Global Workspace Theory and its associated Theater Metaphor are empirically plausible, but why should it result in consciousness? Why should globally available information being processed by separate cognitive modules make us talk about being conscious?
Sure, that's how brains see stuff, but why would that make us think that it's happening to anyone? What in the world corresponds to a self?
So far, I've only encountered two threads of thought that try to approach this problem: the Social Cognitive Interface of Kurzban, and the Self-Model theories like those of Metzinger and Damasio.
I’ll be talking about the latter, starting off with what self-models are, and a bit about how they’re constructed. Then I’ll say what a self-model theory is.
Humans as Informational Processing Systems
Questions: What exactly is there for things to happen to? What can perceive things?
Well, bodies exist, and stuff can to happen to them. So let's start there.
Humans have bodies which include informational processing systems called brains. Our brains are causally entangled with the outside world, and are capable of mapping it. Sensory inputs are transformed into neural representations which can then be used in performing adaptive responses to the environment.
In addition to receiving sensory input from our eyes, ears, nose, tongue, skin, etc, we get sensory input about the pH level of our blood, various hormone concentrations, etc. We map not only things about the outside world, but things about our own bodies. Our brain's models of our bodies also include things like limb position.
From the third person, brains are capable of representing the bodies that they're attached to. Humans are information processing systems which, in the process of interacting with the environment, maintain a representation of themselves used by the system for the purposes of the system.
Answers: We exist. We can perceive things. What we see as being our "self" is our brain's representation of ourselves. Generalizably, a "self" is a product of a system representing itself.
Note: I don't mean to assert that human self-modeling accomplished by a single neurological system or module, but I do mean to say that there are a nonzero set of systems which, when taken together, can be elegantly expressed as being part of a self-model which presents information about a person to the person's brain.
Bodily Self Models
Human self-models seem to normally be based on sensory input, but can be separated from it. Your bodily self-model looks a lot like this:
Freaky stuff happens when a body model and sensory inputs don't coincide. Apotemnophilia is a disorder where people want to amputate one of their otherwise healthy limbs, complaining that their body is "overcomplete", or that the limb is "intrusive". They also have very specific and consistent specifications for the amputation that they want, suggesting that the desire comes from a stable trait rather than say, attention seeking. They don't want want to get an amputation, they want a particular amputation. Which sounds pretty strange.
This is distinct from somatoparaphrenia, where a patient denies that a limb is theirs but is fairly apathetic towards it. Somatoparaphrenia is caused by damage to both S1 and the superior parietal lobule, leading to a limb which isn't represented in the self-model, that they don't get sensory input from. Hence, its not theirs and its just sorta hanging out there, but its not particularly distressing or creepy. Apotemnophilia can be described as lacking a limb in the self-model, but continuing to get input from it. Imagine if you felt a bunch of armness coming into your back.
In some sense, your brain also marks this model of the body as being you. I'll talk more about it in another article, but for now just notice that that's important. It's useful to know that our body is in fact ours for planning purposes, etc.
Self Models and Global Availability
Anosognosia is the disorder where someone has a disability, but is unable/unwilling to believe that they have that disability. They insist that they don't move paralyzed arms because they don't want to, or that they can actually see while they're stumbling around bumping into things.
This is also naturally explained in terms of self-model theory. A blind person with anosognosia isn't able to see, and doesn't receive visual information, but they still represent themselves as seeing. So when you ask them about it, or they try and plan, they assert that they can still see. When the brain damage leading to blindness and anosognosia occurs, they stop being able to see, but their self-model isn't updated to reflect that.
Blindsight is the reverse case where someone is able to see, but don't represent themselves as seeing.
In both cases, the person's lack of an ability to represent themselves as having particular properties interferes with those properties being referred to by other cognitive modules such as those of speech or planning.
Self-Model Theories of Consciousness
Self-Model Theories hold that we're self aware because we're able to pay attention to ourselves in the same way that we pay attention to other things. You map yourself based on sensory inputs the same way that you map other things, and identify your model as being you.
