The leading science journal, Nature, reports: The experiment helped to change John-Dylan Haynes’s outlook on life. In 2007, Haynes, a neuroscientist at the Bernstein Center for Computational Neuroscience in Berlin, put people into a brain scanner in which a display screen flashed a succession of random letters. He told them to press a button with either their right or left index fingers whenever they felt the urge, and to remember the letter that was showing on the screen when they made the decision. The experiment used functional magnetic resonance imaging (fMRI) to reveal brain activity in real time as the volunteers chose to use their right or left hands. The results were quite a surprise.
“The first thought we had was ‘we have to check if this is real’,” says Haynes. “We came up with more sanity checks than I’ve ever seen in any other study before.”
The conscious decision to push the button was made about a second before the actual act, but the team discovered that a pattern of brain activity seemed to predict that decision by as many as seven seconds. Long before the subjects were even aware of making a choice, it seems, their brains had already decided.
As humans, we like to think that our decisions are under our conscious control — that we have free will. Philosophers have debated that concept for centuries, and now Haynes and other experimental neuroscientists are raising a new challenge. They argue that consciousness of a decision may be a mere biochemical afterthought, with no influence whatsoever on a person’s actions. According to this logic, they say, free will is an illusion. “We feel we choose, but we don’t,” says Patrick Haggard, a neuroscientist at University College London.
You may have thought you decided whether to have tea or coffee this morning, for example, but the decision may have been made long before you were aware of it. For Haynes, this is unsettling. “I’ll be very honest, I find it very difficult to deal with this,” he says. “How can I call a will ‘mine’ if I don’t even know when it occurred and what it has decided to do?”
Philosophers aren’t convinced that brain scans can demolish free will so easily. Some have questioned the neuroscientists’ results and interpretations, arguing that the researchers have not quite grasped the concept that they say they are debunking. Many more don’t engage with scientists at all. “Neuroscientists and philosophers talk past each other,” says Walter Glannon, a philosopher at the University of Calgary in Canada, who has interests in neuroscience, ethics and free will.
There are some signs that this is beginning to change. This month, a raft of projects will get under way as part of Big Questions in Free Will, a four-year, US$4.4-million programme funded by the John Templeton Foundation in West Conshohocken, Pennsylvania, which supports research bridging theology, philosophy and natural science. Some say that, with refined experiments, neuroscience could help researchers to identify the physical processes underlying conscious intention and to better understand the brain activity that precedes it. And if unconscious brain activity could be found to predict decisions perfectly, the work really could rattle the notion of free will. “It’s possible that what are now correlations could at some point become causal connections between brain mechanisms and behaviours,” says Glannon. “If that were the case, then it would threaten free will, on any definition by any philosopher.” [Continue reading…]