CONSCIOUSNESS AS AN EXPERIMENTAL VARIABLE - PROBLEMS OF DEFINITION, PRACTICE, AND INTERPRETATION
CONSCIOUSNESS AS AN EXPERIMENTAL VARIABLE - PROBLEMS OF DEFINITION, PRACTICE, AND INTERPRETATION
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DOI：
10.1017/s0140525x00044988
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发表时间：
1985-12-01
影响因子：
29.3
通讯作者：
LATTO, R
中科院分区：
文献类型：
--
作者：
LATTO, R
自愿性行为之前有电生理“准备电位”（RPs）。自发行为没有预先计划，主要的负RP移开始于约550毫秒。这样的RPs被用来指示在完全内源性自愿行为之前大脑活动的最小发作时间。有意识行动意图的时间是通过被试回忆他最初意识到有意或想要移动时旋转点的空间时钟位置获得的(W)。W发生在约200ms。对照实验中，对皮肤刺激进行计时(S)，有助于评估每个受试者在报告任何感知事件的时钟时间时的错误。对于自发性自愿行为，RP比未纠正的Ws早约350 ms，而Ws比S早约400 ms。这种差异的方向在整个过程中是一致和显著的，无论使用哪种RP发作或W的测量方法。结论是，自发自愿行为的大脑启动是在无意识中开始的。然而，研究发现，在特定的有意识意图出现后的150毫秒左右的剩余时间里，最终的行动决定仍然可以被有意识地控制。事实上，在预先安排的行动时间之前的100-200毫秒内，受试者可以“否决”运动表现。有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的结果。有人提出，有意识的意志可以以一种允许的方式发挥作用，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，没有它，最终的运动输出就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.