Environmental regularities shape visual search strategy selection

Visual search can be guided by multiple strategies, some of them relying on bottom-up salience, others on top-down expectations. However, little is known about how we arbitrate between these strategies. Here, we tested whether environmental regularities that incentivize different strategies can influence this arbitration. Participants performed a visual search task in which targets appeared in one of two color-defined groups of items whose relative sizes varied across trials. Because smaller groups are more visually salient, prioritizing them constitutes a bottom-up search strategy, and prioritizing the larger group requires top-down control. By manipulating the probability that the target appeared in each group, we created environments in which abstract structural properties of the display (the relative size of the groups) incentivized different strategies. Participants adapted their search strategy to these abstract regularities, but in an asymmetric fashion. Reliance on salient minority groups readily increased when it was advantageous, whereas people only became willing to prioritize the majority group when alternative salience-based cues were minimized. These results suggest that visual search strategies are shaped by environmental statistics, but their adoption is constrained by the cognitive costs of overriding bottom-up salience.