Acceso usuarios
In a first experiment, the haptic (with a hand-held dowel) and the visual perception of whether a slanted surface can support an upright stance was studied with ascending and descending methods of limits. Confirming the results found by Fitzpatrick, Carello, Schmidt and Corey (1994) and contrary to those found by Klevberg and Anderson (2002), the perceptual threshold did not differ for visual and haptic judgments. Moreover, in both modalities, the perceptual threshold varied with ascending and descending judgments reflecting an « enhanced contrast ». Response time increased and confidence decreased around the value of this transition. Furthermore, a significant positive correlation was found between haptic and visual perceptual thresholds suggesting the presence of similar information (amodal information) . In Experiment 2, two contrasted textures (smooth vs rough) were used. Results showed a fit between actual and perceptual thresholds and a positive correlation in haptic judgments for rough texture, highlighting the existence of a perception of affordance. Results are discussed in relation to amodal information and modality-dependent factors that could play a role in this task.
