Do individuals with developmental prosopagnosia benefit from motion during face recognition?

Research has shown that individuals with typical face recognition abilities are more accurate when recognising familiar faces from dynamic images, compared to static. One explanation for this motion advantage is the social signals hypothesis, which proposes that social cues carried in movement benefit face recognition by attracting attention to identity-specific facial features such as the eyes, nose and mouth. The current study sought to a) examine whether individuals with developmental prosopagnosia (DP), who show severe deficits in face recognition, benefit from motion during face recognition; and b) examine the validity of the social signals hypothesis as an explanation for any observed motion advantage effect. Fourteen prosopagnosics and 16 controls completed a famous faces recognition task while their eye movements were tracked. Both DP and control participants demonstrated higher accuracy for faces presented in motion. Both groups directed a higher proportion of time and fixations to the internal features (eyes, nose and mouth) when faces were presented in motion, relative to a static presentation. Conversely, the proportion of time and fixations directed to the external features (cheeks, chin and hair) was higher during the presentation of static faces. These results support the social signals hypothesis as a theory of the motion advantage in DP by demonstrating that social cues present in facial motion attract attention to identity-specific features, facilitating identity processing.