A FUZZY SET PERSPECTIVE OF THE LIMBIC SYSTEM - IMPLICATIONS FOR COGNITION AND MEMORY

This paper attempts to merge two quite diverse major themes: the appli cation of Paul MacLean's ideas on the evolution of the brain and certa in of the principles and ideas arising from the relatively recent deve lopments in ''fuzzy set theory.'' MacLean proposes three major divisio ns of mammalian brains that have been elaborated over the course of ev olution: an R-Complex (reptile-like), a limbic system. and a Neomammal ian (Neocortical) system. Neural elements in all of these systems at v arious times, contribute to goal oriented behaviors and to the analysi s of the environment. All of these major categories of brain organizat ion have mechanisms of plasticity that allow alterations in behavior t o be made on the basis of environmental contingencies. However, these major components of the nervous system in the MacLean model cannot be firmly defined in traditional anatomical terms, In fact, given the com plexity and variability of the mammalian nervous system, firm definiti ons may be impossible, In a real sense the brain areas involved and th e interconnections among brain regions are uncertain and, therefore, ' 'fuzzy.'' The significance of conceptualizing the nervous system in Fu zzy Set terms and the implications to come from doing so are discussed .