Arianne Richer¹ (), Camille Saumure², Daniel Fiset¹, Caroline Blais¹; ¹University of Quebec in Outaouais, ²University of Fribourg

Although individuals recognize pain facial expressions (PFE) above chance, they often confuse them with expressions of other negative affective states (Kappesser & De Williams, 2002; Roy et al., 2015; Simon et al., 2008). Moreover, pain is less easily recognized in women's faces compared to men’s (Riva et al., 2011). At last year’s VSS, we presented findings based on stimuli from the Delaware Pain Database (DPD; Mende-Siedlecki et al., 2020), showing that automatic recognition algorithms identified men’s posed PFE as more frequently containing features typically associated with pain. Furthermore, when presented to a group of human observers, women’s posed PFE were more often perceived as conveying emotions such as fear, sadness, and surprise, despite no greater signal of these emotions being present in the stimuli. This project examines whether similar effects emerge when using dynamic stimuli of both genuine and posed PFE. We used the Pain E‑motion Faces Database (PEMF; Fernandes‑Magalhaes et al., 2023) containing 55 videos of White young adults (38 women, 17 men) posing PFE and 55 videos of genuine PFE. OpenFace was used to quantify the activation levels of 17 Action Units (AUs). A Principal Component Analysis revealed four significant components. The first component includes AUs typically associated with pain and is significantly more associated with posed than genuine PFE. Additionally, the fourth component is significantly more associated with men’s PFE than women’s. Ongoing analyses investigate how these differences in terms of expressive signal predict the way they are perceived by external observers. This approach enables us to explore the interplay between encoding and decoding processes in PFE, which may help us understand why women’s pain expressions are not recognized as easily as men’s.

Acknowledgements: The present study is supported by the Canada Research Chair in cognitive and social vision to Caroline Blais (#CRC-2023-00019) and by the Canada Graduate Scholarship - Doctoral program of the Natural Sciences and Engineering Research Council of Canada to Arianne Richer (#CGS D - 589787).