Self-Corrected Reaching in a Three-Location Delayed-Response Search Task

Infants watched an experimenter hide a toy in one of three wells and then attempted to retrieve it after a brief delay. Seven-month-olds performed at chance. Nine-month-olds reached correctly on 43% of trials, which is significantly better than chance. After an incorrect reach, infants were allowed to choose between the two remaining locations. Seven-month-olds responded at a chance level on their second reach, but 9-month-olds chose correctly more often than would be expected by chance despite a 10- to 20-s delay between hiding and search. One cause of error on the initial reach was a profound bias toward the center well. In Experiment 2, the wells were covered simultaneously, and the infant's spatial orientation was disrupted during the delay; this procedure eliminated the centripetal bias. Nine-month-olds still responded correctly more often than would be expected by chance on their second reach. These findings suggest that 9-month-olds sometimes have a more durable working memory for location than is generally reported for that age group.