# Popular Science Monthly/Volume 22/April 1883/Perceptional Insanities

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* PERCEPTIONAL INSANITIES.
By W. A. HAMMOND, M. D.
THE simplest forms of insanity are those which consist merely of false perceptions, and they are not of such a character as to lessen the responsibility of the individual. There are two forms of false ​perceptions—illusions and hallucinations. Uncomplicated illusions are rare; still there is no doubt that there are illusions not the results of disease in the organs of sense or of circumstances unfavorable to exact perception, but which are due to a morbid condition of the perceptional ganglia, and the unreal nature of which is clearly recognized by the individual.
Illusions of sight often relate merely to the size of objects. Thus, a young lady who had overtasked herself at school saw everything of enormous size at which she looked. The head of a person seemed to be several feet in diameter, and little children looked like giants. So far as her own person was concerned there were no illusions. Her own hands appeared of the natural size, but those of other people seemed to be of enormous proportions. Sauvages refers to a case in which a young woman, suffering from epilepsy, had the illusion of seeing objects greatly magnified. A fly seemed to her to be as large as a chicken. In the case which came under my observation, the unreal character of the perception was fully recognized, and hence the intellect was not involved.
Morbid illusions of hearing, unaccompanied by other evidences of mental derangement, are not very common. One case only has come under my observation. It was that of a gentleman to whom the ticking of a clock was resolved into articulate words. Generally the expressions were in the form of commands. For instance, if at dinner, they would be, "Eat your soup!" "Drink no wine!" and so on. One day he made the discovery that, if he closed the right ear firmly, the illusion disappeared; but, if the left ear were closed, the words were still distinctly heard. It was hence clear that the center for hearing on the right side was the one affected, and that that on the left side was normal. For a long time this gentleman resisted accepting any of these illusions as facts, but after a time he began to be influenced by them to the extent of regarding them as guides. Eventually he put clocks in every room in his house, and professed to be governed altogether by the directions they gave him.
Illusions of touch, as Michea says, may relate to temperature, movement, weight, and the character of surfaces. Thus, to some patients, substances that are hot feel cold, and vice versa; others feel the things on which they sit or lie glide from under them. Illusions of a general character as regards the whole body are quite common—giving the sensation of extreme weight or lightness, or as if the body were immensely lengthened or shortened.
As regards frequency, illusions of the sense of touch occupy the front rank; next are those of sight, and next those of hearing. Illusions of taste and of smell, except with persons who are otherwise insane, are not common. A few instances of the latter, however, have occurred within my personal experience. To one of these, a lady, everything she put into her mouth tasted like cauliflower; in another ​instance, the flavor was that of strong Roquefort cheese, and in another of pears.
The difference between illusions and hallucinations can be recognized without difficulty, for the latter are entirely cerebral in origin, and do not require, as do the former, a material basis. They can not be produced by any defects or derangements of the sensory organs, or by any external circumstances tending to interfere with the normal action of these organs. We have to consider them now as resulting from disorder of the perceptional ganglia without the implication of those parts of the brain which are concerned in the production of intellect, emotion, or will.
The case of Nicolai, the German bookseller, is a striking instance of hallucinations of sight. For ten months he had been a good deal disturbed by several melancholy incidents. A customary blood-letting was omitted, and added to all was an unusual press of business matters. One morning he suddenly perceived, at apparently the distance of ten steps, a form like that of a deceased person. The phantom continued only for about ten minutes, but in the afternoon it reappeared. He arose and went to another room, the apparition accompanying him—disappearing, however, at intervals, and always maintaining the erect posture. Later there appeared other figures, unlike the first.
After the first day the figure of the deceased person no longer appeared, but its place was supplied by many other phantoms, sometimes representing acquaintances, but mostly strangers. After about four weeks he began to hear them talk. The application of leeches to the arms relieved him promptly of his hallucinations.
Hallucinations of hearing are more common than those of any other of the special senses, and, according to my experience, are more apt to lead to further mental disorder. Far more people kill themselves under the influence of hallucinations of hearing than from those of all the other senses combined. The reiteration in the ears, during every minute of the day, of the command to jump into the river, to plunge a convenient knife into the heart, and so on, day in and day out, is calculated to shake the power of control of the strongest-minded.
Sometimes a single word or a few words constitute the hallucination, but in their more complex character they are sentences and even long discourses. No instance that has come under my observation equals that of a lady who hears recited to her long pieces of original poetry or prose. She has repeatedly written down these recitations and brought them to me. This lady had a strong hereditary tendency to insanity, and, shortly after the development of the hallucinations referred to, she imbibed the delusion that she had committed the "unpardonable sin." She made two attempts at suicide, and is still insane, but has—an unusual circumstance—lost the ​delusion of the "unpardonable sin," and contracted the idea that she has no bowels.
