We know the brain works a lot like a computer, with neuron firings and synapses acting like bit states and switches. Brain-as-computer works very well to account for sensory processing, control of behavior, learning and other cognitive functions. These functions may in some cases be non-conscious, and other times associated with conscious experience and control. Scientists seek the distinction – the essential feature, or trick for consciousness.

Some suggest there is no trick, consciousness emerges as a by-product of cognitive computation among neurons. Others say we don’t know, that consciousness may indeed require some feature related to, but not quite the same as neuron-to-neuron cognition.

In either case, humans and other creatures could in principle become devoid of consciousness while maintaining cognitive behaviors, appearing more-or-less normal to outside observers. Such hypothetical non-conscious behaving entities are referred to in literature, films and philosophical texts as ‘zombies’. Philosopher David Chalmers introduced the philosophical zombie, a test case for whether or not consciousness is distinct from cognitive neurocomputation.

I’ve studied and researched consciousness for over 35 years, and work as an anesthesiologist, erasing and restoring consciousness several times per day for surgery. Patients under anesthesia are not zombies. They lack consciousness but also lack cognition. On the other hand, for a very brief period after first emerging from anesthesia following surgery, my patients seem like zombies, behaving purposely but blankly. Like in the old song “She’s not there” by…..The Zombies.

During a routine surgery recently, one of the nurses was talking about a book called ‘Patient Zero’ in which a terrorist group turned people into zombies the terrorists were then able to control. I later discovered there exists an entire genre of zombie terror books and films (‘Invasion of the body snatchers’ being perhaps the original). Could it be possible? How could we protect ourselves from consciousness-snatchers who want to turn us into zombies? Well, we need to understand what consciousness is (but, so do ‘they’).

We do know consciousness correlates with a particular coherent EEG gamma synchrony. Somehow selectively blocking EEG brain-wide coherence while sparing neuron-to-neuron computation and cognition could conceivably erase consciousness. But I would bet on an even more subtle and profound feature or trick. For example I personally believe (with Sir Roger Penrose) that consciousness involves quantum computations in microtubules inside brain neurons.

Microtubules are the major structural component of the neuronal cytoskeleton whose disruption is an essential feature of Alzheimers disease. Microtubules dynamically organize intra-neuronal and synaptic activities, conduct signals, have collective vibrational and electromagnetic modes and quite possibly mesoscopic quantum states. Motor proteins and biomolecular agents traverse and interact with microtubules.

I became obsessed with microtubules in medical school in the early 1970s. Their cylindrical lattice structure of ‘tubulin’ protein subunits looked to me like a computing switching circuit. Through the 1980s, colleagues and I developed models of microtubule information processing in which states of tubulin subunits were bits interacting with lattice neighbor tubulins. With about 10^7 (10 to the seventh) tubulins per neuron switching at 10^-9 seconds, we calculated a potential for 10^16 operations per second in each neuron. This was, and remains unpopular in AI/Singularity circles because it potentially pushes the goalpost for brain capacity significantly. Recent evidence has shown collective microtubule excitations at 10^-7 seconds (rather than the 10^-9 seconds we assumed), indicating a neuronal information capacity of ‘only’ 10^14 operations per second.

But here’s the really good news. Microtubules self-assemble. With proper conditions tubulins polymerize into microtubules, and with associated proteins into networks of cross-linked microtubules. In principle, tubulin and other necessary proteins can be genetically mass-produced, and then self-assemble into large arrays. If microtubules process molecular-scale information (quantum or classical), appropriate arrays of microtubules could serve as a repository of consciousness — a ‘Lifeboat’.

These could be useful. Evil forces aside, consciousness-snatchers include aging, disease and death. In 1987 I wrote a book about microtubule information processing based entirely on classical (non-quantum) processes. The brief, concluding chapter considered arrays of microtubules as orbiting consciousness Lifeboats. It foreshadowed the Singularity, and in retrospect also applies to quantum processes. The chapter follows below. And we should understand consciousness not just to preserve it, but to enhance it in any way possible.

From
Ultimate computing: Biomolecular consciousness and nanotechnology
Elsevier, 1987
http://www.quantumconsciousness.org/ultimatecomputing.html

11 The Future of Consciousness

Nanotechnology may enable the dream of Mind/Tech merger to materialize. At long last, debates about the nature of consciousness will move from the domain of philosophy to large scale experiments. The visions of consciousness interfacing with, or existing within, computers or mind piloted robots expressed by Moravec, Margulis, Sagan and Max Headroom could be realized. Symbiotic association of replicative nanodevices and cytoskeletal networks within living cells could not only counter disease processes, but lead to exchange of information encoded in the collective dynamic patterns of cytoskeletal subunit states. If these are indeed the roots of consciousness, a science fiction-like deciphering and transfer of mind content may become possible. One possible scenario could utilize a small window in a specific brain region. Hippocampal temporal lobe, a site where memories enter and where electromagnetic radiation from outside the skull penetrates most readily and harmlessly, is one possible area where information distributed throughout the brain may perhaps be accessed and manipulated. Techniques such as laser interferometry, electroacoustical probes scanned over brain surfaces, or replicative nanoprobes immunotargeted to key hippocampal tubulins, MAPs, and other cytoskeletal components might be developed to perceive and transmit the content of consciousness.

What technological device would be capable of receiving and housing the information emanating from some 10^15 tubulin subunits changing state some 10^9 times per second? One possibility is a customized array of nanoscale automata, perhaps utilizing superconducting materials. Another possibility is a genetically engineered array of some 10^15 tubulin subunits (or many more) assembled into parallel tensegrity arrays of interconnected microtubules, and other cytoskeletal structures. Current and near future genetic engineering capabilities should enable isolation of genes responsible for a specific individual’s brain cytoskeletal proteins, and reconstitution in an appropriate medium. Thus the two evident sources of mind content (heredity and experience) may be eventually reunited in an artificial consciousness environment. A polymerized cytoskeletal array would be highly unstable and dependent on biochemical, hormonal, and pharmacological maintenance of its medium. Precise monitoring and control of cytoskeletal consciousness environments may become an important new branch of anesthesiology. Polymerization of cell-free cytoskeletal lattices would be limited in size (and potential intellect) due to gravitational collapse. Possible remedies might include hybridizing the cytoskeletal array by metal deposition, symbiosis with synthetic nanoreplicators, or placement of the cytoskeletal array in a zero gravity environment. Perhaps future consciousness vaults will be constructed in orbiting space stations or satellites. People with terminal illnesses may choose to deposit their mind in such a place, where their consciousness can exist indefinitely, and (because of enhanced cooperative resonance) in a far greater magnitude. Perhaps many minds can comingle in a single large array, obviating loneliness, but raising new sociopolitical issues. Entertainment, earth communication, and biochemical mood and maintenance can be supplied by robotics, perhaps leading to the next symbiosis-robotic space voyagers (shaped like centrioles?) whose intelligence is derived from cytoskeletal consciousness.

Yes, this is science fiction. Will it become reality like so much previous science fiction has? Probably not precisely as suggested; but if past events are valid indicators, the future of consciousness may be even more outrageous.