Infants' visual preferences in the presence and absence of auditory stimulation.

Two experiments were conducted to explore the hypothesis that altering rate of change of an auditory stimulus will affect infants' fixation of changing visual stimuli. Experiment 1 revealed that average percent time that infants preferred looking at the less stimulating of two meaningless visual displays was highest under conditions of auditory stimulation. Experiment 2 demonstrated a significant inverse linear relation between rate of change of loudness in auditory stimulation and attentiveness to rapidly changing visual stimulation, due largely to decreased looking at the most stimulating display under conditions of auditory stimulation. In addition, the heart rates of a significant number of subjects were found to be accelerated in the presence of auditory stimulation. The results are interpreted as indicating that this type of sensory interaction is mediated, at least in part, by a subject's level of arousal.