Statistical regularities in natural scenes that support figure-ground segregation by neural populations
Fig 5
Within sRFs, figure regions tend to move more coherently than the ground regions.
(A) The frequency distribution of differences in circular variance between figure and ground is plotted as a measure of coherence difference. Positive values indicate lower coherence in the figure region and negative values indicate higher coherence in the figure region. Note that the x axis is flipped. (B) The average and 95% confidence intervals for these figure-ground variance differences are plotted separately for each sRF eccentricity. (C) For relative direction, we show the frequency across all points in the sRFs (gray shading), and separately for the figure regions and ground regions (red and blue lines, respectively). 0 deg corresponds to the dominant motion in each sRF. (D) The mean figure and ground results from panel C are plotted as a probability ratio as a function of relative motion direction. Values greater than 1 (red background) indicate that points are more likely to be in figure regions and values less than 1 (blue background) indicate that points are more likely to be in ground regions. In C and D, dashed lines indicate 95% confidence intervals, but in some panels the intervals are barely wider than the line thickness.