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 | "The Division of Minds" |  |
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| The machine does not exist before the purpose. But new purposes may make use of existing machinery, This observation came about by examination of the theory that consciousness (self-awareness) was not present in the actors of the Iliad; and in light of the theory that the sub-conscious resides in the right brain. It caused the question as to the existence of the left brain before its apparent need. There is no conflict if the left brain was originally developed to 'manage' external affairs while the right brain managed the internal responses; the corpus callosum being the interface. It is only when consciousness of the organism's separation from the rest of nature came about, and the awareness that humanity had the ability to write his own role, that the focus of attention became more fixated on external events. From a lack of self-awareness, to a belief of being a plaything of a greater, external power; to the realisation that we are able to influence external events, within our own spheres of jurisprudence. Our problems lie in the dichotomy of still believing ourselves playthings of fate, or some other god, and our desire to extend that circle of influence. It is possible to picture a far distant ancestor gazing with wonder at his own reflection in a pool of water; suddenly struck by the realisation that he was a separate identity from all of nature that surrounded him. A shattering revelation! Where did that knowledge come from? From what source did the 'voice' come from; telling him who he was? The birth of ego probably coincided with the birth of mankind's first external gods. The eminent geneticist, Francis Galin, believed that during moments of disconnection, the left brain alone governs consciousness. Mental events in the right hemisphere, however, continue a life of their own and act as a 'Freudian' unconscious, as an 'independent reservoir of independent cognition,' which may create uneasy emotional states in a person. Latter day brain surgery has revealed much about the workings of the minds. |
| Commissurotomy: The Left and Right Brains - collectively known as the cerebral cortex - sit over and around our earlier brains; laying inside the bulge of our skull above the ears and behind the forehead. They are connected by a thick bundle of fibres (the corpus callosum) along which neuro-messages pass backwards and forwards. The operation (commissurotomy) involves the severing of this nerve trunk, leaving the two brains unable to communicate directly; all messages having to be re-routed via the stem brain. The American neurophysiologist, Roger Sperry, holds that the patient may then have two minds, or two selves. "Everything we have seen so far indicates that the surgery has left these people with two separate minds, that is, two separate spheres of consciousness. What is experienced in the right brain appears to lie entirely outside the realm of experience of the left brain. This mental dimension has been demonstrated in regard to perception, cognition, volition, learning and memory." "A Divided Mind: Observation on the Conscious Properties of the Separated Hemispheres." Annals of Neurology. LeDoux, Wilson, and Gazzaniga. In that writing they discuss observations of a patient, known as P.S., who has undergone commissurotomy. "Each brain in P.S. has a sense of self, and each possesses its own system for subjectively evaluating current events, planning for further events, setting response priorities, and generating personal responses. On those days that P.S.'s left and right hemispheres [brains] equally valued himself, his friends, and other matters, he was a calm, tractable, and appealing adolescent. On the days that the right and left brains disagreed on these evaluations, he became difficult to manage. Clearly, it is as if each mental system can read the emotional differences harboured by the other at any given time. When they are discordant, a feeling of anxiety, which is ultimately read out by the hyperactivity and general overall aggression, is engendered." |
| The following paragraphs are from, "The Oxford Companion to the Mind", edited by Richard L. Gregory. "Cerebral commissurotomy, the split-brain operation; has been performed with varying completeness on a small number of human beings since the mid-1940s, always in hopes of checking crippling epilepsy, to stop the non-functional neural discharges reverberating between the hemispheres and severely damaging the cortical tissues. The breakthrough in estimation of the mental effects of this operation came from investigations in Roger Sperry's laboratory at the California institute of Technology. In Los Angeles, the neurosurgeons Philip Vogel and Joseph Bogen concluded that selected epileptic patients would benefit from the surgery and suffer no serious mental loss. Between 1962 and 1968, nine complete operations were performed with success in reducing fits. Psychological tests performed by Michael Gazzaniga, Sperry, and Bogen at the California Institute soon revealed that, while the general psychological state and behaviour was, in most cases, little affected, there was a profound change in mental activities. By far the most dramatic finding of the early tests was the total failure of the right cerebral cortex on its own to express itself in speech. It could not utter words to explain its awareness or knowledge. These events not only confirm a division of awareness, but they raise important questions which have been debated in clinical neurology for over a century. Taken with evidence that the systematic calculation and forming of logical propositions with words were better performed by the left hemisphere, these results favoured the idea that the right hemisphere is better at taking in the structure of things systematically without analysis, assimilating all components at once in an ensemble, figure, or gestalt.[Gestalt, pattern] Recently, experiments with the same subjects have demonstrated that the right hemisphere tends to be superior at metaphorical rather than literal perceptions. and that it perceives the emotions or moods in facial expressions or vocalisations better than the left. The brain is adapted to create and maintain human society and culture by two complementary conscious systems. Specialised motives in the two hemispheres generate a dynamic partnership in the mind of each person, between the intuitive, on the one side, and the analytical or rational, on the other. This difference appears to have evolved in connection with the human skills of intermental co-operation and symbolic communication." |