Practical psychology and psychiatry; for use in training-schools for attendants and nurses and in medical classes, and as a ready reference for the practitioner

Front matter

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PRACTICAL PSYCHOLOGY

Preface

TO FIFTH EDITION

In this revision important additions have been made to the Chapters on Psychology and Forms of Insanity. As to classification, the recommendations of the National Committee for Mental Hygiene have been largely adopted. A new chapter on the Prevention of Insanity has been incorporated.

Very sincere thanks are extended to Dr. M. W. Clift, of Flint, for the drawing of the Sympathetic Nervous System which appears in Part I.

C. B. B.

Flint, Mich.

Part I. ^^^^ Life; the Brain; the Mind; Faculties of Mind

Thinking 13

Development of the Mind; the Senses; Sensation; Perception; Memory; Ideation; Reasoning; Judgment.

The Localization of Function in the Brain 26

Feeling : Emotion 29

Volition 35

General Considerations 43

Sensation; Perception; Hallucinations; Illusions; Delusions; Witchcraft; Ideation; Memory; Higher Reflexes; Volition; Concept Association; Inattentiveness; Incoherence; Flight of Ideas; Verbigeration; Stereotypy; Pressure of Activity; Retardation; Opposition; Negativism.

Part II. Word Association and Obsession

Part IIL

Definition.

Causes V. 70

Direct Physical; Indirect Physical and Emotional; Vicious Habits; Constitutional and Evolutional.

Forms of Insanity 74

Infection Psychoses 77

Fever Delirium 77

VI CONTENTS.

PAGE

Infection Delirium 78

Postfebrile Conditions 79

Simple Neuritis 80

Treatment 81

Exhaustion Psychoses 81

Collapse Delirium 81

Acute Confusional Insanity 83

Chronic Nervous Exhaustion (Neurasthenia) . 85

Intoxication Psychoses 89

Lead Poisoning 89

Alcoholic Intoxication 89

Delirium Tremens 90

I Dipsomania 93

Chronic Alcoholism 94

Alcoholic Delusional Insanity 94

Alcoholic Pseudoparesis 95

Alcoholic Paranoia 98

Alcoholic Epilepsy 99

' Morphine and Opium Addiction 99

Cocaine Habituation 105

Insanities from Disturbance of Function of the

Thyroid Gland 106

Myxedema 106

Cretinism 106

Hypo- and Hyper- thyroidism 107

Dementia Precox 108

Hebephrenic Form 110

Katatonic Form 116

Paranoid Form 117

Paralytic Dementia 123

Elated Type; Depressed Type; Differential

Diagnosis.

Juvenile Paresis 137

Dementia with Paralysis 138

Insanity from Syphilis 139

Manic-depressive Insanity 139

Excited Phase 140

Depressed Phase 144

Alternating Type 150

CONTENTS. vii

PAGE

The Presenile and Senile (Involutional) Insanities. 156

/ Epileptic Insanity 160

Psychoneuroses and Neuroses 161

Hysterical Type 161

Psychasthenic Type 165

Dual Personality 169

Fugues 171

Anxiety Neuroses 172

Idiocy and Imbecility : 175

/ Paranoia " 176

Pellagrous Insanity 190

Part IV. Management of Cases of Insanity from the Medical

Standpoint 193

Medical Examiners; Diagnosis; Nursing Attention; Medicinal Treatment; Bed Treatment; Enemata; Hydrotherapy; Mechanical Feeding; Othematoma; Travel; Hospital Care.

Part V. Management of Cases of Insanity from the Nursing

Standpoint 220

Qualifications of Nurse; Administration of Food; Administration of Medicine; Nursing; Correction of Pernicious Habits and Checking Morbid Impulses; Mechanical Restraint; Ethics.

Part VL

Discipline in Home; Self-helpfulness; Good Literature; Work; Children's Caprices; Military Training; Day Dreaming; Autistic Thinking; Sex Education; Marriage.

Index 259

ILLUSTRATIONS

PAGE

The Brain as Seen from the Right Side 5

Physiological Lobes of the Cerebrum 9

Neurone 11

Sensation 15

Perception 16

Concept 21

Zones and Centers of Cerebrum 26

Great Sympathetic Nervous System 31

Volition 38

Stereotypy 55

Handwriting in Paralytic Dementia 129

(viii)

Part I, Psychology

Psychology : the Science of Mind.

The word Psychology is derived from two Greek words: Psyche, Soul, Mind; and Logos, Discourse.

The problems of the mind involve those of Biology : the Science of Life (Bios, Life; Logos, Discourse); and Physiology : the Science of properties and functions of Living Beings (Physis, Nature; and Logos).

