The Mind body problem: Specific energies, Parallelism, Psychophysics

Allport states the mind body problem as the problem of the relation of the mental to the physical. One of the most naïve but nature early views of mind was the conception of an inner being or agent that receives some form of communication from the outside and acts accordingly. In the earlier days the inner recipient of information from the outer world was called the sensorium. It was thought that objective give off direct copies or images of themselves which, being carried to the sensorium by the nerves, inform the Sensorium of the world outside. Psychologists soon became dissatisfied with this simple picture. Stimulation, afferent nerve conduction and cortical process must have characteristics of their own that enter into the process. It was considered unlikely that an exact and realistic image of the object was conveyed to the inner perceiving agent. In 1826 and 1838 Johannes Muller published his famous doctrine of the specific energies of nerves, maintaining that the Sensorium is aware only of the states of sensory nerves, not of the external objects themselves, and that each of the senses has nerves that possess their own specific energies. The same stimulus acting on different nerves gives to difference qualitative experiences, and different stimuli acting on the same nerve give rise to the same sensory quality. The seat of the specificity lies in the nerve or in its termination in the brain, not in the respected organ. Muller’s theory has had great influence. Minus the concept of sensorium and with certain other modification, it remains even today as a working postulate. But because each type of respect organ has its homologous or proper stimulus, even thought it may be excited by other forms of energy, theories of the special senses have been elaborated, such, for example, as the Helmholtz theories of audition and vision and the color vision theory of Hering. According to modern positivistic behaviorists, Sensation means to then merely the route taken by the impulses in leading to a response of discriminating the stimulus employed or its magnitude. Anything experienced as quality or dimension by the subject is irrelevant. In this view the notion of specific energies would not have been needed; it is only the specific stimulus-response connections that would be significant. Because of the failure to find a definite law of specificity or a suitable referent to explain it little is left of the specific energies doctrine. Furthermore it was not general, since it postulated a relationship only for quality and not for sensory, magnitudes or intensities.