Development of prospective control of catching moving objects in preterm at-risk infants.

Healthy term infants and infants classified as neurologically at-risk because of low birthweight and preterm birth were tested longitudinally between 20 and 48 weeks on the ability to use visual information predictively. Reaching for an object moving at different speeds was assessed; the object was occluded from view by a screen during the last part of its approach. At each infant's first reaching session, gaze anticipated the reappearance of the moving toy; however, onset of reaching and prospective control of gaze and hand varied considerably between the normal and at-risk groups. In addition, some at-risk infants geared their actions not to the time but to the distance that the toy was from the catching place, causing problems with faster-moving toys. The two children who anticipated least well were the only two of the at-risk group who were later diagnosed as having cerebral palsy.