Bodily Changes in Pain, Hunger, Fear and Rage

A second theory, apparently suggested by obser- vations on cases of hyperacidity, is that the ache or pang is due to the natural hydrochloric acid of the stomach but secreted while the organ is empty. Again the facts are hostile. Nicolai ^* reported that the gastric wash-watei; from his hungry sub- jects was neutral or only slightly acid. This testimony confirms Beaumont's statement, and is in complete agreement with the results of gastric examination of fasting animals reported by numerous experimenters. There is no secre- tion into the empty stomach during the first days of starvation. Furthermore, persons suffering from absence of hydrochloric acid (achylia gas- trica) declare that they have normal feelings of hunger. Hydrochloric acid cannot, therefore, be called upon to account for the sensation.

Hunger Not Due to Turgescenoe of the Gastric Mucous Membrane Another theory, which was first advanced by Beaumont,^^ is that hunger arises from turges- cence of the gastric glands. The disappearance of the pangs as fasting continues has been accounted for by supposing that the gastric glands share in the general depletion of the body, and that thus the turgescence is relieved.* This turgescence theory has commended itself to several recent writers. Thus Luciani^^ has accepted it, and by adding the idea that nerves distributed to the mucosa are

* A better explanation perhaps is afforded by BoldirefE's discovery that at the end of two or three days the stomachs of fasting dogs begin to secrete gastric juice and continue the secretion indefinitely. (Boldireff, Archives Biologiques de St. Petersburg, 1905, xi, p. 98.) specially sensitive to deprivation of food lie ac- counts for the hunger pangs. Also Valenti ^* declared a few years ago that the turgescence theory of Beaumont is the only one with a sem- blance of truth in it. The experimental work re- ported by these two investigators, however, does not necessarily sustain the turgescence theory. Luciani severed the previously exposed vagi after cocainizing them, and Valenti merely cocainized the nerves; the fasting dogs, eager to eat a few minutes previous to this operation, now ran about as before, but when offered food, licked and smelled it, but did not take it. This total neglect of the food lasted varying periods up to two hours. The vagus nerves seem, indeed, to convey impulses which affect the procedure of eating, but there is no clear evidence that those impulses arise from distention of the gland cells. The turgescence theory, moreover, does not explain the effect of taking indigestible material into the stomach. According to Pawlow, and to others who have ob- served human beings, the_chewing and swallowing of unappetizing stuff does not cause any secretion of__gastric juice (see p. 8). Yet such stuff when swallowed will cause the disappearance of hunger, and Nicolai found that the sensation could be abol- ished by simply introducing a stomach sound. It is highly improbable that the turgescence of the gastric glands can be reduced by either of these

procedures. The turgescence theory, furthennore,A does not explain the quick onset of hunger, or its intermittent and periodic character. That the cells j are repeatedly swollen and contracted within peri- ods a few seconds in duration is almost inconceiv- able. For these reasons, therefore, the theory that hunger results from turgescence of the gastric mucosa can reasonably be rejected. There remain to be considered, as a possible cause of hunger-pangs, contractions of the stomach and other parts of the alimentary canal. This sug- \ gestion is not new. "^ Sixty-nine Ikears ago Weber ^^ ^^ declared his belief that "strong contraction of the muscle fibres of the wholly empty stomach, whereby its cavity disappears, makes a part of the sensation which we call hunger." Vierordt ^^ drew the same inference twenty-five years later (in 1871), and since then Ewald, Knapp, and Hertz have declared their adherence to this view. These writers have not brought forward any direct evi- dence for their conclusion, though Hertz has cited Boldireff's observations on fasting dogs as prob- ably accounting for what he terms "the gastric constituent of the sensation."

The argument commonly used against the gas- tric contraction theory is that the ^iqmach is not energetically active when empty. Thus Schiff ^^ stated, "The movements of the empty stomach are rare and much less energetic than during diges- tion." Luciani ^® expressed his disbelief by as- serting that gastric movements are much more ac- tive during gastric digestion than at other times, and cease almost entirely when the stomach has discharged its contents. And Valenti ^® stated (1910), "We know very well that gastric move- ments are exaggerated while digestion is proceed- ing in the stomach, but w;hen the organ is empty they are more rare and much less pronounced," and, therefore, they cannot account for hunger.

