AbstractThe location of a distractor influences oculomotor planning times. In particular, a remote – but not proximal – distractor presented concurrent with target onset increases prosaccade reaction time (RT) (i.e., the remote distractor effect: RDE). The competitive integration model asserts that the RDE reflects the time needed to resolve conflict between target- and distractor-related saccade generating commands in the superior colliculus. To our knowledge however, no previous research has examined whether the RDE manifests for multimodal target and distractor combinations. To that end, we included two experiments wherein a visual (N=10) and an acoustic (N=9) target was presented with different modality (i.e., acoustic or visual) remote and proximal distractors. Further, pro- and antisaccades were used to determine if top-down demands in saccade generation influence RT. Results for the visual target/acoustic distractor experiment showed that pro- and antisaccade RTs for proximal and distal distractors were shorter than their no-distractor counterparts; that is, results did not elicit a RDE. In turn, results from the acoustic target/visual distractor experiment showed that prosaccade RTs for distractor and no-distractor conditions did not reliably differ, whereas antisaccade RTs for proximal and distal distractors were respectively shorter and longer than their no-distractor counterparts. These results suggest that the modality of the target and distractor influence expression of the RDE, and that such an effect is limited to a response requiring the top-down decoupling of stimulus-response spatial relations.
Acknowledgments: Supported by NSERC.