Calculation of the Kullback-Leibler distance between point process models

We have developed a method for quantifying neural response changes in terms of the Kullback-Leibler distance between the intensity functions for each stimulus condition. We use empirical histogram estimates to characterize the intensity function of the neural response. A critical factor in determining the histogram estimates is selection of bin-width. We analytically derive the Kullback-Leibler distance between two Poisson processes and two dead time modified Poisson processes in terms of the bin-width selected. Our results show that, for constant intensity processes having the same number of expected counts, the distance between the dead time modified processes is larger than between the Poisson processes