Early American Manual
Studies in the Osteopathic
The Physiology of Consciousness:
Louisa Burns, M.S., D.O., D.Sc.O.
THE GANGLIONAR CENTERS OF THE CEREBRUM.
Those centers of earliest phylogenetic development
lying around the base of the hemispheres are concerned in the reactions
which answer most speedily and forcibly the environmental changes to which
the race has been accustomed. While the cerebral hemispheres were developed
to a certain extent among animals lower than mammals, and while they are
a conspicuous factor of mammalian brains, yet their functional development
seems to be a matter of comparatively recent times. Even among mammals
of considerable development the cerebral cortex seems to be largely non-functional.
The centers around the base of the hemispheres, the nulei of the thalamus
and corpus striatum, the other interbrain centers and the midbrain centers,
seem to perform the functions of properly relating the reactions to the
variations of the surrounding conditions. Even among man these centers
appear to control those reactions of immediate reply to certain environmental
During the phylogenetic development of these centers
they became functional in giving reply to many and varied changes, and
these duties they still perform, in man, without the intermediation of
consciousness. Through the activity of these centers reactions are controlled
which have every appearance of purposeful foresight, and which yet are
not associated with consciousness in any degree. This function of the lower
centers is of great biological significance, since the activities of these
centers secure for the cortical neurons the time and energy needful for
the performance of those duties concerned in the conscious phenomena. The
lower centers control those reactions called instinctive, or emotional,
or affectional, which depend upon racial history for the effectiveness
of the answer which they make to environmental changes.
The structural relationships of these ganglionic
centers may be given in brief. The corpus striatum, the optic thalamus,
the hypothalamic nucleus, the red nucleus and substantia nigra are those
most easily recognized. Probably the claustrum should be included. The
interpeduncular ganglion, the central gray matter around the aqueduct of
the cerebrum (Sylvius), the nucleus pontis, and perhaps others of the groups
of cells in the interbrain, midbrain, pons and medulla may be concerned
in modifying the nature of the instinctive and emotional reactions. The
cerebellar cortex and ganglia seem to be concerned in coordinating the
descending impulses, but not in determining the nature of the reactions.
The Corpus Striatum
The corpus striatum is a part of the cerebral hemisphere.
It is developed from the floor of the cerebral vesicle partly by a thickening
of this floor with an associated specialization of neuron groups, and partly
by the ingrowing of certain fiber groups from its own centers and from
other parts of the nervous system. Phylogenetically, it is of great age.
Its first relationships were with the olfactory impulses, as is the case
also of the cortex itself.
The corpus striatum is of rather complex structure.
It includes centers which are probably of different functions, as they
certainly are of different relationships. The body is divided into two
parts by the internal capsule; the inner of these is called the caudate
nucleus, the outer is called the lenticular nucleus. The lenticular nucleus
is divided by bands of fibers into three parts, at least. The outer of
these is the putamen; the inner masses are grouped as the globus pallidus.
The putamen is the outer zone of the lenticular nucleus.
It is separated from the claustrum by the thin external capsule. The insula
occupies a position just external to the claustrum, and is of about the
same extent as the putamen. The putamen is pigmented, and is rather freely
supplied with blood. This gives it a reddish color, quite different from
the color of the underlying globus pallidus. The putamen sends a large
bundle of fibers to the thalamus, probably chiefly to the median nucleus.
The putamen exchanges fibers with the caudate nucleus, the globus pallidus
and the cortex, chiefly of the insula and the fronto-parietal region. The
relations of the putamen to the claustrum are not well studied.
The Globus Pallidus
The globus pallidus is light in color, partly because
its cells contain no pigment and partly because its blood supply is rather
scanty. Like the putamen, it exchanges fibers with the caudate nucleus,
the thalamic centers, probably the median nucleus chiefly, and with the
putamen and the cortex. The globus pallidus receives collaterals and axons
from the motor area of the cortex, and it sends a bundle of fibers, the
olivary bundle, to the inferior olive and to the nucleus pontis.
The Caudate Nucleus
The caudate nucleus occupies a position beneath
and lateral to the lateral ventricle. The posterior extension, or tail
of the caudate nucleus is continuous with the amygdala. Probably the olfactory
impulses are partly coordinated in this ganglion. The caudate nucleus exchanges
fibers with the lenticular nuclei, the anterior tubercle of the thalamus,
and probably it receives collaterals and axons from the cortex.
