Trial-to-trial variability of granule cell firing reduces noise correlations under global stimulation.

<p><b>A</b>) Raster plots showing responses of four different granule cells to repeated cycles of the sinusoidal stimulus in the deterministic regime for the granule cells (i.e. <i>ρ</i> = 0). <b>B</b>) Raster plots showing trial-to-trial variability in the responses of four different granule cells to repeated cycles of the sinusoidal stimulus in the stochastic regime for the granule cells (i.e. <i>ρ</i>>0). <b>C</b>) Ratio of the noise correlation coefficients obtained under simulated local and global stimulation as a function of the noise intensity <i>ρ</i>. Note that the ratio decreases from 1 as <i>ρ</i> is increased from 0. <b>D</b>) Ratio of the signal correlation coefficients obtained under simulated local and global stimulation as a function of the noise intensity <i>ρ</i>.