Fig. 5. Responses to repeated looming stimulation. (A) Repeated presentations of the same looming stimulus at 1 min intervals produce a progressive reduction of the escape distance (open squares, left axis) and an increase in response latency (filled circles, right axis) (N=14 crabs). (B) Repeated stimulation with longer inter-trial intervals (3 min) causes less changes to the escape distance and did not affect the response latency (N=15 crabs). Broken lines indicate the value of the mean response latency at first trial.