Similarity in the Response of Smooth Pursuit and Manual Tracking to a Change in the Direction of Target Motion

• Published in: Journal of neurophysiology Vol. 84; no. 3; pp. 1149 - 1156
• Main Authors: Engel, Kevin C, Anderson, John H, Soechting, John F
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01-09-2000
• Subjects: Analysis of Variance; Electrooculography; Fixation, Ocular - physiology; Hand - physiology; Humans; Linear Models; Motion; Pursuit, Smooth - physiology; Reaction Time - physiology; Saccades - physiology; Space life sciences
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.2000.84.3.1149

  1 Department of Neuroscience and
  2 Department of Otolaryngology, University of
Minnesota, Minneapolis, Minnesota 55455
Engel, Kevin C.,
John H. Anderson, and
John F. Soechting.
Similarity in the Response of Smooth Pursuit and Manual Tracking
to a Change in the Direction of Target Motion. J. Neurophysiol. 84: 1149-1156, 2000. Subjects were asked
to track, with their eyes or their hand, the movement of a target that
maintained a constant speed and made a single, abrupt change in
direction. The tracking speed and direction of motion after the step
change in target direction were compared for the eyes and the hand.
After removal of the saccades from the eye movement records, it was
found that in both cases, there was a slow rotation from the initial
direction to the new direction. For the eyes and the hand, it was found
that this change in direction of movement occurred at a similar rate that was proportional to the magnitude of the abrupt change in target
direction. This was further described by comparing the direction of
pursuit tracking with the response of a second-order system to a step
input. In addition, it was found that the speed of manual and pursuit
tracking was modulated in a similar manner, with a reduction in
tracking speed occurring before the change in tracking direction. This
reduction in speed following the change in the direction of target
motion was very similar for the hand and the eye, despite the large
difference in the inertias of the two systems. Taken together, these
data suggest that the neural mechanisms for smooth pursuit and manual
tracking have common functional elements and that musculoskeletal
dynamics do not appear to be a rate-limiting factor.