Appendix 9—figure 2. Comparing R1-R6s’ intracellular responses to hyperacute or saccadic bright or dark moving dots.

(A) Mean (thick traces) and individual responses (thin) of three individual R1-R6s to two bright (red, above) or dark (black, below) dots (of different inter-dot-distances and speeds), crossing the cells’ receptive fields in front-to-back direction. Responses to the hyperacute dots (3.4^o inter-dot-distance) are shown left; responses to the saccadic speed stimuli in the middle (205 ^o/s) and right (409 ^o/s). In all cases, these outputs resolved the two dots, but predictably the responses were always smaller to the dark dots at the bright background than to the bright dots at the dark background (as more microvilli should remain refractory when adapting to bright background). (B) The normalized and sign-inverted R1-R6 outputs to dark dots were similar to their normalized outputs to bright dots, with both showing equally good Raleigh-resolvability (cf. Figure 7C). Naturally, as the Drosophila eye samples light information from each point in space by eight photoreceptors (due to neural superposition) and balances this estimate with those of the neighboring lamina cartridges, its perception/resolvability of hyperacute and saccadic image motion is improved further.