Mind, Memory and Modules
Held by Prof. Sitabhra Sinha (The Institute of Mathematical Sciences, Chennai (Madras), India)
Many complex networks occurring in nature have significant meso-level organization. These include the existence of modules, subnetworks whose components are much more densely connected to each other than to members of other modules, and the occurrence of hierarchical levels of organization. In particular, such structures are observed in the brain networks associated with information processing. In this talk, we first explore the evidence for the occurrence of such mesoscopic structures in the nervous system of the nematode C. elegans. Next, we look at their possible functional role in the brain. In particular, we consider the Hopfield model for associative recall of memorized patterns and investigate how modular structures affect the dynamics of convergence to certain attractors. We conclude with a discussion of the general implications of our results for basin size of dynamical attractors in modular networks whose nodes have threshold-activated dynamics. As such networks also appear in the context of intra-cellular signaling, our results may provide a glimpse of a universal (i.e., scale-invariant) theory for information processing dynamics in biology.