Monday, January 21, 2013

Libet's study and his own words on free will

In a local reading group we're reading Eagleman's Incognito. A discussion has ensued on whether we are completely under the power of unconscious processes or if we have any conscious control over our zombie programs. Libet's study is of course seminal in such discussions. I figured I'd go right to the horse's mouth and the following are from his empirical paper. He noted that the initiation of a voluntary act preceded the conscious awareness of the act, but that the awareness preceded the actual action. He concluded that conscious awareness thus exerted control over the action in that it could veto it. He surmised that this conscious veto power is not preceded by an unconscious process. As to what the unconscious initiation of the act says about free will he said and I quote:

"There remains a deeper question about free will that the foregoing considerations have not addressed. What we have achieved experimentally is some knowledge of how free will may operate. But we have not answered the question of whether our consciously willed acts are fully determined by natural laws that govern the activities of nerve cells in the brain, or whether acts and the conscious decisions to perform them can proceed to some degree independently of natural determinism. The first of these options would make free will illusory. The conscious feeling of exerting one’s will would then be regarded as an epiphenomenon, simply a by-product of the brain’s activities but with no causal powers of its own.

"Let us re-phrase our basic question as follows: Must we accept determinism? Is non-determinism a viable option? We should recognize that both of these alternative views (natural law determinism vs. non-determinism) are unproven theories, i.e. unproven in relation to the existence of free will. Determinism has on the whole, worked well for the physical observable world. That has led many scientists and philosophers to regard any deviation from determinism as absurd and witless, and unworthy of consideration. But there has been no evidence, or even a proposed experimental test design, that definitively or convincingly demonstrates the validity of natural law determinism as the mediator or instrument of free will.

"However, we must recognize that the almost universal experience that we can act with a free, independent choice provides a kind of prima facie evidence that conscious mental processes can causatively control some brain processes (Libet, 1994). As an experimental scientist, this creates more difficulty for a determinist than for a non-determinist option. The phenomenal fact is that most of us feel that we do have free will, at least for some of our actions and within certain limits that may be imposed by our brain’s status and by our environment. The intuitive feelings about the phenomenon of free will form a fundamental basis for views of our human nature, and great care should be taken not to believe allegedly scientific conclusions about them which actually depend upon hidden ad hoc assumptions. A theory that simply interprets the phenomenon of free will as illusory and denies the validity of this phenomenal fact is less attractive than a theory that accepts or accommodates the phenomenal fact.

"In an issue so fundamentally important to our view of who we are, a claim for illusory nature should be based on fairly direct evidence. Such evidence is not available; nor do determinists propose even a potential experimental design to test the theory.

"My conclusion about free will, one genuinely free in the non-determined sense, is then that its existence is at least as good, if not a better, scientific option than is its denial by determinist theory. Given the speculative nature of both determinist and non-determinist theories, why not adopt the view that we do have free will (until some real contradictory evidence may appear, if it ever does). Such a view would at least allow us to proceed in a way that accepts and accommodates our own deep feeling that we do have free will.We would not need to view ourselves as machines that act in a manner completely controlled by the known physical laws. Such a permissive option has also been advocated by the neurobiologist Roger Sperry (see Doty, 1998)."

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