Life is defined as "sl relation or combination of matter and force in which peculiar phenomena (appearances) take place, which are: (1) motion from inherent power, (2) a capacity for appropriating nourishing material (assimilation), and (3) the capability of multiplication or reproduction for the preservation of species. In the higher forms differentiation! of structure and development occurs ; and, in the highest, sensibility (feeling), intellection (thought), and will (volition). "2

That which distinguishes the living from the not living is the possession of the three qualities or attributes: Motion, Nutrition, and Reproduction — as above mentioned.

The locomotive moves from the force exerted by expansion of water ; the automobile, from that occasioned

^ A production of diversity of parts by a process of evolution or development.

2 The late Dr. A. B. Palmer.

by the sudden explosion of gases by means of an electric spark. Inorganic substances change their positions from force exerted upon them (as the rolHng of a stone from an earthquake upheaval). Heat and electricity are so-called modes of motion. The acid and the alkali, coming together in solution, make disturbance in the glass (motion from chemical action). All these are illustrations of motion, but not motion from inherent power.

Stones enlarge by additions to their surfaces (accretion), but cannot appropriate (assimilate) substances with which to grow.

Two or more stones may be produced from one by a process of breaking or disintegration. They have no ability, however, to reproduce their kind.

Certain plants, on the contrary, demonstrably have motion from inherent power: as witness the sensitive plant, which closes when its leaves are touched; the morning-glory, which opens and closes its petals; the ivy, which climbs the conductor-pipe or the tree; the insect-eating plant, which closes about and absorbs the prey which alights upon it. Plants also have ability to appropriate nourishing material. This is absorbed from the soil, or from the atmosphere, or, as in the case of the insect-eating plant, as above shown. Plants reproduce their kind by contact of the male and female elements. Conclusion (Judgment) : Plants possess life.

The lowest form of animal life is that of the amoeba. This consists of a simple mass of albuminoid matter, possessing irritability (rudimentary sensation), contractility (enabling motion from inherent power), and the power of segmentation or division, through which

PSYCHOLOGY. O

it reproduces itself. From this low form of life up to man, showing the highest organization, differentiation of structure occurs.

The lowest form of animal life in which a nervous apparatus (and this very rudimentary) appears is the jelly-fish. This animal possesses a muscular, digestive, and circulatory system sufficient for its needs. The oyster has imperfect nervous, muscular, circulatory, respiratory, and reproductive apparatus. The oyster has a bony system, its skeleton being upon the outside and constituting its shell. In the reptile and fish there is a higher development of the bony, muscular, digestive, circulatory, respiratory, nervous, and reproductive systems, with special adaptation of structure to the conditions in which the animal exists.

Special senses (hearing, seeing, etc.), are not developed in the lowest animal organisms. In the very lowest form, as the amoeba, there is irritability; in higher, common sensation (impressions of pain). As the scale is ascended, the touch sense, and from this on, other senses, as vision, hearing, etc., develop.

The nervous system in man is composed of: —

1. A central portion — originating and receptive.

2. A peripheral portion (the nerves) — distributing from, and conducting to, the central.

3. The great sympathetic — bordering the spinal column (see illustration, page 31), a chain of so-called ganglia and their nerve connections. Reference to this is hereafter made under the head of Emotion. ,

The divisions of the central portion are: — 1. The encephalic — within the skull.

2. The spinal (spinal cord) — within the spinal bones.

The part of the nervous system contained within the skull, composed of white and gray matter, and called the encephalon, or brain, has the following principal divisions: the cerebrum, the largest, consisting of two lobes or hemispheres connected by a bridge of white substance; the cerebellum, a smaller mass situated behind and below the cerebrum; the pons Varolii, a bridge which partially surrounds the legs or crura of the cerebrum and assists in binding the lobes of the cerebellum together, and the medulla oblongata, which in its lower portion is continuous with the spinal cord. Three membranes, the dura mater, arachnoid, and pia mater, envelop the brain and spinal cord, the pia lying close to them and the dura directly beneath the bones.

In the higher animals, accompanying certain nervous manifestations, there appears what is called consciousness (mind) . Fishes can be taught to come at the ringing of a bell ; perroquets and canaries to live in (stage) harmony with their hereditary enemy, the cat, to perform acrobatic feats, propel carriages, fire miniature guns, engage in mimic battle and simulate death; lions and leopards to perform tricks and subordinate savage instincts to the will of man; horses and pigs to indicate numbers; dogs to present an entire play, taking the parts of policeman, fireman, sentimental lover, busy housewife, and nurse for baby. Dogs often display a high type of reasoning and judgment. The word "instinct" employed as indicating the conduct-governing force in lower animals, formerly much in use, is now nearly discarded. Habit associations and inherited tendencies (instinctive) are numerous and obvious in these, but the psychologist no longer denies even to those low in the scale of intelligence a certain degree of ability to group concepts (reason) and to form judgments through which action is determined.