Evidence opposed to these suppositions has been in existence for many years. In 1899 Bettmann *" called attention to the contracted condition of the stomach after several days' fast. In 1902 Wolff ^^ reported that after forty-eight hours without food the stomach of the cat may be so small as to look like a slightly enlarged duodenum. In a similar circumstance I have noticed the same ex- traordinary smallness of the organ, especially in the pyloric half. The anatomist His ^^ also re- corded his observation of the phenomenon. In 1905 Boldireff ^^ demonstrated that the whole gastro- intestinal tract has a periodic activity while not di- g^esting. Each period of activity lasts from twenty to thirty minutes, and is characterized in the stom- ach by rhythmic contractions ten to twenty in num-

ber. These contractions, Boldireff reports, may be/ stronger_than during digestion, and his published records clearly support this stateraent. The inteij- vals of repose between periodic recurrences of the contractions lasted from one and a half to two and a half hours. Especially noteworthy is Boldireff's observation that if fasting is continued for two or three days, the groups of contractions appear at gradually longer intervals and last for gradually shorter periods, and thereupon, as the gastric glands begin continuous secretion, all movements cease.

The research, previously mentioned, on the rhythmic sounds produced by the digestive pro- cess, I was engaged in when Boldireff' s paper was published. That contractions of the alimentary canal on a gaseous content might explain the hun- ger pangs which I had noticed seemed probable at that time, especially in the light of Boldireff's ob- servations. Indeed, Boldireff ^* himself had con- sidered hunger in relation to the activities he described, but solely with the idea that hunger might provoke them ; and since the activities dwin- dled in force and frequency as time passed, where- as, in his belief, they should have become more pro- nounced, he abandoned the notion of any relation

between tlie phenomena. Did not Boldireff misin- terpret his own observations? When he was con- / sidering whether hunger might cause the contrac- tions, did he not overlook the possibility that the contractions might cause hunger? A number of experiences have led to the conviction that Boldi- reff did, indeed, fail to perceive part of the signifi- cance of his results. For example, I have noticed the disappearance of a hunger pang as gas was heard gurgling upward through the cardia. That the gas was rising rather than being forced down- ward was proved by its regurgitation immediately after the sound was heard. In all probability the pressure that forced the gas from the stomach was the cause of the preceding sensation of hunger. Again the sensation can be momentarily abolished a few seconds after swallowing a small accumula- tion of saliva or a teaspoonful of water. If the stomach is in strong contraction in hunger, this re- sult can be accounted for, in accordance with the observations of Lieb and myself,^^ as due to the inhibition of the contraction by swallowing. Thus also could be explained the prompt vanishing of the ache soon after we begin to eat, forjepeated swallowing results in continued inhibition.* Fur- thermore, Ducceschi's discovery ^® that hydro-

* The absence of hunger in Busch's patient while food waa being eaten (see p. 239) can also be accounted for in this manner. chloric acid diminishes the tonus of the pyloric por- tion of the stomach .may have its application here ; the acid would be secreted as food is taken and would then cause relaxation of the very region which is most strongly contracted. Although the evidence above outlined had led me to the conviction that hunger results from con- tractions of the alimentary canal, direct proof was still lacking. In order to learn whether such proof might be secured, Washburn determined to be- come accustomed to the presence of a rubber tube in the esophagus.* Almost every day for several weeks Washburn introduced as far as the stomach a small tube, to the lower end of which was attached a soft-rubber balloon about 8 centimeters in diam- eter. The tube was thus carried about each time for two or three hours. After this preliminary experience the introduction of the tube and its presence in the gullet and stomach were not at all disturbing. When a record was to be taken, the balloon, placed just within the stomach, was moder- ately distended with air, and was connected with a water manometer ending in a cylindrical chamber 3.5 centimeters wide. A float recorder resting on

* Nicolai (loc. cit.) reported that although the introduction of a stomach tube at first abolished hunger in his subjects, with repeated use the effects became insignificant. the water in the chamber permitted registering any contractions of the fundus of the stomach. On the days of observation Washburn would abstain from breakfast, or eat sparingly; and without taking any luncheon would appear in the laboratory about two o'clock. The recording apparatus was ar- ranged as above described. In order to avoid any error that might arise from artificial pressure on the balloon, a pneumograph, fastened below the ribs, was made to record the movements of the abdominal wall. Uniformity of these movements would show that no special contractions of the ab- dominal muscles were made. Between the records of gastric pressure and abdominal movement, time was marked in minutes, and an electromagnetic signal traced a line which could be altered by press- ing a key. All these recording arrangements were out of Washburn's sight; he sat with one hand at the key, ready whenever the sensation of hunger was experienced to make the current which moved the signal.

