• Susan J. Lederman Queen's University


As background to the main topic of my presentation, I will begin by highlighting several key aspects of haptic processing that pertain to the haptic recognition of inanimate, non-biological objects and their properties. I will then discuss selected results from a recent research program on haptic processing of facial identity and culturally universal expressions of emotion. We began by posing the following general question with respect to human face perception: What happens if the human perceiver substitutes hand for eye? To date we have used both neurologically intact and impaired populations, and several well-known experimental paradigms (the “face-inversion effectâ€, case studies with prosopagnosic individuals, and functional magnetic resonance imaging). Converging results reveal that with as little as 5-10 minutes practice, humans can haptically discriminate, recognize, classify, and identify facial identity and/or emotional expression in a variety of face displays (live faces, 3-D facemasks molded from live faces, and 2-D raised-outline drawings produced from photos of live faces) at levels generally well above chance. Clearly face perception is a bimodal perceptual phenomenon. I will also consider the implications of our findings for understanding not only the nature of haptic processing per se, but also some of the similarities and differences in visual and haptic face processing. Collectively, our results offer an existence proof that touch constitutes a highly informative channel of social communication.