How people learn while they are asleep

Sleep could be a time when people are learning, new research has suggested. Published in the Journal of Experimental Psychology: General, the study looked into an unconscious form of memory that little is currently known about.

Investigators at Michigan State University said this field may be distinct from more traditional memory systems.

Kimberly Fenn, Assistant Professor of Psychology at the institution - which has been educating students for more than 150 years - said: "There is substantial evidence that during sleep, your brain is processing information without your awareness and this ability may contribute to memory in a waking state."

According to the researchers, people derive varying effects from this sleep memory ability - with some individuals' memory improving significantly while little difference is experienced by others.

Ms Fenn noted the discovery could be the first step in investigating whether the construct is associated with outcomes such as classroom learning.

Dr Jacob Empson, a Chartered Psychologist from the University of Hull, commented: "It is 40 years since I published the results of an experiment which showed improved recall of complex material learned the day before when subjects were allowed REM (rapid eye movement) sleep compared to those who were denied REM sleep.

"It seemed that REM sleep was responsible for the improvement in memory after sleep noted by many experimentalists from the early years of the 20th century, including Ebbinghaus. This was known as the 'reminiscence effect'.

"The phenomenon was ignored for many years, but recently has enjoyed more attention. Dr Caroline Horton, at Leeds Met University, is one of the new wave of younger psychologists studying the effects of sleep on memory."