August 24, 2010
Digital Devices Deprive Brain of Needed Downtime
It’s 1 p.m. on a Thursday and Dianne Bates, 40, juggles three screens. She listens to a few songs on her iPod, then taps out a quick e-mail on her iPhone and turns her attention to the high-definition television.
Just another day at the gym.
As Ms. Bates multitasks, she is also churning her legs in fast loops on an elliptical machine in a downtown fitness center. She is in good company. In gyms and elsewhere, people use phones and other electronic devices to get work done — and as a reliable antidote to boredom.
Cellphones, which in the last few years have become full-fledged computers with high-speed Internet connections, let people relieve the tedium of exercising, the grocery store line, stoplights or lulls in the dinner conversation.
The technology makes the tiniest windows of time entertaining, and potentially productive. But scientists point to an unanticipated side effect: when people keep their brains busy with digital input, they are forfeiting downtime that could allow them to better learn and remember information, or come up with new ideas.
At the University of California, San Francisco, scientists have found that when rats have a new experience, like exploring an unfamiliar area, their brains show new patterns of activity. But only when the rats take a break from their exploration do they process those patterns in a way that seems to create a persistent memory of the experience.
The researchers suspect that the findings also apply to how humans learn.
“Almost certainly, downtime lets the brain go over experiences it’s had, solidify them and turn them into permanent long-term memories,” said Loren Frank, assistant professor in the department of physiology at the university, where he specializes in learning and memory. He said he believed that when the brain was constantly stimulated, “you prevent this learning process.”
At the University of Michigan, a study found that people learned significantly better after a walk in nature than after a walk in a dense urban environment, suggesting that processing a barrage of information leaves people fatigued.
Even though people feel entertained, even relaxed, when they multitask while exercising, or pass a moment at the bus stop by catching a quick video clip, they might be taxing their brains, scientists say.
“People think they’re refreshing themselves, but they’re fatiguing themselves,” said Marc Berman, a University of Michigan neuroscientist.