Figure 5. CCFs in the presence of stimuli with correlations of increasing spatial extent, for pairs of ON parasol cells and pairs of one ON and one OFF parasol cell.

Left: CCFs of activity during constant illumination. Four CCFs are overlaid from recordings interleaved between recordings with visual stimulation. Right: CCFs in the presence of a time-varying stimulus (see text for details). Extent of spatial correlation in the stimulus is expressed as the standard deviation of the low-pass filter used to construct the stimuli. The mean ON parasol receptive field diameter was ∼140 μm. For each condition, the raw CCF, the CCF from shuffled identical stimulus repeats (shift predictor), and the difference between the two (corrected CCF) are shown. Grey shaded region represents 1 s.d. across cell pairs; for clarity this is only shown for the corrected CCF. Bin size: 1 ms.