Scientists can reconstruct a clip you're watching from information about what is happening in your brain. But does the advent of brain reading cast any new light on the nature of mind?
People are good mind readers, because they are good face readers. Are you paying attention? The answer, very often, is written all over your face.
How much better it would be, though, if we could actually get inside another person's head, to see what they see, and feel what they feel, from the inside.
To judge by recent reports, something like this may now be possible for the first time. It's old news that what you see affects your brain. In principle, then, it ought to be possible to figure out what you are seeing -- or thinking or feeling or desiring -- by looking at what is going on in your head. And this is exactly what Jack Gallant and his neuroscience group at U.C. Berkeley seem to have managed to do. They have been able to reconstruct what you are seeing -- they literally make a film clip -- just on the basis of looking at what is going on your brain.
These are remarkable findings and there can be no doubt, as some have worried, that they raise important ethical issues.
This is not the first reported example of this kind of "brain reading." Using computer-assisted pattern recognition and the mathematics of multivariate analysis, John Dylan Haynes and his collaborators in Berlin have been able, reliably, on the basis of neural data, to determine which of two buttons a subject in a scanner has secretly decided to press. Indeed, Haynes has also shown that it is possible to know which button the subject will decide to press, even before the decision has been taken.
These are remarkable findings and there can be no doubt, as some have worried, that they raise important ethical and legal issues. But it is important to put the findings in context. When we do so, I believe, it becomes clear that they are both less interesting, and less dangerous, than people have thought.
The first thing to remember is that there is nothing new about the ability to perceive the thoughts, intentions, and feelings of other people. What a person says about what she wants or feels or needs is just one of the ways we have of telling what is playing out in her mind. To pick a humdrum example: Every time you walk or drive from one place to another, you rely on information about what the people around you see and what they intend to do. Indeed, the ability to make sense of the experience of others is one of our most basic capacities, one without which our distinct form of animal life would not be possible.
Moreover, there's nothing new about the ability to violate a person's privacy by observing them. Remarkably, we can violate a person's privacy by close observation. We can find out more about what she thinks and feels and wants than she may know herself.