Symbols and dynamics in the brain

The work of physicist and theoretical biologist Howard Pattee has focused o n the roles that symbols and dynamics play in biological systems. Symbols, as discrete functional switching-states, are seen at the heart of all biolo gical systems in the form of genetic codes. and at the core of all neural s ystems in the form of informational mechanisms that switch behavior. They a lso appear in one form or another in all epistemic systems, from informatio nal processes embedded in primitive organisms to individual human beings to public scientific models. Over its course, Pattee's work has explored (1) the physical basis of informational functions (dynamical vs. rule-based des criptions, switching mechanisms, memory, symbols), (2) the functional organ ization of the observer (measurement, computation), (3) the means by which information can be embedded in biological organisms fur purposes of self-co nstruction and representation (as codes modeling relations, memory. symbols ), and (4) the processes by which new structures and functions can emerge o ver time. We discuss how these concepts can be applied to a high-level unde rstanding of the brain. Biological organisms constantly reproduce themselve s as well as their relations with their environs. The brain similarly can b e seen as a self-producing, sell-regenerating neural signaling system and a s an adaptive informational system that interacts with its surrounds in ord er to steer behavior. (C) 2001 Elsevier Science Ireland Ltd. All rights res erved.