AROUSALS IN INFANTS

Polygraphic studies of stimulus-induced arousals from sleep in young i nfants have identified a highly consistent sequence of refer responses occurring during the 2-4 second period prior to full behavioral arous al. The initial responses in this sequence are an augmented breath (si gh) coupled with a sleep startle that is then followed by stereotyped ''thrashing'' motor activity. Partial arousals, identified by early co mponents of the sequence (a sigh or a sigh plus startle), were frequen tly elicited. Startles and thrashing activity were identified as havin g a significant external airway protective function during mild asphyx ia induced by covering the infants' nasal and oral airways.