The confirmation and prevalence biases in visual search reflect separate underlying processes

Research by Rajsic, Wilson, and Pratt (2015, 2017) suggests that people are biased to use a target-confirming strategy when performing simple visual search. In 3 experiments, we sought to determine whether another stubborn phenomenon in visual search, the low-prevalence effect (Wolfe, Horowitz, & Kenner, 2005), would modulate this confirmatory bias. We varied the reliability of the initial cue: For some people, targets usually occurred in the cued color (high prevalence). For others, targets rarely matched the cues (low prevalence). High cue-target prevalence exacerbated the confirmation bias, indexed via search response times (RTs) and eye-tracking measures. Surprisingly, given low cue-target prevalence, people remained biased to examine cue-colored letters, even though cue-colored targets were exceedingly rare. At the same time, people were more fluent at detecting the more common, cue-mismatching targets. The findings suggest that attention is guided to "confirm" the more available cued target template, but prevalence learning over time determines how fluently objects are perceptually appreciated. (PsycINFO Database Record (c) 2020 APA, all rights reserved).