Large-Scale Synchronization Transients Serving as Neural Substrates of Consciousness

Abstract

Significant efforts has been made in recent years to identify neural correlates of consciousness. The present report discusses several concepts used in models and interpretations of brain measurements, including self-organized criticality, neural avalanches, phase transitions, and scale-free structures and dynamics. These concepts have various advantages and limitations when applied to brain dynamics and cognitive functions, in particular consciousness. Analysis of the properties of the cortical neural tissue indicates that non-local interactions manifested in the projections by long axons lead to the emergence of spatiotemporal activity patterns, which are unique to the cortex and have not been observed in any other physical or biological substrates. A relevant graph-theoretical model, which includes nonlocal effects, has been used to interpret the experimental findings. We propose the hypothesis that the non-local interactions produce unique physiological conditions with large-scale phase gradients and switches between synchrony and absence of synchrony, are the manifestations of conscious experience. We expand on the Global Workspace Theory (GWT) of consciousness to illustrate the hypothesis and outline the directions for future research.