IOVS Genetics
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 HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ramat, S.
Right arrow Articles by Leigh, R. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ramat, S.
Right arrow Articles by Leigh, R. J.
(Investigative Ophthalmology and Visual Science. 1999;40:1681-1686.)
© 1999 by The Association for Research in Vision and Ophthalmology, Inc.

Conjugate Ocular Oscillations during Shifts of the Direction and Depth of Visual Fixation

Stefano Ramat1, Jeffrey T. Somers2,3, Vallabh E. Das2,3 and R. John Leigh2,3,4

1 From the Dipartimento di Informatica e Sistemistica, University of Pavia, Italy and the Departments of 2 Neurology, 3 Biomedical Engineering, and 4 Neuroscience, Department of Veterans Affairs Medical Center and University Hospitals, Case Western Reserve University, Cleveland, Ohio.

PURPOSE. To characterize dynamic properties of combined saccade–vergence eye movements that occur as the point of visual fixation is shifted between objects lying in different directions and at different depths.

METHODS. Using the scleral search-coil technique, eye movements were measured in 10 normal subjects as they made voluntary, disjunctive gaze shifts comprising a range of saccades and vergence movements.

RESULTS. By analyzing eye acceleration records, the authors identified small-amplitude (0.2–0.7°), high-frequency (23–33 Hz), conjugate horizontal oscillations of the eyes during the vergence movement that followed the initial saccade. When the shift of the fixation point required a large vergence component (17°), every subject showed these oscillations; they were present in approximately a third of responses. Approximately 5% of responses showed oscillations that had horizontal and vertical components. Oscillations were less prominent with shifts that had smaller vergence components and were absent after saccades made between targets located at optical infinity.

CONCLUSIONS. These findings suggest that a common mechanism gates both the saccadic and vergence components of disjunctive gaze shifts, a likely candidate being the pontine omnipause neurons. When a saccade is immediately followed by a prolonged vergence movement, the omnipause neurons remain silent, leading to small-amplitude saccadic oscillations. Shifts in the point of visual fixation that require a large vergence movement may be a useful experimental strategy to induce saccadic oscillations.




This article has been cited by other articles:


Home page
 NeurologyHome page
A. Serra, K. Liao, M. Matta, and R. J. Leigh
Diagnosing disconjugate eye movements: Phase-plane analysis of horizontal saccades
Neurology, October 7, 2008; 71(15): 1167 - 1175.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. R. Van Horn and K. E. Cullen
Dynamic Coding of Vertical Facilitated Vergence by Premotor Saccadic Burst Neurons
J Neurophysiol, October 1, 2008; 100(4): 1967 - 1982.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. R. Van Horn, P. A. Sylvestre, and K. E. Cullen
The Brain Stem Saccadic Burst Generator Encodes Gaze in Three-Dimensional Space
J Neurophysiol, May 1, 2008; 99(5): 2602 - 2616.
[Abstract] [Full Text] [PDF]

Home page
 IOVSHome page
M. Vernet, Q. Yang, G. Daunys, C. Orssaud, T. Eggert, and Z. Kapoula
How the Brain Obeys Hering's Law: A TMS Study of the Posterior Parietal Cortex
Invest. Ophthalmol. Vis. Sci., January 1, 2008; 49(1): 230 - 237.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
A. N. Kumar, Y. Han, L. F. Dell'osso, D. M. Durand, and R. J. Leigh
Directional Asymmetry During Combined Saccade-Vergence Movements
J Neurophysiol, May 1, 2005; 93(5): 2797 - 2808.
[Abstract] [Full Text] [PDF]

Home page
 NeurologyHome page
J. C. Rucker, B. E. Shapiro, Y. H. Han, A. N. Kumar, S. Garbutt, E. L. Keller, and R. J. Leigh
Neuro-ophthalmology of late-onset Tay-Sachs disease (LOTS)
Neurology, November 23, 2004; 63(10): 1918 - 1926.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
C. Busettini and L. E. Mays
Pontine Omnipause Activity During Conjugate and Disconjugate Eye Movements in Macaques
J Neurophysiol, December 1, 2003; 90(6): 3838 - 3853.
[Abstract] [Full Text] [PDF]

Home page
 IOVSHome page
S. Garbutt, Y. Han, A. N. Kumar, M. Harwood, C. M. Harris, and R. J. Leigh
Vertical Optokinetic Nystagmus and Saccades in Normal Human Subjects
Invest. Ophthalmol. Vis. Sci., September 1, 2003; 44(9): 3833 - 3841.
[Abstract] [Full Text] [PDF]

Home page
 IOVSHome page
A. N. Kumar, Y. Han, S. Garbutt, and R. J. Leigh
Properties of Anticipatory Vergence Responses
Invest. Ophthalmol. Vis. Sci., August 1, 2002; 43(8): 2626 - 2632.
[Abstract] [Full Text] [PDF]

Home page
 NeurologyHome page
R. Bhidayasiri, D.E. Riley, J.T. Somers, A.J. Lerner, J.A. Buttner-Ennever, and R.J. Leigh
Pathophysiology of slow vertical saccades in progressive supranuclear palsy
Neurology, December 11, 2001; 57(11): 2070 - 2077.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1999 by the Association for Research in Vision and Ophthalmology