Fig. 8. The response of V1 neurone to combined stimulation of the ocelli and compound eye. (A) The instantaneous firing rate of V1 during stimulation of both the ocelli and compound eye (solid black line) and stimulation of the compound eye only (broken blue line). Data were averaged over 155 repetitions of the stimulus from a single animal. (B) Time course of ocellar stimulation. (C) Time course of the contrast of the compound eye stimulation. The data in A were obtained using a contrast increase of 0% to 20%. (D) The full set of 155 spike train rasters obtained during combined stimulation. (E) The peak ocellar-mediated change in V1 spike rate, R, plotted against the corresponding compound eye-only mediated value, at the time of each peak. Positive y-axis values therefore indicate ocellar-mediated excitation, whereas negative values indicate ocellar-mediated inhibition. To obtain enough data points, both the curves shown in C (0-10% and 0-20%) were used to stimulate the compound eyes. (F) Data from another animal (188 stimulus repetitions), presented in the same way as in E. Black lines in E and F are interpolant smoothing splines, each obtained using the same smoothing parameter (see Materials and methods).