Friday, January 25, 2013

Mind Time 4: Free Will 1

Next, I quote from ``Chapter 4: Intention to Act: Do We Have Free Will'' of the book, ``Mind Time,'' by Benjamin Libet.

How the brain deals with voluntary acts is an issue of fundamental importance to the role of conscious will and, beyond that, to the question of free will. It has been commonly assumed that in a voluntary act, the conscious will to act would appear  before or at the start of the brain activities that lead to the act. If that were true, the voluntary act would be initiated and specified by the conscious mind. But, what if that were not the case? Is it possible that the specific brain activities leading to a voluntary act begin before the conscious will to act, in other words, before the person is aware that he intends to act? ...
we were able to examine this issue experimentally. What we found, in short, was that the brain exhibited an initiating process, beginning 550 msec before the freely voluntary act; but awareness of the conscious will to perform the act appeared only 150-200 msec before the act. The voluntary process is therefore initiated unconsciously some 400 msec before the subject becomes aware of her will or intentions to perform the act. --- pp. 123,124, Mind Time

The finding that the volitional process is initiated unconsciously leads to the question: Is there any role for the conscious will in the performance of a voluntary act (Libet, 1985)? The conscious will ... does appear 150 msec before the motor act, even though it follows the onset of the cerebral action ... by at least 400 msec. ... An interval of 150 msec would allow enough time in which the conscious function might affect the final outcome of the volitional process. ...
The conscious will could decide to allow the volitional process to go to completion, resulting in the motor act itself. Or, the conscious will could block or ``veto'' the process, so that no motor act occurs.
Vetoing of an urge to act is a common experience for all of us. It occurs especially when the projected act is regarded as socially unacceptable, or not in accord with one's overall personality or values. In fact, we showed experimentally that the veto of a planned act was possible even during the last 100-200 msec before the expected time of the action. ...
We may view voluntary acts as beginning with unconscious initiatives being ``burbled up'' by the brain. The conscious will would then select which of these initiatives may go forward to an action, or which of these initiatives may go forward to an action, or which ones to veto and abort so no motor act appears. ... --- pp. 137-139, Mind Time

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