Figure 3.

Strength and impact of noise correlations in synaptic inputs to primate midget ganglion cells. a₁, Two trials of simultaneously recorded conductances during modulated light (gray). a₂, Residual conductances (trials from a₁ with mean subtracted), which estimate noise on each trial. b₁, Cross correlation (mean ± sem, 12 trials) of excitatory and inhibitory residual conductances in an example cell during simultaneous (black) and non-simultaneous recording (green). b₂, Cross correlation for all recorded cells (mean ± sem., 15 cells). c, Logic of dynamic clamp experiments using simultaneously or shuffled simultaneous conductances in place of synaptic input. d, Example spike trains from 12 dynamic-clamp trials of simultaneous conductances (black) or their shuffled counterparts (green). e, Signal-to-noise ratio of spike trains generated from simultaneous vs. shuffled conductances (dots). SNR for simultaneous conductances was 1.22±0.04 times higher than that for shuffled conductances (p = 0.0015, 7 cells).