Video feedback is a classic example of complex and chaotical dynamical behaviour. It was a memorable if unnerving experience during an LSD-induced trip that got me thinking. I hallucinated almost identical imagery, only intensely saturated with colour. It struck me then there might be a connection between these recurring patterns and the operation of the mind.

What is special about the conscious brain, I propose, is that some of those pathways are turned upon themselves, much like the signal from the camera in the case of video feedback. This causes a self-referential cascade to blossom with astronomical complexity, and it is this that we experience as consciousness. Video feedback, then, may be the nearest we have to visualising what conscious processing in the brain is like.

Researchers recently discovered a way to accurately index the amount of consciousness someone has. They fired magnetic pulses (https://www.ncbi.nlm.nih.gov/pubmed/23946194) through healthy, anaesthetised, and severely injured peoples’ brains. Then they measured the complexity of an EEG signal that monitored how the brains reacted. The complexity of the EEG signal predicted the level of consciousness in the person. And the more complex the signal the more conscious the person was.

Also relevant is evidence from studies of anaesthesia. No-one knows exactly how anaesthetic agents annihilate consciousness. But recent theories suggest that compounds including propofol interfere with the brain’s ability to sustain complex feedback loops in certain brain areas. Without these feedback loops, the functional integration between different brain regions breaks down, and with it the coherence of conscious awareness.