The Transition to Reaching: Mapping Intention and Intrinsic Dynamics

• DOI: 10.1111/j.1467-8624.1993.tb04188.x
• Publication Date: 2006-07-03T23:38:50Z
• Authors: Esther Thelen; Daniela Corbetta; Kathi Kamm; John P. Spencer; Klaus Schneider; Ronald F. Zernicke
• Keywords: Coactivation; Dynamics

The onset of directed reaching demarks the emergence a qualitatively new skill. In this study we asked how intentional arises from infants' ongoing, intrinsic movement dynamics, and first reaches become successively adapted to task. We observed 4 infants weekly in standard task identified week arm-extended reach, 2 weeks before after onset. reached at ages ranging 12 22 weeks, they used different strategies get toy. infants, whose spontaneous movements were large vigorous, damped down their fast, forceful movements. quieter generated faster more energetic lift arms. modulated task-appropriate ways following Reaching emerges when can intentionally adjust force compliance arm, often using muscle coactivation. These results suggest that infant central nervous system does not contain programs detail hand trajectory, joint coordination, activation patterns. Rather, these patterns are consequences natural dynamics active exploration match between those