Niigata University of Health and Welfare 1 article published in JoVE Behavior Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task Barbara Sargent1, Hendrik Reimann2, Masayoshi Kubo3, Linda Fetters1 1Division of Biokinesiology & Physical Therapy at the Herman Ostrow School of Dentistry, University of Southern California, 2Department of Kinesiology, Temple University, 3Department of Physical Therapy, Niigata University of Health and Welfare A method is described in which 3-4 month old infants learn a task by discovery and their leg movements are captured to quantify the learning process.