Brain capacity

“ On the contrary, he sees that in the vertebrates those parts of the brain which physiological research and pathological experience prove to be the seat of the higher mental activities keep pace, in their comparative development, with the growth of these activities. Where mental capacity makes the immense leap from the anthropoid apes to man which is indicated by the power of speech, we find a corresponding leap in cerebral mass. ”

“ The whole matter of the relation of intelligence to brain-weight, and of the nature and quantity of energy which is a function of this organ, is, indeed, fundamentally a question of physiological chemistry. The assumption that capacity for muscular work is in direct proportion to the mass is approximately correct; but the assumption that capacity for mental work is in proportion to the mass of nerve substance is a gross error, as anthropologists now very well know. ”

“ Psychology and physiology have been busily engaged in discovering these correlations. So extended are they that the suggestion that consciousness is inseparable from the brain forces itself home ever more obstinately. Mental capacity runs parallel with the finer development of the brain. Is not, therefore, the very meaning of mental capacity connected with the needs and activities of the organism? But the case is still stronger when we note what happens to an individual when something goes wrong with the brain. ”

“ We may also find among some races which are not considered very intelligent a brain or cranial capacity of relatively considerable amplitude. The conditions, moreover, which make the brain to be larger or smaller are manifold. The volume of the encephalus may be related to the size, to the weight of the body, and to the muscular power; and the brain itself may become voluminous in the race and the individual according to the degree of intellectual activity. The most important factor in the degree of the intelligence of the individual is the quality of the cerebral cell ”

“ In the first place we have full control over the intake of thought impulses; and more important, we use multiple wave lengths in feeding impulses to The Brain and throughout all the impulse-processings. Even the human brain has some capacity of simultaneous thought on different levels of consciousness, but its range in this respect is extremely limited. The Brain by way of contrast operates on two thousand different wave lengths, which means that The Brain can process at least 2000 problems at one time. ”

“ He can predict all the movements that will take place as certainly as a chemist knows in advance the reaction he will obtain from mixing certain bodies.
Pathology confirms our conclusion respecting these higher functions of the cerebrum. Loss of cerebral substance, in man, is followed by a weakening of the intellectual powers. They make a very childish mistake who attempt to deal with the physiological materialism of our day by citing the American crow-bar case, or any number of cases of brain-loss unaccompanied by marked intellectual enfeeblement. ”

“ In ordinary discourse we use the words brain and mind as interchangeable terms, because it is quite evident that where there is lack of intelligence there is deficiency in the brain and where there is a high degree of intelligence there is a correspondingly high development of brain. The immense advance in recent times in our knowledge of the physiology of cerebral process serves more and more to emphasize the entire and absolute dependence of mind on brain, and particularly of the higher processes of mind on the development of the cells and fibres of the cerebral cortex. ”

“ Functionally, also, the importance of the brain has been unduly emphasized by certain anthropologists. There is far less direct connection between intelligence and brain mass and form than was at one time presumed. It is true that the cerebral lobes are the seat of consciousness; but the brain is no more essential to intelligence than is the circulation, or digestion, or the liver. Intelligence is the mediation of action, and all organs and tissues which cooperate in forming an association, are equally important with the brain. ”

“ "It is a question of cubic capacity," said he; "a man with so large a brain must have something in it." ”

“ Hence the data thus far accumulated in evidence of the actual structure, size, and weight, of the human brain fall far short of what is requisite for a solution of many questions in reference to the relations between cerebration and mental activity. From time to time men of science have sought by example, as well as by precept, to lessen such impediments to scientific research. ”

“ A peculiar fact relating to these convolutions is observed by all anatomists: mental [pg 99] development is always accompanied by an increasing dissimilarity between their proportional size.
The cerebral hemispheres may be injured or lacerated without any pain to the patient. The effect seems to be one of stupefaction without sensation or volition. A well-developed brain is a very good indication of intelligence and mental activity. That the cerebrum is the seat of the reasoning powers, and all the higher intellectual functions, is proved by three facts. ”

“ Authorities differ as to how far it is possible to localise the functions of the brain; but this at least seems pretty clear--that none of the functions of mind are performed without real activity in the mass of grey and white nervous matter named 'the brain.' Now, this is not a matter for the physiologist alone, but for every mother and father of a family ”

“ I would desire this evening to lay down and to enforce a principle that is, I think, not sufficiently, and often not at all, considered in practical medicine and surgery. It is founded on a physiological basis, and it is of the highest practical importance. The principle is that the brain cortex, and especially the mental cortex, has such a position in the economy that it has to be reckoned with more or less as a factor for good or evil in all diseases of every organ, in all operations and in all injuries. ”

“ This is the rationale of the pathological treatment of the brain. Tell an overworked president of a railway company, who falls asleep at the directors' meeting, that he must rest, or die of softening of the brain, and he will smile a sad reply that he can not rest. He is right, thus far: he can not rest his whole brain, but he can rest the cerebellum—the seat of the will-power—by bringing into higher activity and more frequent exercise the upper and frontal lobes. ”

“ There is, however, no doubt that the various races, when carefully compared and measured, differ much from each other,—as in the texture of the hair, the relative proportions of all parts of the body,283 the capacity of the lungs, the form and capacity of the skull, and even in the convolutions of the brain.284 But it would be an endless task to specify the numerous points of structural difference. The races differ also in constitution, in acclimatisation, and in liability to certain diseases. Their mental characteristics are likewise very distinct; ”

