THE IMPORTANCE OF REM-SLEEP FOR BRAIN MATURATION

A number of studies, some done by us, are reviewed concerning the func tion of foetal/neonatal REM sleep. The hypothesis is put forward that REM sleep in early life serves as an indicator for: (1) the degree of brain maturation, and (2) the promotion of further brain development. This hypothesis, although not exclusive, differs from: the original th eory of Roffwarg et al. (1966) that REM sleep serves as ''wakefulness' ' during the period in which wakefulness is limited; and also from the theory of Crick and Mitchson (1983-the ''unlearning'' hypothesis of R EM sleep). As the functions of sleep in general, and REM sleep in part icular, are still unclear, we hope this review will suggest new possib ilities for future research.