Sometimes the observations were started before any hunger was noted ; at other times the sensa- tion, after running a course, gave way to a feeling of fatigue. Under either of these circumstances there were no contractions of the stomach. When Washburn stated that he was hungry, however, powerful contractions of the stomach were invari- ably being registered. As in my own earlier expe- rience, the sensations were characterized by peri- odic recurrences with free intervals, or by peri- odic accesses of an uninterrupted ache. The record of Washburn's introspection of his hunger pangs' agreed closely with the record of his gastric con-

FiGUBE 37. — One-half the original size. The top record represents intragastric pres- sure (the small oscillations due to respiration, the large to contractions of the stomach) ; the second record is time in minutes (ten min- utes) ; the third record is W's report of hunger pangs; the lowest record is respiration regis- tered by means of a pneumograph about the abdomen. tractions. Almost invariably, however, the con- traction nearly reached its maximum before the record of the sensation was started (see Fig. 37). { This fact may be regarded as evidence that the contraction precedes the sensation, and not vice versa, as Boldireff considered it. The contrac- tions were about a half -minute in duration, and

the intervals between varied from thirty to ninety seconds, with an average of about one minute. The augmentations of intragastric pressure in Wash- burn ranged between eleven and thirteen in twenty minutes ; I had previously counted in myself eleven hunger pangs in the same time. The rate in each Figure 38. — One-half the original size. The same conditions as in Fig. 37. (Fifteen minutes.) There was a long wait for hunger to disappear. After x, W. reported himself "tired but not hungry." The record from y to z was the continuance, on a second drum, of X toy.

of US was, therefore, approximately the same. This rate is slightly slower than that found in dogs by Boldireff ; the difference is perhaps corre- lated with the slower rhythm of gastric peristalsis in man compared with that in the dog.^'' Before hunger was experienced by Washburn the recording apparatus revealed no signs of gas- tric activity. Sometimes a rather tedious period of waiting had to be endured before contractions dccurred. And after they began they continued for a while, then ceased (see Fig. 38) . The feeling of hunger, which was reported while the contrac- tions were recurring, disappeared as the waves stopped. The inability of the subject to controR . the contractions eliminated the possibility of their j ' "^ '^'^^ being artifacts, perhaps induced by suggestion.! The close concomitance of the contractions with hunger pangs, therefore, clearly indicates. that they are the real source of those pangs.

Boldireff's studies proved that when the empty stomach is manifesting periodic contractions, the intestines also are active. Conceivably all parts of the alimentary canal composed of smooth mus- cle share in these movements. The lower esopha- gus in man is provided with smooth muscle. It was possible to determine whether this region in "Washburn was active during hunger. To the esophageal tube a thin-rubber finger-cot (2 centimeters in length) was attached and lowered into the stomach. The little rubber bag was dis- tended with air, and the tube, pinched to keep the bag inflated, was gently withdrawn until resistance was felt. The air was now released from the bag' and the tube farther withdrawn about 3 centi- meters. The bag was again distended with air at a manometric pressure of 10 centimeters of water. Inspiration now caused the writing lever, which: recorded the pressure changes, to rise; and a:

slightly farther withdrawal of the tube changed the rise, on inspiration, to a fall. The former posi- tion of the tube, therefore, was above the gastric cavity and below the diaphragm. In this position Figure 39. — One-half the original size. The top record represents compression of thin rubber bag in the lower esophagus. The pressure in the bag varied between 9 and 13 centimeters of water. The cylin- der of the recorder was of smaller diameter than that used in the gastric records. The esophageal contractions compressed the bag so completely that, at the summits of the large oscillations, the respirations were not registered. When the oscillations dropped to the time line, the bag was about half inflated. The middle line registers time in minutes (ten minutes). The bot- tom record is W's report of hunger pangs.

the bag, attached to a float recorder (with chamber 2.3 centimeters in diameter), registered the peri- odic oscillations shown in Fig. 39. Though indi- vidually more prolonged than those of the stomach, these contractions, it will be noted, occur at about the same rate. This study of hunger, reported by Washburn and myself in 1912, has since been taken up by Carlson of Chicago, and in observations on a man with a permanent gastric fistula, as well as on him- self and his collaborators, he has fully confirmed our evidence as to the relation between contrac- tions of the alimentary canal and the hunger sensa- tion. In a series of nearly a score of interesting papers, Carlson and his students ^^ have greatly amplified our knowledge of the physiology of the "empty" stomach. Not only are there the contrac- tions observed by Washburn and myself, but at times these may fuse into a continuous cramp of the gastric muscle. The characteristic contrac- tions, furthermorej, continue after the vagus^ nerve supply to the stomach has been destroyed, and, therefore, are not dependent on the reception of impulses by way^of^the cranial autonomic fibres. Recently Luckhardt and Carlson have brought for- ward evidence that the blood of a fasting animal -, if injected into the vein of a normal animal is j capable of inducing in the latter the condition of ! cramp or tetanus in the gastric muscle mentioned above — an effect which does not occur when the j blood of a well-fed animal is injected. It seems i possible that a substance exists in the blood which acts to excite the gastric hunger mechanism. But this point will require further investigation.

