Plasticity (psychology)

“ The only thing they can do, in short, is to deepen old paths or to make new ones; and the whole plasticity of the brain sums itself up in two words when we call it an organ in which currents pouring in from the sense-organs make with extreme facility paths which do not easily disappear. For, of course, a simple habit, like every other nervous event—the habit of snuffling, for example, or of putting one's hands into one's pockets, or of biting one's nails—is, mechanically, nothing but a reflex discharge ”

“ So far we have dealt with the space of sight; but there is also a space of touch; and we have next to ask whether the perception of distance can be couched in terms of touch alone. Our appeal lies to those who are born blind. Observations show that, in their case, the direct perception of solidity, of plasticity, is rare and fleeting; it arises, perhaps, when they clasp a child to their breast, or when they have been trained by long manipulation to distinguish objects of various shapes and sizes; it does not form a permanent item of their mental furniture. ”

“ Nothing modifies them, nothing impairs them; good or bad, they are solid as the diamond. At the other end of the scale let us place the amorphous, who, by their very definition, are plasticity incarnate. Between these two extremes we may arrange seriatim all modes of character, so as to pass by imperceptible gradations from one end to the other. It is clear that, as we descend towards the amorphous, the individual becomes less refractory to the influences of his environment, and the proportion of acquired character increases in the same ratio. ”

“ Consequently docility has been identified with imitativeness, instead of with power to re-make old habits, to re-create. Plasticity and originality have been opposed to each other. That the most precious part of plasticity consists in ability to form habits of independent judgment and of inventive initiation has been ignored. ”

“ Whatever the extent of these bodily changes may be, if we grant the correctness of our inferences in regard to the plasticity of human types, we are necessarily led to grant also a great plasticity of the mental make-up of 65human types. We have observed that features of the body which have almost obtained their final form at the time of birth show modifications of great importance in new surroundings. ”

“ Relative plasticity.—Is there any relation between the degree of mental modifiability which remains in adult life, and the character of the mental evolution in respect of mass, complexity, and rapidity? The animal kingdom at large yields reasons for associating an inferior and more rapidly-completed mental structure, with a relatively automatic [356] nature. Lowly organized creatures, guided almost entirely by reflex actions, are in but small degrees changeable by individual experiences. ”

“ The plasticity of a psychic group is due to the plasticity of the infant mind and brain, which is wonderfully capable of acquiring the language, thought forms, and differentiating characteristics of any group in which it may be reared. ”

“ The period of plasticity is evidently prolonged in proportion to the degree in which conscious intelligence has superseded mere brute force in promoting successful survival—that is to say, the transmission of mental ability rather than of physical strength postpones maturity. ”

“ The principle "Be Childlike" is paramount in the education of mankind. The child represents the future, all the possibilities, all the coming greatness of the human race. We, the adults, are contaminated by the brutal passions and vices incident to the struggle for existence and self-preservation.
Plasticity of mind is characteristic of genius. Plasticity of mind and body is preeminently characteristic of the child. Adaptability and plasticity are found in all young tissue, muscle, gland, and nerve. ”

“ Even when the objective stimulus is imperfect, we shall still see the full convexity of a human face, the correct inclination of an angle or sweep of a curve, or the distance of two lines. Our mind will be like a polyhedron, whose facets are the attitudes of perception in which it can most easily rest. These are worn upon it by habitual objects, and from one of these it can pass only by tumbling over into another. ”

“ As we have seen, the acquiring of habits is due to an original plasticity of our natures: to our ability to vary responses till we find an appropriate and efficient way of acting. Routine habits, and habits that possess us instead of our possessing them, are habits which put an end to plasticity. They mark the close of power to vary. There can be no doubt of the tendency of organic plasticity, of the physiological basis, to lessen with growing years. ”

“ The same physiologist suggests, that as there is considerable plasticity in the human frame, not only in youth and during growth, but even in the adult, we ought not always to take for granted, as some advocates of the developement theory seem to do, that each advance in psychical power depends on an improvement in bodily structure, for why may not the soul, or the higher intellectual and moral faculties, play the first instead of the second part in a progressive scheme? ”

“ The evolution of intelligence as such runs parallel with the evolution of plastic behaviour; and this plasticity is necessitated by the variety and the complexity of the conditions of life—a variety and a complexity requiring many subtle modifications of response to enable the behaviour to reach accommodation to the changeful exigencies of diverse circumstances. ”

“ Indeed, if it be illogical to talk of mechanisms evolving themselves and giving rise to the beings whose ends they serve, we have no choice but to accept this dualism of mind-shaping and matter inert. No choice, that is, unless we can establish the primacy of the psychological standpoint. Here we have duality but not dualism, and the object is not inert, i.e. is not matter. But still there remain two difficulties—possibly resolvable into one—the plasticity already referred to as involved in all biological development and hereditary transmission ”

“ It is only by a visual fiction that we come to regard our active selves as distinct from the dynamic system. We cannot, in fact, shake off the bonds of corporeality, of gravity, of all the various restraints of our organic activity.
Relatively, however, the cerebral activity of Thought is liberated from the stresses of the dynamic environment ”

