Cardiac reactivity and adaptive behavior.

The relationship between adaptive behavioral function and cardiac reactivity to auditory, somatosensory, and visual stimuli was evaluated using a heterogeneous population of developmentally disabled infants and young children. Stimuli of all sensory modalities resulted predominantly in a cardiac deceleration, and the magnitude of these responses varied systematically between subjects. A multiple regression analysis revealed that 60% of the variance in adaptive behavior, as measured by the Adaptive Behavior Scale for Infants and Early Childhood, could be accounted for by age and the cardiac responses. The factor with the greatest predictive weighting was cardiac reactivity to a vibrotactile stimulus, which showed a correlation of .65 with adaptive behavior scores.