Posted on behalf of Richard Van Noorden
Two years ago, psychologist Daniel Wegner received surgery to remove a brain tumour. Surgeons drilled into the left side of his skull. Six weeks after the successful operation, he says, he found his right hand moving without him seeming to will it. It did what he wanted – as he would have decided in ordinary circumstances. “But I did not feel I was the author of the movement. I didn’t need to be there for my hand to move; I had lost the feeling that I was doing it.”
At an entrancing World Science Festival discussion on fate and free will, Wegner, together with Nobel laureate Paul Nurse, philosopher Al Mele and neuroscientist Patrick Haggard discussed what science is adding to the debate on whether we have control over our actions – whether simply moving our limbs, or making a choice about wider moral actions.
Wegner’s tale – and neuroscience research discussed at the session – suggested that our conscious experience of having ‘willed’ an action may be an add-on, something that the brain reports alongside or after an action but not that action’s direct cause, or necessary for it to take place. (Haggard added a directly contrasting tale to Wegner’s first-hand account – describing paralysed patients who had the feeling that they could control their limbs, and told researchers that they had moved them, even though the limb remained limp.)
To what extent then, are we in control of (‘will’) our non-reflex actions? Haggard said that many of the actions generated by neurons firing in the motor cortex depend on our laid-down memories – we take the action we did last time, and we rely on previous experience.
Are we morally responsible for the more complex actions we take? “The will is very susceptible to instruction,” Haggard said, pointing out that society spends 20 (or 30) years teaching children what kind of intention leads to what kind of consequence. Mele suggested that a future question for neuroscientists to investigate, probably in consultation with lawyers, would be under what conditions people are accountable for what they do – and when we feel their actions are excusable.
Fate, determinism, and quantum mechanics didn’t get much of a look-in during the evening, which was probably a wise decision. “Using quantum mechanics to explain free will is taking one unknown to explain another,” said Wegner, and the panel left it at that. A thought-provoking evening played, again, to a packed crowd.