The spatio-temporal modulation of saccades in a double-step paradigm.

Casteau, S.; Walker, R.

Abstract

Studies of saccades made in the double-step paradigm have shown that saccade landingposition is modulated by the time between target-step and saccade initiation. At short de-lays, first saccade land accurately on the second location, for long delays first saccades aredirected towards the first location; whereas at intermediate delays saccades land at an inter-mediate position (i.e. saccade averaging). This spatial averaging effect has been interpretedas the integration, during a “time-window”, of the spatial representations of the two targetlocations (Becker & J ̈urgens, 1979).Here the “time-window” hypothesis was investigated in relation to the assumption thatsaccade averaging reflects the distributed spatial coding in the purported collicular saliencymap. We hypothesized that for intermediate delays, landing position would be modulateddepending on target eccentricity and step-size.Target direction, spatial separation between target-steps and inter-stimulus interval (ISI)were manipulated. As expected, for intermediate ISI’s saccade averaging was observed, butonly for short spatial separations; for large separations saccades landed accurately on thetarget. These effects on landing position indicate that the computation of saccade amplitudedepends not only on the “time-window” but also on the spatial separation, suggesting thatthe spatial integration fields coding for target positions are modulated over-time.

Citation

Casteau, S., & Walker, R. (2015). The spatio-temporal modulation of saccades in a double-step paradigm. In U. Ansorge, T. Ditye, A. Florack, & H. Leder (Eds.),

• Conference Name: 18th European Conference on Eye Movements
• Conference Location: Vienna, Austria
• Start Date: Aug 16, 2015
• End Date: Aug 21, 2015
• Publication Date: 2015
• Deposit Date: Mar 9, 2017
• Volume: 8
• Series Title: Journal of Eye Movement Research
• Series ISSN: 1995-8692
• Edition: 4
• Public URL: https://durham-repository.worktribe.com/output/1676210
• Related Public URLs: https://doi.org/10.16910/jemr.8.4.1