London, March 22 (IANS): Short naps during the day can boost memory performance by up to five times, a research says.

Even a short sleep lasting 45 to 60 minutes produces a five-fold improvement in information retrieval from memory, according to the study published in Neuropsychology.

A short nap at the office or in school is enough to significantly improve learning success.

"Wherever people are in a learning environment, we should think seriously about the positive effects of sleep," said professor and study supervisor Axel Mecklinger of Saarland University in Germany.

In the study, the control group watched DVDs and performed significantly worse than the nap group when it came to remembering certain word pairs such as milk-taxi.

"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," Mecklinger said.

The researchers were particularly focussed on the role of the hippocampus - a region of the brain in which memories are "consolidated", that is, previously learned information is transferred into long-term memory storage.

"We examined a particular type of brain activity, known as 'sleep spindles', which plays an important role in memory consolidation during sleep," said researcher Sara Studte.

A sleep spindle is a short burst of rapid oscillations in the electroencephalogram (EEG). The stronger a person's memory of something, the greater the number of sleep spindles appearing in the EEG.

"We suspect that certain types of memory content, particularly information that was previously tagged, is preferentially consolidated during this type of brain activity," added Mecklinger.

A concentrated period of learning followed by a short relaxing sleep is all that is needed to enhance information recall, the study said.