Bodily Changes in Pain, Hunger, Fear and Rage

Only a few instances of the combination of ex- treme pain, rage, terror or excitement, and trei- mendous muscular power have been given in the preceding pages. Doubtless in numerous other conditions these two groups of phenomena occur together. In the lives of firemen and the police, in the experiences of escaping prisoners, of ship- wrecked sailors, in the struggles between pioneers and their savage enemies, in accounts of forced marches or retreats, search would reveal many ex- amples of such bodily disturbances as have been described in earlier chapters as augmenting the effectiveness of muscular efforts, and such exhibi- tions of power or endurance as are evidently far beyond the ordinary. There is every reason for believing that, were the conditions favorable to ex- perimental testing, it would be possible to demon- strate and perhaps to measure the addition to the dynamics of bodily action that appears as the ac- companiment of violent emotional disturbance.

In this connection it is highly significant that in times of strong excitement there is not infrequent testimony to a sense of overwhelming power that sweeps in like a sudden tide and lifts the person to a new high level of ability. A friend of mine, whose nature is somewhat choleric, has told me that when he is seized with anger, he is also pos- sessed by an intense conviction that he could crush and utterly destroy the object of his hostility. And

I have heard a football player confess that just before the final game such an access of strength seemed to come to him that he felt able, on the signal, to crouch and with a jump go crashing through any ordinary door. There is intense sat- isfaction in these moments of supreme elation, when the body is at its acme of accomplishment. And it is altogether probable that the critical dan- gers of adventure have a fascination because fear is thrilling, and extrication from a predicament, by calling forth all the bodily resources and setting them to meet the challenge of the difficulty, yields many of the joys of conquest. For these reasons vigorous men go forth to seek dangers and to run large chances of serious injury. "Danger makes us more alive. We so love to strive that we come to love the fear that gives us strength for conflict. Fear is not only something to be escaped from to a place or state of safety, but welcomed as an ar- senal of augmented strength."^^ And thus in the hazardous sports, in mountain climbing, in the hunting of big game, and in the tremendous ad- venture of war, risks and excitement and the sense of power surge up together, setting free unsus- pected energies, and bringing vividly to conscious- ness memorable fresh revelations of the possibili- ties of achievement.

^ Sherrington : The Integrative Action of the Nervous System, New York, 1906, p. 265. ^ Darwin : The Expression of Emotions in Man and Ani- mals, New York, 1905, p. 79. On the same plane with pain and the dominant emotions of fear and anger, as agencies which de- termine the action of organisms, is the sensation of hunger. It is a sensation so peremptory, so dis- agreeable, so tormenting, that men have commit- ted crimes in order to assuage it. It has led to cannibalism, even among the civilized. It has re- sulted in suicide. And it has defeated armies — for the aggressive spirit becomes detached from larger loyalties and turns personal and selfish as hunger pangs increase in vigor and insistence.

In 1905, while observing in myself the rhythmic sounds produced by the activities of the alimentary tract, I had occasion to note that the sensation of hunger was not constant but recurrent, and that the moment of its disappearance was often associ- ated with a rather loud gurgling sound as heard through the stethoscope. This and other evidence, indicative of a source of the hunger sensations in the contractions of the digestive canal, I reported in 1911.^ That same year, with the help of one of my students, A. L. Washburn, I obtained final proof for this inference.

The sensations of appetite and hunger are so complex and so intimately interrelated that any discussion of either sensation is sure to go astray unless at the start there is clear understanding of the meanings of the terms. The view has been propounded that appetite is the first degree of hunger, the mild and pleasant stage, agreeable in character; and that hunger itself is a more ad- vanced condition, disagreeable and even painful — the unpleasant result of not satisfying the appe- tite.^ On this basis appetite and hunger would differ only quantitatively. Another view, which seems more justifiable, is that the two experiences are fundamentally different.