the immediate cause of hunger, most of the diffi- culties confronting other explanations are readily obviated. Thus the sudden onset of hunger and its peculiar periodicity — phenomena which no other explanation of hunger can account for — are at once explained. In fever, when bodily material is being most rapidly used, hunger is absent. Its absence is understood from an observation made by F. T. Murphy and myself,*"* that infection, with sys- temic involvement, is accompanied by a total cessation of ^11 movements of the alimentary canal. Boldireff observed that when his dogs were fa- tigued the rhythmic contractions failed to appear. Being "too tired to eat" is thereby given a rational explanation.

A pathological form of the sensation — the inor- dinate hunger (bulimia) of certain neurotics — is in accordance with the well-known disturbances of the tonic innervation of the alimentary canal in such individuals. Since the lower end of the esophagus, as well as the stomach, contracts periodically in hunger, the reference of the sensation to the sternum by the ignorant persons questioned by Schiff was wholly natural. The activity of the lower esopha- gus also explains why, after the stomach has been removed, or in some cases when the stomach is distended with food, hunger can still be experi-

enced. Conceivably the intestines also originate vague sensations by tbeir contractions. Indeed, the final banishment of the modified hunger sen- sation in the patient with duodenal fistula, de- scribed by Busch, may have been due to the les- sened activity of the intestines when chyme was injected into them. The observations recorded in this paper have, as already noted, numerous points of similarity to Boldireff's observations '"' on the periodic activ- ity of the alimentary canal in fasting dogs. Each period of activity, he found, comprised not only wide-spread contractions of the digestive canal, but also the pouring out of bile, and of pancreatic and intestinal juices rich in ferments. Gastric juice was not secreted at these times; when it was se- creted and reached thejntestine, the periodic activ- ity ceased. What is the significance of this exten- sive disturbance 1 I have elsewhere presented evi- dence *^ that gastric peristalsis is dependent on the stretching of gastric muscle when tonically con- tracted. The evidence that the stomach is in fact strongly contracted in hunger — i. e., in a state of high tonus — has been presented above.* Thus

* The "empty" stomach and esophagus contain gas (see Hertz : Quarterly Journal of Medicine, 1910, iii, p. 3Y8 ; Mikulicz : Mittheilungen aus den Grenzgebieten der Medi- cin und Chirurgie, 1903, xii, p. 596). They would naturally manifest rhythmic contractions on shortening tonically on their content. the very condition which, causes hunger and leads to the taking of food is the condition, when the swallowed food stretches the shortened muscles, for immediate starting of gastric peristalsis. In this connection the observations of Haudek and Stigler *^ are probably significant. They found that the stomach discharges its contents more rap- idly if food is eaten in hunger than if not so eaten. Hunger, in other words, is normally the signal that the stomach is contracted for action; the unpleas- antness of hunger leads to eating; eating starts gastric digestion, and abolishes the sensation. Meanwhile the pancreatic and intestinal juices, as well as bile, have been prepared in the duodenum to receive the oncoming chyme. The periodic ac- tivity of the alimentary canal in fasting, therefore, is not solely the source of hunger pangs, but is at the same time an exhibition in the digestive organs of readiness for prompt attack on the food swal- lowed by the hungry animal.

* Cannon : The Mechanical Factors of Digestion, London and New York, 1911, p. 204. *Bardier: Richet's Dictionnaire de Physiologie, article Faim, 1904, vi, p. 1. See, also, Howell : Text-book of Physi- ology, fourth edition, Philadelphia and London, 1911, p. 285. * See Sternberg : Zentralblatt f iir Physiologie, 1909, xxii, p. 653. Similar views were expressed by Bayle in a thesis presented to the Faculty of Medicine in Paris in 1816. ♦See Hertz: The Sensibility of the Alimentary Canal, London, 1911, p. 38.

