Figure 7. JNWFs between the (geometric) mean orientations (left) and just-noticeable differences (JNDs) in variance (right) of two successively displayed, uncrowded circle arrays.

SDs and variances, respectively, refer to parameters σ_C and ${\sigma }_{\mathrm{C}}^2$ of the lognormal distributions from which circle diameters were drawn. Numerals denote N, the number of circles per array. They have been nudged horizontally for better legibility. Error bars contain 95% confidence intervals. Blue, red, black, and magenta curves illustrate the best 3-parameter fit to the data on the left for N = 1, N = 2, N = 4, and N = 8, respectively. (Fits to N = 4 and N = 8 were identical for subject KM. They were also identical for HLW.) Simultaneous fits for variance discrimination, where N = 8, are shown on the right.