Effects of mean firing on neural information rate

We investigated the effect of mean firing on the information rate of a spik ing motion-sensitive neuron in the fly (H1-cell). In the control condition, the cell was stimulated repeatedly by identical zero-symmetrical white-noi se motion. The mean firing rate was manipulated by adding a constant veloci ty offset either in the same area of the receptive field where the dynamic stimulus was displayed or in a separate one. We determined the information rate in the resulting spike trains in the time domain as the difference bet ween the total and the noise entropy rate and found that the information ra te increases with increasing mean firing under both stimulus conditions.