Careful observation indicates that appetite is re- lated to previous sensations of taste and smell of food. Delightful or disgusting ta^stes^and odors, associated with this or that edible substance, de- termine the appetite. It has, therefore, important psychic elements in its composition. Thus, by tak- ing thought, we can anticipate the odor of a de- licious beefsteak or the taste of peaches and cream, and in that- imagination we can find pleasure. In

the realization, direct effects in the senses of taste and smell give still further delight. As already noted in the first chapter, observations on experi- mental animals and on human beings have shown that the pleasures of both anticipation and realiza- tion, by stimulating the flow of saliva and gastric juice, play a highly significant role in the initiation of digestive processes. Among prosperous people, supplied with abun- dance of food, the appetite seems sufficient to en- sure for bodily needs a proper supply of nutri- ment. We eat because dinner is announced, be- cause by eating we avoid unpleasant consequences, and because food is placed before us in delectable form and with tempting tastes and odors. Under less easy circumstances, however, the body needs are supplied through the much stronger and more insistent demands of hunger.

The sensation of hunger is difficult to describe, but almost everyone from childhood has felt at times that dull ache or gnawing pain referred to the lower mid-chest region and the epigastrium, which may take imperious control of human ac- tions. As Sternberg has pointed out, hunger may be sufficiently insistent to force the taking of food which is so distasteful that it not only fails to rouse appetite, but may even produce nausea. The hungry being gulps his food with a rush. The pleasures of appetite are not for him — he wants

Hunger and appetite are, therefore, widely dif- ferent— in physiological basis, in localization and in psychic elements. Hunger may be satisfied while the appetite still calls. Who is still hungry when the tempting dessert is served, and yet are there any who refuse it, on the plea that they no longer need it? On the other hand, appetite may be ia abeyance while hunger is goading.^ What ravenous boy is critical of his food? Do we not all know that "hunger is the best sauce" ? Although the two sensations may thus exist separately, they nevertheless have the same function of leading to the intake of food, and they usually appear to- gether. Indeed, the cooperation of hunger and ap- petite is probably the reason for their being so frequently confused.

Hunger may be described as having a central core and certain more or less variable accessories. The peculiar dull ache of hungriness, referred to the epigastrium, is usually the organism's first strong demand for food ; and when the initial or- der is not obeyed, the sensation is likely to grow into a highly uncomfortable pang or gnawing, less definitely localized as it becomes more intense. This may be regarded as the essential feature of hunger. Besides the dull ache, however, lassitude and drowsiness may appear, or faintness, or vio- lent headache, or irritability and restlessness such that continuous effort in ordinary affairs becomes increasingly difficult. That these states differ much with individuals — ^headache in one and faint- ness in another, for example — indicates that they do not constitute the central fact of hunger, but are more or less inconstant accompaniments. The "feeling of emptiness," which has been mentioned as an important element of the experience,* is an inference rather than a distinct datum of con- sciousness, and can likewise be eliminated from further consideration. The dull pressing sensa- tion isjfift, therefore, as the constant character- istic, the central fact, to be examined in detail.

Hunger can evidently be regarded from the psychological point of view, and discussed solely on the basis of introspection ; or it can be studied with reference to its antecedents and to the physi- ological conditions which accompany it — a consid- eration which requires the use of both objective methods and subjective observation. This psycho- physiological treatment of the subject will be de- ferred till the last. Certain theories which have been advanced with regard to hunger, and which have been given more or less credit, must first be examined.

first is supported by contentions that hunger is a general sensation, arising at no special region of the body, but having a local reference. This the- ory has been more widely credited by physiologists and psychologists than the other. The other is supported by evidence that hunger has a local source and_ therefore a local reference. In the course of our examination of these views we shall have opportunity to consider some pertinent new observations.

