Figure 7. Effect of terrain (controlling for vertical gaze) on retinal motion direction and speed.

While the vertical field asymmetry is slightly greater for the flat terrain, the effects of terrain on retinal motion direction and speed are modest. (a) Average retinal motion speeds across the visual field. (b) Five distributions sampled at different points in the visual field, as in Figure 4. (c) Average retinal flow patterns for leftward and rightward gaze angles. (d) Histograms of the average directions plotted in (c). Data are pooled across subjects.