Groups of 7 1/2-month-old infants heard 1 of 8 episodes consisting of no, slight, moderate, or large discrepancy between a habituated standard and a transformed auditory stimulus. Patterns of cardiac deceleration supported the hypothesis that attentiveness is an inverted-U function of the degree of discrepancy between stimulus event and schema.…

Examined the effect of heart rate and behavioral measures of attention on infants' distractibility. Found longer distraction latencies during attentional engagement as defined by heart rate changes or behavior than for inattentive periods. Infants had longest distraction latencies when heart rate and behavior measures both indicated engagement.…

Examined visual fixation in infants 6 months to 2 years old for fit with theory of attentional inertia. Found that fixations had lognormal distribution, heart rate decreased during a look, and heart rate returned to prestimulus levels immediately before look offset. Older children showed different looking patterns to two types of stimuli; younger…