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This is a question that has always perplexed me. On one hand I know I make decisions everyday (what to wear, what to eat, which friends to visit) but on the other hand I don't know how those decisions are made. Society has adopted the mind-body duality and the underlying meaning that one can be separated from the other. But that doesn't sit well with me, when it comes down to it your brain is subject to the same set of physical and biochemical processes whether it is decoding hunger, pain, drowsiness, and even decisions.
Long before you're consciously aware of making a decision, your mind has already made it. If that's the case, do people actually make decisions? Or is every choice -- even the choice to prepare for future choices -- an unthinkable, mechanistic procedure over which an illusory self-awareness is laid?
These questions are raised by a study conducted at the Max Planck Institute and published Sunday in Nature Neuroscience. Test subjects chose to push a button with their right or left hand; seven seconds before they experienced making the choice, their brain activity already predicted their final decisions.
John-Dylan Haynes, a Max Planck neuroscientist and co-author of the study says, "your decisions are strongly prepared by brain activity. By the time the consciousness kicks in, most of the work has already been done."
Seven seconds before Hayne's test subjects chose to push a button, activity shifted in their frontopolar cortex, a brain region associated with high-level planning. Soon afterwards, activity moved to the parietal cortex, a region of sensory integration. These patterns were monitored using a functional MRI machine.
These results show that decisions are unconsciously prepared much longer ahead than previously though. But we do not now yet where the final decision is made. The decision could be reversed at some point which is totally reasonable.
Maybe "free will" isn't a sensible concept, and you don't need neuroscience to reject it -- any mechanistic view of the world is good enough, and you could probably argue on purely conceptual grounds that the opposite of determinism is randomness, not free will. Maybe we should replace the concept of free will with the concept of rationality -- that we select our actions based on a kind of practical reasoning, and there is no conflict between rationality and the mind as a physical system -- After all, computers are rational physical systems.
I feel that the very existence of neuroscience and physchology precipitates the idea that free will is not that large of a component in our lives. As with chemisty and physics, observation with predictable outcomes has shaped these sciences. People placed in a set of conditions will usually come up with a predictable response or action.
Mental illness offers another look into the idea of free will. Being able to predict how someone with depression, bipolar, or any other number of conditions will act is rather an easy task for phychiatrists. But these are easy to observe since they are out of the social norms. Who says that a healthy brain doesn't precipitate the same kind of predictive actions but they are less noticable since they fall within the frame of social norms.
I'll end the diatribe here but will be revisiting this later on this week I hope.
Technorati Tags: free will, neuroscience, science
April 17, 2008
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