Chapter I: Preface

Fear, rage and pain, and the pangs of hunger are all primitive experiences which human beings share with the lower animals. These experiences are properly classed as among the most powerful that determine the action of men and beasts. A knowledge of the conditions which attend these experiences, therefore, is of general and fundamental importance in the interpretation of behavior.

During the past four years there has been conducted, in the Harvard Physiological Laboratory, a series of investigations concerned with the bodily changes which occur in conjunction with pain, hunger and the major emotions. A group of remarkable alterations in the bodily economy have been discovered, all of which can reasonably be regarded as responses that are nicely adapted to the individual’s welfare and preservation. Because these physiological adaptations are interesting both in themselves and in their interpretation, not only to physiologists and psychologists, but to others as well, it has seemed worth while to gather together in convenient form the original accounts of the experiments, which have been published in various American medical and physiological journals. I have, however, attempted to arrange the results and discussions in an orderly and consecutive manner, and I have tried also to eliminate or incidentally to explain the technical terms, so that the exposition will be easily understood by any intelligent reader even though not trained in the medical sciences.

My first interest in the conditions attending pain, hunger and strong emotional states was stimulated during the course of a previous series of researches on the motor activities of the alimentary canal. A summary of these researches appeared in 1911, under the title, “The Mechanical Factors of Digestion.” The studies recorded in the present volume may be regarded as a natural sequence of observations on the influence of emotional states on the digestive process, which were reported in that volume.

W. B. Cannon.

CONTENTS

CHAPTER I

PAGES
THE EFFECT OF THE EMOTIONS ON DIGESTION

Emotions favorable to normal secretion of the digestive
juices--Emotions unfavorable to normal secretion of
the digestive juices--Emotions favorable and unfavorable
to contractions of the stomach and intestines--The
disturbing effect of pain on digestion 1-21

CHAPTER II

THE GENERAL ORGANIZATION OF THE VISCERAL
NERVES CONCERNED IN EMOTIONS

The outlying neurones--The three divisions of the outlying
neurones--The extensive distribution of neurones
of the “sympathetic” or thoracico-lumbar division
and their arrangement for diffuse action--The
arrangement of neurones of the cranial and sacral
divisions for specific action--The cranial division a
conserver of bodily resources--The sacral division
a group of mechanisms for emptying--The sympathetic
division antagonistic to both the cranial and
the sacral--Neurones of the sympathetic division and
adrenal secretion have the same action 22-39

CHAPTER III

METHODS OF DEMONSTRATING ADRENAL SECRETION
AND ITS NERVOUS CONTROL

The evidence that splanchnic stimulation induces adrenal
secretion--The question of adrenal secretion
in emotional excitement--The method of securing
blood from near the adrenal veins--The method of
testing the blood for adrenin 40-51

CHAPTER IV

ADRENAL SECRETION IN STRONG EMOTIONS
AND PAIN

The evidence that adrenal secretion is increased in emotional
excitement--The evidence that adrenal secretion
is increased by “painful” stimulation--Confirmation
of our results by other observers 52-65

CHAPTER V

THE INCREASE OF BLOOD SUGAR IN PAIN AND
GREAT EMOTION

Glycosuria from pain--Emotional glycosuria--The rôle
of the adrenal glands in emotional glycosuria 66-80

CHAPTER VI

IMPROVED CONTRACTION OF FATIGUED MUSCLE
AFTER SPLANCHNIC STIMULATION OF THE
ADRENAL GLAND

The nerve-muscle preparation--The splanchnic preparation--The
effects of splanchnic stimulation on the
contraction of fatigued muscle--The first rise in the
muscle record--The prolonged rise in the muscle
record--The two factors: arterial pressure and adrenal
secretion 81-94

CHAPTER VII

THE EFFECTS ON CONTRACTION OF FATIGUED
MUSCLE OF VARYING THE ARTERIAL
BLOOD PRESSURE

The effect of increasing arterial pressure--The effect of
decreasing arterial pressure--An explanation of the
effects of varying the arterial pressure--The value
of increased arterial pressure in pain and strong
emotion 95-109

CHAPTER VIII

THE SPECIFIC RÔLE OF ADRENIN IN COUNTERACTING
THE EFFECTS OF FATIGUE

Variations of the threshold stimulus as a measure of
irritability--The method of determining the threshold
stimulus--The lessening of neuro-muscular irritability
by fatigue--The slow restoration of fatigued
muscle to normal irritability by rest--The quick restoration
of fatigued muscle to normal irritability
by adrenin--The evidence that the restorative action
of adrenin is specific--The point of action of
adrenin in muscle 110-134

CHAPTER IX

THE HASTENING OF THE COAGULATION OF BLOOD
BY ADRENIN

The graphic method of measuring the coagulation time--The
effects of subcutaneous injections of adrenin--The
effects of intravenous injections--The hastening
of coagulation by adrenin not a direct effect on the
blood 135-160

CHAPTER X

THE HASTENING OF COAGULATION OF BLOOD IN
PAIN AND GREAT EMOTION

Coagulation hastened by splanchnic stimulation--Coagulation
not hastened by splanchnic stimulation if
the adrenal glands are absent--Coagulation hastened
by “painful” stimulation--Coagulation hastened
in emotional excitement 161-183

CHAPTER XI

THE UTILITY OF THE BODILY CHANGES IN PAIN
AND GREAT EMOTION

The reflex nature of bodily responses in pain and the
major emotions, and the useful character of reflexes--The
utility of the increased blood sugar as
a source of muscular energy--The utility of increased
adrenin in the blood as an antidote to the
effects of fatigue--The question whether adrenin
normally secreted inhibits the use of sugar in the
body--The vascular changes produced by adrenin
favorable to supreme muscular exertion--The changes
in respiratory function also favorable to great effort--The
effects produced in asphyxia similar to those
produced in pain and excitement--The utility of
rapid coagulation in preventing loss of blood 184-214

CHAPTER XII

THE ENERGIZING INFLUENCE OF EMOTIONAL EXCITEMENT

“Reservoirs of power”--The excitements and energies of
competitive sports--Frenzy and endurance in ceremonial
and other dances--The fierce emotions and
struggles of battle--The stimulating influence of
witnesses and of music--The feeling of power 215-231

CHAPTER XIII

THE NATURE OF HUNGER

Appetite and hunger--The sensation of hunger--The
theory that hunger is a general sensation--Weakness
of the assumptions underlying the theory that
hunger is a general sensation--Body need may exist
without hunger--The theory that hunger is of general
origin does not explain the quick onset and the
periodicity of the sensation--The theory that hunger
is of general origin does not explain the local reference--Hunger
not due to emptiness of the stomach--Hunger
not due to hydrochloric acid in the empty
stomach--Hunger not due to turgescence of the gastric
mucous membrane--Hunger the result of contractions--The
“empty” stomach and intestines contract--Observations
suggesting that contractions
cause hunger--The concomitance of contractions and
hunger in man 232-266

CHAPTER XIV

THE INTERRELATIONS OF EMOTIONS

Antagonism between emotions expressed in the sympathetic
and in the cranial divisions of the autonomic
system--Antagonism between emotions expressed
in the sympathetic and in the sacral divisions
of the autonomic system--The function of
hunger--The similarity of visceral effects in different
strong emotions and suggestions as to its psychological
significance 267-284