Figure 3.

Stimulus Representation in Network Activity

(A) Activity in one oscillating and three asynchronous sender networks during 50 ms. (A1) Spike raster. (A2) Average principal cell firing rate for 20 subpopulations, each of 400 neurons. (A3) Spatial pattern of gamma amplitude (population firing-rate oscillation amplitude at 41 Hz) across the 20 subpopulations.

(B) Postsynaptic input obtained by summing activity in the four sender networks.

(C) Average 0 Hz amplitude (solid line) and gamma amplitude (dashed line) as function of stimulus orientation for (C1) presynaptic activity in oscillating (red) and asynchronous (blue) networks and (C2) summed postsynaptic input. Error bars represent standard deviation. For the combined input, both gamma amplitude and firing rate (0 Hz amplitude) show stimulus tuning, but the gamma amplitude is far less variable because of the small contribution of distracting inputs.

(D) Accuracy of stimulus representation as measured by the orientation estimate standard deviation (D1) and Fisher information (D2); estimates decoded from activity in the sender network (S) or from the combined input from sender and distractor populations when the sender network was in an asynchronous state (A) or an oscillatory state (O).