Abstract
Humans are capable of extracting and learning spatial regularities in their visual environment and use these regularities to direct behavior. Studies investigating visual statistical learning (VSL) have shown that observers can learn to ignore a distractor more efficiently when it is presented more frequently at one specific location. To account for this, it has been proposed that through statistical learning a frequent distractor location becomes proactively suppressed in the priority map with the result that it is less likely to capture attention. In the present study, we aimed to probe whether the presence of regularities in both the distractor and the target location leads to proactive modulations in the attentional priority map. Participants performed the additional singleton search task in which the target singleton was presented more often in one location while the distractor singleton was presented more often in another location. On a subset of trials, participants performed a probe task in which they had to detect the offset of a probe dot presented at one of the locations used in the search task. The results showed that observers had successfully learned both the target and distractor regularities, as search was most efficient when the target and distractor were presented at their respective high-probability locations. Crucially, the results of the probe task showed that probe offsets were detected faster at the high-probability target location and slower at the high-probability distractor location, suggesting that spatial enhancement and suppression were present before the onset of the actual search display. These findings indicate that VSL leads to the proactive modulation of weights within the priority map with regard to both a likely target and a likely distractor location, ensuring search behavior to be optimally adapted to the simultaneous presence of different types of regularities.