Figure 4.

Sensitivity to motion direction varies systematically around the visual field. (A) Mean sensitivity for cardinal compared to oblique motion directions in cartesian reference frame. Each plotted point represents the mean performance for each condition across observers at eight polar angle locations. Each value prior to averaging was derived from four psychometric fits per condition for a given observer. Lines connect the dots. Error bars not visible were smaller than the plotting symbols. (B) Same data points as in A but re-grouped to compare mean sensitivity for polar cardinal compared to polar oblique directions at eight polar angle locations. (C) Mean sensitivity for radial compared to tangential directions at eight polar angle locations.