Seeing and touching: the role of sensory-motor experience on the development of infant reaching.

Researchers agree that infants must learn from prior sensory-motor experiences to plan, perform, and fine-tune their actions to the environment. Yet, little is known about the actual influences of these experiences on the development of infants' perception and action. This study investigated how repeated experiences of seeing, reaching for, touching, grasping, and manipulating objects of same sizes and textures contributed to the refinement of subsequent object-oriented motor responses in 6-9-month old infants. In addition, to understand whether infants relied on vision, touch, or both to tailor their motor response to objects, we analyzed the reach-to-grasp sequences. Results show that the youngest infants did not benefit from the repeated experiences. Seemingly stereotypical motor responses appeared to interfere with the process of perceptual-motor mapping. The older infants relied more effectively on prior experience, on touch initially and then vision, to match their motor responses to objects. Consistent with a dynamic systems approach, we interpret the observed developmental progression as a change in tensions between perception and action.