In the highest form of life (mankind) the development of the brain and- nervous system reaches its

The brain as seen from the right side. (Mills, "Nervous Diseases," J. B. L. Co.)

greatest perfection, and manifestations of mind are of the most complex character.

The Brain is the organ of the mind.

The cerebrum, with which in this connection we are chiefly concerned, is composed of white and gray matter. The white matter is fibrous, and makes up its bulk. The gray matter contains the cell elements, and

O PSYCHOLOGY.

is for the most part found upon its surface, although there are islands of this substance in the interior. The cortex, or covering of gray matter, dips down into grooves upon the surface of the brain, increasing its superficial area very considerably. The raised or prominent portions of the brain found between these grooves are called convolutions, and upon their depth and perfection of development mental strength largely depends. In lower formi of life and in primitive peoples they are smaller and less definitely outlined than in the higher orders of mankind.

The gray matter receives impressions from without conveyed by the sensory nerves and nerves of special sense and conducted through the white matter.

The gray matter originates and sends out impulses through the white matter to other gray portions and through the white matter and nerves to the outside.

The white matter conveys impulses from portions of the gray matter to others and conducts impressions to the gray matter received from without through the nerves. It also carries commands to the remotest portions of the body which result in movement.

Nervous force originates in the gray matter. The nervous system is comparable roughly to an electric circuit, with its battery of cells, in which force originates ; with its white matter of insulated wires, by which the current is conveyed ; and with relay stations or substations, the gray islands at the base, in which messages from the central station are grouped and co-ordinated, and in which, under certain conditions, messages from without, carried by the nerves of sensation and special sense, are responded to without the intervention of the main office.

Simplicity in the structure of the brain indicates low mental development, as shown in idiots and imbeciles. As complexity in structure increases, convolutions grow deeper, and gray matter becomes more abundant, mental operations are correspondingly higher. The size of the head, unless it exceeds or falls far below certain limits, is not indicative of the degree of mental development. ^

"No mental modification," says James, "ever occurs which is not accompanied or followed by a bodily change," and experiments upon the lower animals and observations in disease in man show that the brain is the organ of thought. Disturbance of its structure or function interferes with the play of emotion and the faculty of ideation. Serious and long-continued impairment of its nutrition displays itself in settled perversions of thought and feeling. Injury resulting in 'cerebral concussion may cause temporary or permanent suspension of intellection, and defects in cerebral development are accompanied by partial or complete absence of the higher psychical processes. A child is born into the world the structure of whose brain is anatomically deficient, or the growth of which is impeded by mechanical compression. The result is idiocy or imbecility ; the development of the higher intelligence, of judgment and reasoning, is impossible. "The pursuance of future ends and the choice of means for their attainment," which, according to James, are "the mark and criterion of the presence of mentality," are absent.

That the Brain is the organ of the mind, and that in

1 There are both microcephalic (small-brained) and macrocephalic (large-brained or at least large-headed) idiots.

the Cerebrum (the large brain) reside the higher mental faculties, is shown : —

1. By experiments on the lower animals. The pigeon deprived of the cerebrum remains apathetic and drooping. If thrown into the air, contact with this element produces, through what is known as reflex action, the muscular movements of flying, but these gradually become feebler until the bird sinks to the ground. If food is placed within its reach it is not voluntarily appropriated. If inserted far back in the mouth, food is swallowed through reflex action. The frog deprived of its cerebrum rights itself if an attempt is made to turn it over. If pricked or prodded, it jumps, but is quiet and motionless unless disturbed by contact with something. It initiates nothing. The behavior of animals thus deprived of the cerebrum is akin to that of human beings suffering from profound dementia (acquired mental impairment).

2. By disease of the brain, which is so often associated with disturbance of the mental operations.

3. By the mental deficiencies which exist in connection with lack of cerebral development, as in idiots and imbeciles.

A definition of mind is impossible. It is known only through its operations. I am conscious of my mind from evidence within (subjective). I am conscious of mind in others because they act in obedience to outward, or apparent, circumstances as I do myself under similar conditions (objective evidence). Their so-called "reaction to their environment" is similar to my own.

