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We are conscious of only a tiny fraction of the information that our brains process in each moment.1 Although we continually notice changes in our experience—in thought, mood, perception, behavior, etc.—we are utterly unaware of the neurophysiological events that produce them. In fact, we can be very poor witnesses to experience itself. By merely glancing at your face or listening to your tone of voice, others are often more aware of your state of mind and motivations than you are.
I generally start each day with a cup of coffee or tea—sometimes two. This morning, it was coffee (two). Why not tea? I am in no position to know. I wanted coffee more than I wanted tea today, and I was free to have what I wanted. Did I consciously choose coffee over tea? No. The choice was made for me by events in my brain that I, as the conscious witness of my thoughts and actions, could not inspect or influence. Could I have “changed my mind” and switched to tea before the coffee drinker in me could get his bearings? Yes, but this impulse would also have been the product of unconscious causes. Why didn’t it arise this morning? Why might it arise in the future? I cannot know. The intention to do one thing and not another does not originate in consciousness—rather, it appears in consciousness, as does any thought or impulse that might oppose it.
The physiologist Benjamin Libet famously used EEG to show that activity in the brain’s motor cortex can be detected some 300 milliseconds before a person feels that he has decided to move.2 Another lab extended this work using functional magnetic resonance imaging (fMRI): Subjects were asked to press one of two buttons while watching a “clock” composed of a random sequence of letters appearing on a screen. They reported which letter was visible at the moment they decided to press one button or the other. The experimenters found two brain regions that contained information about which button subjects would press a full 7 to 10 seconds before the decision was consciously made.3 More recently, direct recordings from the cortex showed that the activity of merely 256 neurons was sufficient to predict with 80 percent accuracy a person’s decision to move 700 milliseconds before he became aware of it.4
These findings are difficult to reconcile with the sense that we are the conscious authors of our actions. One fact now seems indisputable: Some moments before you are aware of what you will do next—a time in which you subjectively appear to have complete freedom to behave however you please—your brain has already determined what you will do. You then become conscious of this “decision” and believe that you are in the process of making it.
The distinction between “higher” and “lower” systems in the brain offers no relief: I, as the conscious witness of my experience, no more initiate events in my prefrontal cortex than I cause my heart to beat. There will always be some delay between the first neurophysiological events that kindle my next conscious thought and the thought itself. And even if there weren’t—even if all mental states were truly coincident with their underlying brain states—I cannot decide what I will next think or intend until a thought or intention arises. What will my next mental state be? I do not know—it just happens. Where is the freedom in that?
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