Fig. 4. The attenuation of visually elicited motor responses is not a linear function of the magnitude of haltere stimulation. With set to 1, the scaling factor ß was calculated for multiple flies during concurrent oscillations in which the amplitude of the visual stimulus was fixed at 30° and the amplitude of the mechanical stimulus (u) was varied. (A) ß (mean ± S.E.M.) versus u for three phase relationships (): 180°, 270° and 90° (N=8, 9 and 9 flies, respectively). (B) Amplitude of sine fit to time-averaged wingbeat responses versus u for =180°, 270° and 90° (N=8, 9 and 9, respectively). Data fit by weighted sum (spline approximation of the fit), R_m+ßR_v, with =1.17 and ß=0.65.