As to the relation between mind and brain, this much, ^nd only this much, is definitely known, that upon the relative integrity of the latter, the natural operations of the former more or less closely depend. As to what consciousness is — that subtle something through which we are made aware of ourselves, of our environment, of our relations to society, through which our feelings are stirred, by means of which we act. and think intelligently— we are on no better ground of knowledge than were the philosophers of long ago who knew

Physiological lobes of the cerebrum, lateral aspect: S, Sylvian fissure; C, central fissure or fissure of Rolando; Po, parieto-occipital fissure. (Mills, "Nervous Diseases," J. B. L. Co.)

not the use of the scalpel, the microscope, and the staining agent.

The prefrontal lobes of the brain have been designated the ''higher psychical." This is perhaps objectionable, inasmuch as the brain in its entirety is the great psychical organ, and all portions of it in some way participate in the thinking processes; but it has been shown by investigations upon the brains of lower animals that, as a result of destruction of portions of these lobes, inhibitory (checking) control and capacity for close attention and intelligent observation are impaired. If they are destroyed completely there arise alterations in the personality and incapacity to form serially groups of images or re-presentations.

The cortex, or gray covering of the brain, is largely composed of layers of nerve cells of different shape and size and of infinite number. Those of the so-called pyramidal cell layer are thought to be chiefly concerned with the psychical functions because of the peculiarities of their distribution and their numerical diminution and imperfection in the brains of those of low order of mental development, as idiots. The so-called psychical neurone is of tree-like form, the body, with the thicker portion of the process extending from it, representing the trunk, and the tuft-like expansion, the foliage. The neurone also has a body with nucleus^ and nucleolus^ and a system of fibers passing through it which unite at the basal end into the axis cylinder or axone, through which impulses generated within the cell-body are conveyed outward.

The prolongation from the cell, called the axone, is insulated by a sheath throughout its entire extent. This insulation is for the apparent purpose of preventing dissemination of impulses along the fiber. Berkley says that the researches of Flechsig have shown that at the time of birth the human infant possesses only a narrow region bordering on a fissure, called the Rolandic, which contains fibers having these sheaths. In the first month two other small areas in the cortex show

1 A center of growth — a kernel. 2 A body within the nucleus,

PSYCHOLOGY.

Illustration of the neurone. A, axone with collaterals; B, apical dendrite, showing gemmules; C, lateral dendrites; D, cell-body. (With grateful acknowledgment to J. F. Burkholder, M.D,, Chicago.)

beginning insulation, and from this time on, as intellectual activities increase, further and further insulation of fibers shows itself in other areas. He also says that in the earliest stages of brain growth when the nerve cells have reached nearly their adult proportions, Flechsig finds only four centers that show signs of a tendency toward individual insulation of the nerve fibers of the cortex. The principal fibrous prolongation after leaving the cell body throws off collateral branches. Through these collaterals association contacts in the brain are established, and upon the perfection of their development and the multiplicity of their connections with other cells the faculties of discriminating judgment and of comparison of impressions with other impressions are supposed by some to depend.

Association paths between the different areas of the same hemisphere and between the two hemispheres by the bridge called corpus callosum are more numerous and intricate as mental development increases. Microscopical anatomy demonstrates that up to maturity there is a steady increase in means of association between cells of the cortex. Each, cell with its processes is separate and distinct from its fellows. It exists as an individual unit anatomically, and is independent of the myriads of others in the nervous system. Contact is not made directly between the prolongations of one cell and the tufts of others, but an interval exists, and upon the theory of failure of contact or delayed contact has been built up the retraction theory of psychical cell association. It has been assumed that in the rapid flow of ideation, this contact is continuous and exact, discontinuance or break resulting when the particular association in thought is no longer required or when the flow of ideation is arrested by fatigue or changed conditions. Thus the inabiHty to recall a name or an incident may be due to the failure of contact between the different nerve-cell elements concerned in the association which would in normal conditions arouse the memory.

The faculties of mind are three : —

1. Thinking (intellection, thought).

2. Feeling (sensibility, emotion).

3. Acting (will, volition).

Thinking.

