Correlated Firing Improves Stimulus Discrimination in a Retinal Model

Garrett T. Kenyon, James Theiler, John S. George, Bryan J. Travis, David W. Marshak
2004 Neural Computation  
Synchronous firing limits the amount of information that can be extracted by averaging the firing rates of similarly tuned neurons. Here, we show that the loss of rate-coded information between retinal ganglion cells due to synchronous oscillations can be overcome by exploiting the information encoded by the correlations themselves. Two very different models, one based on axon-mediated inhibitory feedback, the other on oscillatory common input, were used to generate artificial spike trains
more » ... synchronous oscillations were similar to those measured experimentally. Pooled spike trains were summed into a threshold detector whose output was classified using Bayesian discrimination. For a threshold detector with short summation times, oscillatory input yielded superior discrimination of stimulus intensity compared to ratematched Poisson controls. Even for summation times too long to resolve synchronous inputs, gamma band oscillations in the input spike trains still contributed to improved discrimination by reducing the total spike count variability, or Fano factor. In separate experiments in which neurons were synchronized in a stimulus-dependent manner without attendant oscillations, the Fano factor increased markedly with stimulus intensity, implying that stimulus-dependent oscillations can offset the increased variability due to synchrony alone.
doi:10.1162/0899766041941916 pmid:15476601 fatcat:eao6kj5k5nabjhbudlprsu7xc4