Researchers have found that before test subjects made a conscious decision about pushing a button, a change had already been seen in brain activity that was able to predict the decision 70% of the time.
This is creating a stir in the scientific and scientific-loving Internet community, especially as scientists like NIH scientist Mark Hallett are saying that they doubt that they doubt free will exists as a separate independent force. Whoa. This is how quickly neuroscience can slide into neurophilosophy. But this theory, that free will is an illusion, is centuries old (Free Will at Wikipedia).
Certainly this mostly predictive brain activity is an interesting observation, but don't forget that we don't know much about the sensitivity of imaging studies such as fMRI - surely it is missing many indicators of activity that have been subtracted from background noise. Perhaps this pre-conscious decision-making is similar to the absence of brain activity seen before a problem is solved by intuition. A big burst in activity appears to arise at the time the test subject says "Aha!", but the pattern matches that are likely occur before this aren't large enough to register a blip.
It was fun coming across this subject because our son had just written a Socratic dialogue on free will for his online logic course. If you'd like to read his imaginary conversation between Socrates and a Greek doubting the existence of free well, click here.
Brain Scanners Can See Your Decisions Before You Make Them