AUDITORY EVOKED RESPONSES OBTAINED FROM THE SCALP ELECTROENCEPHALOGRAM OF THE FULL-TERM HUMAN NEONATE DURING SLEEP

1. Two distinct stages of sleep were identified in sixteen newborn infants, 1½ hours to 15 days old, by behavioral observations and electroencephalographic, electromyographic, and rapid eye-movement recordings. 2. Evoked responses to an auditory stimulus were obtained from the scalp in all sixteen infants. The responses of eight were analyzed for differences during the two sleep stages by three-way analysis of variance. 3. The amplitudes and latencies of the response components are smaller during the active stage, characterized by a low-voltage EEG and rapid eye movements, than in the quiescent stage with a characteristic high-voltage EEG. 4. The results demonstrate that the nervous system of the human neonate can respond to a simple auditory signal with a complex pattern of electrical activity, and that the pattern of the response changes in amplitude and latency with changes in the states of sleep.