Researchers headed by Professor Axel Mecklinger have shown that a short nap lasting about an hour can significantly improve memory performance. The study involved examination of memory recall in 41 participants.
The volunteers had to learn single words and word pairs. Once the learning phase was over, the participants were tested to determine how much information they could remember. About half of the participants were then allowed to sleep, while the others watched a DVD. After that, the participants were re-tested and those who had taken a nap were shown to have retained substantially more word pairs in memory than the participants in the control group who had watched a DVD.
Generations of school students have gone to bed the night before a maths exam or a vocabulary test with their algebra book or vocabulary notes tucked under their pillow in the hope that the knowledge would somehow be magically transferred into their brains while they slept. That they were not completely taken in by a superstitious belief has now been demonstrated by a team of neuropsychologists at Saarland University, who have shown that even a brief sleep can significantly improve retention of learned material in memory.
Sara Studte, a graduate biologist specializing in neuropsychology, working with her PhD supervisor Axel Mecklinger and co-researcher Emma Bridger, is examining how power naps influence memory performance. The results are clear: ‘Even a short sleep lasting 45 to 60 minutes produces a five-fold improvement in information retrieval from memory,’ explains Axel Mecklinger.
Strictly speaking, memory performance did not improve in the nap group relative to the levels measured immediately after the learning phase, but they did remain constant. ‘The control group, whose members watched DVDs while the other group slept, performed significantly worse than the nap group when it came to remembering the 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, says Professor Mecklinger.