The striato-thalamic fibers include fibers from both
lenticular and caudate nuclei to several of the thalamic, hypothalamic
and other interbrain and midbrain centers, both of the same and of the
The Optic Thalamus
The optic thalamus is developed from the second
cerebral vesicle, and is a part of the interbrain. It includes many centers
of varying functions and relationships. Probably the fact of the various
connections and functions of the thalamus is the reason why such various
and often contradictory accounts are given in both experimental and clinical
data concerning this body. It is evident that with many centers of varying
functions the clinical evidence and the experiments which do not recognize
the subdivisions could hardly be expected to harmonize. The description
given by Nissl includes twenty different thalamic nuclei. These may be
grouped, for convenience sake, into the median, lateral, ventral and posterior
nuclei, the nucleus of the anterior tubercle, the pulvinar, the nucleus
habenulae, and the internal and external geniculate bodies. The relationships
of these may be briefly given. In the first place, each of these centers
probably exchanges axons or collaterals from each of the others, both of
the same and of the opposite sides. With the exception of the nucleus of
the anterior tubercle, the gray matter of each nucleus is more or less
continuous with neighboring nuclei. Thus the difficulty of describing the
nuclei as separate centers is apparent. The nuclei seem to be all associated
with the corpora striata of both sides. This relationship is more intimate
in some cases than in others. The nuclei of the thalamus seem to exchange
fibers with almost or quite all of the primary sensory areas, and probably
of all areas of the cortex.
The individual connections of the thalamic nuclei
have been described in part as follows:
The lateral nucleus receives the fibes of the lateral
fillet, the spino-thalamic tract, and the fibers from some of the lower
centers concerned in the common sensory conduction path. It transmits the
impulses concerned in the sensations called common sensory to the cortex
of the parietal lobe, chiefly the postcentral gyrus and the neighboring
cortical areas. Descending fibers from the same areas are carried to the
The ventral nucleus sends fibers to the insula and
the operculum, and to the region which bounds the Sylvian or lateral fissure.
It also receives fibers from these areas.
The median nucleus receives fibers from the insula,
the second and third frontal gyri, and the neighboring areas. It sends
fibers to these areas also. It seems to be chiefly a descending path for
the impulses concerned in written or spoken speech. Injuries of the thalamus
are sometimes associated with peculiarities of speech, not resembling aphasia.
The median nucleus sends fibers to the same areas.
The posterior nucleus lies between the internal and
the external geniculate bodies. It is associated with the cortical area
between the visual and the auditory overflow areas. Fibers pass both to
and from the cortex.
The external geniculate body receives the fibers
of the optic tract, together with the pulvinar, and transmits the impulses
carried by these fibers to the primary visual area in the occipital lobe.
Descending fibers from the large pyramidal and stellate cells of the primary
visual area enter the external geniculate body.
The pulvinar receives also the optic tract fibers,
and transmits visual impulses to the visual cortex. The gray matter of
the pulvinar and the external geniculate body is continuous.
The internal geniculate body receives the fibers
of the lateral fillet, and transmits the auditory impulses carried thereby
to the primary auditory area of the first and perhaps the second temporal
gyri. Descending fibers from the same and probably neighboring areas are
carried to the internal geniculate body, and to the posterior quadrigeminates.
The anterior tubercle of the thalamus is concerned
in the reflex actions, and probably also the instinctive and emotional
reactions, following olfactory impulses. By means of the fornix, the corpora
mammillaria and the fasciculus mammillaria the olfactory cortex is related
to the nucleus of the anterior tubercle and to the gray matter around the
aqueduct. This center sends impulses to the viscero-motor centers of the
medulla, pons and midbrain, and probably indirectly to the viscero-motor
centers of the cord.
The ganglion habenulae receives the fibers of the
medullary striae, which transmit the olfactory impulses to the habenulae.
This center sends impulses by way of the fasciculus retroflexus to the
interpeduncular ganglion, which in turn transmits impulses to the nuclei
of the motor cranial and spinal nerves.
Other masses of gray matter in and upon the surface
of the thalamus have been described, but not fully enough for any conclusions
to be drawn concerning their functions or relationships.
