Abstract
Statistical regularities in the environment can bias attention towards frequently encountered targets and away from frequently occurring distractors. While most research has investigated how experience with such regularities biases spatial attention, recent work suggests that experience with non-spatial features also influences attention. However, it is not clear whether experience-driven feature-based attention – especially for ignoring distractors – arises primarily from short-term reinforcement (e.g., inter-trial priming) or if it affects attention more durably (e.g., even when the statistical environment changes). To test this, we conducted experiments of learned feature-based enhancement (Exp. 1; N = 75) and suppression (Exp. 2; N = 75). Participants searched for a Landolt C of a target orientation (left or right gap) among seven distractor Cs (top or bottom gap). Each array contained four items in each of two colors, selected from among four possible colors. In Experiment 1, during a 432-trial training phase the target appeared in one color on 75% of trials (vs. 8% for the other three colors), with a subsequent 216-trial testing phase presenting targets equally often in all four colors. Despite not being informed of the probability manipulation, participants responded faster when targets appeared in the high-probability color versus when distractors appeared in that color during both training and testing phases. In Experiment 2, to test whether learned distractor color probabilities also benefit search performance, non-targets appeared more often in one color on 75% of trials. Similar to Exp. 1, participants responded faster when non-targets appeared in the high-probability color versus when targets appeared in that color during both training and testing phases, suggesting that the frequent non-target color was suppressed. These results demonstrate that statistical regularities in the environment can persistently enhance selection of colors associated with targets and attenuate processing of colors associated with distracting information.