Neurophysiological Mechanisms and Consciousness

Consciousness may be understood as a behavioural state and thus levels of consciousness may be distinguished. But consciousness as we understand it is an experience. Any critical reasoning about it will lead to a dualistic formula. A neurophysiological mechanism may exist for this. In the neocortex various aspects of the world and of the physical and social relationships of the individuum to the world are represented through thalamocortical projection systems. There is no unified representation of the world in any single cortical area. All neocortical outputs feed into action systems of the brain. The synthesis of the distributed cortical representations of the world is thus realized through the action elicited by their combination. The action systems of the midbrain-cerebellum and the basal ganglia feed back into neocortical areas (internal loops). The action itself changes the relationship of the individual to the outside world and thus its representation in the brain (external loops). The role of the basal ganglia in the normal functioning of processes in consciousness and in the synthesis of cortical representations is described, which further emphasizes the intricate connections between motor performance and consciousness. The function of the reticular substance and related structures is seen as a gating mechanism for the (thalmic) access gates to the cortex and thus to mechanisms of conscious experience. The basis for the experience of consciousness is the symbolic representation of the world and of the individual to that individual's brain. This self-representation is based on the linguistic competence of the brain in a broad sense and is therefore possible only for brains with such a competence. The symbolic self-representation is called the reflective loop and its conditons are briefly discussed.