Hand and joint paths during reaching movements with and without vision.

摘要: This study examines whether the kinematics of pointing movements are altered by sensory systems used to select spatial targets and guide movement. Hand joint paths visually guided reaching human subjects were compared with two non-visual conditions where only proprioception was available: (1) same blindfolds, (2) congenitally blind subjects. While hand-path curvatures overall quite small, sighted wearing a blindfold showed statistical increase in curvature their movements. Blindfolded also greater than These increases for blindfolded did not always lead decrease joint-path curvature. there differences between using vision some movement directions, no systematic difference these groups. The magnitude much variation across directions. We found be correlated factors, one geometrical. For all subject groups, tended smaller sagittal-plane transverse or diagonal As well, we that related relative motion at each joint. Joint-path when predominantly involved changes shoulder angle minimal elbow motion. consistently small hand trajectory emphasize powerful tendency motor system generate goal-directed relatively straight trajectories, even deprived visual feedback from very early life.