"These findings further highlight the importance of sleep in our educational populations, where the need for learning is great, yet late bedtimes and early school start times prevent adequate sleep amounts," Mander said.
On average, adults spend one-third of their lives sleeping. Yet, no scientific consensus has been reached on why humans need sleep, Walker said. Previous research led by Walker has shown that a good night's rest helps us regulate our moods and cope with emotional challenges, while sleep deprivation can make otherwise reasonable people emotionally shaky, indicating a strong correlation between sleep loss and psychiatric disorders.
For this latest study, Walker and his team took 44 healthy young adults and subjected them to a rigorous memorizing task intended to tax the hippocampus. All participants performed at similar levels. The group was then divided, with one half taking a 90-minute nap while the other half stayed awake.
That evening, the entire group was subjected to another round of learning. The ability to memorize new information deteriorated for those who had remained awake throughout the day. In contrast, those who had napped not only performed better than the waking group, but actually improved their capability for learning, as if sleep had refreshed their memory capacity, the study found.
Electroencephalogram tests, which measured electrical activity in the brains of the nappers, showed that the more sleep spindles the nappers produced, the more refreshed they were for learning. Furthermore, researchers were able to link sleep spindles to brain activity looping between the lobes of the brain that house the hippocampus and prefrontal cortex two critical areas for memory.
"Our findings demonstr
|Contact: Yasmin Anwar|
University of California - Berkeley