Exploring conflict- and target-related movement of visual attention

Abstract

Intermixing trials of a visual search task with trials of a modified flanker task, the authors investigated whether the presentation of conflicting distractors at only one side (left or right) of a target stimulus triggers shifts of visual attention towards the contralateral side. Search time patterns provided evidence for lateral attention shifts only when participants performed the flanker task under an instruction assumed to widen the focus of attention, demonstrating that instruction-based control settings of an otherwise identical task can impact performance in an unrelated task. Contrasting conditions with response-related and response-unrelated distractors showed that shifting attention does not depend on response conflict and may be explained as stimulus-conflict-related withdrawal or target-related deployment of attention.

Keywords:

• Response conflict
• Visual attention
• Flanker task
• Visual search
• Cognitive control.

This research was funded by a grant from the German Research Foundation (Deutsche Forschungsgemeinschaft) [grant number WE 4105/1-1] to Mike Wendt.

Notes

1 The probe task method applied by Wendt et al. (2012) deviates from previous investigations of conflict adjustment in that conflict adjustment is not inferred from sequential modulation or ratio modulation of the congruency effect. This has the advantage of ruling out alternative nonattentional accounts based on confounds of the congruency level sequence and the sequence of specific stimulus and response features (e.g., Hommel, Proctor, & Vu, 2004) or of congruency level frequency and the frequency of specific stimulus and response features (e.g., Stürmer , Leuthold, Soetens, Schröter, & Sommer, 2002; Wendt & Luna-Rodriguez, 2009).

2 This discrepancy accords with other recently found dissociations of ratio and sequential modulations (e.g., Fernandez-Duque & Knight, 2008; Funes, Lupiáñez, & Humphreys, 2010; Iani, Rubichi, Gherri, & Nicoletti, 2009; Purmann, Badde, & Wendt, 2009). Together, these findings suggest that transient and sustained conflict adjustment are mediated by different mechanisms.

3 We thank two anonymous reviewers for drawing our attention to the possibilities of inhibition of return and, more generally, stimulus-conflict-related attention shifts.