Fig. 7. Measurement of the polarization sensitivity of a head-down motoneuron. (A) The post-stimulus time histograms represent responses to 1.0s flashes at 12 e-vector angles. 0° is parallel to the long axis of the eyestalk. Each histogram indicates the firing rate over a 2.0s span at 20ms per bin and averaged over 40 responses. The bar beneath each histogram indicates the timing of the light flash and the number adjacent to each histogram is the e-vector angle in degrees. The histogram labeled 135° is presented for comparison. It is identical to the histogram at –45°. (B) Peak impulse rate versus e-vector angle. (C) Peak impulse rate versus the intensity of unpolarized illumination. Unit intensity was 1.2mWcm^-2.