Most of you here have read Blindsight<\/i>. Some of you have made it almost to the end. A few have even got as far as the references (I know this, because some of you have asked me questions about them). And so you might remember that old study Libet did back in the nineties, in which it was shown that the body begins to act on a decision a full half-second before the conscious self is aware of having made<\/i> the decision. A lot of Blindsight<\/i>‘s punchline hung on this discovery\u2014 because obviously, whatever calls an action into being must precede it. Cause and effect. Hence, the johnny-come-lately sense of conscious volition is bogus. We are not in control. I mean, really: a whole half a second<\/i>.<\/p>\n
Half a second? Chun Siong Soon and his buddies piss<\/i> on Libet’s half a second. Nature Neuroscience <\/i>just released a study<\/a> that puts Libet’s puny electrodes to shame; turns out the brain is making its decisions up to ten full seconds<\/i> (typically around seven) before the conscious self “decides” to act.<\/p>\n Ten whole seconds. That’s longer than the attention span of a sitting president.<\/p>\n It all comes down to stats. Soon et al<\/i> took real-time fMRI recordings of subjects before, during, and after a conscious “decision” was made; then they went back and looked for patterns of brain activity prior to that “decision” that correlated with the action that ultimately occurred. What they found was a replicable pattern of brain activity that not only preceded the decision by several seconds, but which also correlated with the specific “decision” made (click a button with the right or the left hand). (Interestingly, these results differ from Libet’s insofar as subjects reported awareness of their “decision” prior<\/i> to the activation of the motor nerves, not afterwards. Whereas Libet’s results suggested that action precedes conscious “decision”-making by a very brief interval, Soon et al<\/i>‘s suggest that actual decision-making precedes conscious “decision”-making by a much longer one. Bottom line is the same in each case, though: what we perceive as “our” choice has already been made before we’re even aware of the options.)<\/p>\n This isn’t exactly mind reading. Soon and his buds didn’t find a circuit that explicitly controls button-pressing behavior or anything. All they found was certain gross patterns of activity which correlated with future behavior. But we could not read that information if the information wasn’t there; in a very real sense, your brain must know what it’s going to do long before you <\/i>do.<\/p>\n Obviously this can’t be the whole story. If the lag between processing and perception was always that long, we would feel no sense of personal agency at all. It’s one thing to think that you told your muscles to leap from the path of an approaching bus when the time discrepancy is a measly 400 millisecs; but not even organisms with our<\/i> superlative denial skills could pretend that we were in control if our bodies had leapt clear ten seconds before it even occurred to us to move. So I would think this is more proof-of-principal than day-in-the-life. Still. As IO9 points out<\/a>, given these results, how long before we can do without that stupid conscious part of us entirely?<\/p>\n