Typical Perceptual Sensitivity to Changes in Interpersonal Distance in Developmental Prosopagnosia.

Social perception research has traditionally sought to elucidate the visual processing engaged by the faces and bodies of individuals. Recently, however, there has been growing interest in how we perceive dyadic interactions between people. Early findings suggest that dyads arranged face-to-face may engage neurocognitive processing similar to that recruited by faces. Given these parallels, we sought to determine whether developmental prosopagnosics (DPs), who exhibit lifelong face recognition difficulties, also exhibit impaired perception of facing dyads. The focus of our investigation was interpersonal distance-a key visual feature of dyadic social interactions. Participants completed three distance change detection tasks. Two of the tasks depicted distance changes during dyadic social interactions (fighting and dancing). A third task depicted distance changes using nonsocial objects (a pair of grandfather clocks). If DP is associated with impoverished perception of dyadic interactions, we reasoned that DPs should exhibit diminished sensitivity to distance changes on the dancers task and the boxers task, but not on the clocks task. Contrary to this prediction, however, DPs and typical controls did not differ significantly in their ability to detect distance changes on any of the tasks. Although the visual processing of faces and facing dyads exhibit certain similarities, these findings suggest that the underlying perceptual mechanisms may dissociate.