Visual stimulation and wake-sleep behavior in human neonates.
Sixteen male and 16 female infants were exposed to 1 of 4 visual stimulus conditions during pre- and postprandial wakefulness. Whereas a nonpatterned gray stimulus minimized the amount of alert inactivity and maximized the amount of subsequent rapid eye movement (REM) sleep, black-and-white checkerboard patterned stimuli produced greater amounts of alert inactivity and correspondingly lesser amounts of subsequent REM sleep. Amounts of alert inactivity and of subsequent REM sleep produced by the checkerboard patterns depended upon pattern size, infant gender, and stimulus presentation strategy. Inversely correlated stimulus control of wakefulness and subsequent REM sleep was proposed as the functional basis of the inversely correlated ontogenesis of wakefulness and REM sleep.