The Integrated Information Theory of Consciousness has been garnering some attention lately. There was even a very high profile piece in Nature. Having just listened to Hakwan Lau’s talk on this (available at this conference website) I thought I would write down a couple of reactions.

Like everyone else who is interested in consciousness, I have been interested in the integrated Information Theory. I attended a talk by Tononi back in 2012 (and wrote about it here) but I also attended a workshop at NYU on it back in 2015. I had always meant to write something about it (John Horgan did here) and thought I would do so now. I wish I had written about this sooner, but to be completely honest I found out about the Paris attacks as I was leaving the workshop and it shook me up enough to distract me from blogging.

I had a couple of take-away’s from that workshop and these have really influenced how I have thought about IIT. I suppose I would sum it up by saying that IIT doesn’t look like a theory of consciousness. In the first place it purports to be a theory of phenomenal consciousness, what it is like for one to have a conscious experience, but it starts from the phenomenon of fading into a dreamless sleep. This makes it look like the main phenomenon is creature consciousness. Is IIT trying to give an account of the transition(s) from sleeping to wakefulness (and vice versa)? This is where ‘levels of consciousness’ talk seems most at home. Is being in hypnogogic reverie ‘in between’ sleeping and wakefulness? Probably yes, but does that translate to phenomenal consciousness being graded? There it seems less clear. You either have phenomenal consciousness or you do not (pace Dennett). It is the contents of consciousness that can be graded, distorted, etc. So right from the beginning it seems to me to be off on the wrong foot: the comparison is not that between waking and dreamless sleep, it is the comparison between conscious (i.e. reported) and unconscious (denied) states that one should begin with if one is looking to explain consciousness.

Another of the main ideas that came out of the workshop (again, for me) was that the ‘axioms’ of IIT seem to encode assumptions about conscious experience that are controversial. For example, is some kind of higher-order awareness necessary (and/or sufficient) for conscious experience? The axioms are silent on this, seeming to suggest that the answer is no, but a lot of people seem to think that there is a kind of higher-order awareness that is manifest in our phenomenology (old examples like Aristotle, and newer ones like Brentono, and even newer ones like Uriah Kriegel). So could we have another version of IIT that adds an axiom about consciousness requiring higher-order awareness? Can this axiom be mathematized? Or could we interpret the first axiom (i.e. consciousness exists from *my* perspective) as implying higher-order awareness?

The current defenders of IIT clearly have a first-order theory of consciousness in mind when they discuss Sperling. They say in their Nature Neuroscience Reviews paper,

In short, the information that specifies an experience is much larger
than the purported limited capacity of consciousness

But there is no argument for this other than that IIT predicts it! Doesn’t it seem the least bit fishy that a theory that starts off with axioms that encode first-order assumptions about consciousness ends up ‘predicting’ first-order readings of controversial experiments? There is nothing in IIT that seems to indicate that we should not instead say that the Sperling distinctions encoded in the integrated information are unconscious and what is conscious is just what the subjects report.

Thus it seems to me that IIT is best interpreted as giving an account of mental content. This mental content may be conscious but it may also be unconscious. To resolve this debate we need to go back to the usual debate between first-order and higher-order theories of consciousness. IIT seems to have added nothing to this debate and we would need to resolve it in the usual way (by argument, appeal to phenomenology, and experimental evidence).

Finally another of the main ideas to come out of the workshop, for me, was that IIT, can be interpreted differently from the metaphysical point of view as well. Is IIT physicalist or dualist? Well, it seems you could have a version of it that went ether way. You could, like David Chalmers seems to incline towards, view IIT as giving you a handle on what the physical correlates of consciousness might be, and then one would posit, in addition, a fundamental law of nature connecting states of physically integrated information with conscious states. This is clearly not the way that Tononi wants the theory to be developed but it is a consistent way to develop the theory. On the other hand one might end up with a physicalist version of IIT, identifying consciousness with the physical implementation of the integrated information. Or you could, like Tononi, claim that consciousness is identical to the ‘conceptual structure’ which exists over and above the parts which make it up (conceptual structures are irreducible to their physical parts for Tononi). So which one of these is the real IIT? Well, there is Tononi’s IIT and then there might be Chalmers’ IIT, etc.

This is not even to mention the problems others have pointed out, that it is hard to know what to make of a grid being ‘more conscious’ than a typical Human, or which of the many (many) different ways of formulating phi are correct, or whether it is even possible to measure phi in humans at all. Even if one wasn’t worried by any of that it still seems that IIT leaves open all of the most important questions about the ultimate nature of consciousness.