THE FUNCTION OF FETAL NEONATAL RAPID EYE-MOVEMENT SLEEP

The hypothesis is put forward that rapid eye movement (REM) sleep in e arly life serves as (1) an indicator for the degree of brain maturatio n and (2) the promoter of further brain development. This hypothesis, although not exclusive, differs (a) from the theory of Roffwarg et al. that REM sleep substitutes for 'wakefulness' during the period (early life) in which wakefulness is limited, (b) from the theory of Crick a nd Mitchson, i.e., the 'unlearning' hypothesis of REM sleep, (c) from the theory of Jouvet, i.e., that REM sleep is a time for genetic read- out and (d) from the theory of Freud, i.e., that dreams fulfil our wis hes (in other words, activation of neuronal systems that were dispropo rtionally activated during wakefulness).