IOVS The FASEB Journal
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Weir, C. R.
Right arrow Articles by Knox, P. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Weir, C. R.
Right arrow Articles by Knox, P. C.
(Investigative Ophthalmology and Visual Science. 2001;42:2297-2302.)
© 2001 by The Association for Research in Vision and Ophthalmology, Inc.

Modification of Smooth Pursuit Initiation by a Nonvisual, Afferent Feedback Signal

Clifford R. Weir1,2 and Paul C. Knox3

1 From the Vision Sciences, Glasgow Caledonian University, Scotland, United Kingdom; the 2 Tennent Institute of Ophthalmology, Gartnavel General Hospital, Glasgow, Scotland, United Kingdom; and the 3 Division of Orthoptics, University of Liverpool, United Kingdom.

PURPOSE. To investigate the role of extraocular muscle afferent signals in the initiation and early maintenance of smooth-pursuit eye movements.

METHODS. A suction scleral contact lens was used to impede the movements of the right eye while subjects tracked small targets in a step–ramp pursuit paradigm. Movements of the left eye were measured by infrared oculography. Pursuit latency, eye acceleration, and velocity were analyzed trial-by-trial and compared before, while, and after the right eye was impeded.

RESULTS. When the right eye was impeded, initial acceleration and eye velocity were reduced. Pursuit latency was unchanged. The velocity effect had a rapid onset and offset; there was no evidence that the effects built up over a number of trials. Detailed analysis suggested that the reduction in velocity occurred approximately 40 msec after pursuit was initiated.

CONCLUSIONS. These results are consistent with the hypothesis that extraocular muscle afferent signals provide a feedback signal of the movements of the eyes that may be used to modify the initiation and early maintenance of smooth pursuit on-line. It appears that for pursuit, as with saccades, the priority in these conditions is to maintain conjugacy.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2001 by the Association for Research in Vision and Ophthalmology