Go Ahead and Hit Snooze: Sleep Can Nearly Double Recall
Getting plenty of sleep is associated with a sharp mind and active body.
And today, many researchers are zeroing in on the effects that a lack of sleep can have on the brain.
One area of study focuses on the negative effects poor sleep has on your memory. In fact, a number of reports have found that deep sleep helps transfer the short-term memories in your hippocampus to long-term memories in your pre-frontal cortex. At the same time, a lack of sleep can hinder this process.
Sleep Your Way to a Better Memory
Now, we’re learning that sleep may also help you recall facts you might not remember when you’re awake. It may even make memories easier to access.
In the most recent analysis, researchers re-analyzed two previous studies showing how sleep positively influences memory.
In these studies, researchers asked participants to memorize words that were “made up.” They weren’t real words at all. The subjects were asked to recall the words immediately after learning them, and retested again after a period of sleep or wakefulness.
In particular, the new analysis looked at items remembered in the original test, but forgotten by the time retesting rolled around. Just as importantly, the researchers wanted to know about items not recalled right after the original testing, but suddenly remembered at retesting.
In both cases, sleep had a strong influence when it came to recalling information. To the study authors, this suggests that sleep promotes access to memories are initially too weak to be retrieved.
Nicholas Dumay, who was involved in the study, believes the memory boost comes from the hippocampus. That perhaps it “unzips and encodes” episodes and replays them to regions of the brain originally involved in their capture. This would lead the subject to effectively re-experience the major events of the day.
“Sleep almost doubles our chances of remembering previously unrecalled material,” notes Dumay. “The post-sleep boost in memory accessibility may indicate that some memories are sharpened overnight. This supports the notion that, while asleep, we actively rehearse information flagged as important.”
Sleep makes our memories more accessible, study shows. News Release. University of Exeter. July 2015.