Friday, September 07, 2007

Finding Free Will in the Brain

Every now and then incautious neuroscientists (or more likely science journalists) claim to have found the site in the brain responsible for some universally shared bit of behavior or psychology. It's much like the tendency to tout discoveries of a "gene" for obesity, addiction or extroversion: often it turns out on closer inspection that there's no single gene, or site in the brain, responsible for the trait in question. Rather it's a more complex story of how genes and environment and multiple brain systems interact. But the fascination with such findings, oversimplified or not, reflects the attractiveness of physicalism as an explanatory story. Once we've identified the physical embodiment or correlate of something - the mechanism constituting it or causing it - it becomes categorically real. This is probably because mechanistic explanations are the most transparent we've got. Everything's out in the open, observable and pinned down, even if it's fiendishly complex, such as the neural reward system that regulates our cravings for sex, drugs and Monteverdi. Everyone now agrees the placebo effect is real since it's been shown that believing a sugar pill is a drug actually changes the brain!

So when neuroscientists announce they've found the place in the brain where free will resides, it might generate some puzzlement. Isn't free will supposed to be that which escapes mechanism, such that we choose freely, independently of deterministic causation? If it's the brain that gives us free will, then it must boil down to the physical goings-on of neurons and neurotransmitters, in which case how does that make us truly free and responsible? Finding free will in the brain doesn't make it real, it destroys it.

This question points up the fact that there are different meanings of free will floating around. Looking at the various articles about this research (here and here for instance), it's clear that what these scientists mean by free will is a specific capacity, namely to consciously reconsider an intended action. Why call that free will? Well, the ability to control impulses by means of higher level cognitive processes arguably gives us an important kind of freedom, namely freedom from being simple slaves to our appetites. We gain tremendously in flexibility by virtue of all the brain-instantiated firmware that decides what actions are appropriate given one's situation, long-term goals, and present urges.

This is clearly quite different from the folk-metaphysical concept of free will: a conscious capacity that transcends the mechanistic workings of the brain. The folk concur that free will is about self-control, but real self-control comes from a self beyond mechanism; if not, it's obvious that people are just the working out of mindless physical parts, and what's free about that? Doesn't that make us mere robots? If not having an immaterial soul makes us robots, then yes. Some, such as Keith Stanovich, have argued that being a sufficiently complex organic robot is all we need to be. But of course many balk at this prospect.

Many scientists (and most philosophers) know full well that the physicalist/functionalist downsizing of free will doesn't cut it for laypeople, so they tend to soft-pedal the implications for our self-image. But a few, such as neurophilosophers Patricia Churchland and Joshua Greene, are pretty forthright in laying out the implications. If free will isn't a magical quality that people can just choose to exercise, but rather a physically-based capacity for self-control, then we can't blame someone who lacks this capacity, such as an addict, for not having exercised their free will. This is one aspect of the moral significance of moving from dualism to physicalism: we'll be more likely to cure or rehabilitate, rather than punish, those who, for one reason or another, lack normal capacities for self-control. Another aspect is that we'll see that those who do have normal capacities but misuse them in anti-social, damaging ways are products of specific conditions that shaped their values; they are not self-made. This suggests that originative responsibility for behavior doesn't inhere in the person alone, but also in the culture, community and family that produced him. So our responsibility practices should take this into account, which again means not merely punishing, but preventing and rehabilitating.

Some will say we'll never find free will in the brain since free will by definition is that which transcends mechanism. Others will say that free will, mechanistic or not, is just that which makes us morally responsible. Or (my preference), we can clarify the debate by dropping talk about free will, which will always be ambiguous since it has multiple meanings, and argue about what sorts of freedom and responsibility we plausibly have on a naturalistic understanding of ourselves. Getting a fix on these will then inform our responsibility practices, making them more effective, and more humane.

1 Comments:

Blogger Juno Walker said...

Tom -

"Isn't free will supposed to be that which escapes mechanism, such that we choose freely, independently of deterministic causation? If it's the brain that gives us free will, then it must boil down to the physical goings-on of neurons and neurotransmitters, in which case how does that make us truly free and responsible? Finding free will in the brain doesn't make it real, it destroys it."

That last line is a great point, and probably the most important point to take away from the research!

Juno

Sep 10, 2007, 9:28:00 AM  

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