Dynamic coordination of body parts during prism adaptation

J Neurophysiol. 2002 Oct;88(4):1685-94. doi: 10.1152/jn.2002.88.4.1685.

Abstract

We studied coordination across body parts in throwing during adaptation to prisms. Human subjects threw balls at a target before, during, and after wearing laterally shifting prism eyeglasses. Positions of head, shoulders, arm, and ball were video-recorded continuously. We computed body angles of eyes-in-head, head-on-trunk, trunk-on-arm, and arm-on-ball. In each subject, the gaze-throw adjustment during adaptation was distributed across all sets of coupled body parts. The distribution of coupling changed unpredictably from throw to throw within a single session. The angular variation among coupled body parts was typically significantly larger than angular variation of on-target hits. Thus coupled body parts changed interdependently to account for the high accuracy of ball-on-target. Principal components and Monte Carlo analyses showed variability in body angles across throws with a wide range of variability/stereotypy across subjects. The data support a model of a dynamic and generalized solution as evidenced by the distribution of the gaze-throw adjustment across body parts.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptation, Physiological / physiology*
  • Adult
  • Biomechanical Phenomena
  • Eyeglasses
  • Female
  • Humans
  • Male
  • Motor Activity / physiology
  • Perceptual Distortion / physiology*
  • Psychomotor Performance / physiology*