The substantia nigra, hypothalamic nuclei and the
red nucleus may be described together in this connection. All receive collaterals
or axons from the cortex, especially the prefrontal, frontal and temporal
lobes. All receive fibers from the thalamus, striatum, and other ganglionar
centers of the cerebrum; each exchanges fibers with the others, and each
sends fibers to the nucleus pontis and perhaps also to the cerebellum directly.
The red nucleus receives fibers from the nucleus
dentatus of the cerebellum, and sends fibers to the lateral nucleus of
the thalamus. It is thus part of the indirect sensory conduction path.
The red nucleus thus appears to be an important station both in the motor
and the sensory paths. It is also, probably because of this double relationship,
an important center for the coordination of the instinctive and emotional
The interpeduncular ganglion receives fibers from
the red nucleus, substantia nigra, hypothalamic nuclei and the cortex,
either directly or indirectly. The fibers from this ganglion pass to the
motor nuclei of the cranial and spinal nerves. The ganglion is thus mainly
a part of the descending pathway.
The gray matter around the aqueduct includes nerve
cells whose axons descend near the rubro-spinal tract to enter the viscero-motor
centers, chiefly of the medulla and pons, but also, probably, of the cord
and the midbrain.
Other centers of the basal region have been described
by different authors. The nuclei and centers of the pons, medulla, cerebellum
and cord are concerned in the transmission and coordination of the motor
impulses resulting from the activity of the cortical and the ganglionar
centers of the cerebrum.
Experimental stimulation of the ganglionar centers
causes various reactions. It is not possible to locate exactly the centers
stimulated by the electrodes in animals so small as cats, dogs, guinea
pigs and white rats. (These are the only animals subjected to these tests
in the Pacific College Laboratory of Physiology.) The animals were anesthetized
before the skull was opened. Stimulation of the region of the red nucleus
gave rise to movements resembling those of the normal animal when angered
The arching back and tail, the spitting of the cat or growling of the dog,
the clawing and fighting movements, illustrated very well the expressions
of anger. The stimulation of the median nucleus of the thalamus and of
the subthalamic region gave practically the same results. When the animal
had been kept under the anesthetic for too long a time, or after the stimulation
had been too long continued, or when the animal subject to the test was
sick or starved, the reactions were sometimes rather, characteristic of
fear than of anger. (Stray and half-starved animals and those which are
sick are often sent to us for speedy and easy death.)
Stimulation of the same centers increases the heart beat and apparently
the blood pressure. The gall bladder may be emptied into the intestine.
The peristaltic movements of the stomach and intestines are usually increased
by the same stimulation. No other manifestations of emotional states than
fear and anger were observed.
Function of the Ganglionar Centers
These facts are in harmony with the effects of certain
emotional states upon physiological conditions. According to Mayer, Pawlow
and others, it is the emotional or affective states of pleasure, desire,
etc., which cause the increased glandular activities in the so-called “psychic”
secretions. Cannon and De la Paz, at Harvard, have shown that in the cat
fright increases the secretion of the adrenals. The presence of bile in
the circulating blood after right or anger is well known. The increased
secretion of tears in grief, laughter and other emotional states is due
to the activities of the ganglionar centers.
Lesions of these centers cause various symptoms.
Lesions of the striate bodies are associated usually with paralysis, due
to the involvement of the internal capsule. Lesions involving the nuclei
of the striate bodies alone either have not been described, or no symptoms
referable to the injured part were noted before death. Lesions of the thalamus
give various symptoms. Authors do not agree very well. Dejerine gives the
thalamic syndrome as including paresthesias, lack of coordination of delicate
movements, probably including speech, and an emotional instability or a
loss of the emotional reactions.
Dana recognizes three groups of symptoms from thalamic
lesion: First, disturbance of the intelligence due to the general effects
of brain injury; second, symptoms due to pressure upon adjoining parts,
or their involvement in the lesion; third, those due to the thalamic injury
itself. The general symptoms vary according to the individual, and have
little bearing upon the question of localization. The pressure symptoms
include hemiplegia, due to the injury of the internal capsule. Dana’s cases
include papillary disturbances and paralysis of reflexes, but not the disturbances
of the eye movements, the forced movements of the body, the choreic and
athetoid movements described by other observers. Dana finds the most definite
symptoms connected with injury to the thalamus to be central pain, some
anesthesia, and perhaps hemianopsia. The two latter may be due to extrathalamic
lesion. Dana considers that some of his cases indicate an effect produce
upon the visceral centers and the temperature of the body.
