EVOLUTION of sleep patterns as a primary component of sleep-wakefulness cycles has received much attention in recent years, from both phylogenetic1 and ontogenetic viewpoints.2 It has become clear that in the premature human infant there is a marked preponderance of "activated" sleep (rhombencephalic, or rapid eye movement [REM] sleep).3,4 This phase of sleep in the adult has been strongly associated with dreaming,5 and decreased REM sleep in the early postnatal period is associated with appearance of more finely graded sleep patterns which are thereafter separable into light, intermediate, deep, and dream phases.6
The role that such factors as somatic sensory influxes might play in maintenance of normal sleep patterns has not been extensively investigated. At a behavioral level, studied by Berger7 in our laboratory have indicated a relationship between conditioned eye movements in the waking state and the amount of eye movements in