Selection and memory of a lower limb motor-perceptual task in 3-month-old infants

The purpose of this study was to test infants' ability to learn and memorize a specific motor-perceptual task using a constraining reinforcement mobile protocol. Fifteen three-month-old infants received a mobile reinforcement for every correct movement they performed. The task was to cross 85 degrees of flexion with the right knee. Infants were tested over a series of three sessions, spaced 24 and 72 hr apart. Results indicated that infants increased the frequency of mobile jiggles by selecting a new and efficient motor solution: smaller movements around the required threshold. These data suggest infants modulated their preferred movement patterns in an economical way. The data also showed that infants memorized the task by the third session, indicating they can learn and retain a specific motor-perceptual task. This implies that infants at this age are sensitive to environmental information and to the consequences of their own posture and movements. (C) 2002 Elsevier Science Inc. All rights reserved.