Woongjin Seo^1,2, George R. Mangun^1,2, Joy J. Geng^1,2; ¹University of California, Davis, ²Center for Mind and Brain, University of California, Davis

Cuing and implicit learning of likely distractor locations have both been used to study distractor suppression in visual search, but some evidence suggests that the underlying mechanisms differ. We directly compared these two methods during singleton-search mode using eye tracking to assess how suppression operates in each case. In separate studies, the salient distractor location was either pre-cued on every trial, or uncued in a statistical-learning paradigm in which the distractor appeared more often at a single high-probability location (HPL). Manual RTs were faster when distractors appeared in the expected location (cued: 1.06s vs. 1.09s; learned: 1.18s vs. 1.25s both p<.01). However, the proportion of first saccades to the singleton-distractor was significantly higher than non-singleton-distractors, suggesting a lack of suppression (cue: 25.9% vs. 5.5%, p<.001; learning: 16.9% vs. 6.0%, p=.025). Yet, for both cued and learned conditions, the proportion of looking to the singleton distractor was lower for the valid/HPL than the invalid/LPL conditions, (Valid: 25.9% vs. Invalid: 31.7%, p < .05; HPL: 16.9 % vs. LPL: 38.6%, p < 0.001), showing reduced capture when the salient distractor appeared in the expected location, although the effect was larger in the learned case (p < .05). Interestingly, the reduction in capture in all conditions was accompanied by looking-away. In both experiments, there were significantly more looks to the location opposite the cued/HPL location compared to all other locations; the other locations did not differ from each other (Cue-to look-distance 1–4: 9.2%, 10%, 13.9%, and 33.9% p < .001; HPL-to-look-distance 1–4: 11.5%, 11.1%, 13.0%, and 28.8%, p < .001). In conclusion, while neither cue-based nor learning-based distractor control provided strong evidence for spatial suppression below the nonsalient-distractor baseline, they both produced a similar look-away gaze strategy to avoid capture by the salient distractor.