Marie-Pier Plouffe-Demers^1,2,3, Chaona Chen³, Angélica Pérez Motta², Valentina Gosetti³, Caroline Blais², Rachael E. Jack³; ¹University of Quebec in Montreal, ²University of Quebec in Outaouais, ³University of Glasgow

Ethnic minorities expressing pain are often under-diagnosed and under-treated (Cintron et al., 2006). The misinterpretation of pain signals conveyed through facial expressions across different ethnicities might be a key factor contributing to these variations (Dildine et al., 2023). Current theories of social perception suggest that such misclassifications could be due to ethnic stereotype knowledge that could amplify confusions between pain and similar-looking facial expressions, like anger or disgust (Hugenberg et al., 2004; Kunz et al., 2019; Roy et al., 2015). However, no study has explicitly examined the interaction between these factors. Here, we addressed this question by first examining whether face ethnicity influences the interpretation of facial expressions of pain as other negative emotions. Using a generative model of the human face, we displayed 40 facial expressions of pain, sadness, anger, fear and disgust on each of 40 face identities varying in ethnicity (Black, East Asian, White) and sex (male, female). Participants (30 White Western; sex-balanced; 18-35 years) classified each stimulus in an alternative forced choice task (5AFC). Combining a within-subject bootstrap analysis (10,000 resamples) with the Bayesian estimate of population prevalence (Ince et al., 2021), we investigated the effect of ethnicity on accuracy and confusion patterns between pain and other negative emotions. Preliminary results (n = 22) show that, across face ethnicities, facial expressions of pain are the least accurately identified and generate more systematic confusions with disgust for black compared to white faces. To explore these confusions further, we plan to conduct a second complementary discrimination task where participants will detect the presence of target emotions (measured using d-prime, n = 30). By investigating the role of face ethnicity in interpreting facial expressions of pain, our study aims to shed light on how and why disparities in pain perception arise and provide potential insights into mitigating these effects.

Acknowledgements: This work was supported by a European Research Council Starting Grant (Rachael E. Jack), a Canada Research Chair in Cognitive and Social (Caroline Blais), and by graduate scholarships from the Social Sciences and Humanities Research Council and Mitacs Globalink (Marie-Pier Plouffe-Demers)