Abstract
The present study aimed to clarify development of anticipatory heart rate deceleration in infants. ECGs were recorded during a mother played peek-a-boo game, using her face or a doll. Four babies from four to 8 months old were examined in Experiment 1, and one subject was recorded longitudinally from zero to 9 months old at one interval of one month (Experiment 2). HR acceleration to S1 was observed in infants for zero to 2 months old. HR deceleration after S2 occurred in infants for three to 5 months old. Anticipatory HR deceleration was observed in infants for six to 9 months old. The result indicated that developmental change of recognizing contingency of stimuli occurred in 6-7 months old infants, which was reflected in anticipatory HR deceleration to S1.
