Thursday, September 1, 2011

Neuroscientists against free will

The current Nature magazine (the British Scientific American, 31 August 2011 | Nature 477, 23-25 (2011) | doi:10.1038/477023a) features Neuroscience vs philosophy: Taking aim at free will:
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 letters1. 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.
(Free registration required for the whole article.) Using brain scans, they can predict choices a couple of seconds in advance 60% of the time, whereas random guessing would predict 50%.

The new atheists have declared that nature is deterministic, that these experiments prove that we have no free will, and that religion falsely makes us morally responsible for our actions.

I think that it is baffling why anyone would think that the above experiment has anything to do with free will. The article gives some explanation, but also cites philosophers who say that the atheist neuroscientists are wrong.

It seems obvious to me that it is very difficult to make a decision faster than about ten seconds. Athletes, cops, traders, and others seem to make faster decisions, but only after extensive training that allows them to decide in advance about a wide range of scenarios. Given an unfamiliar situation, and they cannot make a quick decision.

There is no evidence against free will. These experiments only show that our detection equipment is much quicker than our decision making ability.

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