On Wednesday I attended the inaugural lecture of the new NYU Center for Mind and Brain by Giulio Tononi. Tononi’s basic idea is that where there is information there is consciousness, but when you have integrated complex information then you get the kind of consciousness that matters to us. I don’t have time to lay out the thesis in detail but you can see something along these lines in this Youtube video or see the full paper here. (I also recommend this talk by Christof Koch especially around the 23 minute mark)
The discussion afterwards was very interesting in particular because he addressed Eric Schwitzgabel’s recent argument that if Tononi is right the the United States is (probably) conscious. His response was that this was rued out by one of his phenomenological axioms. In particular the one he called exclusion. The intuitive idea behind this is that the system with the highest amount of integrated information (what he calls phi) wins out and is the locus of phenomenal consciousness, all other information (and so low levels of consciousness) are excluded. So, in a system like the U.S. he denies that the U.S. has a higher phi than any of us individuals. Thus by the exclusion principle the U.S. is not conscious even though we are. He did admit that if it ever became the case that the U.S. came to have a higher phi than any of its individuals then it would become a conscious subject and that individual would cease to be conscious! Dave Chalmers asked him if some person were shrunk down and used to replace one of his (Dave’s) neurons would it then be the case that they (the person shrunk) would case to be conscious, and he said yes!
Another interesting idea that came out was that Tononi thinks that there can be consciousness in the absence of any nerual firing at all. This is because the mathematical formalization of phi works using the possible states the system could be in not the ones that it is actually in. In fact teh phi will be at its highest value when the system is in good working order but is not actually being used. This is because no actual states are ruling out possible past or future states. He mentioned contemplative states as one possible case where this happens, and it may help to explain certain studies that found deactivation of brain activity in association with intense hallucinogenic experience. I asked him if he thought that this would be the case even if there were absolutely no activity in the brain and he said yes. That is, yes, as long as it is the case that the neurons could be stimulated and function normally. So, according to him, if you take out on component of that system so that it is damaged instead of just not doig anything then you will lower the phi and so should expect a change in the conscious experience of the system. He went so far as to say that if we were able to do this experiment and there were no change in conscious experience then he would take his theory as empirically refuted.
I didn’t follow up with him on this but I wondered whether on his view this would account for near death experiences. I think it is pretty standardly thought that if there is conscious experience when there is no brain activity at all then this would show that physicalism was not true. Tononi would seem to have an interesting response to this. In the few moments when there is brain death but the neurons have not ceased being functional he would predict very vivid consciousness, (though perhaps without content?) I am not sure about this, as I tend to be on the other side of this issue. When I have looked at near death cases (I commented on a paper making this argument against physicalism a few years back and did some research) it seems fairly clear that the conscious experience is occurring just before and just after the stoping and starting of brain activity respectively. So I am unconvinced that there is any good evidence that there is indeed conscious experience in the total absence of brain activity. Still, very interesting…
There is a lot more interesting stuff that came up but I don’t have the time to talk about it now.