Experimental Brain Research

, Volume 61, Issue 2, pp 386–394

Motion of the eye immediately after a saccade

  • Z. A. Kapoula
  • D. A. Robinson
  • T. C. Hain
Article

DOI: 10.1007/BF00239527

Cite this article as:
Kapoula, Z.A., Robinson, D.A. & Hain, T.C. Exp Brain Res (1986) 61: 386. doi:10.1007/BF00239527

Summary

Dynamic overshoot is a small saccade that follows a main saccade, in the opposite direction, with no delay. To re-examine prior reports of dynamic overshoot, the properties of dynamic overshoot were studied in six normal subjects. The postsaccadic drift of eye movements was studied as well. Horizontal eye movements were recorded with the magnetic-field/search-coil method. System noise level was 0.05 deg. Dynamic overshoot occurred with a frequency of about 13% and was more frequent for saccades 10 deg or less. Its mean size was 0.15 deg and its peak velocity showed it to be saccadic in nature. Binocular recordings for three subjects showed that when dynamic overshoot occurred it was almost always in the abducting eye which also had the least post-saccadic drift. The adducting eye seldom had dynamic overshoot and consistently had a more pronounced post-saccadic drift, almost always in the onward direction. We suggest that, at the end of a saccade, the eye normally is brought to rest by a braking pulse and dynamic overshoot occurs when the braking pulse is accidentally too large. It would appear to serve no useful purpose. Why dynamic overshoot is monocular and coincides with the eye having less post-saccadic drift is unclear.

Key words

Eye movement Saccades Dynamic overshoot Post-saccadic drift Active braking pulse 

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Z. A. Kapoula
    • 1
  • D. A. Robinson
    • 1
  • T. C. Hain
    • 1
  1. 1.Departments of Ophthalmology and NeurologyThe Johns Hopkins University, School of MedicineBaltimoreUSA
  2. 2.Rm. 355, Woods Research Building, The Wilmer InstituteThe Johns Hopkins HospitalBaltimoreUSA

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