The pain involves the paralyzed side only; it involves
the arms and hands most, the leg and foot next, and rarely the head. The
peripheral parts cause most distress—that is, the hands and feet are more
painful than arms and legs. The pain is not like ordinary pain, but is
a sort of burring discomfort, more distressing than sharp or aching pain.
Even when the pain itself seems only slight it causes great annoyance.
In none of his cases was there any paralysis of the
emotional expressions, or any decided explosions of laughter or crying,
unless there were symptoms involving other parts of the brain. Dana agrees
with Roussy, who believes that the thalamus itself does not control the
emotional reactions. He agrees also with Meynert, who considers the thalamus
the organ which receives sensations and registers them in consciousness.
The lesions as described involve the lateral nucleus, but not the subthalamic
The extreme complexity of the relationships existing
between the various ganglionar centers of the cerebrum probably accounts
for the lack of symptoms referable to the lack of activity of these centers;
that is, the lack of function of one might be scarcely noticed if the other
centers were able to perform their duties in a normal manner. The lack
of emotional reactions does not arouse attention in as great degree as
the excess of such reactions, especially when the person attending the
patient has not been associated with him during his normal periods. Post
mortem records of lesions of these centers, with accounts of the symptoms
preceding death, rarely give any exact account of the location of the lesion.
It is greatly needed that more exact descriptions of the location of lesions
should be given.
The reactions characteristic of the emotional states
and the reactions called instinctive are, at least in part, governed by
the ganglionar centers. The consciousness of the emotional or affective
states is due to several factors: First, the conditions responsible for
the emotional state are usually a matter of consciousness; second, the
visceral and somatic reactions as they are being performed are made conscious.
Phylogeny of the Ganglionar Functions
The development of the emotional reactions is lost
in the beginnings of life itself. The securing of foods and the resistance
of the attacks of enemies make up the sum total of the activities of the
lower animals. The taking up of food materials from the surrounding fluids
is a process which greatly resembles the union of atoms, at least in a
superficial manner. It may be that the assimilation of food is, indeed,
a matter of the affinity of the molecules of the biogen for certain atoms
or radicals capable of being used as sources of energy, but this is a matter
of theory only.
Certainly the reactions concerned in the life processes
of cells seem to indicate that the use of the food materials of the surroundings
is largely a matter of chemical attraction. The use of foods probably represents
the beginning of the complex metabolism reactions which underlie the more
complex activities necessary to the seeking of foods by the higher organisms.
In seeking foods, a process made necessary by the development of organisms
of complex structure, the function of the nervous system comes prominently
into play. The actions concerned in this process necessitate the resistance
Positive chemotaxis may represent the beginning of
food seeking; the attraction of the foodstuffs may represent the beginnings
of sex attraction, such as is displayed in the union of parameciums, and
the beginnings of the sum of what are included in the terms friendship,
love, patriotism, and all the feelings we have for beautiful, and admirable,
and desirable things. Negative chemotaxis, then, must represent the beginnings
of the repulsion which the simple organisms exert toward those things in
their neighborhood which are harmful or merely useless. This repulsion
affects those organisms also which are harmful, or which may be merely
useless. The chemical configurations of the living molecules or biogens
probably are of a certain structure, and the structures of different biogens
should account for the different reactions of the different organisms.
From this negative chemotaxis of the unicellular organism to the sum of
the negative chemotaxis of the cells of the multicellular organism there
is never any exact line to be drawn. It would certainly be an unwarranted
conclusion that atoms “hate” one another, or that conjugating parameciums
“love” one another, as it is an unwarranted conclusion that the sum of
the positive chemotaxis of the cells of our own bodies represents all that
there is in ourselves of loving or admiring, or our feelings of patriotism,
and loyalty, and friendship. Between these limits of negative and positive
chemotaxis, phototaxis, and the tropisms and other physical forces, to
the complex emotional reactions of man, lie infinite gradations, but never
any unpassable gulf.