We think that things are happening to someone because we're able to notice that things are happening to something
That's true of lots of animals though. What makes humans more conscious?
Humans are better at incorporating further processing based on the self-model into the self-model. Animals form representations of and act in the environment, but humans can talk about their representations. Animals represent things, but they don't represent their representation. The lights are on, and somebody's home, but they don't know they're home.
To be continued...
Kurzban, R., & Aktipis, C. A. (2007). Modularity and the social mind: are psychologists too self-ish? Personality and social psychology review : an official journal of the Society for Personality and Social Psychology, Inc, 11(2), 131-49. doi:10.1177/1088868306294906
Ramachandran, V. S., Brang, D., McGeoch, P. D., & Rosar, W. (2009). Sexual and food preference in apotemnophilia and anorexia: interactions between “beliefs” and “needs” regulated by two-way connections between body image and limbic structures. Perception, 38(5), 775-777. doi:10.1068/p6350
I liked the article in general, but I experienced this line as sort of "coming out of left field".
It is not clear to me that humans as a class are categorically "more conscious" than animals if we drop the definitional assumption that consciousness is largely "what it feels like to be a human from the inside" and try to give it a more cybernetic basis in arrangements of computational modules or data flows.
It seems to me like an empirical question whether there are some animals that are "more conscious" than some humans, and it seems to me that very very little of the necessary science that would need to be done to answer the question has actually been published. I can imagine science being done after we have better cognitive neuroscience on the subject of consciousness and discovering the existence of a kind of animal (octopus? crow? bee hive? orca? dog?) that has "more consciousness" than many reasonably normal humans do.
In the meantime, when I talk with people about the cognitive neuroscience of consciousness, I notice over and over how people conflate the capacity for consciousness with something like "higher levels of brain-mediated efficacy" and also conflate the capacity of consciousness with something like "moral status as a agent with interests". The "animals don't count" content comes up over and over, and has come up over and over in philosophic musings for thousands of years, and I rarely see evidence based justification for the claim.
Irene Pepperberg has a theory (which seems plausible to me) that humans use animals to such an extent that we have deeply engrained tendencies to see them as edible/trainable/killable rather than friend-able. It would actually be surprising if it were otherwise, considering the positive glee dogs and cats take from the torture and dismemberment of smaller animals. If Pepperberg is right, then there is an enormous amount of confabulated hooey in our culture basically "justifying the predation of animals by people who do not want to think of themselves as evil just because they love bacon". I'm not trying to take a position here, so much as pointing out an area of known confusion and dispute where the real answer is not obvious to many otherwise clear-thinking people.
If I saw a vegan arguing against animal consciousness or an omnivore arguing in favor of it, I would tend to suspect that they were arguing based on more detailed local knowledge of the actual neuroscience... rather than due to cached moral justifications for their personal dietary choices. Most people are omnivores and most people think animals are not conscious or morally important, so most people trigger my confabulation detecting heuristic in this respect... as you just did.
It is probably worth pointing out that I'm an omnivore I'm not trying to start a big ole debate on vegetarianism. What I'm hoping to do is simply to encourage the separation of conclusions and data about animal minds that I've marked as "40% likely to be garbage" so it doesn't contaminate very pragmatically worthwhile theoretical thinking about the nature of consciousness, morality, cognitive efficacy, and self-reflective or inter-subjective assessments of agency. I think you can say a lot that is very worthwhile in this area without ever mentioning animals. If you need to talk about animals then it is better to do so with care and citations, rather than casually in the concluding remarks.
I think I read in Daniel Gilbert's Book "Stumbling on Happiness" a very good approximation to what I always thought an animal "thinks" like:
Imagine you're reading a long text and your mind starts wandering and gets lost in shallow feelings like the warm weather or the sounds of the birds, while your eyes keep reading the letters. Suddenly you're at the end of the paragraph and you realize that you can't remember anything you just read... or did you actually read it at all? You look over it again and the words sure look familiar, but you... (read more)