Berechnung und Messung des Informationsflusses der Nervenfaser

Firstly two possible principles for the coding of messages into sequences of nerve spikes - the pulse-count-modulation and the pulse-interval-modulation - are compared; for several reasons the pulse-interval-modulation was choosen as the convenient basis for the following calculations. The information rates of afferent nerve fibers are calculated by means of data concerning the statistical properties of the spike-sequences evoced by stimulation; this data were found in the literature as well as in some own experiments. The non-linear relationship of input-signals (i.e. stimulus strength) and output-signals (mean-spike-interval = reciprocal of the firing rate) has no effect on the information rate; the influences of the channel transfer function and of the probability distribution of the input signals (the channel capacity accounts to the optimal distribution) are studied. Finally, numerical results for some kinds of afferent channels are presented; the importance of such calculations is discussed.