Fig. 7. Effect of stimulus position and expansion rate on the time course of the wing response. Responses to stimuli presented within ± 10° of the position were pooled. Each trace represents the mean ± S.D. (shaded area) of the average responses taken from multiple flies. The time course of the responses does not vary with stimulus position but does vary greatly with rate of expansion. The number of flies at each expansion rate is given in Fig. 5. L, left; R, right.