I will present an empirical comparision between neural interspike interval sequences obtained from two different kinds of sensory receptors, the paddlefish electroreceptors and the crayfish mechanoreceptors. Both differ in their internal structure as well as in the amount of correlations and predictability found in the respective spike trains. The approach in comparing these sequences is based on the concept of symbolic dynamics and information theory. As a further tool in this context, the local uncertainty is suggested. It is demonstrated to reveal significant patterns within the interspike interval sequences, even when the overall structure is (almost) random.
In cooperation with W. Ebeling (HU-Berlin), D. Russell, S. Bahar, A. Neiman, and F. Moss (Center for Neurodynamics, St. Louis)