Statistical Learning of Distractor Suppression

The cognitive system has a remarkable capacity to extract and make good use of statistical information (statistical learning, SL), including for attentional guidance. In the attention domain, most SL studies so far explored the influence on performance of manipulating probability of target occurrence at various spatial locations. However, an emerging literature is starting to address changes in the efficiency of distractor suppression triggered by the unequal spatial distribution of distracting stimuli. Here we systematically assessed the latter form of learning. Our main focus here was to look for any interaction (cross-talk) between distractor suppression and target selection mechanisms; specifically, we wished to ask whether any changes in performance reflecting SL of distractor suppression would transfer to the efficiency of target selection across locations. In a series of experiments, participants had to report the pointing direction of an arrow target while ignoring a task-irrelevant salient distractor, when present (50%). While target probability was equal across locations, the distractor was more likely to appear at one particular display location and less at another location (and intermediate at two further locations). The results showed greater interference (capture) when the distractor was presented at the low probability location compared to any other location. Moreover, we demonstrated that this effect could not be explained in terms of inter-trial effects (e.g., repeated distractor location across consecutive trials). Importantly, although the target occurred equally often at all locations, the efficiency of target selection differed across locations, with faster responses for targets at the location with rare distractors. These results confirm that SL can modulate distractor suppression mechanisms. Furthermore, our findings indicate some degree of interdependence between distractor suppression and target selection processes, suggesting at least partly shared underlying mechanisms. The results will be discussed in relation to the notion of spatial priority maps. Meeting abstract presented at VSS 2017