SLEEP FOR DEVELOPMENT OR DEVELOPMENT FOR WAKING - SOME SPECULATIONS FROM A HUMAN PERSPECTIVE

The issue of the relationship between sleep and development could be p osed in the following terms: (1) does sleep have a function for develo pment? and (2) which is the specificity of sleep function during devel opment? Is it possible to assess critical ages of emergence and declin e of specific sleep functions? The results of recent investigations re lated to the so-called ontogenetic hypothesis for the function of rapi d eye movement (REM) sleep will be reviewed; suggestions are put forwa rd concerning the possible role of non-rapid eye movement (NREM) sleep . Because of the difficulties to provoke long-lasting sleep deprivatio n in humans during development, two different approaches were used. Th e results of one set of analyses concerned the secretion of growth hor mone during sleep under normal and pathological conditions and the rel ationship between sleep organization and nutritional supply utilisatio n in infants and children. The second approach aimed at investigating the long-term development of children suffering from sleep abnormaliti es at earlier ages. Furthermore, the role of dreaming during developme nt will be discussed. The data summarized here only partly support the function of sleep during development; we would like to underscore the difficulty to dissociate the function of sleep from that of waking.