We present a hypothesis to explain how the brain operates to generate different degrees of consciousness. We relate our model to recent evidence from brain morphology and physiology, indicating that the central nervous system contains two parallel networks (neuronal and astroglial) establishing positive and negative feedback loops. Variable levels of consciousness are proposed to depend on the degree of resonance between these networks. The resonance can occur in the absence of salient external stimulation and, even when such stimulation occurs, the response of the coupled networks is always dependent on the previous state of their interaction domain. We also explain complex processes occurring below the threshold of awareness as those that deploy the brain’s computational resources, although without producing resonant states of sufficient magnitude to determine the individual´s overt acknowledgment. Finally, our model affords a plausible account of phenomenal and self-consciousness which, by resting at the outskirts of reportable cognitive activity, traditionally compound the 'hard problem' of consciousness.