Abstract
Previous research on figure/ground perception has demonstrated that although convexity typically indicates figure, the context of the border between regions affects the extent to which convexity influences figure/ground perception. Specifically, increasing the number of regions in a stimulus promotes the perception of the convex region as the figure (Peterson & Salvagio, J. Vis., 2008). Although a great deal is known about figure/ground perception in younger observers, it is not clear whether figure/ground perception is affected by aging. Therefore, the current study examined how the effect of context on figure/ground perception is affected by aging. To address this issue, we investigated the effect of region number on figure/ground perception in 10 older (≥60 years) and 11 younger (≤30 years) participants. Subjects viewed brief (100 ms) stimuli from Peterson and Salvagio in which a small red dot appeared either on a white or black region, with convexity equally likely on different polarities across trials, and the task was to say whether the dot appeared on the figure or ground. In separate blocks, stimuli contained either 2 or 8 regions, and different observers started with different conditions. The dependent measure was the proportion of times the convex region was perceived as the figure, and this proportion was compared across groups and conditions. Our results for younger adults replicated those originally found by Peterson and Salvagio: The convexity cue was significantly stronger for 8-region stimuli than for 2-region stimuli. Older subjects showed a general trend in the same direction, however the effect of number of regions was significantly reduced for older subjects. These preliminary results suggest that context affects older observers less than younger observers. Future work will examine the effect of stimulus order and duration to determine, for example, whether older observers can make use of increased context with additional time.
Meeting abstract presented at VSS 2012