Why taking 40 winks will improve your learning (probably)
Does the prospect of taking quick a nap fill you with guilt at the thought of all the other, seemingly more pressing, productive things that you could be doing? Fear the afternoon nap no more, new research from UC Berkley suggests that the time spent napping outside of the REM phase of sleep may just improve your learning.
Researchers at the University College of Berkley, California, studied the non–REM phase of sleep in the learning process on a group of 44 volunteers, by subjecting them to rigorous tasks aimed at the hippocampus & memorisation. During the non-REM phase of sleep (where there is no rapid eye movement or REM), sharp spikes of electrical activity called sleep spindles were recorded from the hippocampal region. Normally, these spikes occur about a 1000 times per night, and are thought to be associated with the process of leaving the hippocampus free of short-term memory traces, helping further short-term memory at accumulation once we wake up. The study found, half of the subjects were allowed to have a 90 minutes nap in between two learning sessions in the afternoon and in the evening. These sleep spindles were noted in the above group, and they typically demonstrated better learning in the evening session, compared to the other half who were not allowed to sleep.
One of the important implications of the study is that non-REM sleep serves an important purpose than previously thought — recharging the brain for learning. Concomitantly performed electroencephalogram (EEG) studies mapping the brainwaves of the participants showed a correlation between the amount of sleep spindles and the quality of learning soon afterwards. These spikes where seen selectively in the hippocampus, also looping to the prefrontal cortex, the two parts of the brain that are thought to be the key areas involved in learning. Walker, the lead researcher of this study published in a recent edition of Current Biology, stated that sleep selectively restores critical learning functions of the brain. In their opinion, non-REM sleep deprivation typically seen in the older population may account for the reduced memorisation capacity during learning.
So the next time you feel like a quick 40 winks give yourself a break, it might just improve your performance.