Purchase this article with an account.
Christianne Jacobs, Charlotte Raskopf, Kirsten Petras, Valerie Goffaux; High-level image structure modulates low-level orientation sensitivity. Journal of Vision 2018;18(10):748. doi: 10.1167/18.10.748.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Orientation selectivity has been investigated mainly with simple, narrowband visual stimuli, such as gratings or Gabor patches (e.g. Appelle, 1972) showing a so-called oblique effect, i.e. lower sensitivity for oblique orientations compared to cardinal orientations. However, for broadband natural scene stimuli the visual system actually shows a reverse pattern of orientation preference with higher sensitivity to oblique than cardinal orientations (i.e. cardinal effect), which has been related to the cardinal dominance in natural image statistics (Hansen and Essock, 2004). In addition to these low-level stimulus properties, orientation sensitivity might be influenced by high-level properties, like the differential diagnosticity of orientation cues. Until now such high-level modulations of orientation sensitivity have barely been considered. Here, we used an orientation detection paradigm to investigate orientation sensitivity across different broadband image categories varying in phase, spectral slope, and the diagnosticity of information across orientations: upright, inverted, and scrambled faces, intact and scrambled scenes. We selected orientation-matched face and scene images and made them isotropic (i.e. all orientations carry equal amplitude). We created an orientation increment by increasing the relative amplitude of a 45°-wide broadband centered on one of four possible orientations: horizontal (0°), 45°, vertical (90°), and 135° (Hansen and Essock, 2004). In each session, isotropic and incremented stimuli of one of five categories were presented to the participants (N =10) who indicated the presence or absence of the orientation increment on each trial. Our results suggest that the cardinal effect generalizes to all tested categories. However, we also find a main effect of stimulus category, with orientation sensitivity being highest for scrambled scenes (and scrambled faces), and lowest for intact scenes. This indicates that even when image properties are matched, the high-level structure of the image modulates low-level orientation sensitivity.
Meeting abstract presented at VSS 2018
This PDF is available to Subscribers Only