Are you conscious right now?

That’s a pretty easy question to answer. You might say that’s the only thing in life you can ever be totally sure of. You are experiencing existence from moment to moment, and everything else beyond that is… well, just conjecture.

Is a dog conscious? What about a spider? Or a tree? Where do we draw the line of conscious experience, and how can we ever understand something so abstract?

We are always getting closer to understanding how our brains work – and we can link certain physical processes in the brain with behaviours and thoughts – but that still doesn’t answer the hard question: why conscious experience exists. As a philosopher might put it, why is there “something-that-it-is-like-to-be” me? Why does experience seemingly arise from physical systems?

One argument, supported by logical reasoning, is that conscious experience can’t be explained reductively; that is, we can’t explain how I experience colours by reducing the problem down to its most basic parts. Reductive explanation could show me how my brain processes colours, and how it produces all sorts of colour-related behaviours (i.e. stopping at a red light), but it could never explain my own perception of the colour red. Why is my perception of the colour red like this, and not like feeling rain on my skin, or hearing a musical note?

To address this question, some people believe we have to treat conscious experience as a fundamental property of the universe, and work backwards. A group of computational neuroscientists have come up with a theory of consciousness called “integrated information theory”, or IIT. This theory treats consciousness as a fundamental force in the universe, like gravity. In a similar way to how mass produces gravity, complex physical systems might produce consciousness as a natural law.

IIT attempts to explain the physical properties that account for consciousness, by first defining the qualities of our conscious experience and working back to the physical systems that support it. Yes, it sounds like it’s probably quite a complicated theory – and it really is! – but in simple terms, IIT says that a physical system is at least a tiny bit conscious if it has any sort of recurrent connections, or feedback. So IIT predicts that our brains produce high levels of consciousness, because our neurons form a network with lots of feedback and integration.

This means that lots of things we wouldn’t think of as being conscious would actually possess some form of experience. Even something as simple as a photodiode, a small device that detects light and converts it into electricity, could be a tiny bit conscious… if it had a feedback system within its circuitry. IIT suggests that consciousness is a sliding scale, from the tiniest form of awareness that we couldn’t even possibly imagine (can you imagine what it’s like to be a photodiode?), to an ultimate awareness in the most complex systems imaginable.

IIT can answer some questions about the brain that have been puzzling neuroscientists and philosophers for decades. Why, for example, is the cerebellum not a part of our consciousness? The cerebellum is a part of the brain with a high density of neurons and many connections; yet we can damage it and still experience the world in the same way (although we might not be able to walk very well any more). Why is the cerebellum not involved in our conscious experience? IIT suggests that the types of connections within the cerebellum are to blame; the cerebellum works as many small groups of neurons with simple connections, not producing enough feedback or integration to create a highly conscious system.

IIT also answers why people can report they have become two separate people living within the same body when the left and right hemispheres of their brains become separated. IIT proposes that there will be a precise moment, during the separation of the left and right hemispheres, where the single integrated system breaks into two equally integrated and equally conscious (but separate) systems.

Although it may sound like IIT is a new form of panpsychism (the belief that everything in the universe is conscious to some degree), IIT actually posits that many things are not conscious (or at the absolute universal minimum of consciousness). For example, a rock is not conscious because it contains no feedback systems. Similarly, a machine that mimics human behaviours through a feed-forward system (i.e., a machine that says “hello” when you say “hi” just because it was programmed to produce that output from that input) is not conscious because it has no feedback and is not using any other information to modify its behaviour. In this way, a feed-forward system that perfectly mimics human behaviour could pass the Turing test, but according to IIT would not actually be conscious.

IIT proposes a new way of thinking about consciousness; as a fundamental law of the universe that is linked to physical systems. Although the IIT doesn’t really answer the ‘hard problem’ of consciousness, it certainly puts it in a new light. Instead of asking ‘why am I experiencing?’ we can now ask ‘why is experiencing a fundamental law of the universe?’. And that’s like asking why mass curves space-time. Maybe it’s something we can never answer.

Undoubtedly, IIT won’t satisfy everyone. But its arguments are based in logic and its postulates can be examined in the physical world. Even if it can’t tell us why consciousness is a fundamental aspect of the universe, IIT could help us understand what it means to be conscious.

In my next post, I talk about how the psychedelic experience fits in with this model of IIT, and what this can tell us about different states of consciousness.

Bibliography:

Oizumi, Albantakis & Tononi (2014) Integrated information theory 3.0. PLOS Comp. Biol. 10(5)

Tononi & Koch (2015) Consciousness: here, there and everywhere? Phil. Trans. R. Soc. B. 370

Integrated Information Theory on Scholarpedia