As hallucinations of sight often exist while the eyes are closed, or in persons who are totally blind, so hallucinations of hearing continue though the ears be stopped, or originate in persons who are entirely deaf. A deaf-mute who came to my clinique at the University Medical College was constantly subject to hallucinations of hearing. It is said that in the last years of his life Beethoven became completely deaf, but that he heard his compositions as distinctly as when he actually listened to them when performed by an orchestra.
Hallucinations of hearing, like those of sight, are sometimes unilateral—that is, heard by only one ear. Baillarger cites several examples of the kind.
Calmet gives some interesting details relative to hallucinations. In one case a M. de S—— entered his study one afternoon, and, turning toward the door to go to his bedroom again, was much surprised to see it shut and barricade itself with the two bolts that belonged to it. At the same time the doors of a large press opened behind him and rather darkened his study, because the window which was open was behind these doors. "At this sight the fright of M. de S—— is more easy to imagine than to describe; however, he had sufficient calmness left to hear, in his left ear, a distinct voice, which spoke to him in very good terms, and ordered him to do some one particular thing which he was commanded to keep secret."
Hallucinations of smell, though not so common as those of sight and hearing, are yet often met with. A gentleman of my acquaintance was almost constantly subject to the hallucination of smelling paint or turpentine; another had the odor of coffee ever present in his nostrils; and another, a physician, was always annoyed with the smell of the dissecting-room. It is well known that some epileptic seizures are preceded by the sensation of a horrible stench.
Hallucinations of taste are not common. Indeed, it is sometimes difficult to say whether they exist or not, as various visceral irregularities may cause the production of tastes by modifications impressed upon the saliva. Mental excitement will cause a like effect in some persons. I am acquainted with a gentleman who can not participate in any engrossing conversation without having a bitter taste developed in his mouth.
Hallucinations of the sense of touch are, on the other hand, very frequently met with. Sensations apparently not based on any real impression are experienced in various parts of the body. It is difficult, however, to discriminate between illusions and hallucinations of touch.
Occasionally persons have the power of voluntarily producing hallucinations. A practice fraught with danger, for the time is apt to come at which they can not get rid of their false perceptions. As an ​instance, I cite the following case from Wigan. The painter referred to is Blake:
"A painter, who inherited much of the patronage of Sir Joshua Reynolds, was so fully engaged that he told me he had painted three hundred large and small portraits in one year. The fact appeared physically impossible, hut the secret of his astonishing success was this: he required but one sitting of his model. I begged him to detail to me his method of procedure, and he related what follows: 'When a sitter came, I looked attentively on him for half an hour, sketching: from time to time on the canvas. I removed the canvas and passed to another person. When I wished to continue the first portrait I recalled the man to my mind, and placed him on the chair. Then I went on painting, occasionally stopping to examine the posture, as though the original were before me. This method made me very popular, for the sitters were delighted that I spared them the annoying sittings of other painters. 'By degrees I began to lose all distinction between the imaginary and the real figure; then all became confusion. I lost my reason, and remained for thirty years in an asylum.'"
It is related of Talma, the great actor, that he could cause the audience to appear to him like skeletons, and that, when the hallucination was complete, his histrionic genius was at its height.
Goethe states that he had the power of giving form to the images passing before his mind, and, upon one occasion, saw his own figure approaching him.
Several like cases have come under my own observation. In one, the power was directly the result of attendance at spiritual meetings, and of the efforts made to become a good "medium." The patient, a lady, at first thought very deeply of some particular person, whose image she endeavored to form in her mind. Then she assumed that the person was really present, and addressed conversation to him. At this period she was not deceived, for she clearly recognized the fact that the image was not present.
One day, however, she was thinking very intently of her mother, and, happening to raise her eyes, she saw her mother standing before her exactly as she had imagined her. In a few moments the phantom disappeared, but she soon found that she had the ability to recall it at will. During the spiritualistic meetings she attended, she could thus reproduce the image of any person upon whom she strongly concentrated her thoughts, and was for a long time sincere in her belief that they were real appearances. At last she lost control of the operations, and became constantly subject to hallucinations of sight and hearing.
Although no one presumes to question the honesty of Jerome Cardan, or of Swedenborg, it is probable that their visions were also induced by intense mental concentration. In some persons very slight thought is sufficient to cause hallucinations of great distinctness.
​The causes of central illusions and hallucinations are generally to he found in derangements of some kind in the blood circulating in the brain. These may either relate to its quantity or its quality.