During the series of changes, which can not yet be
truly termed developmental processes, the reactions become more complex
as the structure becomes more complex, and as increasing size and organic
demands necessitate more and more variated supplies. The demands necessitated
by the development of sexual reproduction modifies the nature of the reactions
in the processes of constant variation and constantly acting evolutionary
The activities necessitated by hunger include the
chase of food and the fight of offense. The protection of the individual
against the attacks of other individuals also hungry, necessitates flight
and the fight of defense. Among animals of higher types the fight is associated
with the display of certain phenomena: the showing of the teeth, which
has for its worth the increased ferocity of appearance as well as the increased
speed of their use; the tension of the muscles, which has for its value
the increased speed and energy of their contractions; the increased blood
pressure, which increases both the efficiency of the muscles and of the
nervous system; the protrusion of the claws, which thus are ready for attack
or defense, and the inhibition of the nerve centers concerned in other
reactions. The animal stimulated to the fighting reactions shows no indications
of hunger, thirst, or any other physical need; he seems to suffer no pain
or sense of heat or cold, nor does he seem able to see or to hear anything
except the object of his attack or his defense.
Human beings suffer the same quality of inhibition
under emotional stress. The angry man feels no hunger, thirst, pity, loyalty,
and scarcely any sense of pain. He lacks humor or affection, and often
the sense of truth is lost. The angry man is apt to say things untrue,
and unjust, and disloyal, though he may be true, and honest, and faithful
at all times except during anger. The cortical neurons exercise the same
inhibitory effects upon the action of the emotional centers which they
do upon the spinal centers. The control of the emotional centers may be
secured by the lowering of the liminal value of system of neurons which
relate the cortical and basal center in function.
The feeling called anger is the consciousness aroused
by the occurrence of the somatic and visceral changes produced by the action
of the ganglionar centers controlling the reaction, and of the circumstances
calling these activities into play. A fairly good imitation of the feeling
of anger may be produced by imitating the appearance of anger, while the
best appearance of anger is produced by imagining the circumstances productive
of anger to be true, while the somatic reactions are imitated as nearly
Relations of Anger and Fear
When the circumstances of life are such as to render
an efficient reply difficult or impossible, then the activities characteristic
either of fear or of anger result. If the individual is competent to meet
the emergency, the reaction resembles anger; if the individual is not competent
to meet the emergency, then the reaction resembles fear.
Among human kind the same thing is true. If any person
meets environmental conditions which are abhorrent to him at a time when
he is tired, or overfatigued, or suffering from some exhausting and non-stimulating
disease, then the tendency is for him to “give up,” to display fear and
a lack of urgent endeavor to correct the conditions as he finds them. He
is more apt to overvalue the strength of the opposing forces than those
of his own side. He is incapable of meeting the emergency, and knows it;
therefore he fears. He may be merely absurdly conservative, which is a
human development of fear.
But the same abhorrent conditions may meet him at
another time, when he is strong and well, and with normal blood pressure
and clean blood; then he reacts to the conditions with the manifestations
of that power and earnestness and certainty of success which is the higher
development among mankind of anger.
The lack of food is associated with increasing restlessness
or increasing irritability. The long-continued lack of food is associated
with the loss of the energy required for movements, and starvation results.
At first lack of food increases the irritability of the unicellular organism
and of the individual cells of the multicellular organism. The presence
of hunger is associated with the motor restlessness which aids in the finding
of foods, in the unicellular organism. Among animals whose nervous systems
are efficient, the neuron threshold is lowered by the lack of food. The
motor restlessness thus initiated is helpful in the finding of food. The
same thing is true among the human race. The lack of food in the fluids
of the body lowers the liminal value of the neurons, so that less stimulation
is required to initiate the nerve impulse. Since the neurons of the greatest
specialization are first affected by the condition, it is evident that
there is a certain amount of common sense in the idea that it is necessary
to starve a talent in order to make a genius. Unfortunately, if talent
is starved too long, a dead talent rather than a live genius results.
The very fact of the seeking of foods by any number of animals brings
about two conditions: one is, that animals seeking food may themselves
be sought as food; the other is, that of two animals finding the same food,
only one can eat. Warfare thus results. The struggle for existence necessitates
the survival of the fittest to eat. The fact that any individual uses the
food in the producing of the greatest amount of energy therefrom is, in
the earliest developmental stages, reason for the survival of that animal.
The struggles for food or for mates, with the visceral and somatic variations,
make up the reaction called anger in animals. In man the term anger is
used in two senses. Anger as a form of activity includes the series of
reactions, both somatic and visceral, which are associated with an attack
upon some force which is, or may be, injurious or an impediment to the
activities of the person attacked, or for whose sake the attack is being
made. This series of phenomena may be observed in a slight degree among
animals of very inferior development, even those without the nervous system.
