中科院分区：
文献类型：
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作者：
ECCLES, JC
自愿行为之前是电生理学的“准备电位”(RP)。对于不涉及预先计划的自发行为，主要的负 RP 偏移开始于大约 550 毫秒。此类 RP 用于指示完全内源性自愿行为之前的大脑活动的最短起始时间。有意识意图行动的时间是通过受试者在最初意识到意图或想要移动时对旋转点的空间时钟位置的回忆而获得的（W）。 W 发生在约 200 毫秒时。控制实验中，皮肤刺激是定时的 (S)，帮助评估每个受试者在报告时钟时间以了解任何感知事件时的错误。对于自发的自愿行为，RP 开始先于未校正的 Ws 约 350 毫秒，而针对 S 校正的 Ws 约 400 毫秒。无论使用 RP 起始或 W 的几种测量方法中的哪一种，这种差异的方向始终是一致且显着的。结论是，大脑自发自愿行为的启动是无意识地开始的。但研究发现，在特定意识意图出现后剩余的150毫秒左右的时间里，最终的行动决定仍然可以被有意识地控制。事实上，受试者可以在预先安排的行动时间之前的 100-200 毫秒内“否决”运动表现。意识意志的作用不是发起特定的自愿行为，而是选择和控制意志结果。有人提出，有意识的意志可以以一种宽容的方式发挥作用，要么允许要么阻止无意识地产生的行动意图的运动实现。或者，可能需要有意识的激活或触发，否则最终的运动输出将不会遵循无意识的大脑启动和准备过程。
Voluntary acts are preceded by electrophysiological" readiness potentials"(RPs). With spontaneous acts involving no preplanning, the main negative RP shift begins at about—550 ms. Such RPs were used to indicate the minimum onset times for the cerebral activity that precedes a fully endogenous voluntary act. The time of conscious intention to act was obtained from the subject's recall of the spatial clock position of a revolving spot at the time of his initial awareness of intending or wanting to move (W). W occurred at about-200 ms. Control experiments, in which a skin stimulus was timed (S), helped evaluate each subject's error in reporting the clock times for awareness of any perceived event.For spontaneous voluntary acts, RP onset preceded the uncorrected Ws by about 350 ms and the Ws corrected for S by about 400 ms. The direction of this difference was consistent and significant throughout, regardless of which of several measures of RP onset or W were used. It was concluded that cerebral initiation of a spontaneous voluntary act begins unconsciously. However, it was found that the final decision to act could still be consciously controlled during the 150 ms or so remaining after the specific conscious intention appears. Subjects can in fact" veto" motor performance during a 100-200-ms period before a prearranged time to act. The role of conscious will would be not to initiate a specific voluntary act but rather to select and control volitional outcome. It is proposed that conscious will can function in a permissive fashion, either to permit or to prevent the motor implementation of the intention to act that arises unconsciously. Alternatively, there may be the need for a conscious activation or triggering, without which the final motor output would not follow the unconscious cerebral initiating and preparatory processes.