Figure 5.

A model of signal routing by gamma-band synchrony reproduces gating characteristics as observed in the experiments. A, The model consists of three neuronal populations with threshold-linear gain functions (circles). One input population (InP) such as V1 receives the flicker tag A as feedforward input, and a second input population is driven by the flicker tag B. The third population represents V4, which receives a superimposed signal from both input populations. Each population contains a noisy gamma oscillator whose signal is added to the feedforward input. LFP measurements are modeled by convolving the neural signal with an exponentially decaying kernel. Both internal dynamics and external observation are subject to additional, independent noise. Attention was modeled by synchronizing the V4 gamma oscillator with the gamma oscillator of the population receiving input from the attended stimulus. The gamma oscillator of the other input population, processing the non-attended stimulus, is set into anti-phase (or to a random phase) with respect to the V4 population. B, The model quantitatively reproduces the SC in the attended (left) and non-attended (right) conditions (compare to experimental data in Figs. 3, 4).