Molly McKinney¹ (), Mianzhi Hu², Darrell Worthy³, Brian Anderson⁴; ¹Texas A&M University

Studies attempting to elucidate the visual search strategies individuals bring to bear in the performance of a task have identified vast individual differences; of note is the large proportion of suboptimal, or slow, visual search strategies. Our first experiment examined whether reward considerations, search efficiency, or the confluence of the two better predicted search strategy for each of 100 participants. Using the Adaptive Choice Visual Search (ACVS) task, a large and small subset of potential target items each contained one target; the target in either the smaller or larger subset was associated with greater reward and participants could choose which target they wanted to search for on each trial. Searching among the smaller subset of items is the fastest way to perform the task. Computational modelling revealed three different strategies participants used: value-based, in which they searched to maximize reward, response-time-based, in which they searched to maximize speed above and beyond reward outcome, and a reward-per-unit-time-based strategy, which highlighted a potentially joint influence of these priorities. Given that some participants deviated from a purely reward-maximizing strategy, our second and ongoing experiment set out to evaluate whether reward variability could modulate the priority for reward and/or speed. Each stimulus subset (small and large) in the task was assigned a reward variability (high or low) and value (high or low), counterbalanced such that all combinations of value and variability were assigned across groups of participants. The results suggest that the variability of rewards does not modulate the preference for searching among the higher-value subset. Contrasted with involuntary attentional biases for cues associated with more variable reward outcomes, our findings suggest a possible dissociation between how reward variability influences voluntary and involuntary attentional control. Overall, our findings speak to the factors that motivate the choice of visual search strategy.