Cardiac and behavioral responsivity to tactile stimulation in premature and full-term infants.

Attempted to determine whether psychophysiological differences exist between prematurely born and full-term infants in their responsivity to tactile stimulation and in their ability to discriminate among different intensities of such stimulation. The performance of 20 full-term neonates in active sleep was compared with that of 20 premature infants of comparable conceptional age (average, 38.5 wks). Whereas the full-term Ss showed both behavioral responsiveness and heart rate acceleration to the stronger levels of stimulation, the premature Ss showed weaker behavioral responses and no significant cardiac response. Even on those trials where the premature infants did show strong behavioral response, their cardiac response was smaller than that of the full-term infants. A significant sex difference for premature Ss indicated that the lower behavioral responsiveness was due mainly to males. Issues raised were whether the lack of cardiac responsivity in the premature infant is secondary to his/her heightened level of autonomic arousal whether it reflects a lack of integration between motor and autonomic systems. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)