The simultaneous attack upon foodstuffs by two unicellular organisms may
resemble anger, though the resemblance must be only superficial. The problem
of the feelings associated with the manifestations of anger and other passions
is that of consciousness in general.
Physiology of Anger
The phenomena associated with the reaction called
anger have undoubted biological value. The hairs and other forms of exoskeleton
are raised by the activities of the pilo-motor nerves. This makes the animal
more ferocious in appearance, and also it protects him from the claws of
his enemy. The contraction of the pilo-motors among man causes the phenomenon
of “goose flesh.” As a means of protection or of causing a more ferocious
appearance, this reaction is of very little biological value among mankind.
The lips are raised and the teeth protruded. This is the beginning of the
attack, and it also causes the more ferocious appearance. The pupils are
dilated; the eyes thus seem larger, and sight may be made more acute. The
blood pressure becomes higher through the increase in the heart’s action,
and the energy of the contracting muscles is greater because of the increased
blood supply. The peristalsis of stomach and intestines are lessened, the
kidneys secrete less freely, the glands of the body secrete less freely,
except the sweat and salivary glands, whose secretion is, among certain
animals, a mode of defense. The “frothing at the mouth” of the insanely
angry has this significance, as has also the free perspiration associated
with certain conditions of anger. Among men, also, a difference of the
circulation is noted during anger.
While the blood pressure is higher by the increased
heart’s action, the splanchnic vessels are contracted. By this means the
blood pressure is increased also, and the blood is diverted to the skeletal
muscles, where it is needed during the fight. If the stimulation continues
and the storm increases, the activities of the vaso-constrictor center
are increased, and the peripheral vessels also are contracted. In the first
instance the fact and hands of the angry person are red, but during the
more ferocious stimulation the face and hands become white. So the white
anger represents usually the more intense reaction. This varies to a certain
extent among individuals.
Consciousness of Anger
The term anger is also applied to the feeling. Anger
in this sense is the consciousness of the visceral and somatic activities,
plus the consciousness of the conditions which initiated the reactions.
Anger does not result from the recognition of the conditions, no matter
how abhorrent, which do not have any personal effect. The interference
with the liberties of a neighbor affect us, because he is our neighbor;
but people do not become angry in any marked degree on account of the injury
or the slavery of people with whom one has no relationship. It is true
that relationship may be of many degrees, and that by the multiplication
of methods of intercourse the term neighbor is beginning to include many
who would have been strangers in the older times.
With the development of the intermediate areas the
phenomena included in the term anger becomes more or less dissociated and
the elements recombined, both in reactions and in consciousness. As a result,
instead of the simple manifestations of attacking and of repelling attacks,
of employing the fight as an agent for the securing of foods or of mates,
among men the same forces are employed in slightly different manners, with
great increase in the efficiency of human effort.
The recognition of an impediment to the motor activities
of certain animals leads to a manifestation of anger, and to the movements
of destruction and attack. Among men, the recognition of an impediment
to activities leads, or should lead, to a study of the nature of the impediment,
with a view to its efficient and speedy removal. Among savages, as among
animals, the immediate and angry attack is the result of unwelcome deeds
or words of other persons or animals, and the fight thus initiated is apt
to be very destructive and ferocious. Among civilized people the occurrence
of unwelcome deeds or words on the part of acquaintances should lead to
the inhibition of any reaction, until the action of the intermediate areas,
the recollection of past deeds and words, and perhaps further sensory impulses
of sight and sound, may affect the nature of the ultimate reaction. It
may be that this postponement of the reaction will increase the vigor and
destructiveness of that expression of anger, but more often the proper
appreciation of the surroundings inhibits altogether the angry reaction,
and much destruction is prevented.
Value of Anger
The proper appreciation of the surroundings which
lead to the beginning of anger may result in determining a new mode of
activity. The existence of an impediment to the activities of a normal
person may lead him to endeavor to remove the obstacle. If a river impedes
his progress, he may bridge the river. If a strip of land prevents the
sailing of his vessels from one ocean to another, he may dig a canal across
the isthmus. If things are too far away for him to see them clearly, he
may make himself magnifying lenses and other instruments. If he is very
much in earnest about finishing any piece of work, the increased blood
pressure, the contracted muscles of mastication, the shortened breath,
the tension of the lips, all show the resemblance to the primeval anger
which met an obstacle. The manifestation of urgent endeavor is associated
with the phenomena of anger, whose elements are isolated and recombined
in a manner which makes for increased efficiency and wisdom of reaction.
