Fig. 6. Directional sensitivity of the escape response. The looming stimulus was presented to each animal once in each of the four different visual regions corresponding to the position of the monitors, and the sequence of presentation was varied among animals. (A) Polar plots show the trajectories of the escape responses to the stimulus approaching from each one of the four screens: upper left, stimulus above; upper right, stimulus in front; lower left, stimulus at left side, lower right, stimulus at right side. Black circles denote the direction of escape for each animal. (B) Response distance of the responses shown in A. (C) Latency to initiate the escape of the responses shown in A. Values are mean response scores ± s.e.m.; N=10 crabs, one trial at each stimulus location.