Ultrametricity is a very general and abstract concept of mathematic but accurate data analysis and study of sequence of data has revealed that it represents collection of information grouped in categories. This is also the way the information are grouped and collected by humans. In this book we try to show that such structured information can be retrieved and stored in the hippocampus finding in this way the neurobiological background for such cognitive processes. In the book both the mathematical framework and the simulation of the neuronal processes are explained for people not expert of the field.

B. Tirozzi is a professor of Mathematical Physics at the Department of Physics of the University of Rome"La Sapienza". He has published research papers on many different topics: systems of ising spins, quantum spins,dynamics of infinite system of classical particles, renormalization group, dynamical systems, neural networks