Complementarity of Phenomenal and Physiological Observables: A Primer on Generalised Quantum Theory and Its Scope for Neuroscience and Consciousness Studies

Abstract

We argue in this chapter that complementarity is a feature governing the relationship between neurophysiological aspects and phenomenological aspects of our mind. Hence a formal framework that is derived from quantum theory is applicable, generalized or weak quantum theory. This is a formal axiomatic framework that relaxes some of the requirements of quantum theory proper. Thereby it becomes relevant to more diverse kinds of systems, for instance to our mind. Basic elements of quantum theory are retained, such as the notion of observables, measurement, system, state of a system, and most importantly the handling of complementary or incompatible observables, such as physical and mental aspects of a human being. Allowing for complementary observables, however, also introduces by formal necessity an aspect peculiar to quantum theory, entanglement. We introduce the framework briefly and discuss how it might be useful for consciousness studies. We first show that complementarity has to be used to describe mental and physical states of the human mind. We show that the neuroreductive credo is not consistent with the analysis resulting from generalised quantum theory and that complementarity is an irreconcilable feature of our conscious existence. Hence generalised entanglement also becomes a notion that needs to be taken into account.