Abstract
The present study investigated whether explicit knowledge and awareness regarding the regularities present in the display affects statistical learning (SL) in visual search. Participants performed the additional singleton paradigm in which a salient color singleton distractor was presented much more often in one location than in all other locations. Previous studies have shown that participants learn this regularity as the location that is most likely to contain a distractor becomes suppressed relative to all other locations, but little is known about the role of awareness in this learning process. The present experiments investigated whether this type of SL would be influenced by explicit knowledge or awareness of this regularity. In this study in addition to the search task, we used a second report task to make people fully aware of the regularity regarding the distractor or not aware at all. After each search task, participants from separate groups had to either indicate the location of the color singleton distractor or the location of the shape singleton target. Those participants that reported the distractor location, were very much aware of the regularity present in the display. However, participants that reported the target location, were basically unaware of the regularity regarding the distractor. The results showed no difference between these groups in the amount of suppression of the high probability location. This indicates that regardless of whether participants had explicit knowledge or not, the suppression was basically the same. We conclude that explicit knowledge and awareness does not contribute to learning to suppress a location. This conclusion is consistent with the notion that statistical learning is automatic, operating without conscious effort or awareness.