“ The persistence or permanence of the paths is a physiological property of the brain-tissue of the individual, whilst their number is altogether due to the facts of his mental experience. Let the quality of permanence in the paths be called the native tenacity, or physiological retentiveness. This tenacity differs enormously from infancy to old age, and from one person to another. Some minds are like wax [Pg 660] under a seal—no impression, however disconnected with others, is wiped out. Others, like a jelly, vibrate to every touch, but under usual conditions retain no permanent mark. ”

“ The mental processes have long since lost their plasticity and capacity for functioning except in the most circumscribed orbit, and even here the mental powers soon feel the blighting shadows creeping over them. ”

“ We can possibly best realize the relation of instability to complexity of structure, if we regard life, including both physiological and psychic processes, as an ascending organization of sensori-motor reactions to the influences of the external environment. ”

“ The histories of the most civilized nations show us that in their earlier times the modifiability of ideas and habits was less than it is at present. And, if we contrast classes or individuals around us, we see that the most developed in mind are the most plastic. To inquiries respecting this trait of comparative plasticity, in its relations to precocity and early completion of mental development, may be fitly added inquiries respecting its relations to the social state, which it helps to determine, and which reacts upon it. ”

“ It is better to talk of objects usually combined, and which are now divided between the two 'selves,' in the hysteric and automatic cases in question. Each of the selves is due to a system of cerebral paths acting by itself. If the brain acted normally, and the dissociated systems came together again, we should get a new affection of consciousness in the form of a third 'Self' different from the other two, but knowing their objects together, as the result.—After all I have said in the last chapter, this hardly needs further remark. ”

“ The most insignificant objects are guarded like priceless jewels, corresponding to their value in the complex. The whole environment is considered sub specie amoris. Whatever does not suit the complex glides by; all other interests sink to nothing, hence there results a standstill and a temporary reduction of the personality. Only that which suits the complex excites affects and is psychically elaborated. All thought and action move in the direction of the complex. ”

“ The plasticity, or educability, of the pupil is the fundamental postulate of pedagogics.
The concept plasticity, or capacity for being moulded, extends far beyond the confines of pedagogics. It takes in even the primary components of matter. It has been traced as far as the elementary substances entering into the chemical changes of organic bodies. Signs of plasticity of will are found in the souls of the higher animals. ”

“ The more complex the psycho-motor structure is, and the further it is removed from the original nucleus, the more easily does it become disintegrated in the downward course of the process of degeneration. ”

“ Our higher æsthetic, moral, and intellectual life seems made up of affections of this collateral and incidental sort, which have entered the mind by the back stairs, as it were, or rather have not entered the mind at all, but got surreptitiously born in the house. No one can successfully treat of psychogenesis, or the factors of mental evolution, without distinguishing between these two ways in which the mind is assailed. [Pg 628] The way of 'experience' proper is the front door, the door of the five senses. The agents which affect the brain in this way immediately become the mind's objects. ”

“ What is so clearly true of the nervous apparatus of animal life can scarcely be otherwise than true of that which ministers to the automatic activity of the mind. For, as already shown, the study of psychology has evolved no more certain result than that there are uniformities of mental action which are so entirely conformable to those of bodily action as to indicate their intimate relation to a 'mechanism of thought and feeling,' acting under the like conditions with that of sense and motion. ”

“ As the organism ages, becomes differentiated, and adapted to special functions and conditions of life, it loses its original plasticity. The tissues become fixed and the functions set. The adult’s brain and mind begin to work in ruts. The child is superior to the adult. ”

“ What is to be the test of mind? Indeed, mind and plasticity are almost the same thing. Race, therefore, as being the stiffening in the evolution of life, might seem by its very nature opposed to mind as a limiting or obstructing force. Are we, then, going to return to the old pre-scientific notion of soul as something alien to body, and thereby simply clogged, thwarted and dragged down? That would never do. Body and soul are, for the working purposes of science, to be conceived as in perfect accord, as co-helpers in the work of life, and as such subject to a common development. ”

“ Those who contend that knowledge results wholly from the experiences of the individual, ignoring as they do the mental evolution which accompanies the autogenous development of the nervous system, fall into an error as great as if they were to ascribe all bodily growth and structure to exercise, forgetting the innate tendency to assume the adult form. Were the infant born with a full-sized and completely-constructed brain, their position would be less untenable. ”

“ I am, however, bound to say that the missing faculty seems to be replaced so serviceably by other modes of conception, chiefly, I believe, connected with the incipient motor sense, not of the eyeballs only but of the muscles generally, that men who declare themselves entirely deficient in the power of seeing mental pictures can nevertheless give lifelike descriptions of what they have seen, and can otherwise express themselves as if they were gifted with a vivid visual imagination. ”

“ It is constituted by a bundle of tendencies essentially physiological in character, and these tendencies have nothing added or external; they are life in action. Each anatomical element, each tissue, each organ has but one end, to exercise its activity; and the physiological individual is nothing but the convergent expression of all these tendencies. They may present themselves under a double form. In the one case they express a lack, a deficiency; the anatomical element, the tissue, the organism has need of something. In this form the tendency is imperious and irresistible ”

“ In this case the action is double, for it implies the disuse of certain connections which have been made and the forming of others; for the breaking of a bad habit means the beginning of a good one.
The plasticity of neurone groups seems to vary in two respects--as to modifiability and as to power to hold modifications. The neurone groups controlling the reflex and physiological operations are least easily modified, while those controlling the higher mental processes are most easily modified. The neurone groups controlling the instincts hold a middle place. ”