Experimental Brain Research

, Volume 103, Issue 2, pp 287–293

Effects of warning signals and fixation point offsets on the latencies of pro- versus antisaccades: implications for an interpretation of the gap effect

  • P. A. Reuter-Lorenz
  • H. M. Oonk
  • L. L. Barnes
  • H. C. Hughes
Original Paper

DOI: 10.1007/BF00231715

Cite this article as:
Reuter-Lorenz, P.A., Oonk, H.M., Barnes, L.L. et al. Exp Brain Res (1995) 103: 287. doi:10.1007/BF00231715

Abstract

The present study was designed to evaluate whether fixation point offsets have the same effects on the average latencies of prosaccades (responses towards target) and antisaccades (responses away from target). Gap and overlap conditions were run with and without an acoustic warning signal. The ‘gap effect’ was taken to be the difference in mean reaction time between gap and overlap trials. This effect was dramatically reduced by the presentation of the warning signal. Without this signal, fixation offsets can serve as warning signals themselves, which artifactually inflates the magnitude of the gap effect. The warning effect of fixation offsets was equivalent for pro and antisaccades. A significant gap effect is still evident with the acoustic warning signal; however, in this case it is associated primarily with prosaccades. These results replicate and extend our previous work demonstrating that, if their warning effects are controlled, the facilitatory effects of fixation point offsets are response dependent, and suggesting the existence of a component process (fixation release) which is closely linked with the processing architecture underlying target-directed saccades.

Key words

Gap effect Express saccades Oculomotor Human 

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • P. A. Reuter-Lorenz
    • 1
  • H. M. Oonk
    • 2
  • L. L. Barnes
    • 1
  • H. C. Hughes
    • 3
  1. 1.Department of PsychologyUniversity of MichiganAnn ArborUSA
  2. 2.Department of PsychologyUniversity of WashingtonSt. LouisUSA
  3. 3.Department of PsychologyDartmouth CollegeHanoverUSA

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