Figure 7.

Dynamics of correlation. A, In a separate data collection period in 6 out of the 7 array implants, we recorded 15–30 min of spontaneous activity. The value of r_sc for 2738 pairs decreased with distance, but was much higher at all distances than during the evoked response. Using a smaller 0.1 s epoch, the same as in panels B–C, resulted in a lower value for r_sc. However, it was still significantly higher than that observed in the ISI after the end of the visual stimulus (Figure 7C). B, The average geometric mean firing rate across all 12 stimulus directions and all neurons. The stimulus period (1.28 s) is indicated by the gray shaded region, and the non-shaded regions represent the blank inter-stimulus intervals. Each data point represents the average value for a 100 ms window centered at the time on the abscissa. C, The value of r_sc computed in the same 100 ms windows as above.