Orientation Discriminations with Flickering Stimuli Based on Directional Components

Abstract

Derrington and Henning (1981)¹⁾ reported that orientation discrimination performance has a low-pass spatial frequency characteristic, and argued that a mechanism for spatial pattern processing functions at fairly low spatial frequencies. To test their claim, we measured spatial frequency characteristics for orientation discrimination using vertical and horizontal Gabor patches with either counter-phasing or on-off temporal modulation. The results showed that the orientation discrimination sensitivity for counter-phasing stimuli was about twice that for on-off patterns at low spatial frequencies. These results indicate that orientation discriminations in these conditions are based on the directional components contained in the temporally modulated patterns instead of pattern information that is related to total depth of modulation.