Comparison of responses under conditions of complete darkness versus visual fixation, plotted separately for translation (A, C, E) and rotation (B, D, F). All comparisons were made at the peak time of fixation responses. (A), (B) Scatter plots of peak-trough response amplitudes (Rmax−Rmin) during translation (n=41) and rotation (n=31), respectively. (C), (D) Scatter plots of DDI for the same cells as in A, B. (E), (F) Distribution of the difference in preferred direction under conditions of fixation and darkness, shown for translation (n=16) and rotation (n=4), respectively. Only neurons with unimodal spatial tuning at peak time for both fixation and darkness conditions are included in this comparison.