Thus anger and the reactions associated with the
adverse environment may be made a source of power. What is ordinarily called
force of character depends largely upon the manner in which the occurrence
of adverse environmental conditions affects the individual. Efficiency,
self-control, the control of others, the power of attainment in any line,
ambition in its best as well as in its unadmirable sense, all these depend
upon the dissociation and recombination of the forces concerned in the
series of activities called anger.
Fear as a series of reactions to impending attack
includes both somatic and visceral changes. The feeling of fear is the
consciousness of these somatic and visceral changes, plus the consciousness
of the circumstances to which the reactions are due. The last factor in
the feeling of fear may be absent, as in the fear present when awakening
from nightmare. The somatic changes are such as adapt the body to concealment
or to flight. The motor centers are wholly or in part inhibited. The body
thus becomes relaxed. Among certain animals this relaxation is so complete
as to cause feigned death. The animals thus affected by fear are saved
from the attacks of other animals who refuse to eat food found dead. The
complete relaxation causes complete quiet, so that such animals may be
unseen by their enemies. The inhibition of the motor centers may be partial,
as in the case of the “lame” quail, with which many children are familiar.
The visceral manifestations of fear are such as lessen
the injury about to be inflicted. The sweat glands usually increase in
activity. This lessens the efficiency of the claws of the attacking animal.
The pilo-motors are increased in activity, and the hairs, feathers, and
other forms of exoskeleton become erect. Thus the claws, etc., of the enemy
are less efficient than otherwise. The peripheral blood vessels are contracted,
and thus the danger of bleeding is lessened. The heart is increased in
activity and the blood pressure is raised, partly as the result of the
peripheral constriction and partly as the result of the increased heart
action. The efficiency of the muscles of defense is thus increased, and
the danger of the attack is lessened. Also, if flight be possible, this
increased blood pressure increases the efficiency of the muscles concerned
in that performance. It has lately been shown by Cannon and De la Paz,
at Harvard, that fright increases the secretion of adrenalin. This probably
is one factor in the rise of the blood pressure under fear. The peristalsis
of the stomach and intestines is first decreased, then increased under
fear, as under anger. The same thing is true of the bile ducts. Among human
beings the visceral effects of fear and anger are somewhat modified by
the activities of the cortical centers. This control produces irregular
and often disadvantageous reactions, and the visceral effects of the emotional
reactions may be decidedly serious under certain conditions. Rarely there
results more than temporary disorders, unless the person so affected suffered
some abnormal conditions before the occurrence of the emotional state.
The reactions characteristic of fear are, like all
other emotional and instinctive reactions, unmodified by the surrounding
circumstances not associated with the disturbance. Thus, the phenomena
of stage fright include the increased perspiration, the contraction of
the pilo-motors, the partial inhibition of the motor centers, and the contraction
of the peripheral vessels, which should be efficient in protesting from
impending attack, even though the cause of the stage fright lies in the
very fact that only friends of undoubted worth are present; in other words,
the urgency of the desire to make the most perfect reply to the demands
of any occasion increases the danger of stage fright and renders the apt
reaction the more improbable. By the activities of the cortical centers
the danger of the stage fright may be recognized; the person may prepare
himself so fully for the impending demands that no incongruity between
his preparation and the requirements of the occasion exist. Stage fright
is then almost impossible.
Value of Fear
Fear is concerned in like manner with the forces
which inhibit too urgent and immediate reaction. Too great stimulation
of certain centers causes inhibition of other centers. The use of fear
in its biological sense by the human race is one of the forces of the race.
Not cowardly is the fear which preserves life and makes advancement possible.
