[Nightmares and behavior during REM sleep].

This study reports the current neurobiologic data on REM sleep including psychoanalysis, distinguishing between the "instincts of pleasure" and the "instincts of death" (Beyond the principles of pleasure, S. Freud, 1920). The award and punishment systems are also reported and current data related to nightmares and mainly dream behavior during REM sleep without atonia are presented underlining the frequency of parasomnia in ponto-cerebellous atrophy and Parkinson's disease. The author emphasizes the need for establishing discussions among the different neuroscientific fields related to these questions.