What Is Consciousness and Where Is It Located?
People often ask where consciousness is in the brain, but that question is problematic. The question assumes that consciousness is some special entity embedded within the nervous system. This assumption is a descendent of the philosophical position of dualism promoted by Descartes, who believed that all the body and most of the human brain were material substances like that of any animal, but the soul that contained human consciousness resided in a special place (the pineal gland for Descartes, because it is one of the very few unpaired brain structures).
One problem with dualism is that there is no way for the spiritual soul to interact with the material body because such an interaction must involve a transfer of energy between body and soul for communication and control, but a purely spiritual entity can’t absorb or emit energy — otherwise, it wouldn’t be purely spiritual. A deeper problem for dualism is that it doesn’t explain anything about the relationship between consciousness and brain function, because consciousness is hidden away in a non-material soul. But we know that brain dysfunction can produce altered consciousness. Is the altered consciousness due to the intact spiritual entity within the brain being corrupted by having to use a broken machine to operate in the world, or is the altered consciousness a product of the brain itself?
Many spiritual traditions take the view of the first alternative — that the spiritual entity within the brain is immutable and everlasting, but it functions in the world we know through the physical brain, like a lens focusing the rays of the sun. If the lens is imperfect, the image is corrupted, but the sun remains perfect as the real source of the image.
No neurophysiological experiment has revealed energy leaking out of the brain into some sort of non-material conscious entity, nor has it shown any energy coming into the brain from anything other than known material sources in such a way that the firing of recorded neurons was modulated by any non-physical entity.
A better question about consciousness would be to ask what areas of the brain need to be active for the specific sort of consciousness humans have versus the sort of consciousness other mammals have. For example, consciousness is not possible without an intact reticular formation in the brainstem that controls wakefulness, but this formation is equally necessary for rodents to be awake. What humans seem to have is a very large frontal lobe that interacts with the parietal, temporal, and occipital lobes that interact with each other directly and through the thalamus. The simultaneous, coordinated firing of neurons in the frontal lobe with neurons in the other lobes is necessary for humans’ ability to make choices and responses. Within this loop of billions of neurons is the knowledge of our linguistic categorization of the world — the content of our consciousness.