A scientific paradigm for consciousness: a theory of premotor relations.
Consciousness has become a holy grail for scientific research only in the last few decades. In spite of the extensive recent research in the field agreement on a correct approach to a theory has been elusive. We all have an intuitive idea of what we mean by the term and at the very least relate awareness to a descriptive phenomenology. I present a theory of consciousness based on motor capacity. An organism may exert control through movement and any action it performs on its surroundings results in a reaction. This type of reafference generated by movement provides the organism with a unique opportunity to compare perceptual information, for example, a retinal image of a ball with what the body is telling the agent about the object. In other words, limb movements will describe a certain physical distance to the object and the shape will be conveyed by the arc described around it by any part of the body that comes into contact with it. The reafference, also called motor efference copy, can modulate neocortical networks strictly associated with concurrent perceptual information via input to thalamocortical projections. Concurrent perceptual and motor reafferent input provide the critical organizing principles bestowing on a neural assembly the capacity of conscious awareness. The cortical neural coding represents an interactive history and is what I call a premotor relation. It avoids the trap of behaviorism by emphasizing a developmental causality such that, once the networks are established no further motoric component is required. Supportive evidence for this position comes from the classic psychological studies of perceptual adaptation to distorting lenses facilitated by movement and elegant animal experiments dissociating sensorimotor development from visual exposure. One of the most innovative and useful conceptions advanced in the paper is a component theory of motor efference copy analyzing the two key parameters of any action namely force and proprioceptive change. There is massive neocortical input to the basal ganglia and cerebellum and recent research has implicated cognitive roles for these structures. I propose they serve the respective component parameters of motor efference copy. Finally, a theory of premotor relations provides a model for understanding how dysfunction in the basal ganglia and cerebellum relates to cognitive features of schizophrenia and autism, respectively. Motor dysfunction figures prominently in the early literature on these syndromes and I make the case for a fundamental causal connection between motor and cognitive symptoms.
Vakalopoulos
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171 McKean Street, North Fitzroy, 3068 Melbourne, Australia. hinemoa@bigpond.net.au
D001921:Brain / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003243:Consciousness / Q000502:physiology*; D006801:Humans; D008960:Models, Psychological; D009043:Motor Activity / Q000502:physiology*; D010465:Perception / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*