Smooth pursuit tracking of an abrupt change in target direction: vector superposition of discrete responses

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.

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Development of smooth pursuit tracking in young infants

Vision Research ◽

10.1016/s0042-6989(96)00332-x ◽

1997 ◽

Vol 37 (13) ◽

pp. 1799-1810 ◽

Cited By ~ 119

Author(s):

Claes Von Hofsten ◽

Kerstin Rosander

Keyword(s):

Smooth Pursuit ◽

Young Infants ◽

Pursuit Tracking

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Real-time smooth pursuit tracking for a moving binocular robot

10.6028/nist.ir.4826 ◽

1992 ◽

Cited By ~ 7

Author(s):

David Coombs ◽

Christopher Brown

Keyword(s):

Real Time ◽

Smooth Pursuit ◽

Pursuit Tracking

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Reference frames for covert spatial attention during smooth pursuit tracking of visual targets

Journal of Vision ◽

10.1167/7.9.901 ◽

2010 ◽

Vol 7 (9) ◽

pp. 901-901

Author(s):

R. Niebergall ◽

J. C. Martinez-Trujillo

Keyword(s):

Spatial Attention ◽

Smooth Pursuit ◽

Reference Frames ◽

Pursuit Tracking ◽

Visual Targets

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Tracking Capacity Measured by Informational Statistics

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/1071181379023001141 ◽

1979 ◽

Vol 23 (1) ◽

pp. 568-572 ◽

Cited By ~ 1

Author(s):

Tarald O. Kvålseth

Keyword(s):

Information Rate ◽

Maximum Information ◽

Continuous Response ◽

Tracking Tasks ◽

Pursuit Tracking ◽

Discrete Band ◽

Continuous Responses ◽

Discrete Responses ◽

Band Limited ◽

Reference Input

Information-theory statistics were used as performance measures during selfpaced pursuit tracking tasks with a time-discrete band-limited white Gaussian noise reference input and both time-discrete and time-continuous response signals. The experimental results from 64 subjects showed that the generated information rate increased exponentially with increasing input variance or input entropy. The spacing between successive input points had no general significant effects on the information rate. Discrete responses produced significantly higher information rates than continuous responses. The maximum information capacity was determined to be centered at about 10 bits/sec with asymptotes at about 11 bits/sec for discrete responses and 9 bits/sec for continuous responses.

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