Fig. 5. Optomotor responses vary with the vertical extent of pattern motion. (A) Diagram of visual stimuli. Top row: stimuli used to find the vertical location of the strongest sensitivity to horizontally moving stripe patterns. Bottom row: representations of stimuli that vary in vertical stimulus extent. (B) Response magnitude for a single pixel row of expansion stimuli plotted against the vertical location of the row in the arena, indicating maximum sensitivity in the middle of the arena, where the fly is positioned. (C) Mean response waveforms to visual expansion (top) and visual rotation (bottom) that vary for the vertical extent of image motion (color coded). Insets indicate responses to motion restricted to only the front or rear 180° of the cylindrical arena. (D) Steady-state response amplitude of the waveforms indicated in C for N=50 flies.