Abstract
It is well known that the human visual system has neural mechanisms sensitive to co-circularity among oriented edges, which play an important role in the detection of object contours. Here, we report a novel aftereffect in which the appearance of a texture is dramatically altered after adaptation to a texture composed of elements with co-circular structure. Following prolonged viewing of a texture made of pairs of adjacent Gabor elements arranged to form obtuse angle co-circular pairs, i.e. shallow curves, the subsequently viewed random texture appeared to be composed of acute angle pairs, i.e. V shapes. Conversely, following adaptation to a texture made of V shapes, subsequently viewed random textures appear to be composed of shallow curves. A possible explanation of this aftereffect is that mechanisms sensitive to co-circularity are organized in an opponent manner, with one pole sensitive to shallow curves the other V shapes. This notion was tested further in a non-adaptation 2AFC experiment in which co-circular and non-co-circular Gabor pairs were mixed within a single texture. Results revealed summation between pairs that fell on one side of the opponent continuum, and cancellation between pairs that fell on opposite sides of the continuum. These results support opponent interactions between mechanisms sensitive to pairwise co-circular texture features.
Meeting abstract presented at VSS 2018