Organizational closure through regenerative signaling as a possible basis for conscious awareness.

Along the lines of neuronal global workspace theories, the paper hypothesizes that active neural signal regeneration in recurrent, re-entrant circuits could constitute an organizational basis for states of conscious awareness. In this view, brains are self-production systems that regenerate their own informational, signal states ("neural autopoiesis"). States of awareness themselves depend critically on sustained regeneration of sets of neural signals in local and global circuits. The set of regenerated signals at each moment determines the specific contents of consciousness. Two hypotheses are proposed. H1: Organizational closure and with it, awareness, is achieved when regenerative, self-production loops are completed, such that a stable set of signal productions is sustained. The organization of informational processes stabilizes and closes on itself. H2: Neural coding is critical for signal regeneration. Neural signals must be properly encoded in order for them to be regenerated and thereby affect the contents of awareness. In addition to simple signal suppressions at their points of origin, one means by which general anesthetic agents may abolish awareness is by scrambling neural signals. Rendering internal control signals incoherent by altering within- and across-neuron rate profiles and/or temporal patternings may disrupt signal regeneration in local and global circuits. The two hypotheses are agnostic with respect to neural coding. Our own signal-centric time-domain (TD) brain theory framework is presented to illustrate how signal regeneration could be mediated by local and global temporal codes and neural temporal processing networks. Similarities and differences between TD, global neuronal workspaces (GNW), recurrent processing (RP), integrated information (IIT) and predictive processing (PP) are discussed. Empirical testing will necessitate solving the neural coding problem at multiple system levels. This will involve investigating correlations and causal linkages between regeneration of tracked neural signals and states of awareness as well as between alternative candidate neural codes and the contents of awareness. Rhythm-tagged stimuli and high temporal resolution neural recordings are proposed to enable tracking of specific neural signals throughout the brain under conditions of waking vs. sleep vs. anesthesia, with masking and unmasking signal/noise levels. Some philosophical comments regarding organization as a potential basis for consciousness are made.