The issue of where "the person" or the I-function resides in the nervous system has been bothering me. In class you said that we know that their is a I-fuction that feels and is able to express what it has felt in the brain. You also said that we have no way of finding out whether or not the spinal cord has such an ability because we have no way of communicating with the spinal cord. The way I see it, the brain and spinal cord, just like the heart and lungs, each have their individual functions. The heart will never control breathing and the lungs will never control the circulation of blood, eventhough each organ is dependant on the function of the other. I think that the same kind of distribution of function is true for the nervous system. I think that the I function depends on the inputs from the spinal cord, and that the spinal cord responds to inputs from the I fuction, but I don't think that the spinal cord also has a component I function. By taking a look at people in Persistive Vegetative State, ie people who have lost cortical fuction but have retained brainstem function, it is possible to examine what kind of role the spinal cord plays in term of the I function and conciousness. These people exhibit bodily functions such as breathing,gagging, coughing, but seem to have lost the ability to be concious and aware of themselvesaand their surrounding, the ability to comprehend, the ability to question, and so on. It is as if these people are living, but not really alive. I think by looking at these cases and examining the effects of the loss of cortical function, we can say with as much certainity as allowed in science that the I fuction does reside in the brain. It is true that we cannot say with complete certainty that an I-fuction does not also reside in the spinal cord. But chances are, the spinal cord, which is concerned with the more primitive life forces, is not complex enough to house an I function. I believe that the development of the brain, specifically certain regions of the brain,have evolved to take on this so called I function.
I'm inclined to agree with you, but I still think its important to understand that we don't yet have a definition of consciousness which would allow us to be certain about the capabilities of the spinal cord ... and that we could be missing something simply because the spinal cord doesn't "talk" in the ways we normally use to assess consciousness. My point is less that the spinal cord might be conscious than to critically examine what we MEAN by conscious. And that many important properties of things (including the spinal cord) have been missed because people didn't look for them in the right way and hence presumed them to be absent. You're right, though, that additional observations make consciousness in the spinal cord less likely. PG