“ There is no more interesting subject of inquiry open just now than that of the interaction between the thoughts of the mind and the configuration of the brain. The fair conclusion appears to be that each is greatly the cause of the other; that the character of the persistent thoughts actually shapes the cerebrum, while on the configuration of this organ depends in turn the manner of thoughts we think. Now, thought is, for the most part, automatic. We think, without intention or effort, as we have been accustomed to think, just as we walk or write without any conscious arrangement of muscles. ”

“ For the two halves of the brain being once thus knit together, the progress of cerebral complexity is traceable through a complete series of steps from the lowest Rodent, or Insectivore, to Man; and that complexity consists, chiefly, in the disproportionate development of the cerebral hemispheres and of the cerebellum, but especially of the former, in respect to the other parts of the brain. ”

“ If a vitalistic principle were needed to enable us to understand the workings of the ordinary body cells, how much more is it required for the workings of brain cells. There is something behind that guides and rules the brain, and through which it accomplishes its work. It is this that brings about an unconscious cerebration accomplishing intellectual results for us even when the brain machine itself is at rest as when asleep, or fails, for some reason, to be in readiness to take up the work that we demand of it. ”

“ There is only one point at which control of action can be effective, and that is where the responsive movement of the body to a stimulus received is initiated, that is in the cerebral cortex. Because the mind is acting there it seems to come into existence there. That is our reason for saying that everything must happen just as if the mind was produced by the brain. But the mind is a reality of an entirely different order to that which alone can be produced by physical movement or by the material disposition of such things as atoms and molecules. ”

“ It is hard to imagine them as having special centres; it is harder still to invent peculiar forms of process in each and every centre, to which these feelings may be due. And let one try as one will to represent the cerebral activity in exclusively mechanical terms, I, for one, find it quite impossible to enumerate what seem to be the facts and yet to make no mention of the psychic side which they possess. However it be with other drainage currents and discharges, the drainage currents and discharges of the brain are not purely physical facts. ”

“ And is not this the conception we moderns form of the brain? We do not imagine the cerebral mass, as a mere mass, and unrelated to the rest of the organism, to have in itself sensibility; but we conceive it as the centre of a great system, dependent for its activity on a thousand influences, sensitive because sensibility is the form of life peculiar to it, but living only in virtue of the vital activities of the whole organism. ”

“ An individual having a narrow, high head, may determine readily enough upon a course of action, but he requires a longer period for its completion than one whose head is both high and broad. Such a cerebral conformation cannot accomplish its objects without enjoying regular rest, and maintaining the best of habits. Breadth of this region of the brain indicates ample resources of energy, both psychical and physical. It denotes greater vigor of constitution, one that continually generates volitive forces, and its persistency of purpose may be interpreted as functional tenacity. ”

“ When animal life reaches a high development, the functions which are diffused become concentrated into special organs. Intelligence or psychic life is concentrated in the cerebrum, and entirely removed from the spinal cord. The physiological energy apart from the psychic, is concentrated in the cerebellum, and thus the intermediate psycho-physiological organ, the optic lobes or quadrigemina, being no longer important, dwindles to become the smallest part of the brain. ”

“ We meet with the preponderance of nervous diseases in the refined and cultivated classes, where, by premature and stimulating processes of education, there has been forced an elaboration of brain-structure, hastening the functional activity of the brain, with no due regard to the law of evolutional precedence. Normal growth and development will give us healthy minds, while a structurally degraded centric nervous system, or an altered quality of blood, and secondary disturbance of nerve-function, will antagonize healthy mental manifestation. ”

“ After the discovery of man’s complicated and complex brain and the clinical correlation between brain injury and effects on man’s performance, the brain and mental factors began to be related to one another. As descriptions of man’s brain became more and more exact and clinical correlations increased sufficiently in numbers, new investigations on the relationships between brain size and intelligence in Homo sapiens were started. ”

“ But his planning is often impractical and for this reason he does not succeed when working independently as does the Osseous.
Capitalizes His Cerebrative Instinct
¶ The Cerebral gets his name from the cerebrum or thinking part of the brain, because this is the system most highly evolved in him. Its great size in the large-headed man causes it to dominate his life.
Thus his chief instinct is cerebration—dreaming, meditating, visualizing, planning. Since these are the real starters of all progress this type should be encouraged, with a view to making him more practical. ”

“ But if it be deficient, the volitive energies preponderate, and there is a lack of those susceptibilities of constitution, which prevent excessive waste. The cerebral faculties are Fear, Anxiety, Sensibility, Servility, Relaxation, and Melancholy, and their excessive predominance indicates a weak, vacillating, irresolute character, and the existence of those bodily conditions which produce general excitability and chronic derangement. A full development of this portion of the brain indicates that the person is naturally dependent, inferior, and subservient to stronger characters. ”

“ In other words, there is every reason to believe that numerous "centres," in this restricted sense, exist in the brain that have as yet eluded the investigator. Indeed, the current conception regards the entire cerebral cortex as chiefly composed of centres of ultimate co-ordination of impressions, which in their cruder form are received by more primitive nervous tissues—the basal ganglia, the cerebellum and medulla, and the spinal cord.
This, of course, is equivalent to postulating the cerebral cortex as the exclusive seat of higher intellection. ”