Laurianne Côté¹ (), Jérémy Lamontagne¹, Alexis Bellerose¹, Caroline Blais¹, Daniel Fiset¹; ¹Université du Québec en Outaouais

An important body of literature is dedicated to understanding how humans compute the complex information required for face recognition. Specifically, many have stated that the eyes and mouth regions play a fundamental role in this process, supported by evidence from individual differences and prosopagnosic patients (Caldara et al., 2005; Royer et al., 2018; Tardif et al., 2019). While psychophysical studies have established the importance of these regions in identification, few studies have explored the preceding step: face detection. That said, a study by Xu and Biederman (2014) suggests a link between these two processes, showing that a prosopagnosic patient experienced notable difficulties in a face detection task, suggesting that the same facial information might be used for both processes. The present study therefore aims to identify the key regions involved in face detection, a crucial step before delving deeper into this aspect in patients with acquired prosopagnosia. In this study, twenty participants completed 3,000 trials divided in two face detection tasks (1 - Does the presented stimulus contain a face? 2 - Which of the two stimuli contains a face?), with the non face stimuli being 100% wavelet decomposed faces (Koenig-Robert & VanRullen, 2013). In both tasks, stimuli were overlaid with Bubbles across five spatial frequency (SF) bands (Gosselin & Schyns, 2001). The resulting classification images reveal that face detection relies on all facial features (eyes, nose, and mouth, p = .001) across all spatial frequency bands, with the presence of the eyes being associated with higher Z-scores. These results suggest that face detection and face recognition processes are closely linked, as both rely on the same facial regions to accomplish the task. This opens new perspectives for understanding and diagnosing deficits associated with prosopagnosia, but also for better understanding the underlying processes of face recognition.

Acknowledgements: Natural Sciences and Engineering Research Council of Canada (Discovery) and Master's Research Scholarship (B1X) from the Fonds de recherche du Québec - Nature et technologies (FRQNT)