Fig. 10. Outputs of two EMD system types in freely flying fruit flies. (A) According to previous findings on yaw torque production in tethered flies, we simulated a rotation-sensitive EMD system (upper pictogram) and an expansion-sensitive system with a lateral focus of expansion (lower pictogram). (B,C) Relative mean EMD output of the rotation system estimated from the Gaussian fit to the histograms shown in Fig. 9A and B, respectively. Errors represent the standard deviation of the fit, which is 0.5 the width of the Gaussian curve at half-peak height. Data in B and C show the mean difference (left-minus-right eye) and sum (left-plus-right eye) of the EMD response between the two eyes, respectively. (D) Relative mean EMD output (left-minus-right eye) of an expansion-sensitive system estimated from Gaussian fits similar to those shown in Fig. 9A,B. (E,F) EMD response of the rotation (black)- and expansion (red)-sensitive EMD system in flight sequences derived from two flies flying in a stationary environment in E and during 300° s^–1 arena velocity in F. See text for details. cw, clockwise turning (grey area); cww, counter clockwise turning.