^ Johanson, Landergren, Sonden and Tigerstedt : Skandi- navisches Arehiv fiir Physiologie, 1897, vii, p. 33. ^^ Busch : Arehiv fiir pathologische Anatomie und Physi- ologie und fiir klinische Medicin, 1858, xiv, p. 147. 1" Nicolai : Ueber die Entstehung des Hungergef iihls, In- augural Dissertation, Berlin, 1892, p. 17. 23 Luciani : Archivio di Fisiologia, 1906, iii, p. 54. Tiede- mann long ago suggested that gastric nerves become increas- ingly sensitive as fasting progresses. (Physiologie des Men- schen, Darmstadt, 1836, iii, p. 22.)

3^ Cannon and Murphy : Journal of the American Medi- cal Association, 1907, xlix, p. 840. Emotions gain expression through discharges along the neurones qf the autonomic nervous sys- iem. The reader will recall that this system has three divisions — the cranial and sacral, separated hy the sympathetic — and that when the neurones of the mid-division meet in any organ the neurones of either of the end divisions, the influence of the two sets is antagonistic. As previously stated (p. 35), there is evidence that arrangements exist in the central nervous system for reciprocal innervation of these antagonistic divisions, just as there is reciprocal innervation of antagonistic skeletal muscles. The characteristic affective states mani- fested in the working of these three divisions have been described. Undoubtedly, these states have correspondents — activities and inhibitions — in the central neurones. The question now arises, are the states which appear in opposed divisions also in opposition?

Antagonism Between Emotions Expressed in the Sympa- thetic AND IN the Cranial Divisions of the Autonomio System The cranial autonomic, as already shown, is con- cerned with- the quiet service of building up re- serves and fortifying the body against times of stress. Accompanying these functions are the relatively mild pleasures of sight and taste and smell of food. The possibility of existence of these gentle delights of eating and drinking and also of their physiological consequences is instantly abol- ished in the presence of emotions which activate the sympathetic division. The secretion of saliva, gastric juice, pancreatic juice and bile is stopped, and the motions of the stomach and intestines cease at once, both in man and, in the lower animals, whenever pain, fear, rage, or other strong excite- ment is present in the organism.

All these disturbances of digestion seem mere interruptions of the "normal" course of events unless the part they may play in adaptive reac- tions is considered. In discussing the operations of the sympathetic division, I pointed out that all the bodily changes which occur in the intense emo- tional states — such as fear and fury — occur as results of activity in this division, and are in the highest degree serviceable in the struggle for exist- ence likely to be precipitated when these emotions are aroused. From this point of view these per-

turbations, which, so readily seize and dominate the organs that in quiet times are commonly con- trolled by the cranial autonomic, are bodily reac- tions which may be of the utmost importance to life at times of critical emergency. Thus are the body's reserves — the stored adrenin and the accumulated sugar — called forth for instant service ; thus is the blood shifted to nerves and muscles that may have to bear the brunt of struggle ; thus is the heart set rapidly beating to speed the circulation ; and thus, also, are the activities of the digestive organs for the time abolished. Just as in war between nations the arts and industries which have brought wealth and contentment must suffer serious neglect or be wholly set aside both by the attacker and the at- tacked, and all the supplies and energies developed in the period of peace must be devoted to the pres- ent conflict; so, likewise, the functions which in quiet times establish and support the bodily re- serves are, in times of stress, instantly checked or completely stopped, and these reserves lavishly drawn upon to increase power in the attack and in the defense or flight.*

It is, therefore, the natural antagonism between these two processes in the body — between saving * One who permits fears, worries and anxieties to disturb the digestive processes when there is nothing to be done, is evidently allowing the body to go onto what we may regard as a "war footing," when there is no "war" to be waged, no fighting or struggle to be engaged in. and expenditure, between preparation and use, be- tween anabolism and catabolism — and the corre- lated antagonism of central innervations, that un- derlie the antipathy between the emotional states which normally accompany the processes. The desire for food, the relish of eating it, all the pleasures of the table, are naught in the presence of anger or great anxiety. And of the two sorts of emotional states, those which manifest them- selves in the dominant division of the autonomic hold the field also in consciousness.

Antagonism Between Emotions Expressed nsr the Sympa- thetic AND IN THE SaCRAL DIVISIONS OF THE AUTONOMIC The nervi erigentes are the part of the sacral autonomic in which the peculiar excitements of sex are expressed. As previously stated, these nerves are opposed by branches from the sympa- thetic division — the division which is operated characteristically in the major emotions. The opposition in normal individuals betweenihe emotional states which appear in these two antag- onistic divisions is most striking. Even in animals as low in the scale as birds, copulation is not per- formed "until every condition of circumstance and sentiment is fulfilled, until time, place and partner all are fit."^ And among men the effect of fear or momentary anxiety or any intense emotional interest in causing inhibition of the act can be sup-