We're learning when we're idling (as long as we studied hard before we took a rest)

When I was a college freshman I couldn't stay up all night, so I thought I was at a disadvantage to my fellow students who engaged in all-night cram sessions before an exam. I was puzzled as to why I scored higher than they did on the test. Now I know:

Studies: An Idle Brain May Be Ripe for Learning
By Anita Hamilton
Jan. 29, 2010
Time

Why is it so hard to remember even things we don't want to forget? The problem, suggests a growing body of research, may be that we're thinking about them too much in the first place.

Popular wisdom once held that a mind at rest was like an engine idling — not much going on under the hood. To glean insights into how the brain worked, scientists would study only volunteers in action, measuring their physiological or biochemical responses as they completed specific mental tasks. But more recently, thanks in large part to the proliferation of functional magnetic resonance imaging (fMRI), which precisely maps brain activity based on changes in blood-oxygen levels, neuroscientists have found that important activity in the brain — related in particular to memory and learning — may occur when it is at rest.

Many studies over the past decade have suggested that sleep is crucial to the consolidation of memories and learning; people who take a nap after learning a new task, for instance, remember it better than those who don't snooze. And now a small but compelling new study from the lab of New York University (NYU) cognitive neuroscientist Lila Davachi finds similar evidence that the brain at rest, even while remaining awake, is conducting meaningful activity. "Your brain is doing work for you even when you're resting," says Davachi, who just published a study in Neuron showing that certain kinds of brain activity actually increase during waking rest and are correlated with better memory consolidation. "Taking a rest may actually contribute to your success at work or school," she adds...

The purpose of the scans was to compare the relative levels of spontaneous neural activity in two key brain regions involved in memory — the hippocampus and visual cortex — during rest, both before and after the visual tasks... That suggests that the visual-learning tasks had affected the brain's seemingly random firings during rest, and perhaps that the brain was conducting memory-consolidating activity during that time...

The brain activity in those who were best at finding the hidden pattern onscreen was most strongly related...

While the NYU, Washington University and Harvard studies all used different approaches, their overall findings were remarkably similar. "The brain is trying to weave ideas together even when you don't think you are thinking of anything," notes Johns Hopkins behavioral neurologist and memory expert Dr. Barry Gordon. That's something to keep in mind the next time you catch yourself daydreaming in a meeting or idly surfing Facebook when you should be studying.