August 2010
Volume 10, Issue 7
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2010
Online and offline trajectories characterize the respective control of pro- and antisaccades
Author Affiliations
  • Matthew Heath
    Faculty of Health Sciences, University of Western, Ontario
  • Katie Dunham
    Faculty of Health Sciences, University of Western, Ontario
  • Lindsay Dryden
    Faculty of Science, University of Western, Ontario
Journal of Vision August 2010, Vol.10, 509. doi:10.1167/10.7.509
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Matthew Heath, Katie Dunham, Lindsay Dryden; Online and offline trajectories characterize the respective control of pro- and antisaccades. Journal of Vision 2010;10(7):509. doi: 10.1167/10.7.509.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

The antisaccade task entails decoupling the spatial relations between target and response and looking mirror-symmetrical to the location of a target. Extensive work documents that antisaccade reaction times are longer than prosaccades: a finding attributed to the top-down nature of inhibiting a stimulus-driven response. The present investigation sought to determine whether the top-down nature of antisaccading influences the extent to which saccade trajectories are modified online. Participants completed pro- and antisaccades to target stimuli that were visible (Experiment 1) or occluded (Experiment 2) throughout the response. To index trajectory modifications, we computed the proportion of variance (R2) explained by the spatial location of the eye at 10% increments of normalized movement time (i.e., 10%, 20%, … 80%, 90% of movement time) relative to the saccade's ultimate movement endpoint. The basis for this analysis is that robust R2 values indicate that the location of the eye at any point in the trajectory provides a strong prediction of the ultimate saccade endpoint – thus evidencing a primarily offline mode of control. In turn, modest R2 values indicate that the location of the eye does not reliably predict saccade endpoint - thus evidencing a more online mode of control. Results showed that endpoints for prosaccades were more accurate and less variable than antisaccades. What is more, prosaccades yielded lower R2 than antisaccades from 20% to 70% of movement time: a finding consistent across Experiments 1 and 2. That prosaccades were characterized by weak R2 values in combination with their accurate and stable endpoints suggests that stimulus-driven actions allow for online corrections to the saccade trajectory. In contrast, the robust R2 values and increased endpoint error and variability of antisaccades suggests that top-down decoupling of the spatial relations between target and response renders a primarily offline mode of control.

Heath, M. Dunham, K. Dryden, L. (2010). Online and offline trajectories characterize the respective control of pro- and antisaccades [Abstract]. Journal of Vision, 10(7):509, 509a, http://www.journalofvision.org/content/10/7/509, doi:10.1167/10.7.509. [CrossRef]
Footnotes
 Natural Sciences and Engineering Research Council of Canada.
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×