Haptic size aftereffect is shape dependent A Kappers1, W Bergmann Tiest2 |
|---|
1VU University Amsterdam, Netherlands |
| Recently, we showed a strong haptic size aftereffect by means of a size bisection task: after adaptation to a large sphere, subsequently grasped smaller test spheres feel even smaller, and vice versa [Kappers & Bergmann Tiest, IEEE WHC 2013]. An additional result was that subjects used volume as a measure of size and not surface area or diameter, as might have been expected from a discrimination task using different shapes [Kahrimanovic et al., 2010, Attention, Perception & Psychophysics, 72(2), 517-527]. In the current study, the adaptation stimuli were still spheres, but the test stimuli were replaced by tetrahedrons. The results are clear: the aftereffect completely disappeared. This indicates that adaptation processes are quite specific. Apparently subjects do not adapt to size (be it volume, surface area, or length) but to another object property. A suitable candidate is curvature, but more research is needed for this claim. Interestingly, subjects no longer use volume as a measure of size but either length or surface area. This confirms our earlier finding that haptic perception of volume has to be inferred from other object properties, but only if the objects are geometrically different. [This work was supported by the EC Project THE Hand Embodied] |
| Up Home |
|---|