Parametric study of virtual curvature recognition: Discrimination thresholds for haptic and visual sensory information

The senses of vision and touch are vital modalities used in the discrimination of objects. In this research effort, a haptic device is used to determine thresholds of curvature discrimination in visual-haptic experiments. Discrimination thresholds are found for each sense independently as well as for combinations of these with and without the presence of conflicting information. Results indicate that on average, the visual sense is about three times more sensitive than the haptic sense in discriminating curvature in virtual environments. It is also noticed that subjects seem to rely more heavily on the sense that contains the most informative cues rather than on any one particular sense, in agreement with the sensory integration model proposed by Ernst and Banks. The authors believe that the resulting thresholds may serve as relative comparisons between perceptual performance of the sensory modalities of vision and haptics in virtual environment.