The Influence of Attentional State and Stimulus Characteristics on Infant Distractibility

To examine the interactive effects of stimulus characteristics and attentional state on the allocation of attention in infancy, we presented distractor stimuli to 7-month-old infants while they explored novel objects, and we measured the infants' latencies to turn toward the distractors. Two different types of distractor stimuli (single-tone vs. alternating-tone) were used. For each stimulus presentation we determined whether the infant was engaged in focused or casual attention toward the novel object before the distractor was presented. As in previous studies, we found that distraction latencies were shorter during casual attention than during focused attention, but this effect was found to interact with the type of distractor stimulus. There was no effect of attentional state for the alternating-tone distractor, whereas there was an effect of attentional state for the single-tone distractor. Thus, external stimulus variables interact with an infant's internal attentional state to determine the moment-by-moment allocation of attention.