Abstract
Developmental prosopagnosia (DP) is a condition characterized by impairments in facial recognition. A prominent theory of face perception posits that facial identity and facial expression processing have distinct functional pathways (Bruce & Young, 1986; Haxby, Hoffman, & Gobbini, 2000), such that the superior temporal sulcus is thought to process the dynamic aspects of a face such as facial expressions, while the fusiform face area is thought to process invariant facial features such as identity. DP has previously been used as a model to test this theory (Duchaine, Parker & Nakayama, 2003; Biotti & Cook, 2016). However, these studies have been limited to static stimuli, suggesting the need to systematically characterize emotion recognition in individuals with DP using dynamic stimuli.
In the present study, we first tested individuals with and without DP on an emotion detection task utilizing static faces with varying levels of emotional expressions. Specifically, we morphed neutral faces with angry, happy, and fearful expressions to create a spectrum of emotional content within faces. On each trial, participants were asked to indicate if the face displayed a happy, fearful, angry, or neutral expression. In a separate perceptual control task, participants indicated if the face displayed an open or closed mouth. We hypothesized that individuals with DP would show similar detection thresholds as controls on our emotion detection and control tasks. Four individuals with DP and seven control subjects completed both tasks. Preliminary results indicated that individuals with DP have similar thresholds as controls for detection of happiness and fear, but slightly higher thresholds for anger. In addition, individuals with DP performed similarly to controls on the perceptual control task. These results suggest that DPs may have subtle deficits in facial expression processing. Additional ongoing studies using dynamic faces and body expressions will further characterize emotion processing in developmental prosopagnosia.