Michael Graziano published a brief article in the New York Times on his attention schema theory of consciousness, which a number of my fellow bloggers have linked to and discussed. I’m not sure this article was the clearest description of it that he’s given, and I suspect the title biased readers to think his theory is another consciousness-is-an-illusion one, which affected some of the discussion.
I’ve written about this theory before when I reviewed his book, ‘Consciousness and the Social Brain’, and alluded to it in several other posts. I’m doing another post on it, partially to take another shot at describing it, partially to reaffirm my understanding of it, and partially to do my small part to call attention to a scientific theory of consciousness that I think deserves your attention.
Before starting on the theory, I think it’s important to understand that the scientific evidence doesn’t point to the brain operating under any central control. There’s no homunculus, no little person inside controlling the brain. The brain is more of a distributed set of modules that operate somewhat independently.
The first thing to understand with the theory is the distinction between attention and awareness. Attention is the process of your brain deciding which sensory inputs to give priority processing to. It’s a messy emergent process with, again, no central control. It can be top down, such as your attention to reading this blog entry, or bottom up, such as the attention you’d give to a spider crawling up your arm.
These sensory signals are constantly streaming into your brain, each signal is constantly striving for attention. There is an ongoing contest in your brain with signals effectively forming coalitions, coming to prominence, and then receding to the next ascendant coalition of signals.
Some philosophers of mind stop here and say that this is consciousness, and that the feeling that there is anything else, that there is an inner experience of some kind, is an illusion. But if this is an illusion, then what is experiencing the illusion? And how is the illusion arising? And how are the top down attentional states referenced above developed?
The answer may be awareness. Awareness is not attention. Your attention can be drawn to something without you being aware of it. This is something every magician and illusionist knows. They often misdirect your attention, without you being aware of it, which allows them to perform seeming feats of magic.
But if awareness isn’t attention, then what is it? According to this theory, it is information. Awareness is a model, an executive summary in your brain of the messy and emergent process of attention. Like any executive summary, it lacks a lot of detailed information, it isn’t always accurate, and is by nature incomplete.
Compare this to what we know about the relationship between consciousness and the subconscious. We are conscious of many things, but a lot more things go on within our subconscious that we have only incomplete or hazy information about, and much goes on that we simply have no information on.
In other posts, I’ve used the metaphor of a city newspaper. The city is the brain, and the newspaper is awareness. The newspaper gathers information, summarizes and simplifies it, and then makes it available to the rest of the city. It is a feedback mechanism that allows the components of the city to know a summary of what is happening with all the other components of the city.
Awareness serves the same function in your brain. It’s a feedback mechanism that allows the brain to monitor its attentional state. According to the theory, it’s this feedback mechanism, this schema, that gives us our feeling of inner experience, of essentially experiencing our experience.
Another aspect of this theory is the idea that, just as we have an attention schema for our own attention state, we also have attention schemata for other minds. The idea is that the same brain circuitry that processes awareness for our inner experience also processes our perceptions of what others are thinking. For example, when we watch another person look at an apple, we model their attentional state and understand that their attention is on the apple.
In other words, consciousness is our theory of mind pointed back at ourselves, and our theory of mind is our awareness feedback mechanism pointed at other perceived minds. (I’m tempted to go off on a tangent here about the importance of understanding yourself in order to understand others, but I think I’ll save that for some other time.)
Graziano feels that consciousness has at least some control over our actions, that asserting that it doesn’t, as many epiphenomenon theories of consciousness do, ignores the main thing we can know for sure about consciousness, that we can describe it. I think that’s why his preferred metaphor for describing the attention schema is of a general plotting strategies with a map and toy soldiers serving as a model of the real battlefield.
I’m sure Graziano has his expert reasons for believing this, but based on all I’ve read, I’m less sure about consciousness being in control, thinking that maybe a better description might be to say that consciousness has causal influence. I think this is one reason why I prefer the newspaper metaphor. Unlike a general, a newspaper doesn’t have control over what happens in the city (at least not directly), but it has substantial causal influence through the information that it makes available. The city, or more accurately the various faction within the city, may or may not use the information provided by the newspaper in their decisions.
This conception also melds well with Michael Gazzaniga‘s description of the interpreter functionality which seems to be revealed by split-brain patient experiments. These experiments are some of the indications that we have that the brain isn’t controlled by any one central point. The mechanism producing the attention schema is the interpreter, or at least a crucial part of it.
So, why am I enthusiastic about this theory? Well, first, it seems solidly rooted in neuroscience and psychology. In his book, Graziano discusses the empirical support for the theory. He admits that the support is still incomplete, and that the theory may have to be modified as more data becomes available. This is normal for a scientific theory.
Second, the theory doesn’t invoke an unknown magical step. For example, the integrated information theory posits that consciousness arises from the integration of information without being able to describe exactly how much integration is necessary, or why integrated entities like the internet or the tax code aren’t conscious (at least not without making counter-intuitive assertions that they are conscious but with no ability to communicate with us). The attention schema theory sees integration as necessary for consciousness, but not sufficient by itself.
Third, the theory doesn’t dismiss inner experience as an illusion. It’s description of a feedback mechanism actually gives an explanation for the intuitive feeling of the homunculus that we all have.
And fourth, it gives insight into the type of architecture that might eventually be necessary for an artificial intelligence to be conscious, while showing how unlikely it is that such an architecture will come about by accident.
Is this theory the natural selection of consciousness, as Graziano admits he is looking for? I don’t know, but it feels like at least an important step toward that theory. This theory will rise or fall on whether or not the data support it, but it being rooted in the data that is already available makes me think it’s a closer approximation of that final theory than most of the other theories that often get tossed around.
- A theory of consciousness worth attending to (elusiveself.wordpress.com)
- Are We Really Conscious? (extragoodshit.phlap.net)
- Steve Fleming – A Theory of Consciousness Worth Attending to (integral-options.blogspot.com)
- Cogito Ergo Su(m/n)day Review in the NY Times: Graziano’s Eliminativism (Ausomeawestin.wordpress.com)