The Neuropathologies of the Self
The neuropathologies of the self are the subject of increasing neuropsychiatric interest. These disorders are linked to right frontal damage and create perturbations in the individual's view of her personal identity, body, persons close to them, or relationship with the world. They include anosognosia for hemiplegia, somatoparaphrenia, the delusional misidentification syndromes, and delusions and fantasies about imaginary persons. Although known for a hundred years, these syndromes are still somewhat "scientific orphans" not regarded as completely psychiatric or neurological in origin, but some complex hybrid of the two. Therefore, they offer a fertile source of information on the neurobiological underpinnings of the self and identity.
I argue the key to understanding these conditions is their previously unrecognized relationship with patterns of thought, defense, adaptation, and motivation considered normal in childhood - such as the use of denial, projection, splitting and wishful fantasy - and that this relationship can serve as a Rosetta Stone for understanding the adult conditions. I propose in the course of normal human brain maturation, between ages 3-8, there is a shift from immature defensive functions and fantasies to mature defenses and fantasy inhibition that critically depends upon maturational processes within the right hemisphere. In the adult cases, right frontal damage creates a state of ego disequilibrium and a return to developmentally immature styles of thought and ego functioning. The preservation and activation of the verbal defenses are the result of the remaining, and presumably relatively intact left verbal hemisphere, and this hemisphere may be "dominant" for these defenses.
Neural Models of the Self and Consciousness
I believe that the reason for our current lack of understanding of the relationship between consciousnesss, the self and the brain is that we have not paid sufficient attention to the hierarchical arrangement of the nervous system. Nervous systems have evolved toward the creation of a hierarchy of brain structures of ever increasing complexity and abstractness, and by understanding the nature of these hierarchies many mysteries about the self and consciousness may be resolved. The functioning of the nervous can be understood as the result of the two great developmental trends, a medial-lateral trend in which the nervous systemn expands from its center outward, like the growth rings of a tree, and a caudal-rostral trend that results in the hierarchical growth of later developing and more complex neurological sructures upon those with more simple and basic organization and function. Progressive growth under the influence of the medial-lateral trend in both evolution and in the course of development of the individual gives rise to an interoself system that is primarily involved with the internal milieu and homeostatic needs of the organism, and an exterosensorimotor system that is primarily concerned with organism's interactions with the environment. A third system - the integrative self system - serves to assimilate the interoself systems with the extero systems, and integrate the organism's internal needs with the external environment. It is within the integrative self systems that the most advanced aspects of the self and those we consider the most characteristic of the human individual take center stage.
I use the basic hierarchical neural architecture of the self to examine some of the fundamental scientific enigmas of our era, such as how the brain maintains mental unity and the unique design features displayed by the brain that make the self and consciousness possible. I suggest that it is through a deeper understanding of the nature of neural hierarchies that the biological basis of the wholeness of self and consciousness can be explained. This hypothesis leads to a solution for what is commonly known as the mind body problem - why consciousness and the self seem so different in form and function from the material brain.
I present what I call the Nested Hierarchy Theory of Consciousness (NHTC)as a way to explain these unique and perplexing problems regarding the relationship between the brain and consciousness. My analysis leads naturally to the conclusion that we must conceive of our personal consciousness as a process. We generally conceive of ourselves as discrete entitities, things, and that is certainly true to an extent. We have material bodies that include material brains, things that can be weighed and measured, touched and divided. But here I will present my belief that many of our common sense notions of what we are as selves are misguided and the true nature of the self, as others have suggested before me, is not what the brain is, but what it does. The self, what you may think of as "you," is an ever-changing process that cannot be located in any specific physical component of the brain itself. It only by appreciating this dynamic that we can understand how we progress from axons to identity.