PERSEVERATIVE REACHING IN INFANCY - THE ROLES OF HIDDEN TOYS AND MOTOR HISTORY IN THE AB TASK

Two experiments tested the roles of hidden toys and motor history in t he AB task with 10-month-old infants. In Experiment 1 (N=24), infants were tested in lid and toy versions of the task, each comprised of A a nd B trials. No toys were ever hidden in the lid condition. On all A t rials, an experimenter directed infants' attention to one of two lids (the A lid) and allowed infants to reach following a 5-s delay. On B t rials in the lid condition, the experimenter directed infants' attenti on to the other, B lid On B trials in the toy condition, the experimen ter directed infants' attention to a toy that was then hidden undernea th the B lid. Following a 5-s delay, infants reached perseveratively t o A-producing the AB error-in the lid condition (replicating Smith, Mc Lin, Titter, & Thelen, 1995), but not in the toy condition. In Experim ent 2(N=24), infants were tested in similar lid and toy versions of th e task, except that on all A trials the experimenter directed attentio n to a toy that was then hidden underneath the A lid. Infants produced AB errors across lid and toy conditions. Contrary to Smith ct al.'s ( 1995) claims, these findings indicate that infants distinguish hidden toys From lids alone in the AB task. The presence of hidden toys on A trials and on B trials, not simply infants' motor history, influences production of the AB error.