Not cowardly is wise conservatism. Cowardly is the fear which constantly
inhibits all reaction; cowardly is the fear which refuses to accept the
unity of the race, which saves one’s self alone. The fear which preserves
all, which leads to that inhibition which permits the association of the
impulses concerned in memories and judgments, that is the fear which enters
into every good judgment, which modifies every step toward advancement
until it can be determined whether advancement and not retrogression is
the direction in which the proposed step is taken. The development of the
intermediate areas, with their unlimited powers of recombinations of the
elements of experience, would lead to unlimited absurdities without the
inhibitory effects of fear in its biological sense. What death is to sexual
reproduction in evolution, that is what fear is to the activities of the
intermediate areas in consciousness. Sexual reproduction necessitates the
variations of hereditary qualities, the development of the intermediate
areas necessitates the variation of experiences; death in the one case
and fear in the other prevent too great variations from the accepted order,
and wholly support the laws which make for steadfast, and certain, and
The feeling called horror resembles that of fear
in part. The difference is due to the fact that in horror the impending
danger is perceived as tending toward some other person or thing. Thus,
in horror the consciousness is modified by the fact that the posterior
intermediate areas are active, rather than the anterior intermediate areas.
Thus, the differences between horror and fear are not apparent among animals
whose cortical centers are not functional. Among people whose posterior
association areas are not well developed, as in the excessively egoistic
or self-centered person, the emotional states of horror and fear are almost
or quite identical.
Disgust is a feeling produced by the consciousness
of increased salivary flow, reversed peristalsis, and the contraction of
the pilo-motors, with more or less of increased sweat. In its most pronounced
type disgust is associated with vomiting, and the preliminary symptoms
of vomiting are the source of the consciousness of disgust. The feeling
may be aroused by the presence of conditions not directly related to the
digestive tract, as in the consideration of repulsive acts, unethical or
immoral actions, etc. The word disgusting is used improperly as applied
to conditions of loss, failure, and the like, unless some factor associated
with physical repulsion be present. Disgust as applied to the acts of others
is not present when these acts are considered in an impersonal manner.
The most abhorrent crimes arouse no feelings of any kind in the person
who studies those crimes in the effort to determine their causes scientifically
and with the view of adding to the knowledge which is to prevent crime
in the future.
The psychology of sex has been studied thoroughly
by Havelock Ellis. Any attempt at a resume of his five volumes would be
beyond allowable limits. For a discussion of the psychical phenomena associated
with sexual manifestations recourse must be had to his studies. For the
present purpose it is necessary only to suggest the basic nature of the
phenomena which lie at the very beginning of all advancement of the race.
For by asexual reproduction no opportunity, or at least very little opportunity,
is found for variation. With sexual reproduction begins the possibility
of endless variations of the hereditary traits, and, as a result of this
variation, the possibilities of survivals and death by means of which the
development of the races become assured. Sexual reproduction means sexual
selection, and, through this selection in its widest meaning, the selection
of those qualities which make for advancement. The sexual psychology, then,
must underlie much of what we are ordinarily pleased to think of as pertaining
to things higher than the physical. As the sensory impulses reaching the
primary sensory areas may be combined and interpreted through the activity
of the overflow areas, and the significances and memories thus brought
into being again combined through the activity of the intermediate areas
into abstractions and ideals and prophecies for future grandeur, so the
basic principles of the elements of sexual selection may be dissociated
from one another and from physical reproduction, and the elements of choice,
and pleasure, and admiration may be recombined and again dissociated.
The decisions made in this way may be variously affected
by the associational processes, until a series of ideals and concepts arises
from which all that is fine in art, and music, and architecture, and education
have been developed. All that is admirable in social life, and much of
the enthusiasm and joy of living, have thus been made a part of consciousness,
and form a large, and important, and admirable part of daily life.
Limitations of Instincts
The laws acting through the ages, which make for
the persistence of constantly higher types, of constantly more complex
structure, constantly able to make greater and more economic use of natural
forces, are efficient in storing within the nervous systems of the higher
animals those reactions which are for the good of the race in the ordinary
environment of the race. No account is taken, in the development of the
instinctive and emotional reactions, of the possibility of the exceptional
cases, either of the individual or of his environment. Thus instinctive
reactions are perfectly adapted to ordinary cases; indeed, the instinctive
reactions appear to surpass in wisdom and perfection the most thoroughly
studied voluntary actions. But the instinctive reactions fail in the exceptional
The limits of the value of the emotional and instinctive
reactions lies in this, that these reactions are apt to fail in wisdom in the
exceptional cases. It is true that often they do not fail in the exceptional
cases, and that persons often do “instinctively” the things which are decidedly
wise and fortunate in the exceptional cases. But such conditions are themselves
exceptional. Under the exceptional cases the activities of the cortical neurons
are preeminently the efficient sources of the associational and volitional impulses
upon which wise reactions must depend.