20.05.2014

Guillermo Aguilar: New abstract accepted as a poster at ECVP from 24.08.-28.08.2014

Title: "On the role of two-dimensional cues for perceived differences in slant" by Guillermo Aguilar, Felix Wichmann, Marianne Maertens

Abstract:

On the role of two-dimensional cues for perceived differences in slant

An experimental paradigm frequently used in the study of human depth perception is the inference of surface slant from texture. Previous work has shown that slant is consistently underestimated when close to fronto-parallel, and this has been interpreted as a reduced sensitivity to fronto-parallel slants. For textures with discrete elements, such as 'polka dots', a number of two-dimensional cues change concomitantly with slant. While it was assumed that these cues are used to infer slant, and that differences in discrimination performance reflect thus differences in slant sensitivity, it has been recently suggested that some differences might rather reflect sensitivity differences to the two-dimensional cues themselves (Todd et al., 2010).

To further test this possibility, we derived perceptual scales for slants defined by texture using the maximum likelihood difference scaling method (Maloney & Yang, 2003). We studied the influence of different two-dimensional cues that varied contingently with slant (elements' aspect and area ratios, scaling contrast, among others), and compared the experimental results with observer models that selectively responded to each cue. The derived perceptual scales confirm lower sensitivities at slants close to fronto-parallel. Interestingly, none of the different cues was sufficient in explaining the sensitivity differences across the entire perceptual scale.

This work was supported by the German Research Foundation, Research Training Group GRK 1589/1 and grant DFG MA5127/1-1.