The conception that hunger arises from a gen- eral condition of the body rests in turn on the no- tion that, as the body uses up material, the blood becomes impoverished. Schiff ^ advocated this notion, and suggested that poverty of the blood in food substance affects the tissues in such manner that they demand a new supplyj The nerve cells of the brain share in this general shortage of pro- visions, and because of internal changes, give rise to the sensation. Thus is hunger explained as an experience dependent on the body as a whole.

Three classes of evidence are cited in support of this view: 1. "Hunger increases as time passes" — a partial statement. The development of hunger as time passes is a common observation which quite ac- cords with the assumption that the condition of the body and the state of the blood are becoming con- stantly worse, so long as the need, once estab- lished, is not satisfied. While it is true that with the lapse of time hun- ger increases as the supply of body nutriment de- creases, this concomitance is not proof that the sensation arises directly from a serious encroach- ment on the store of food materials. If this argu- ment were valid we should expect hunger to become more and more distressing until death follows from starvation. There is abundant evidence that the sensation is not thus intensified; on the con- trary, during continued fasting hunger, at least in some persons, wholly disappears after the first few days. Luciani,*' who carefully recorded the ex- perience of the faster Succi, states that after a cer- tain time the hunger feelings vanish and do not return. And he tells of two dogs that showed no signs of hunger after the third or fourth day of fasting; thereafter they remained quite passive in the presence of food. Tigerstedt,'' who also has studied the metabolism of starvation, declares that although the desire to eat is very great during the first day of the ordeal, the unpleasant sensations disappear early, and that at the end of the fast the subject may have to force himself to take nourish- ment. The subject, "J, A.," studied by Tigerstedt and his co-workers,^ reported that after the fourth day of fasting, he had no disagreeable feelings.

Carrington,^ after examinmg many persons who, to better their health, abstained from eating for different periods, records that "habit-hunger" usually lasts only two or three days and, if plenty of water is drunk, does not last longer than three days. Viterbi,^" a Corsican lawyer condemned to death for political causes, determined to escape execution by depriving his body of food and drink. During the eighteen days that he lived he kept careful notes. On the third day the sensation of hunger departed, and although thereafter thirst came and went, hunger never returned. Still fur- ther evidence of the same character could be cited, but enough has already been given to show that after the first few days of fasting the hunger feel-, ings may wholly cease. On the theory that hunger is a manifestation of bodily need, are we to sup- pose that, in the course of starvation, the body is ' mysteriously not in need after the third day, and; that therefore the sensation of hunger disappears? The absurdity of such a view is obvious.

2. "Hunger may be felt though the stomach be full" — a selected alternative. Instances of duo- denal fistula in man have been carefully studied, which have shown that a modified sensation of hunger may be felt when the stomach is full. A famous case described by Busch ^^ has been re- peatedly used as evidence. His patient, who lost nutriment through a duodenal fistula, was hungry soon after eating, and felt satisfied only wlien the chyme was restored to the intestine through the distal fistulous opening. As food is ahsorhed mainly through the intestinal wall, the inference is direct that the general bodily state, and not the local conditions of the alimentary canal, must ac- count for the patient's feelings.

A full consideration of the evidence from cases of duodenal fistula cannot so effectively be pre- sented now as later. That in Busch's case hunger disappeared while food was being taken is, as we shall see, quite significant. It may be that the restoration of chyme to the intestine quieted hunger, not because nutriment was thus intro- Iduced into the body, but because the presence of i material altered the nature of gastro-intestinal activity. The basis for this suggestion will be given in due course.

