Evidence for a functional role for active (REM) sleep in infancy.

Roffwarg et al. have proposed two complementary hypotheses to account for the finding that rapid eye movement (REM), or Active, Sleep occurs in large quantities in infancy and then drops off as the organism matures. The first assumes that the immature nervous system lacks inhibitory control and that the diminution of REM sleep reflects the maturation of the CNS. The second hypothesis postulates that REM sleep also serves a functional role, namely, to stimulate the central nervous system, thereby facilitating growth and maturation. A set of deductions, derived from the second hypothesis, was tested by analyzing the sleep-wake data of 22 normal infants. These were confirmed. The key findings were that the behavioral state of Quiet Alert correlated -0.82 with the state of Active Sleep and that this correlation was independent of maturational changes in the infants.