Xueqi Ao¹ (), M.D. Rutherford¹; ¹McMaster University

Introduction: Category-contingent aftereffects occur when individuals adapt to distortions in opposite directions for two socially meaningful categories. Prior work has shown that social labels such as religious identity or food preferences delivered in the auditory domain can generate opposing aftereffects. We tested whether race-related auditory cues impact adaptation ambiguous faces randomly assigned to East Asian versus Caucasian categories . Methods: Participants (N = 83) completed a three-phase aftereffect paradigm (pre-adaptation, adaptation, post-adaptation) and were randomly assigned to one of four conditions, varying by audio type (explicit race vs. control) and distortion direction (East Asian expanded vs. Caucasian expanded). Stimuli were human-validated AI-generated racially ambiguous faces and race-related word lists. In the explicit condition, faces were paired with race-revealing auditory information (e.g., culturally related names, foods, hobbies, countries). In the control condition, the same faces were paired with neutral, non-racial information. In the pre- and post- adaptation, participants selected their preference between faces pairs that were slightly expanded and slightly contracted, where in the adaptation phase, participants saw heavily distorted faces paired with auditory information. Results showed that ambiguous faces paired with East Asian labels produced significantly different aftereffects compared to the same faces without race information (t(38.96) = -2.23, p = .031; 95% CI [-3.52, -0.17]). Importantly, this effect was specific to the East Asian expanded condition, highlighting the asymmetric influence of racial cues. Even more compelling, significant opposing aftereffects emerged in the East Asian expanded/Caucasian contracted condition, where preferences shifted in opposite directions depending on the assigned racial label (t(19) = -2.10, p = .04; 95% CI [–3.09, –0.01]). Conclusion: Explicit racial auditory cues enhance the social meaning of racially ambiguous faces, enabling category-specific adaptation and reshaping perceptual representations of race. These findings advance our understanding of how social categories impact the visual perception of faces.

Acknowledgements: This research was funded by a NSERC - Natural Sciences and Engineering Research Council grant to MDR