Journal of Neurophysiology, Vol 70, Issue 3 1137-1150, Copyright © 1993 by APS

ARTICLES

Parallel, interdependent channels for location and orientation in sensorimotor transformations for reaching and grasping

J. F. Soechting and M. Flanders
Department of Physiology, University of Minnesota, Minneapolis 55455.

1. Subjects were presented with a cylinder, whose orientation with respect to the vertical and location in space varied from trial to trial. They grasped a similar cylinder in their hands and were instructed to align the grasped cylinder with the target cylinder. In some experiments the task was performed from memory, and subjects attempted to reproduce both location and orientation of the cylinder. In others, they attempted to reproduce only its orientation, either from memory or while the cylinder was in view. 2. Multivariate linear regression analysis was used to determine persistent and variable errors in performance. This analysis related the subjects' performance (reproduced orientation) to target parameters (location and orientation). 3. We have interpreted the experimental results starting from the assumption that there are two parallel neural processes underlying reaching and grasping: one relating proximal arm motion to target location and the other relating distal hand motion to target orientation. 4. Variable errors did not vary with task conditions, even when subjects were asked to dissociate target orientation from target location by matching target orientation with the arm at the side, irrespective of the location of the target. This finding suggests that the neural transformations involving target location and target orientation are performed in parallel. 5. Persistent errors did vary with task condition. The subjects made the largest errors in matching target orientation when the target was in view, but they were asked to match its orientation at a location that differed from that of the target. These errors depended mostly on the elevation of the target and on its slant (inclination relative to the vertical). They were related to the posture of the arm in a manner that suggested that matching orientation is influenced by both extrinsic (spatial) and intrinsic (arm posture) parameters. 6. The fact that persistent errors depend on target location and on arm posture as well as on target orientation implies that the neural transformation from target orientation to hand orientation is not independent of the transformation dealing with target location.

This article has been cited by other articles:

				N. Gosselin-Kessiby, J. Messier, and J. F. Kalaska Evidence for Automatic On-Line Adjustments of Hand Orientation During Natural Reaching Movements to Stationary Targets J Neurophysiol, April 1, 2008; 99(4): 1653 - 1671. [Abstract] [Full Text] [PDF]

				E. Stark, I. Asher, and M. Abeles Encoding of Reach and Grasp by Single Neurons in Premotor Cortex Is Independent of Recording Site J Neurophysiol, May 1, 2007; 97(5): 3351 - 3364. [Abstract] [Full Text] [PDF]

				E. B. Torres and D. Zipser Simultaneous control of hand displacements and rotations in orientation-matching experiments J Appl Physiol, May 1, 2004; 96(5): 1978 - 1987. [Abstract] [Full Text] [PDF]

				D. C. Knill and D. Kersten Visuomotor Sensitivity to Visual Information About Surface Orientation J Neurophysiol, March 1, 2004; 91(3): 1350 - 1366. [Abstract] [Full Text] [PDF]

				J. J. Marotta, W. P. Medendorp, and J. D. Crawford Kinematic Rules for Upper and Lower Arm Contributions to Grasp Orientation J Neurophysiol, December 1, 2003; 90(6): 3816 - 3827. [Abstract] [Full Text] [PDF]

				G. F. Koshland, J. C. Galloway, and C. J. Nevoret-Bell Control of the Wrist in Three-Joint Arm Movements to Multiple Directions in the Horizontal Plane J Neurophysiol, May 1, 2000; 83(5): 3188 - 3195. [Abstract] [Full Text] [PDF]

				M. Santello, M. Flanders, and J. F. Soechting Postural Hand Synergies for Tool Use J. Neurosci., December 1, 1998; 18(23): 10105 - 10115. [Abstract] [Full Text] [PDF]

				M. Santello and J. F. Soechting Gradual Molding of the Hand to Object Contours J Neurophysiol, March 1, 1998; 79(3): 1307 - 1320. [Abstract] [Full Text] [PDF]