Haptic identification of curved surfaces.
In two experiments, the active haptic identification of three-dimensional mathematically well-defined objects is investigated. The objects, quadric surfaces, are defined in terms of the shape index, a quantity describing the shape, and curvedness, a quantity describing overall curvature. Both shape index and curvedness are found to have a significant influence on haptic shape identification. Concave surfaces lead to a larger spread in responses than convex ones. Hyperbolic surfaces show a slight tendency to be identified with more difficulty than elliptic ones. Surfaces with a high curvedness are identified more easily than those with a low curvedness. Results from experiments with constant and with random curvedness are indistinguishable. It is concluded that shape index and curvedness are psychophysically not confounded.
Kappers
A M
AM
Utrecht Biophysics Research Institute, The Netherlands.
Koenderink
J J
JJ
Lichtenegger
I
I
D000328:Adult; D003867:Depth Perception; D005260:Female; D005556:Form Perception; D006801:Humans; D008297:Male; D009949:Orientation; D011601:Psychophysics; D013236:Stereognosis