Dana M. Farmer¹, Natalie A. Paquette¹, Joseph Schmidt¹; ¹University of Central Florida

Expectations often shape how individuals allocate attention during visual search (Schmidt & Zelinsky, 2017). When task-specific expectations are violated, search behavior shifts toward what was expected rather than what is required, producing an expectancy effect. Even subtle changes to task instructions can bias expectations (Cox, et al., 2021), leading behavior to align with expected rather than true task demands. Although expectancy effects have been observed across different stimulus types (Paquette & Schmidt, 2025), it remains unclear whether the magnitude of these effects reflects stable individual differences that generalize across stimulus types and if these effects remain stable over time. The present study employed a within-subjects visual search task to assess if the expectancy effect remains stable across stimulus types and block, with participants searching for Landolt-C’s and real-world-objects while eye movements were recorded. A blocked design was used to reinforce expected search difficulty and expectations were violated 25% of the time (e.g. easy trials in a difficult block, easier-than-expected; difficult trials in an easy block, harder-than-expected). Five performance and oculomotor-based measures were evaluated by block and violation type, resulting in a total of 20 individual correlations. Correlational analyses across stimulus types revealed a significant inverse relationship for target dwell time during block one easier-than-expected trials (r = -0.38, p = .013), suggesting that individual differences in expectancy effects show some consistency, despite a negative relationship. This relationship weakened in the second consecutive block (r = -0.26, p = .095). No significant relationships were observed for harder-than-expected trials in either block. These findings do not provide strong evidence for stable individual differences in performance following expectation violations. However, when stability is present, it weakens with task exposure. The attenuation of this effect over time may reflect an accommodation of existing task-oriented expectations following repeated expectation violations (Pinquart et al., 2021).