Naturalizing consciousness: a theoretical framework

Abstract

Consciousness has a number of apparently disparate properties, some of which seem to be highly complex and even inaccessible to outside observation. To place these properties within a biological framework requires a theory based on a set of evolutionary and developmental principles. This paper describes such a theory, which aims to provide a unifying account of conscious phenomena.

Figure 1

Reentrant pathways leading to primary consciousness. Two main kinds of signals are critical: those from self, constituting value systems and regulatory elements of the brain and body, and those from nonself, signals from the world that are transformed through global mappings. Signals related to value and categorized signals from the outside world are correlated and lead to memory, which is capable of conceptual categorization. This value-category memory is linked by reentrant paths (heavy lines) to the current perceptual categorization of world signals. This reentrant linkage is the critical evolutionary development that results in primary consciousness. When it occurs across many modalities (sight, touch, and so forth), primary consciousness can connect objects and events through the memory of previous value-laden experiences. The activity of the underlying reentrant neural systems results in the ability to carry out high-level discriminations. This ability enhances survival value.

Figure 2

Causal chains in the world, body, and brain affect the reentrant dynamic core. Core activities (C′) in turn affect further neural events and actions. Core processes confer the ability to make high-order distinctions. The entailed qualia (C) consist of those distinctions. The shaded area labeled “phenomenal transform” has no causal efficacy but consistently reflects the C′ states, which are causal. The boundary of the dynamic core in the figure should not be interpreted too strictly, because in real brains it fluctuates in time.