Wouldn't It Be Nice to Not Fall for It Twice? Prior Experience Does Not Abolish the Impact of Expectancy Violations...

In the current study, the impact of an unexpected color swap (from target to distractor color and vice versa) on reaction times (RTs) and eye fixations was investigated. Within a visual search task, participants reported the location of a shape-defined target letter above or below a distractor letter. Across time, participants learned the consistent relationships between the visual target features (shape and color), establishing an according expectancy. To that end, fixed colors were first assigned to both a fixed-shape target (e.g., red) and a fixed-shape distractor (e.g., green). Next, this expectancy was violated by an unannounced swapping of target- and distractor-associated colors in the critical trial. In addition, subsequent color swaps estimated the costs of better anticipated color swaps. Eye movements showed longer fixation times on the distractor letter during and immediately after the critical trial compared to trials before the color swap (precritical trials), and, in line with prior research, we also found longer RTs in critical trials compared to consecutive (postcritical) trials without color swaps (Experiment 1). Finally, varying the number of distractors per trial indicated no set-size effect (Experiment 2), but again costs for all expectancy violations were found. In sum, our results indicate that humans tend to fall for expectancy violations more than once, and costs associated with color swaps cannot be avoided entirely.