Physical influences calculated to produce cerebral hyperæmia or congestion may give rise to illusions or hallucinations. Brierre de Boismont refers to a case, on the authority of Moreau, in which an individual was able to obtain hallucinations of sight by inclining his head a little forward. A similar case was not long since under my own care. A gentleman, while sitting at his table writing, happened to raise his eyes without moving his head, and saw before him the figure of an old woman with black cloak and hood. Throwing himself back in his chair in his amazement, he found that the image slowly disappeared; and, as often as he repeated these movements, a like series of phenomena occurred. On examining him, I found that he wore a very high, old-fashioned stock, which, as he sat at the table with his head bent forward, compressed the large veins of the neck, and prevented for a time the return of blood from the brain. On changing his neck-wear for other of more modern fashion, he was enabled to bend his head and raise his eyes without encountering the apparition.
A gentleman once consulted me who, for several weeks, had seen, just as he lay down, the figure of a very old man, who stood by the side of his bed grinning and beckoning to him. At first he was deceived, and started suddenly from his bed, whereupon his visitor disappeared. He marie several tests which satisfied him as to the real character of the phantom, and then, like a sensible man, tried to get to sleep, but in this attempt he succeeded badly.
The explanation of such cases is very simple. The recumbent posture facilitates the flow of blood to the brain, and at the same time tends, in a measure, to retard its exit. Hence the appearances were due to the resulting congestion. As soon as the individual rose in bed, or stood erect, the reverse conditions existed, the congestion disappeared, and the apparition went with it.
The influence of cerebral hyperæmia in causing hallucinations seems to be clearly established. Ferriar wrote a treatise with the special object of proving that this is the only cause. This is an extreme view, however, which can not be sustained, for that the very opposite condition, cerebral anæmia, is an immediate cause of hallucinations is seen in the facts that, during starvation and other conditions producing great bodily exhaustion, hallucinations are common occurrences.
A striking instance has recently come under my observation, which shows, undoubtedly, that a reduction in the amount of blood circulating within the cranium may give rise to hallucinations. A young woman affected with epilepsy had repeated seizures while in my consulting-room, and, with a view of arresting them, I exerted strong pressure on both carotid arteries. Her face instantly became pale, ​and, without losing consciousness, she uttered a loud shriek, and pointed at an object which she apparently saw near her. I at once discontinued the pressure, when she informed me that she had seen an immense negro rushing toward her with a club, and that as soon as I had stopped pressing on her neck the figure had disappeared. I assured her it was an hallucination, and induced her to let me repeat the experiment. I now exerted moderate pressure, with the view of keeping it up for some little time. In about half a minute she said that she saw the figure, but not very distinctly, and I found that I could make the figure appear distinct or indistinct by varying the degree of pressure.
Children are very liable to be subject to hallucinations, and frequently give circumstantial accounts of incidents which they believe have occurred to them, of voices they have heard, etc. It is often impossible for them to discriminate between the true and the false, and I am afraid they are often punished for lying by ignorant parents, when they have told nothing but what they have had the evidence of their senses for believing.
A great deal has been written relative to the physiology of hallucinations, but without much result so far as any explanation of the process is concerned. There is some evidence to show that the thalami optici are the centers for all real perceptions, and that hence they are the organs, which, through their disease, give rise to all centric illusions and hallucinations. Luys more than any other physiologist has elaborated this idea, and has adduced arguments in its support which it is difficult to overlook. His doctrine is that the optic thalami are reservoirs for all sensorial impressions coming from the periphery of the nervous system, and that, like other ganglionic masses, they elaborate these impressions, and that, by means of the fibers of the corona radiata, they transmit them to the cortex, to be still further perpetuated by being converted into ideas.
If there is no organ of sense, there can be no normal sensorial impression; if the optic nerve be divided, the sensation can not be transmitted to the optic thalamus; if there be a diseased optic thalamus, the sensorial impression will be perverted and there will be an illusion of centric origin; if the cortex be in a normal condition, this illusion will be corrected and understood as such erroneous perception; if, however, the cortex be diseased, the illusion will be accepted as true, and a false idea, or delusion, will be formed. Such an impression formed in the optic thalamus is an hallucination, and will be accepted for reality or not according as the cortex is healthy or diseased.
Such is, I think, the pathology of perceptional insanity. The lesions of the optic thalamus necessary to the production of a false sensorial impression may be of varied character. Congestion is probably that which most commonly exists, especially in the early stages, and in those cases which are not accompanied by derangements of the other ​categories of mental faculties. Anæmia is likewise a condition of frequent occurrence. At later periods, as Luys says, the optic thalami are the seats of degenerations which show that there have been frequent perturbations of the circulation. He is very strong in his conviction that there are secondary changes, which are the cause of the transformation of psycho-sensorial hallucinations into those which Baillarger designated psychic. In my opinion, they are the cause of the hallucination becoming a delusion, and, indeed, between a psychic hallucination and a delusion there is very little difference. The former can not exist without the involvement of the intellect.