Although dreams often do not seem to make much sense, it appears that they are vital for the brain to process information gathered during the day. Many cultures have an expression for “sleeping on it”, and it appears that their may well be some truth in the saying. Research has shown that the brain does not need to “sleep on it ” to process simple memory tasks. However, it appears that the REM (rapid eye movement) phase of sleep is vital for decision-making and procedural learning, a type of learning that involves learning how to do new things, for example mastering a new instrument.
SOURCE/REFERENCE: Science 2001; 294:1052-1057