Biased competition through variations in amplitude of y - oscillations

Experiments in visual cortex have shown that the firing rate of a neuron in response to the simultane­ ous presentation of a preferred and non-preferred stim­ ulus within the receptive field is interm ediate between that for the two stimuli alone (stimulus competition). A ttention directed to one of the stimuli drives the response towards the response induced by the attended stimulus alone (selective attention). This study shows that a simple feedforward model with fixed synap­ tic conductance values can reproduce these two phe­ nomena using synchronization in the gamma-frequency range to increase the effective synaptic gain for the responses to the attended stimulus. The performance of the model is robust to changes in the param eter values. The model predicts that the phase locking between presynaptic input and output spikes increases with attention.