Saccadic inhibition and the remote distractor effect: One mechanism or two?

Abstract

It has been hotly debated whether a single mechanism underlies two established and highly robust oculomotor phenomena thought to index the competitive nature of eye movement plans: the remote distractor effect and saccadic inhibition (SI). It has been suggested that a transient mechanism underlying SI would not be able to account for the shift in the saccade latency distribution produced by early distractors (e.g., those appearing 60 ms before target onset) without additional assumptions or a more sustained source of inhibition. Here we tested this prediction with a model previously optimized to capture SI for late distractors. Where behavioral studies have intermingled stimulus onset asynchronies (SOAs) within the same block, the model captures the pattern of RDEs and SI effects with no parameter changes. Where SOAs have been blocked behaviorally, the pattern of RDEs can also be captured by the same model architecture, but requires changes to the inputs of the model between SOAs. Such changes plausibly reflect likely changes in participants' expectations and attentional strategy across block types.