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 the AB task with l&monthold infants. In Experiment 1 (N = 24), infants were tested in lid and toy versions of the task, each comprised of A and B trials. No toys were ever hidden in the lid condition. On all A trials, 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 trials in the lid condition, the experimenter directed infants’ attention to the other, B lid. On B trials in the toy condition, the experimenter directed infants’ attention to a toy that was then hidden underneath the B lid. Following a 5-s delay, infants reached perseveratively to A-producing the AB error-in the lid condition (replicating Smith, McLin, Titzer, & Thelen, 1995). but not in the toy condition. In Experiment 2 (N= 24), infants were tested in similar lid and toy versions of the task, except that on all A trials the experimenter directed attention to a toy that was then hidden underneath the A lid. Infants produced AB errors across lid and toy conditions. Contrary to Smith et al.% (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.