3. "Animals may eat eagerly after section of their vagus and splanchnic nerves" — a fallacious argument. The third support for the view that hunger has a general origin in the body is derived from observations on experimental animals. By severance of the vagus and splanchnic nerves, the lower esophagus, the stomach and the small in- testine can be wholly separated from the central nervous system. Animals thus operated upon nevertheless eat food placed before them, and may indeed manifest some eagerness for it.*^ How

is this behavior to be accounted for — when the possibility of local stimulation has been eliminated — ^^save by assuming a central origin of the impulse to eat? The fallacy of this evidence, though repeatedly overlooked, is easily shown. We have already seen that appetite as well as hunger may lead to the taking of food. Indeed, the animal with all gas- tro-intestinal nerves cut may have the same in- centive to eat Jhat a well-fed man may have, who delights in the pleasurable taste and smell of food and knows nothing of hunger pangs. Even when the nerves of taste are cut, as they were in Longet's experiments,^^ sensations of smell are still possible, as well as agreeable associations which can be roused by sight. More than fifty years ago Ludwig ^* pointed out that, even if all the nerves were severed, psychic reasons could be given for the taking of food, and yet because animals eat after one or another set of nerves is eliminated, the conclusion has been drawn by vari- ous writers that the nerves in question are thereby proved to be not concerned in the sensation of hunger. Evidently, since hunger is not required! for eating, the act of eating is no testimony what-l ever that the animal is hungry, and, after tha nerves have been severed, is no proof that hunger' is of central origin.

Weakness of the Assumptions Underlying the Theory THAT Hunger is a General Sensation The evidence tlras far examined has been shown to afford only shal^y support for the theory that hunger is a general sensation. The theory, fur- thermore, is weak in its fundamental assumptions. There is no clear indication, for example, that the blood undergoes or has undergone any marked change, chemical or physical, when the first stages of hunger appear. There is no evidence of any direct chemical stimulation of the gray matter of the cerebral cortex. Indeed, attempts to excite the gray matter artificially by chemical agents have been without results ;^^ and even electrical stim- ulation, which is effective, must, in order to produce movements, be so powerful that the move- ments have been attributed to excitation of under- lying white matter rather than cells in the gray. This insensitivity of cortical cells to direct stimu- lation is not at all favorable to the notion that they are sentinels set to warn against too great diminu- tion of bodily supplies.

Still further evidence opposed to the theory that hunger results directly from the using up of or- ganic stores is found in patients suffering from I fever. Metabolism in fever patients is augmented, I body substance is destroyed to such a degree that the weight of the patient may be greatly reduced, and yet the sensation of hunger under these condi- tions of increased need is wholly lacking. Again, if a person is hungry and takes food, the sensation is suppressed soon afterwards, long before any considerable amount of nutriment cjould be _digestfid-^ and- absorbed, and therefore long before the blood and the general bodily condi- tkin, if previously altered, could be restored to normal.

Furthermore, persons exposed to privation have testified that hunger can be temporarily sup- pressed by swallowing indigestible materials. Cer- tainly scraps of leather and bits of moss, not to mention clay eaten by the Otomacs, would not ma- terially compensate for large organic losses. In rebuttal to this argument the comment has been made that central states as a rule can be readily overwhelmed by peripheral stimulation, and just as sleep, for example, can be abolished by bathing the temples, so hunger can be abolished by irritat- ing the gastric walls.^^ This comment is beside the point, for it meets the issue by merely assum- ing as true the condition under discussion. The. absence of hunger during the ravages of fever, and its quick abolition after food or even indigestible stuff is swallowed, still further weakens the argu- ment, therefore, that the sensation arises directly from lack of nutriment in the body.

Many persons have noted that hunger has a sharp onset. A person may be tramping in the woods or working in the fields, where fixed atten- tion is not demanded, and without premonition raay feel the abrupt arrival of the characteristic ache. The expression "grub-struck" is a pic- turesque description of this experience. If this sudden arrival of the sensation corresponds to the general bodily state, the change in the general bod- ily state must occur with like suddenness or have a critical point at which the sensation is instantly precipitated. There is no evidence whatever that either of these conditions occurs in the course of metabolism.

