Effects of Exogenous and Endogenous Distracters on Immediate and Long-Term Recall in Toddlers

We explored the role that exogenous and endogenous competitors for attention play in infants' abilities to encode and retain information over a 6-month period. Sixty-six children visited the laboratory at 15 months, and 32 returned for a second visit at 21 months. Children observed models of conventional- relation and enabling-relation action sequences. Half the children were distracted by a "Mister Monkey" mechanical toy during the conventional-relation sequence, while the other half was distracted during the enabling-relation sequence. The Early Childhood Behavior Questionnaire indexed endogenous factors at both ages. Immediate postmodel production of target actions indexed encoding efficiency, and 6-month production of target actions indexed long-term recall. The exogenous distracter impacted encoding efficiency (i.e., immediate recall), but not long-term recall. Endogenous factors (i.e., temperament) were primarily associated with long-term recall. Of special interest was our finding that endogenous factors, especially surgency, moderated the effect of the exogenous distracter. It appears that when learning conventional-relation sequences in the presence of exogenous distracters, surgency mobilizes attentional resources toward the learning objective; however, when learning enabling-relation sequences under the same conditions, surgency either boosts the saliency of the distracters or boosts children's susceptibility to them.