Prof. Stefan Schweinberger: Person Perception and Social Interaction: Tools for Basic and Applied Science

Abstract

Starting from current models of person perception and nonverbal interaction, the aim of this talk is to demonstrate how parameter-specific morphing techniques can enhance our understanding of the role of sensory information for the processing of social and affective signals from faces and voices. Following the inventions of visual (image) morphing technology by Benson and Perrett around 1990, and of auditory morphing 〜ten years later by Kawahara, we can now go beyond classical morphing, averaging, or caricaturing. Specifically, we use the technology to selectively manipulate independent parameters (e.g., 3D-shape or texture/colouration of faces; fundamental frequency, timbre, or temporal aspects of voices). This allows us to determine the relative importance of these image (or sound) characteristics for social perceptions of age, gender, identity or affect in neurotypical participants. It also can help to assess processing changes in individuals with sensory impairments (e.g., age-related handicaps to vision or hearing) or with central impairments (e.g., autism, prosopagnosia). For example, experiments with faces consistently revealed a dominant role of texture information over shape, at variance with older claims that spatial configural information is crucial to familiar face recognition. Qualifying this pattern, data from individuals with poor face recognition skills suggest that they rely relatively more on shape, and less on texture information. For voices, we present current results both from normal listeners and from cochlear implant users. Overall, we promote parameter-specific morphing to be a promising new approach to objectively assess individual profiles of face or voice perception abilities.