This week's readings are about consciousness, yet again, but this time with a twist. It isn't consciousness itself which is the focus of all five papers, but rather what we can learn about consciousness from examining situations where it doesn't seem to be rearing its ugly(?) head. Each author has their own tidbits to throw into the mill, and their own conclusions to draw from the data, but what they all are considering is how brain damage disorders can tell us about consciousness.

Martha Farah does the best job outlining the types of disorders interesting to us, and the sorts of theories of consciousness we have to check against the empirical data. She cites three main groups of theories about consciousness, the first of which is a "priveleged role" type account, where consciousness is supposedly the explicit function of some system in the brain. The second type is an "integrated state" approach, where the state of many different systems gives shape to consciousness as we know it. The third type, which ultimately she thinks has the most support, is a "graded" model, where consciousness is a result of the quality of the perceptions.

These categories seem at least somewhat useful, as the models discussed by each of the other authors this week seem to fall nicely into these categories. But more important, I think, is her discussion of disorders. She gives good discussions of blindsight, prosopagnosia, perception and neglect, and pure alexia. She discusses the empirical data for each of these, and then discusses how she thinks each of the types of models above would account for the data.

The most important conclusion she draws from this discussion of disorders and theories, though, is that these disorders do not present a single problem. Farah thinks that these disorders cannot share a single cause, and so will each tell us different things about consciousness, if they tell us anything. She still thinks that a "graded" model of consciousness accounts best for the data from all the disorders, but hopes that further research will be done.

Bernard Baars presents a method for studying consciousness, very much in line with what Farah actually discussed in her discussion of the empirical data we have on disorders. He proposes we use "contrastive phenomenology"; that is, that we examine situations in which a person would normally have a "conscious" experience, but isn't, and try to discover from an analysis of the differences what it is that consciousness is doing. He then presents some examples of where to apply his method, but Farah's discussion is more concrete.

Patricia Churchland is a bit more general, and a bit mores specific. More general, in that she argues not for a specific research method, but for the use of a reductionist research paradigm. She believes a reductionist research program would conduct research simultaneously at many different levels, and take into account data from them all, in the hopes of getting a better picture of the mind overall. Consciousness is not necessarily the goal here, but as a phenomenon it is useful to study. She is more specific in the way that she approaches theories of consciousness. She cites two specific theories about visual awareness, and then discusses them in detail, as well as their explanatory power.

Edoardo Bisiach has on his mind the destruction of the concept of the unity of mind, or at least of consciousness. He arrives at a conclusion similar to Farah's conclusion that brain disorders will tell us different things about consciousness. But he takes the evidence for that conclusion to be saying something stronger, and so concludes himself that it isn't just that they will tell us different things about consciousness, but that they disorders affecting discrete compositional parts of consciousness. So, for Bisiach, the data suggests that there is no unity of consciousness.

Tim Shallice needs an editor. But besides that, his main goal is to discuss critically the empirical data available about disorders, and the conclusions we can draw about them for consciousness. More particularly, he discusses blindsight and "split-brain" patients. He concludes from his discussion that there are many different theories about consciousness (Really? ;), and then suggests than none of them will work, since he wants to reject the "priveleged role" type account that Farah presented, and of which type he claims all the theories he discussed were members.

Hope this is helpful; there was a lot to read, and I didn't feel like re-writing it all. :)