THE PHYSIOLOGY OF DREAMS

FrancisE. Cane
1889 The Lancet  
1330 was ordered for the constipation. This, while regulating the bowels, caused an improvement in the urine, which was maintained, but never got beyond a certain degree. -20th: Taking into consideration the marked ill effect of liquid extract of ergot, coupled with the fact that in summer the patient was somewhat improved, I now concluded that here there was some altered condition of blood-pressure, in all probability marked increase, which caused the red blood cells to be forced through the
more » ... nute vessel walls into the secreting tubes, thence to be excreted, and therefore an effort was made to diminish this increased pressure. The bowels being regulated relieved the general congestion of the abdominal viscera, and now the patient was ordered two vapour baths a week. These were regularly taken.-27th : Patient feels better, and says he has more life in him. Urine much improved.-June 1st: The improvement in health and general spirits is marked. Urine clear, but in the lower one-fifth of the vessel there is a pinkish, flocculent mucous deposit. With the tincture of guaiacum and ozonic ether test the presence of blood can be demonstrated.-8th : Specific gravity of urine 1020; acid; no visible deposits; no indication of blood either chemically or microscopically. This is the first time since the present attack.—15th: Urine normal.-22nd : Urine normal; phosphatic deposits. The duration of haematuria from first to last has been a little over two years, seven months, and ten days.—August 14th : I saw the patient to-day. Says he never felt better in his life ; is in excellent health and spirits. There has been no relapse, and his urine is still normal. THE physiology of dreams is a subject of great importance, from its close relation to the pathological conditions of delirium and brain disease. But the many explanations of the cause of dreams which are found in the writings of physiologists and psychologists are all more or less unsatisfactory. A good résumé of these explanations may be found in the works of Sully, Carpenter, and others. Plato considered dreams as the dominant mental impulses or habits resulting from our daily feelings and thoughts. Aristotle wrote a treatise on dreams, and supposed that they are the impressions left on the mind and body by the objects of outward sense. He noticed that it seemed to thunder when a slight sound was produced within the ears, and that phlegm slipping down the throat of the sleeper suggested the idea of swallowing honey. Hippocrates and Galen made no advance on these theories. Nearer our own times, Descartes, Leibnitz, Kant, and Sir William Hamilton taught that we think and dream continually through sleep, although we frequently forget we have done so. Other authorities hold that dreams are not always present during sleep. Hobbes says that dreams all proceed from " the agitation of the inward parts of a man's body," which results in keeping the brain active. Schopenhauer considered that the impressions received from the internal region" of the organism are conveyed to the mind through the sympathetic system of nerves, and there worked into quasi-realities. Professor McKendrick calls dreaming a kind of physiological delirium. Dreams are frequently defined as revivals of former sensory impressions resulting from the action of an untrammelled or uncontrolled imagination, or as an undue excitability of the brain with a suspension of the will. These explanations, however, are all unsatisfactory in one or more aspects. They do not rationally account for the great rapidity of dream thought and for the sometimes orderly yet frequently incoherent arrangement and succession of events. They do not account for the variegated, grotesque, blended, and extravagantpictures upon which we gaze with a total want of surprise, impassively viewing scenes which would puzzle, bewilder, and shock us in our waking moments. They do not explain the great confusion in the order of time and space wherein widely remote events and places are brought together, and persons set in new relations to each other. They do not explain somnambulism and talking in the sleep, or why we sometimes dream the same dreams again and are frequently conscious that we are dreaming; the way in which the whole dream is often dominated by feelings of joy or terror; the way in which the various aspects of an object are exaggerated, so that the seemingly large, beautiful, or horrible becomes strikingly so. In these ways dreams take a firmer hold on us for the time being than waking realities, for although when awake we may consider dreams as unsubstantial and unreal, yet to the dreamer at the moment his imagined surroundings absorb his whole attention, and are consequently very real. Above all, the theories hitherto advanced fail to account for the light and colour or simulation of visual perception which form the main or striking feature of all or most dreams. In order to form a more correct idea of what dreams are, we must remember that the human body is a complicated machine made up of numerous secondary machines in themselves composed of a most intricate molecular machinery. This organism is unified and controlled by the sensory and motor nerve filaments which communicate in leashes with the intellegism in the great central nervous " exchange" of the brain. It is ever changing from minute to minute in its molecular constitution, and these changes result in countless chemical reactions and physical transformations of energy. It is most delicately responsive to all its surroundings, and is presided over by the intelligism which has never been seen or analysed. This intelligism has impressed on itself what I may call a sensographic record of all that it has learned from the moment when the deep sleep of its embryonic existence was first broken by its birth into the external world of matter and of sense. This sensographic record is the only criterion by which the intelligism can judge of objects which are presented to it in the condition of sleep, because in that condition it is deprived of the physiological instruments for measuring size, form, intensity, distance, direction, position, and many-sided aspects. Sleep is a state of repairing time, in which the nervous system does not so easily convey messages either to or from the intellectual presiding principle, but requires a stronger external stimulus or greater mental effort to properly communicate along the full length of the nerve. I wish here to show that all the phenomena of dreams are fully accounted for by the auto-sensations physiologically developed within the body, and which are sometimes increased by pathological or semi-pathological conditions, and modified by external impressions or stimuli. These auto-sensations are so numerous and so frequently developed that a large volume might be written to discuss them. Briefly considering what takes place in the human body while asleep, we find that there are actual and innumerable sounds, sights, and feelings which get partially conveyed to the intelligism, while that intelligism is deprived of its full means to test their nature. We have twitchings or spasms of muscular fibres, of muscles, and of groups of muscles. We have extensions and contractions of limbs, with the sensations of impediment likely to accrue from tight or overmuch bedclothing. We have painful conditions of muscles, nerves, and bloodvessels from awkward positions of the sleeper. We have the movements of the breathing apparatus; heart movements and sensations of beating arteries and distended veins; conditions of the sexual apparatus and states of different organs, such as distended bladder, overloaded stomach, and feeling of flatus in the bowels ; sensation caused by entozoa. Sounds innumerable are developed by the heart and arteries and veins ; by the mouth and nose, as in snoring, grinding of teeth, and working of saliva ; by the whole breathing system ; by the muscular susurrus all over the body ; by the creaking of joints and clicking of tendons and ligaments ; by flatus in the stomach and intestines, and many mechanical noises in the ears themselves. There are, besides, a host of molecular sounds which must be present, although usually not perceived. In the eye we have those extra-retinal entoptic phenomena due to opaque particles in the transparent media which, in our waking moments, frequently appear projected into space as drops, striae, lines, twisted bodies, forms of grotesque shape, and black dancing spots, often mistaken by the ignorant or inexperienced for natural objects, such as flies, worms, or birds. As an intra-retinal appearance I may mention the way in which we can see the branches of vessels in our own retinæ under the form of " Purkinje's Spectre." Tastes and smells may also be originated and perceived during sleep. The external influences which are well known to affect the sleeper are noises, voices, touches, lights, and changes of temperature. We have here
doi:10.1016/s0140-6736(02)10787-2 fatcat:z25nqryagvdrvhiet3oillkbbi