Westhieimers data is valid for untrained subjects tracking with the
reauirement of maintenance of high resolution ability i.e tracking without
overshoot or undershoot of fovea but this is not a valid value for more
normal requirements of tracking to determine direction for interception or
terminus information. Also quite small amounts of trianing make huge
diferences in the peak track speed because much of the limitation is caused
by natural reflex behaviour which abandons pursuit very early probably
because the information gained by high speed smooth pursuit is rarely of
much use. The eye tends to assess a trajectory and saccade to the terminus
rather than pursue the entire trajectory. This early abandonment is easily
overcome with training. It should be noted though that the eyes natural
response to tracking trajectory is more accurate and effecient in terminus
location than high speed pursuit as high pseed pursuit virtually eliminates
stereo information cues.
Scott Strachan
----- Original Message -----
From: "J. W. Senders & A.C-Harris" <[log in to unmask]>
To: <[log in to unmask]>
Sent: 08 November 2000 15:27
Subject: Re: smooth pursuit velocity thresholds
> Steve Rogers,
>
> I suggest you start with
>
> Westheimer, G.H., "Eye Movement Responses to a Horizontally Moving
> Stimulus" Archives of Ophthalmology, 1954, 52, p 932
>
> I believe that Westheimer's data show that 30 degrees per second is
> about the maximum. An SCI search on this Westheimer paper should
> reveal everything done since.
>
> John Senders
>
> >Can anybody direct me to research/papers that has tested for the
> >maximum velocity that the eye can track a moving target (i.e. is
> >there a velocity threshold where smooth persuit movements fail to
> >keep up with a moving target?).
> >
> >Many thanks and best regards
> >
> >Steve Rogers
>
>
>
>
> J.W. Senders, Professor Emeritus
> Faculty of Applied Science
> University of Toronto
> 295 Indian Rd.
> Toronto, Ont
> M6R 2X5 Canada
>
> TEL: 416 769 5071
> FAX: 416 769 6155
> email [log in to unmask]
>
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