“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.

Digital Devices Deprive Brain of Needed Downtime

...in an information-rich world, the wealth of information means a dearth of something else: a scarcity of whatever it is that information consumes... the attention of its recipients. Hence a wealth of information creates a poverty of attention...

Herbert Simon quoted by Chris Anderson. FREE: THE FUTURE OF A RADICAL PRICE.