UNIVERSAL STATISTICAL BEHAVIOR OF NEURAL SPIKE TRAINS

The statistical properties of spike trains generated by a sensory neur on are studied. It is shown that the spike trains exhibit universal st atistical behavior over short times, modulated by a strongly stimulus- dependent behavior over long times. This decomposition is accounted fo r by a ''frequency integrator'' model, under conditions of time scale separation. We provide explicit formulas for the statistical propertie s in both the universal and the stimulus-dependent regimes, which are in very good agreement with the data, The universal regime is characte rized by a dimensionless free parameter, which is observed experimenta lly to remain constant under different external stimuli. [S0031-9007(9 8)07566-8].