MIND-READERS are a step closer to divining the words we are thinking: they have eavesdropped on the brains of volunteers as they mentally rifled through their memories to retrieve words.
Michael Kahana at the University of Pennsylvania in Philadelphia and his colleagues recruited 46 volunteers with epilepsy who had already had electrodes implanted in their brains for treatment purposes. The electrodes allowed the researchers to measure the brain’s activity as the participants viewed lists of 15 to 20 words. A minute later, they were asked to recall the words aloud, in any order.
Subjects tended to recall words of similar…
