Figure 9.

Relation between mean counts and variance of counts in the predimming period for the two attention conditions at the population level (red: attend-RF, blue: attend-away). A, Mean counts plotted against variance of count for broad-spiking cells. B, Mean counts plotted against variance of counts for narrow-spiking cells. C, Mean counts plotted against predicted variance of counts for broad-spiking cells. D, Mean counts plotted against predicted variance of counts for narrow-spiking cells. Solid red and blue lines are best fits of the functions linking variance to mean. Values for the exponents derived from the fits are shown in the lower part of each figure for the two attention conditions.