Many scientists believe free will is an illusion. If so, do we have no control over our actions?
MOST PEOPLE assume that free will is a defining characteristic of being human. All our concepts of praise, blame, reward, punishment and so on depend on belief in the personal responsibility that arises from free will. It is disconcerting, therefore, to learn that many scientists believe that free will is an illusion. Sam Harris argues this point in Free Will (Free Press, 2012).
However, the matter is far from settled. Most experts – neuroscientists and philosophers – who ponder this subject would probably not agree with Harris, but the situation is far more nuanced than the uninitiated might expect. There is significant evidence that what we have is “free won’t”, rather than free will.
The experiments of the pioneering physiologist Benjamin Libet (1916-2007) are central to an understanding of free will. His most famous experiments in the late 1970s and early 1980s were interpreted as a challenge to belief in free will, because they seemed to demonstrate that unconscious brain activity precedes and causes volitional acts that are retrospectively felt by the subject to be consciously motivated.
Libet’s experiments were simple in principle. Subjects were asked to perform a simple action of pressing a button or flexing a wrist whenever they wished to do so. The subjects noted the time on a clock when they consciously decided to take the action. The subject’s scalp was also connected to an electroencephalogram (EEG) machine in order to detect electrical activity in the motor cortex of the brain, indicating the brain’s initiation of action. Electrical activity was also monitored in finger and wrist muscles, indicating the time the voluntary flex or movement was being enacted.
We would expect the experiment to show the following sequence of events: first there is conscious awareness of intention to act; then the brain activates the motor area that sends a signal to the muscles.
But this is not what Libet found.
The experiment showed that although activity (cortical readiness potential) in the motor area of the brain preceded electrical activity in the muscles by 550 milliseconds (ms), participants’ conscious awareness of the decision to move preceded electrical activity in the muscle by only 200ms. In other words, brain activity preceded conscious awareness by one third of a second. It seems that the brain unconsciously begins the process of “voluntary” action and we become aware of this later. Some researchers, therefore, concluded that free will is illusory.
However, as Timothy Pychyl points out in Psychology Today, Libet never made such a claim about free will. He expected that we can consciously veto action that is initiated unconsciously when we become aware of the urge to act and he tested this by experiment. He instructed the subjects to stop the action of pressing the button or flexing the wrist once they became aware of the urge to carry out the action. He calculated that subjects have a window of about 150ms in which to veto the urge.
The results showed that the cortical readiness potential did develop as before but flattened out just before muscle action was initiated, which he interpreted as the vetoing action of conscious choice. So it seems that though we may not have the free will to initiate an action, we have the free will to abort it. Our brains initiate actions unconsciously but we can consciously stop them.
The concept of a two-sided system where the sides coexist in tension with each other has a ring of truth to it in biology. For example, the constant weight of a normal adult does not reflect stasis but rather an equilibrium between two opposing forces – tissue build-up and breakdown. Synthesis and degradation are independently active the whole time, but they balance each other and there is no overall change. This balancing of opposites is characteristic of living systems.
In the decision-making design in the brain, we seem to have an automatic unconscious side and a conscious editing side that can later veto or sanction the unconscious decision. Our free will is actually a free won’t.
There is much debate about the interpretation of Libet’s experiments. This subject is of the utmost importance, cutting right to the heart of what it means to be human.
It seems to me that Libet’s insight into how conscious choice works can be harnessed to help anyone to break an unwanted habit, such as watching too much TV. The urge arises unconsciously and before you know it you have the remote control in your hand.
Now, the moment you become conscious of what you are doing, exercise your “free won’t” and consciously choose to veto the urge.
This is the only freedom you have in the situation.
William Reville is an emeritus professor of biochemistry and public awareness of science officer at UCC. understandingscience.ucc.ie