Abstract
The presentation of a remote - but not proximal – visual distractor concurrent with the onset of a visual target increases saccade 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 (SC). Notably, the SC serves as a sensorimotor interface supporting the uni- and multidimensional (i.e., visual and auditory) integration of task-relevant information. As such, an extension of the RDE is that the conflict related to saccade generation signals is sensory-independent and manifests via visual and/or auditory target/distractor spatial information. To address this issue, the present work employed experiments wherein a visual target was paired with an auditory distractor (proximal and remote) (Experiment 1), and when an auditory target was paired with a visual distractor (Experiment 2). Further, responses were directed to the veridical (i.e., prosaccade) and mirror-symmetrical (i.e., antisaccade) location of visual/auditory targets. The basis for including antisaccades was to determine whether the sensory- or motor-related properties of a distractor influence saccade planning. Experiment 1 showed that pro- and antisaccade distractor trials produced RTs that were longer than their no-distractor counterparts – a result independent of distractor location. Experiment 2 showed that prosaccades were refractory to our distractor manipulation, whereas proximal and remote distractors respectively shortened and iengthened antisaccade RTs. Thus, the RDE is a sensory-specific phenomenon relating to conflicting 'visual' signals within a common retinotopic motor map.Acknowledgments: Supported by NSERC.