Abstract
The visual system parses scenes into different planes and depths, in order to determine the organization of the different objects in the scene itself. A key feature of this process is the designation of an object as the figure or ground in a scene. The current study is focused on how being defined as the ground affects that object's ability to act as a mask upon the figure, in a hyperacuity discrimination task. Using the figure-ground cue of occlusion, the test component was defined as the figure and the lateral masking components as the ground. When making orientation discriminations we observed less masking when the occlusion cue was presented, compared to when the lateral masks were merely abutting. When spatial frequency discriminations were being made we observed a smaller, but still reliable, decrease in the masking condition where the occlusion cue was present, compared to when it was not present. Two of the possible explanations that arise from these results 1) once an object is labeled as ground it can no longer affect the figure (Gilchrist, 1977), 2) Once the object is labeled as being distinct from the test component, no matter how (figure-ground cue, phase difference, color difference …etc), it can no longer affect the test component (Saylor & Olzak, 2006; Malania, Herzog & Westheimer, 2007).
GilchristA. L. (1977). Perceived lightness depends on perceived spatial arrangement. Science, 195(4274), 185–187.
MalaniaM.HerzogM. H.WestheimerG. (2007). Grouping of contextual elements that affect vernier thresholds. Journal of Vision, 7(2), 1–7.
SaylorS. A.OlzakA. (2006). Contextual effects on fine orientation discrimination tasks. Vision Research, 46(18), 2988–2997.