Frith’s article (sadly, closed-access) was discussing a classic experiment in neuroscience that seems to suggest that our brains generate an action before we’re consciously aware of making the choice to move, suggesting our experience of having complete conscious control over our actions may be mistaken:
Curiously, considering it is over 20 years old, a single experiment dominated our discussions. Reported in 1983 (and replicated variously) by Benjamin Libet at the University of California, San Francisco, the experiment is crucial because it seems to show we don’t have free will. Using an electroencephalogram, Libet and his colleagues monitored their subjects’ brains, telling them: “Lift your finger whenever you feel the urge to do so.” This is about as near as we get to free will in the lab.
It was already known that there is a detectable change in brain activity up to a second before you “spontaneously” lift your finger, but when did the urge occur in the mind? Amazingly, Libet found that his subjects’ change in brain activity occurred 300 milliseconds before they reported the urge to lift their fingers. This implies that, by measuring your brain activity, I can predict when you are going to have an urge to act. Apparently this simple but freely chosen decision is determined by the preceding brain activity. It is our brains that cause our actions. Our minds just come along for the ride.
In response, two of the correspondent’s question the appropriateness of the experimental task (is finger lifting a good example of free will?) and whether the result equally applies to the situation where we can stop an intended action.
Another draws parallels between our concept of free will and the influence of peer pressure and conformity, while two letters discuss how compatible free will is with a model of a physical deterministic universe.
In other words, if physics can, in principle, mathematically model the interaction of every atom to predict what will happen, how can we influence this process if we’re nothing more than a collection of atoms?
Finally, two other correspondents highlight some weakness in Frith’s ideas, and indeed many current theories of free will, that arise out of more fundamental problems in understanding fully the best way of linking mind- and brain-level theories.
Just reading the letters gives a good overview of some of the major problems when trying to understand both the concepts and science of conscious control of action.
Link to excellent Wikipedia page on free will.