Fig. 5. Sinusoidal stimulation of the femoral chordotonal organ (fCO) (amplitude 350 µm); SETi activity (female middle legs). (A) Circular phase histogram (bin width 5°) of SETi spike activity (spikes s^-1) recorded during three stimulus cycles at 0.0065 Hz. The mean vector (arrow) is at 280°. (B) Modulation (Mod., filled circles) and mean activity (open circles) of SETi with respect to stimulus frequency (means ± S.D., N=6; except at 5 Hz, where N=1). The shaded lines are the corresponding curves for Carausius morosus (Kittmann, 1997). (C) Phase shift between maximum fCO elongation and the mean vector (see A; means ± S.D., N=6; except at 5 Hz, where N=1). The shaded line shows the corresponding curve for Carausius morosus, as in B.