The antisaccade task: visual distractors elicit a location-independent planning 'cost'

Authors

Jesse C. DeSimone, School of Kinesiology, University of Western Ontario, London, ON, Canada.
Stefan Everling, Department of Physiology and Pharmacology, Department of Psychology, Robarts Research Institute, and Graduate Program in Neuroscience, University of Western Ontario, London, ON, Canada.
Matthew Heath, School of Kinesiology and Graduate Program in Neuroscience, University of Western Ontario, London, ON, Canada.

Document Type

Article

Publication Date

1-1-2015

Journal

PloS one

Volume

10

Issue

4

First Page

e0122345

URL with Digital Object Identifier

10.1371/journal.pone.0122345

Abstract

The presentation of a remote - but not proximal - distractor concurrent with target onset increases prosaccade reaction times (RT) (i.e., the remote distractor effect: RDE). The competitive integration model asserts that the RDE represents the time required to resolve the conflict for a common saccade threshold between target- and distractor-related saccade generating commands in the superior colliculus. To our knowledge however, no previous research has examined whether remote and proximal distractors differentially influence antisaccade RTs. This represents a notable question because antisaccades require decoupling of the spatial relations between stimulus and response (SR) and therefore provide a basis for determining whether the sensory- and/or motor-related features of a distractor influence response planning. Participants completed pro- and antisaccades in a target-only condition and conditions wherein the target was concurrently presented with a proximal or remote distractor. As expected, prosaccade RTs elicited a reliable RDE. In contrast, antisaccade RTs were increased independent of the distractor's spatial location and the magnitude of the effect was comparable across each distractor location. Thus, distractor-related antisaccade RT costs are not accounted for by a competitive integration between conflicting saccade generating commands. Instead, we propose that a visual distractor increases uncertainty related to the evocation of the response-selection rule necessary for decoupling SR relations.