CALIFORNIA NURSING MENTAL DISEASES CHAPTER I PSYCHOLOGICAL INTRODUCTION As a basis for understanding pathological mental states a knowledge of the physiology of the nervous system and of the principles of psychology which deal with the functions of the mind is necessary. Psychology has, from time immemorial, been briefly defined as "the science of the mind." What is meant by mind is so difficult to define that for the purposes of this course it may be said to mean all those thoughts, memories, fancies, feelings, desires, aspirations, decisions, and activities which make up the conscious life of the individual. Consciousness is even more difficult to define, and it can best be understood in terms of function, for it is a fact which is common in the experience of all that consciousness primarily operates in directing our movements and controlling our behavior." Every individual is so constantly adapting himself to his surroundings and environments, or reacting to sensations received from the organs of his own body, that life itself becomes a series of adjustments to conditions which are continually changing, situations which from time to time are ever varying, and needs which are always recurring or arising anew and demand new activity or behavior. This adjustment to changing conditions of environment is made through the nervous system, which, as has already been learned, is that part of the body which through countless ages of evolution has developed the particular function of adapting the different organs of the body to their environment and the organism as a whole to the world about it. Space does not permit of full discussion of the anatomy and physiology of the nervous system in these pages. In earlier courses these subjects have been studied and the knowledge then gained must now be augmented and applied. All adjustments are made by a mechanism of interconnecting neurons. It has been estimated that there are countless millions of these cells and their fibres overspreading the cortex and lying within the central nervous system, apparently crowded together in great confusion, but in reality arranged or grouped in most perfect systems each with different functions, so that to-day physiologists are able to locate definitely certain areas of the cortex as the sensory area, the motor area, the association areas, the centres for sight, hearing, speech, etc. These different areas are closely connected with each other by the fibres of the cells of which they are composed, and although these fibres are not anatomically continuous, and communicate by contact only, it is believed that impulses pass from the cells of one group to those of another. Microscopic anatomy has shown that at birth there are in definite areas of the cortex certain cells whose fibres are insulated with a sheath, the function of which, it is believed, is to prevent the dissemination of impulses which pass along these fibres, so that they may with undiminished force pass to the appropriate connecting fibre. During the early months of life fibres of other cells in other areas develop sheaths, the growth of which has been noted to be coincident with the increase in the number and intricacy of the bodily movements. Upon these anatomical findings is based the theory of association. It has been further shown that as the intellectual activities increase and the person passes from one experience to another there is a steady increase of these association paths, which is believed to continue up to the time of maturity. In man there are an almost infinite number of connecting or associating fibres, which bring all parts of the nervous system into relation and permit an almost endless number and variety of connections and associations which make possible the ready, diversified, complex, and intricate movement and activities demanded by social conditions. Under normal conditions these nerve cells function in perfect harmony, but various factors, like infections, alcohol, drugs, sickness, trauma, fatigue, and mental weakness or defect, tend to upset or impair this harmonious action by increasing the irritability of the nervous system and lowering the resistance of all paths, so that nerve impulses initiated by stimuli which ordinarily would result in definite, wellordered behavior are not confined to their usual pathways, but become disseminated to other pathways and produce a disordered behavior. This is especially obvious during convulsions, when all the muscles are contracting in a purposeless, disconnected manner. The mechanism by which adjustments are made is briefly this: Impressions or stimuli, a sound, a word, a color, a look, a touch, heat or cold, a taste, a smell, are continually being picked up or received by the specialized nerve endings of the various sense organs. The impression so received is transformed into an impulse, which is transmitted or conducted by the nerve fibre to the appropriate cells in the cortex, where it comes into consciousness, its meaning is interpreted in the light of past experience (perception), and it is transferred or passed along to a particular motor or discharging cell, which in turn transmits it to the appropriate gland or muscle, where it is expressed in the necessary or desired action; or, the impulse may be expressed within the mind itself by some purely mental activity. The response or reaction to a stimulus, therefore, may be either a new thought or feeling, which in turn may find expression in some form of activity, or it may be some very definite and immediate act which is the direct answer to the stimulus. Ideas which originate within the mind and to which there has been no external stimulus also carry with them the impulse to muscular action. Reflex acts. The mechanism of the nervous system, as has already been learned, is present at birth in all normal infants awaiting and ready for further development. Many connections between cells are already made by nature. These are the inborn or inherited connections, and over these natural pathways certain stimuli pass to the cells whose function it is to complete their expression in the required action, without ever coming into consciousness or under the control of the mind. Many acts of this kind are unceasingly taking place in the body. These are the physiological or reflex acts concerned in circulation, respiration, digestion, the reaction of the pupil to light, the emptying of the gall bladder, etc., and do not directly influence the behavior. There are other reflex acts of which one may be conscious but which are nevertheless performed without direction of the mind, such as coughing, sneezing, winking when the eye is touched, and the instantaneous movement of the hand when it is in contact with anything which produces pain. In the course of nervous and mental disease some of the reflex responses, like those to excitation of the sole of the foot, various tendons and the eye, may become exaggerated in action, while others may become weakened or abolished altogether. Inasmuch as research has discovered the pathways traversed by the stimuli which produce these responses, these changes are of great importance in the diagnosis of disease for they indicate where in the central nervous system there has been a destruction of cells or fibers, or a weakening of their function. Voluntary activity. The first movements, kicking, grasping, crying, etc., are reflex, but as the mental life develops and a movement made at random brings some definite result and a feeling of pleasure or satisfaction, the result and feeling tend thereafter to be associated with the act, and it is purposely repeated, and therefore becomes an act directed by the will or volition. Every voluntary act is prompted by desire and represents a choice of action. There is always a motive or incentive, something to be acquired or accomplished which furnishes the immediate stimulus. The direction of voluntary activity or behavior is deter mined by the ideas, interests, and desires which are most clearly in consciousness. Myriad impressions are being continually received by the sense organs and only a few of them ever come into consciousness or awaken any response, owing to the fact that the vast majority are not selected by attention to be so brought into consciousness. Attention selects from this vast throng of ideas and impressions which are surging incessantly within and without the portals of the mind only those which are related to the purposes, interests, aims and desires of the individual life. Attention may be gained temporarily by a bright light, a moving object, a familiar or unfamiliar sound, a strong odor, a painful sensation or anything which is novel or unusual, unless other and stronger impressions engross it. Absentminded is a term which is frequently used. This does not mean that there is literally an absence or lack of mind, but that the attention is so occupied with certain trains of thought and trends of interests that other impressions are not perceived. In many forms of mental disorder the attention is so absorbed by imaginings, doubts, fears and other morbid thoughts, that other impressions are excluded from consciousness and little heed is given to things present. To arouse new interests which will gain and hold the attention constitutes a large part of the nursing of these cases. Herein lies the value of occupations, for any bit of work which makes demand for voluntary activity of the hands, must for the time being occupy the attention to the exclusion of other thoughts, and when interest in the work is aroused and the demands on attention increase, the old ideas and interests are crowded out and finally displaced. It is sometimes very difficult to attract the attention and to hold it for any considerable period, and many repetitions of effort must be made by the nurse, who should remember that the work must be something which must appear attractive to the patient, and must bear some relation to the interests and aims of his life before his illness. Inhibition. Just as an act or a movement which produced |