Visual-Haptic Perception of Compliance: Direct Matching of Visual and Haptic Information

Visual-haptic perception of an object's compliance demands integration of haptic position and force information as well as visual position information. In this investigation the role of active exploration on visual perception as well as the influence of visual-haptic information was addressed. Participants were instructed to directly match a compliant stimulus displayed either by vision (static-passive or active), haptics, or both. Active testing of the visually displayed cube resulted in no difference in visual thresholds, suggesting that exploration method did not influence visual position discrimination. However, the threshold of visual matching of the cube's indentation was smaller than for haptic compliance matching, not only unimodally but bimodally, in which case the alternate modality was present and adds noise resulting in an increase in bimodal thresholds.