The Benefits of Power Napping

May 18, 2010 by  
Filed under Health

sleeping

I often rail against unnecessary research, but I confess to a sneaking liking for researchers from the University of California, Berkeley, who have just found that people who take naps during the day are helping to improve their overall brain function.

See, I knew there was a good reason the cats and I closed our eyes after lunch though not for the time frame the researchers were using. Apparently the healthy adults they evaluated in their study were allowed a nap for an hour and a half during the day and then given a cognitive exam.

This was based on a “hard learning” morning task for which all participants performed roughly the same but the difference came later. Half the group then took a nap while the others stayed awake and following the nap everyone repeated the exam. This time, the group that napped performed better than the group that stayed awake – how good is that for when you next have to justify closing your eyes for an hour or so?

Scientists, bless them, have long been trying to discover whether or not mid-day naps are beneficial – presumably without trying them out personally. What the California research seems to suggest is that naps help us process short-term memories into long-term ones, clearing the temporary storage portion of the brain so that new information can take its place. They looked at the subjects’ brain electrical activity and found that the nappers were in a sleep phase somewhere between deep sleep and dreaming sleep. During this time, temporary memories move from the hippocampus to the pre-frontal cortex.

Dr. Matthew Walker, lead author of the study, has a very 21st century way of explaining it as like your e-mail inbox becoming full. Until we sleep, or take a nap, all the new information received since the last sleeping period remains in hippocampus. Once it is full, no new information can be readily processed, inhibiting us from fully functioning throughout the entire day.

There was a dissenter to the new findings, however in Professor Derk-Jan Dijk. He is the Director of the Surrey Sleep Research Centre in the U.K. and doesn’t see that there is necessarily a clear advantage to sleeping more than once in a 24-hour period. He explained that, outside of the lab in the real world, it is difficult to assess whether or not taking a mid-day nap provides the type of cognitive benefit observed in the laboratory. It may simply help someone who was tired to have more post-nap energy and brain functionality.

Not sure how old Professor Dijk is, but I can promise him that a refreshing afternoon nap definitely gets more attractive as you get older!