Life, Catalysis and Excitable Media: A Dynamic Systems Approach to Metabolism and Cognition

Abstract

This chapter examines the remarkable property that life has to maintain its organization in order to determine if there is a hitherto undiscovered principle that unites all living processes, including microprocesses, such as protein folding, and macroprocesses. The hypothesis is that at every scale, living processes are processes of catalysis, and that all biological processes mediate transitions in their environments, employing the same mechanism as enzymes. Enzyme catalysis is a prototype process that elucidates the way in which living processes maintain their organization by mediating transitions via the structure in the environment (in this case, the substrate) leading to energy dissipation. Enzyme catalysis may involve solitons or traveling waves, nondissipative and robust waves that maintain their energy and structure in environments that embody invariance or symmetry. Solitons and/or traveling waves are ubiquitous in biological processes; it has been proposed that they are involved in a variety of biological processes including muscle contraction, protein folding, DNA “zipping” and “unzipping”, action potentials and crucially, in the brain itself. The chapter examines the relationship between microscopic instances of catalysis and traveling waves (solitons) in excitable media. It is then suggested that the brain is an excitable medium, and that cognition (and all mental processes) correlates with the spatiotemporal evolution of traveling waves in the brain. This theory offers an alternative to the functionalist perspective that underlies much of current theoretical biology, by grounding biology and neuroscience within a general understanding of the process of catalysis. By instantiating the same principle at multiple scales, the theory suggests how the many biological processes that comprise an organism work and “cooperate”. Also, if living processes are catalytic, this leads to a better reconciliation between living processes and thermodynamics.