Vision and precision reaching in 15-month-old infants.

Visual information about the location of the hand in space plays a key role in many theories of the development of reaching. Empirical data casts doubt on this assumption, although vision of the hand is clearly used by adults. The current study investigated the role of vision in 15-month-olds' reaching, manipulating both the precision demands of the task and the level of visual information available. Infants reached for both large and small objects, presented with visual feedback of the target and hand (full lighting), or with visual feedback of only the target object (glowing object in the dark). In contrast to findings with younger infants, 15-month-olds' reaches were sensitive to changes in precision demands and visual feedback, reflecting corrective movements that become necessary as reaching tasks become more challenging. Furthermore, these kinematic alterations are similar to those seen in adults, suggesting that visual guidance may become more important over the course of development, as infants engage in increasingly higher precision tasks.