Abstract
Human observers combine haptic (touch) and visual cues to estimate object properties such as slant (Ernst, Banks & Buelthoff, 2000) and size (Ernst & Banks, 2002). In the present study we ask whether haptic cues can change a visual percept; specifically, is the perception of gloss influenced by how an object feels? Observers binocularly viewed a single convex shaded bump, either with or without a specular highlight. The specular highlight was either aligned with the diffuse shading, or offset by up to 120°. On visual-only trials observers simply viewed the stimulus and made a 2AFC shiny vs. matte judgement. On visual-haptic trials, observers touched and viewed the stimulus before making their judgement. Stimuli felt either hard and smooth or soft and rubbery. In agreement with previous work (Anderson & Kim, 2009), specular highlights that were closely aligned with the diffuse shading led to shiny percepts. However, as the misalignment increased, the object was increasingly judged as matte. Importantly, when the object felt hard and smooth, observers classed the objects as shiny for larger highlight misalignments. In contrast, when the object felt soft and rubbery, objects appeared matte with smaller offsets between highlight and diffuse shading. We conclude that haptic information can alter observers' visual percepts of material properties.
ISK was funded by an ESRC studentship.