How to Predict Activity in the Brain?

Recent experiments using functional mri have been reported to show that seven to ten seconds before you make a decision, your behaviour can be predicted. But in fact, if you look at the data, that's not at all what's going on. So when they say they can predict activity, it doesn't mean that what they predict is necessarily going to happen. It just means they are slightly better than they would be if they were just guessing. And that, i think, has very different implications.