A nap lasting between 45-60 minutes produces a five-fold improvement in information retrieval from memory, according to a new study conducted at Saarland University, Germany.

The researchers focused on the role of the hippocampus, the part of the brain where memories are consolidated and transferred into long term memory storage.

“We examined a particular type of brain activity, known as ‘sleep spindles,’ that plays an important role in memory consolidation during sleep,” explained Sara Studte, a graduate biologist specialising in neuropsychology. A sleep spindle is a short burst of rapid oscillations in the electroencephalogram (EEG).

The greater the number of sleep spindles in a person’s brain, the better they will remember newly acquired information.

The control group of participants, whose members watched DVDs – while the other group slept – performed significantly worse than the nap group when it came to remembering information including 90 single words and 120 unrelated word pairs.

“The memory performance of the participants who had a power nap was just as good as it was before sleeping, that is, immediately after completing the learning phase,” said professor Axel Mecklinger, PhD.

In other news, the National Sleep Foundation in the US recently released updated recommended sleep time durations, suggesting adults aged 18 to 64 need to sleep for 7-9 hours a night.