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LOCAL PRISM ADAPTATION RESULTS IN A PARALLEL REORGANIZATION OF MOVEMENT PLANNING Philip N. Sabes Sloan Center for Theoretical Neurobiology, Salk Institute, La Jolla, CA 92037, U.S.A.
Understanding the relationship between posture and movement is of
central importance in uncovering how the central nervous system (CNS)
plans and executes intentional movement. We address this issue by
probing the sensorimotor transformations underlying visually guided
movement with local prism-like perturbations of the visual feedback.
Participants reached to visual targets with feedback constrained to
narrow regions about the target. Perturbing feedback in only one
region of space results in a local adaptation in the mapping from
target location to arm posture. After this reorganization,
corresponding changes were seen in the paths of movements passing
through the remapped portions of the workspace when no visual feedback
is available. These results support the view the CNS explicitly plans
aspects of the movement in the extrinsic (visual) space and that the
postural map (inverse kinematics) plays a fundamental role in movement
control. |