Another peculiarity of hunger, which I have al- ready mentioned, is its intermitteney. It may come and go several times in the course of a few hours. Furthermore, while the sensation is pre- vailing, its intensity is not uniform, but marked by ups and downs. In some instances the ups and downs change to a periodic presence and absence without change of rate. In my own experience the hunger pangs came and went on one occasion as follows : and so on, for ten minutes longer. Again in this relation, the intermittent and periodic character o^hunger_ would require, on the theory under ex- amination, that the bodily supplies be intermittent- ly and periodically insufficient. During one mo- ment the absence of hunger would imply an abundance of nutriment in the organism, ten sec- onds later the presence of hunger would imply that the stores had been suddenly reduced, ten seconds later still the absence of hunger would imply a sudden renewal of plenty. Such zig-zag shifts of the general bodily state may not be im- possible, but from all that is known of the course of metabolism, such quick changes are highly im-^ probable. The periodicity of hui^ger, therefore, is further evidence against t]ie theory that the sensa- tion has a general basis in the body.

The Theory that Hunger is of General Origin Does Not Explain the Local Reference The last objection to this theory is that it does not account for the most common feature of hunger — ^namely, the reference of the sensation to the region of the stomach. Schiff and others " who have supported the theory have met this objection by two contentions. First they bave pointed out that the sensation is not always re- ferred to the stomach. Schiff interrogated igno- ■rjint soldiers regarding the local reference; sev- eral indicated the neck or chest, twenty-three the sternum, four were uncertain of any region, and two only designated the stomach. In other words, the stomach region was most rarely mentioned.

The second contention against the importance of local reference is that such evidence is falla- cious. An armless man may feel tinglings which seem to arise in fingers which have long since ceased to be a portion of his body. The fact that he experiences such tinglings and ascribes them to dissevered parts, does not prove that the sensa- tion originates in those parts. And similarly the assignment of the ache of hunger to any special region of the body does not demonstrate that the ache arises from that region. Such are the argu- ments against a local origin of hunger.

Concerning these arguments we may recall, first, Schiff's admission that the soldiers he questioned were too few to give conclusive evidence. Further, the testimony of most of them that hunger seemed to originate in the chest or region of the sternum cannot be claimed as unfavorable to a peripheral source of the sensation. The description of feel- ings which develop from disturbances within the body is almost always indefinite. As Head ^^ and others have shown, conditions in a viscus which give rise to sensation are likely not to be at- tributed to the viscus, but to related skin areas. Under such circumstances we do not dismiss the testimony as worthless merely because it may not point precisely to the source of the trouble. On the contrary, we use such testimony constantly as a basis for judging internal dis- orders.

With regard to the contention that reference to the periphery is not proof of the peripheral origin of a sensation, we may answer that the force of that contention depends on the amount of acces- sory evidence which is available. Thus if we see an object come into contact with a finger, we are justified ia assuming that the simultaneous sensa- tion of touch which we refer to that finger has re- sulted from the contact, and is not a purely central experience accidentally attributed to an outlying member. Similarly in the case of hunger — all that we need as support for the peripheral reference of the sensation is proof that conditions occur there, , simultaneously with hunger pangs, which might reasonably be regarded as giving rise to those pangs.

With the requirement in mind that peripheral conditions be adequate, let us examine the state of the fasting stomach to see whether, indeed, con- ditions may be present in times of hunger which would sustain the theory that hunger has a local outlying source. Among the suggestions which have been offered to account for a peripheral origin of the sensation is that of attributing it to emptiness of the stom- ach. By use of the stomach tube Nicolai ^* found that when his subjects had their first intima- tion of hunger the stomach was quite empty. But, in other instances, after lavage of the stomach, the sensation did not appear for intervals vary- ing between one and a half and three and a half hours. During these intervals the stomach must have been empty, and yet no sensation was experi- enced. The same testimony was given long before by Beaumont,^" who, from his observations on Alexis St. Martin, declared that hunger arises some time after the stomach is normally evacuated. Mere emptiness of the organ, therefore, does not explain the phenomenon.