REM Sleep and Visuo-Motor Skill Learning: A Correlational Study

S the paper published by Jenkins and Dallenbach in 1924 (1), a considerable number of studies have shown that sleep facilitates memory consolidation (reviews: [27]). Different paradigms have been applied to investigate the relationship between sleep and memory. First, the performances after equal periods of sleep versus wakefulness between acquisition and retrieval have been compared. The critical points are possible confounding effects of circadian rhythms and of sleep deprivation (comparing a normal night with a night awake), although some researchers used as additional groups persons who slept during the day (8-10) or delayed retesting after at least one recovery night to check on fatigue effects (11). Since the discovery of REM sleep (12), this paradigm has been developed by depriving sleep in the first part of the night and the second part of the night (13,14). Early sleep is dominated by slow wave sleep whereas late sleep by REM sleep, so differential effects of different sleep stages could be measured (15). Non-sleep related factors, low cortisol levels (16) and low acetylcholine levels (17) in the first part of the night have been shown to be important in early sleep-dependent declarative memory; demonstrating the importance of considering circadian effects. Another paradigm for studying the effects REM Sleep and Visuo-Motor Skill Learning: A Correlational Study