Infant arousal in an en-face exchange with a new partner: effects of prematurity and perinatal biological risk.

Very low birth weight (VLBW) infants of higher (n = 18) and lower (n = 29) perinatal biological risk were contrasted at 4 months adjusted age with healthy full-term infants (n = 32) in their arousal during a standardized peekaboo game with an examiner. VLBW infants showed less positive arousal, more negative arousal, and 3 mixtures of behavioral cues across the peekaboo game seldom seen for full-term infants-strong cues of both positive and negative arousal, strong cues of negative arousal alone, and no strong cues of either positive or negative arousal. Contrary to expectations, perinatal biological risk did not strongly predict variations in arousal within the VLBW group. Possible changes in how internal and external sources of arousal are integrated provide one explanation for the presence of strong relationships between perinatal biological risk and social responsiveness near term age and their disappearance by 4 months of age.