Reading the brain: Mind-goggling
It is now possible to scan someone’s brain and get a reasonable idea of what is going through his mind
IF YOU think the art of mind-reading is a conjuring trick, think again. Over the past few years, the ability to connect first monkeys and then men to machines in ways that allow brain signals to tell those machines what to do has improved by leaps and bounds. In the latest demonstration of this, just published in the Public Library of Science, Bin He and his colleagues at the University of Minnesota report that their volunteers can successfully fly a helicopter (admittedly a virtual one, on a computer screen) through a three-dimensional digital sky, merely by thinking about it. Signals from electrodes taped to the scalp of such pilots provide enough information for a computer to work out exactly what the pilot wants to do.
That is interesting and useful. Mind-reading of this sort will allow the disabled to lead more normal lives, and the able-bodied to extend their range of possibilities still further. But there is another kind of mind-reading, too: determining, by scanning the brain, what someone is actually thinking about. This sort of mind-reading is less advanced than the machine-controlling type, but it is coming, as three recently published papers make clear. One is an attempt to study dreaming. A second can reconstruct a moving image of what an observer is looking at. And a third can tell what someone is thinking about.
First, dreams. To study them, Martin Dresler, of the Max Planck Institute of Psychiatry, in Munich, and his colleagues recruited a group of what are known as lucid dreamers. They report their results in this week’s Current Biology.