Fig. 3. The effect of stimulus position on behavioral response. (A) A single fly's response to multiple presentations of a square expanding at 500° s^-1 varies with stimulus position. Each individual trace shows the response of the left (blue) and right (red) wing to a presentation of the expansion stimulus. The bold and dotted lines represent the mean response ± S.D. for stimuli between given positions. Expansion in lateral positions evokes the largest change in wing-beat amplitude (WBA), with responses decaying for more frontal and caudal stimulus presentations. (B) Results from multiple flies. The individual traces are the mean left and right wing-beat amplitude response taken from 12 individuals. The bold and dotted lines represent the mean ± S.D., respectively, across individuals.