Brain Imaging Assumes Greater Power, Precision

New machines and approaches are offering neuroscientists unprecedented access to the working human brain By Douglas Steinberg

Photo: Neil Michel/Axiom Sylvia

WIRED FOR AN IMAGE: Research associate Valerie Clark gets her brain waves recorded by Ron Mangun, a psychology professor at the University of California, Davis.

Mind-reading, that staple of science fiction, is inching closer to science fact, thanks to steady progress in the field of brain imaging. In the last few years, neuroimagers have established a new technology while fine-tuning an older one. They are now building more powerful machines and beginning to make headway against their ultimate challenge--determining the order in which brain regions become activated as a person thinks, moves, senses, and learns. Until now, brain scans have been subject to the neural equivalent of physics' Heisenberg uncertainty principle: They could detect the areas or the timing of neural activation, but not both.

"It's a really...