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Let’s consider two scenarios. In one case, John carefully plans and executes a murder. In the other case, Susan kills an assailant who attacks her. With a belief in free will, we assume that John freely made a willful and conscious decision to commit that act and is thus more culpable than Susan who reacted on the spur of the moment out of the instinct for self-preservation and thus did not use her free will. We thus feel justified in punishing John more harshly than Susan.

If there is no free will, that means that both John’s and Susan’s actions were the result of unconscious neural activity, the only difference being that John’s neural activity had sufficient lead time to create conscious thoughts. Shouldn’t the planned murder be treated in the same way as the self-defense? Doesn’t that imply that they should be punished the same? Is this fair? [Read more…]

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Many people are suspicious of the insanity defense, suspecting that it is abused by unscrupulous criminals and their lawyers. The fact that psychiatrists and other experts can be found to argue both sides of the case adds weight to the suspicion that there is no objective basis to many of the claims of insanity.

This problem arose when the grounds for the insanity defense was loosened from the strict M’Naghten rule. In a 1954 court decision Durham vs. United States, a US Appeals Court extended the reach of the insanity defense beyond cognitive incapacity and said that “The rule we now hold is simply that the accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect.” (Steven Pinker, The Blank Slate, p. 184) As a result of the Durham precedent, there was a proliferation of expert testimony on both sides to argue the question of whether the accused did in fact have a mental disease or defect and whether the act that was committed was the product of that defective mental state, and thus not truly ‘free’.
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It is time to examine the consequences if we are forced to conclude, as seems likely, that there is no such thing as free will and that our actions are determined by the unconscious neural activity of a physical brain that was itself the creation of the genes, environment, and stochastic processes that make up our personal and evolutionary history.

The most obvious implications lie in the areas of crime and punishment and personal morality. Does the absence of free will mean that we are condemned to an amoral anarchy, in which people can claim that they are not responsible for any and every action because they did not freely choose to do so, and thus should bear no consequences?

Actually, no. In chapter 10 The Fear of Determinism in his book The Blank State: The Modern Denial of Human Nature, Steven Pinker argues that we need not perpetuate the fiction that there is free will when there is none simply because of fears of such an outcome. Apart from the fact that it is almost always better to base our policies on what is true than on illusions, the lack of free will can actually be more effective than having it because it enables us to see more clearly when and how to assign responsibility for actions.
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The 2008 research findings of Soon et. al., gave the surprising result that when we are allowed time to make decisions, our subconscious neural networks make the decisions up to ten seconds before we are consciously aware of it.

Of course, there are many situations in which we act without seeming to make any conscious decisions at all. If an object is suddenly thrown at us, we may duck, dodge, deflect, hit, or catch it, the ‘choice’ seemingly being made in much less than a second. In such cases, the action seems involuntary and we assign it to instinct, which is just another name for the unconscious neural activity of our brains. The instinct to duck when an object is directed at our head or to withdraw our hands from a hot object is due to the neural system having developed shortcuts because of its obvious survival value and has been selected for over a long time in our evolutionary history. The part of the brain that codes instincts must necessarily act very quickly to give commands to the motor brain in response to stimuli from the environment. Certain stimuli trigger a stimulus-action connection that bypasses those sections of the brain that indulge in time-consuming activities such as processing information and making judgments.
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In a recent paper (Unconscious determinants of free decisions in the human brain, Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze, & John-Dylan Haynes, Nature Neuroscience, vol. 11, no. 5, May 2008, 543-545), researchers used the more sophisticated modern technique of fMRI (functional magnetic resonance imaging) to measure brain activity. The paper is not available online without a subscription but you can read a news report on the results of their paper here.

This experiment was designed to meet two key concerns about the Libet studies: that the time interval between act and the precursor unconscious brain activity prior to act was too small to definitively rule out measurement errors, and that Libet’s team had not shown that the early brain activity was a predictor of a specific decision.

The fMRI studies find that our decisions as to what actions we will take originate in our unconscious neural activity and only later informs our conscious mind of it, thus providing strong evidence against the existence of free will. The paper describes what the researchers asked their test subjects to do while they were hooked up to fMRI measuring devices.
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The idea suggested by Benjamin Libet that what we call free will is not the popularly assumed ability to decide all our seemingly deliberate (as opposed to instinctive) actions but consists of the more limited ability to either let the predetermined action be completed or to veto it may be unsatisfying to some but its implications are worth exploring in case it turns out to be true. What this model says is that I have no control over what I decide to do in any given situation but I do have control over whether that decision is actually carried out. In other words, I cannot control my thoughts and decisions but I can control (within a limited range) my actions.
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People who are determined to keep the Ghost in the Machine alive still have a few options. Ironically, although it was Libet’s early experiments that cast doubt on the idea that we have free will, he himself was disturbed by that implication and has sought to find ways to salvage it. In his many publications, he repeats his belief that his experiments did not rule out free will and suggests ways in which it could still operate.
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In 1983, Benjamin Libet and his associates did some experiments that were similar to the 1963 Grey Walter experiment but with the added feature that the patients could observe the equivalent of a clock and thus note when they made the decision to act. This enabled a more objective determination of the time when they first had the conscious thought to carry out the action and not depend upon a possibly misleading feeling of surprise to infer the ordering of events.

One of the key original papers was published in the journal Brain (Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential): The unconscious initiation of a freely voluntary act, vol.106, p. 623-642, 1983) which does not seem to be available online but you can read online a later review published by Libet in 1999 (Do we have free will?, Journal of Consciousness Studies, vol. 6, No. 8–9, 1999, pp. 47–57) where he summarizes his findings and its implications for free will.
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In post #6 in this series, I discussed the 1963 Grey Walter experiment in which patients who had electrodes implanted in their brain’s motor cortex that could send a signal to advance a slide were surprised that the projector seemed to anticipate their decision to advance the slide. Does this mean that their unconscious neural activity had decided to advance the slide before telling the conscious brain that it had decided to do so? If so, it seriously undermines the idea of free will. In his book Consciousness Explained (1991, p. 167) which discusses the experiment, Daniel Dennett warns that it is premature to accept this conclusion because it is based on the articulated sense of surprise reported by the patients, and the brain is not the most reliable of historians.
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In the previous post, I provided a schematic description of two models of how the brain works, one with free will and the other without it. The traditional brain model with free will is given by

(D)                                    GES
                                        ↓
will → conscious thoughts → unconscious neural activity → action

Our genes (G), environment (E), and the inherent randomness in the laws of nature (S) all contribute right up to the present instant to the brain’s structure and unconscious neural activity. But in this model, there is a separate branch in which our (uncaused) free will makes decisions first which manifests itself as a conscious thought. In this model there should be a definite temporal sequence in which the act of will occurs first, followed by conscious thoughts, then unconscious brain activity caused by that conscious thought, and finally the action.
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