Gentle electrical zaps to the brain can accelerate learning and boost performance on a wide range of mental tasks, scientists have reported in recent years. But a new study suggests there may be a hidden price: Gains in one aspect of cognition may come with deficits in another.
Researchers who study transcranial electrical stimulation, which uses electrodes placed on the scalp, see it as a potentially promising way to enhance cognition in neurological patients, struggling students, and perhaps even ordinary people. Scientists have used it to speed up rehab in people whose speech or movement has been affected by a stroke, and DARPA has studied it as a way to accelerate learning in intelligence analysts or soldiers on the lookout for bad guys and bombs.
Until now, the papers coming out of this field have reported one good-news finding after another.
“This is the first paper to my knowledge to show a cost associated with the gains in cognitive function,” said neuropsychologist Rex Jung of the University of New Mexico, who was not associated with the study. “It’s a really nice demonstration.”