The Importance of Internal and External Features in Face Recognition

Past research in the field of face perception has found that external facial features (hair, ears, face contour) better facilitate recognition of unfamiliar faces, whereas internal facial features (eyes, nose, mouth) support the recognition of familiar faces. In the current study, we investigate the differential use of internal and external features for the recognition of faces that vary in familiarity and race. White-Canadian participants (target sample size = 260) complete an online card sorting task in which they are given a set of cards containing photographs depicting individual faces. They are instructed to sort the cards into piles for each identity present in the set. Each participant sorts a set of cards with either own-race familiar, own-race unfamiliar, other-race familiar, or other-race unfamiliar faces. These faces are modified to contain only internal features, only external features, or both. Face recognition accuracy is measured by calculating the number of piles (or perceived identities) and the number of misidentification errors. Using a signal detection framework, we will calculate a sensitivity score for each participant to assess their recognition accuracy. Preliminary data from 44 adult participants in the whole face conditions reveal a) an own-race advantage in unfamiliar face recognition; participants perceived more identities when sorting other-race unfamiliar faces (mean = 6.93) versus own-race unfamiliar faces (mean = 4.89), and b) a familiar face advantage (mean = 3.98). We are currently recruiting 220 participants for the internal features and external features conditions and expect to find greater reliance on internal features for familiar faces and external features for unfamiliar faces. Moreover, we expect there to be a greater reliance on internal features for own-race as compared to other-race faces. These results will offer insight into how reliance on internal and external facial features differs based on familiarity and race.