This question of stimuli deserves further notice. It is not so difficult to realize the mechanism by which a stimulus which clearly crosses the threshold of consciousness can lead to a given reaction. But it is perhaps difficult to imagine how so many stimuli which do not cross the threshold of consciousness or which, if they do, are not recognized by the patient at the time as having any reference whatever to the special memory can yet set the memory mechanism into action. The result may not be seen till after the relapse of some considerable period of time, as in the case of a man who for years had been disturbed by terrific nightmares, based on the idea of snakes coming out of the ground and attacking him. He complained one day that he was much worse, that three nights before he had had the worst nightmare of his life. On being questioned as to what could have suggested snakes to him he could not tell. A few minutes later he said: "I think I know the cause now. I spent the evening before I had that nightmare with a sergeant who had returned from the service in India." This friend amongst other things had mentioned that whenever they were about to bivouac they had to search every hole under a stone and every tuft of grass to see that there were no snakes there. This, which had been received as an ordinary item of information, had been the stimulus which had set his memory mechanism into action and the nightmare between two and three o'clock in the morning had been the result.
The result in many instances is evidenced by an emotional state alone and the actual memory of the original experience may not come into consciousness. Many examples of this might be given. The sound of a trolley wheel on a tram wire in one case gave rise to terror instead of its normal reaction, viz., that of satisfaction at getting to the destination quickly and without effort. This terror was produced because the sound on the wire resembled that of a shell which came over, blew in a dugout, killed three men, and buried the patient. No memory of this incident came into consciousness, only a terror similar to that experienced at the time of the original incident was experienced. Or, the time four o'clock in the afternoon could act as a stimulus to arouse an emotional state of misery similar to that experienced at the same time of day during an illness some years previously. Or, passing the house of a doctor when on a bus could produce a sudden outburst of anxiety, giddiness, and confusion; the patient had been taken into that house at the time of an epileptic attack. Or, showing photographs of the front could lead to an epileptic attack which was based on the memory of the time when the patient was wounded in the head; this has occurred on two separate occasions separated by an interval of some months. Or, noticing a familiar critical tone in a remark made at a dinner-table could lead to an acute change of feeling so that the subject who, before dinner, had felt she would like to play a new composition on the piano so as to obtain the opinion of the guest who had exhibited the critical tone, after dinner felt incapable of doing so. Her feelings had been hurt on many former occasions by critical remarks made by him in that tone. The critical remarks were not called to memory but there arose the feeling that under no circumstances could she play that piece to him.
Of special importance also are the experiences of childhood. An unhappy home or unjust treatment as a child may warp the development of the personality, lead to a lack of self-confidence, to the predominance of one emotional tendency, and so prevent that balanced equilibrium which will allow a rapid and suitable emotional reaction such as we may consider normal. This may lead to a failure of development or a loss of the sense of value, because the existence of one dominating emotional tendency so often produces a prejudiced view which may render a just appreciation of our general experience almost impossible and may seriously disturb our mental activity.
And if, as Bianchi suggests, all mental activity depends on a series of reflex actions, or, as Bechterew and Pavlov have insisted, a series of conditioned reflexes becomes established, it will assist us to understand how such stimuli can give rise to mental disturbances, to mental illnesses. We shall see that there may be something of real importance underlying such remarks as "I felt I was a changed child"; or "It is because of the treatment I received from my father that I have taken life so seriously." "I have never imagined that what I went through in my childhood could so influence me now"; or "I have never had confidence in myself and often when I have appeared vivacious and interested I have had an awful feeling of incapacity and dread within myself."
The outward and obvious manifestations, therefore, are not necessarily a true index of our mental and emotional conditions. This is true of all mental illnesses, even the most severe.
One patient who had been in an asylum more than ten years illustrated this in a most striking manner. His outward manifestations led one to feel that he thought he possessed the institution in which he was confined and also the surrounding property and that the authorities were a set of usurpers and thieves who kept him incarcerated in order that they might enjoy what was really his money and his property. On one occasion I said to him, "George, what is that incident in your life which you cannot forget and which has troubled you so seriously?" The reply was a flood of abuse. I put the question to him several times without getting any further answer, but when I came to leave the ward, George came up behind me and whispered over my shoulder, "Who told you about it?" No abuse, no shouting as usually occurred, but a whisper, "Who told you about it?" Was not George running away from a memory with its emotion which was unbearable to an idea which allowed him to be angry with others instead of with himself? Many examples of this might be given and really might be found by us in our own experience. It is the mental content which is important, a mental content which can be recalled by various stimuli, and which will be more persistently with us the more intense is the emotion associated with it.
But the basis of the condition is not completely understood when we have apparently arrived at the psychic cause of the disturbance.
It is recognized that the emotions are accompanied by physical changes, changes which are specific for each emotional state. The physical changes which normally are associated with fear differ from those of joy or anger. This has been appreciated for a long time but recent researches have recalled other reactions to us. Reactions in the internal glands which further knowledge will probably prove to be of great importance, in fact to form an integral part of the sum of activities, connect with mental processes. The secretions of the glands exert an influence on the sensibility and reaction of the organs connected with psychic phenomena and their functions themselves are affected by reactions occurring in the nervous system. Revival of a memory may thus affect the functions of these glands, and the changes produced in them may react on the sensibility and reactivity of the nervous mechanisms. If this be so, it will be evident that the organism works as a whole, that a disturbance of one organ may interfere with the function of another and that in the repetition of all these influences we may find an explanation of the chronicity of many of these illnesses. A study of the activities and interactivities of all the organs of the body is therefore essential and must be made before we shall understand the biological significance of mental illness.
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