Development of the Mind. — Knowledge is derived through the medium of the Special Senses and mental development depends upon the reception of impressions from without and their comparison with those already stored in memory. These Special Senses are six in number : —

1. Hearing: mental impressions through the auditory apparatus.

2. Seeing: mental impressions through the visual apparatus.

3. Smelling: mental impressions through nerves supplied to the nasal mucous membrane.

4. Tasting: mental impressions through nerves supplied to the tongue.

5. Touch: mental impressions through sensory nerves supplied to external parts of the body, skin, and mucous membranes.

6. Muscular: mental impressions as to force and resistance derived from contracting muscles. ^

There are necessary to the mental upbuilding : —

1. Sensation.

2. Perception.

3. Memory.

4. Ideation.

5. Reasoning.

6. Judgment.

A Sensation is an impression made upon an organ of sense, which organ must be composed of three parts : —

1. A nervous mechanism to receive the impression.

2. A sensory nerve, or nerve of special sense, to convey the impression to the brain.

3. A nerve cell, or group of cells, to receive the impression.

Take the eye for illustration. A ray of light from some object falls upon the retina. An impression is conveyed through the optic nerve to the center of sight in the brain and there received. This is a simple sensation. Sight, or Seeing, is a different thing, however, and involves, just as hearing, smelling, touch, taste, and the muscular senses do, something else, which is called

Perception. This is at the very foundation of thought and is the conscious recognition of the external causes of sensation.

To illustrate: nothing is so helpless as the human

1 Compare the impression received from compressing a rubber ball with that from a similar attempt upon a piece of steel. The essential difference between the touch and the muscular sense is plainly apparent.

infant at birth. Unlike the chick, which as soon as it emerges from the shell helps itself to food placed in the incubator, the child is utterly dependent and without means for self-preservation or protection. It is an unorganized bundle of tissues and passes during the early weeks of life a purely vegetative, existence. At three months of age or thereabouts the child is said to "notice" — that is to say, it takes cognizance of what comes before it. It follows with the eyes a candle or a

Illustration of simple sensation of touch. Arrow represents impression conveyed by sensory nerve to nerve-center in brain.

ball of bright yarn, watches for them and associates pleasant sensations with them. It perceives that the candle or the ball of yarn is the cause of an agreeable feeling. This, the conscious recognition of the cause, is Perception. When first a nursing-bottle is placed to its lips, these close down about the nipple and the operation of sucking begins. There is an impression conveyed by the touch and taste organs of the mouth, through corresponding nerves, to the sensory, or special sense, centers in the brain ; from those centers reflected upon motor nerve-centers in the brain, and through motor nerves going from the brain to the muscles. Result: the operation of sucking, which is at first a purely reflex act. Later, the child watches for the bottle of milk, extracts its contents when offered, or helps itself if the bottle is placed in the cradle. There is here Perception: the recognition of the external causes of the sensations which the bottle and its contents furnish. There are necessary to Perception : —

1. A nervous mechanism to receive impressions.

2. Sensory nerves, or nerves of special sense, to convey impressions.

M

Illustration of visual perception.

3. Nerve-centers in the brain to receive impressions.

4. Consciousness.

Perception is made up from a number of distinct percepts ; as, for example, form, size, color, vibration, density, taste. These individual impressions united, and with the aid of consciousness, form a percept of the object.

In order that percepts once acquired may be stored up for future use, there is necessary another mental faculty, which is

Memory. This is the faculty which enables the retention and reproduction in mind of impressions received.

Impressions proceed from the different organs of sense to areas of the brain in which they are registered. Memories of percepts are created. Of the function, memory, Scripture writes as follows : "If I were writing a dictionary, I would define memory as that portion of mental life about which everybody has been talking for three thousand years without finding out anything more than anybody of common sense knows beforehand." Bergson, in "An Introduction to Metaphysics," makes use of the vivid expression : "I notice the memories which more or less adhere to these perceptions and interpret them." So much for memory. It is known only through its manifestations.^

There are two kinds of Memory : —

1. Memory of percepts.

2. Memory of self (Organic Memory).

The memory of self (organic memory) permits the registration and storing up of impressions from all

1 During the years of brain evolution, the developmental period of life, memories are being stored constantly. Of many of these, use is made from day to day and every day, others lie dormant and affect conduct only when some special event calls them into activity. Nothing perhaps is completely forgotten vi^hile the brain is normal. Even in mental impairment due to age, there is often ability to recall dates and incidents of earlier years when the brain was recording. In advanced age there is apt to develop disease of the arteries and supplying blood-vessels which interferes with the nutrition of the brain cells. Current events then are not indelibly registered. The individual cannot remember at noonday what he has read or heard at breakfast time, he lives in the past and cannot utilize experiences of the present as a guide to acting or in conversation. A condition comparable with this is also found in certain organic diseases of the brain as paretic dementia.

parts of our bodies : from the skin, bones, muscles, and internal organs. These are for the most part sensory memories carried originally by inward-conducting (sensory) nerves. There are also motor memories originally collected from muscles influenced to action through outward-moving impulses from the brain.

Upon this memory-storing the Ego — the Personality — depends. Sensations such as are here mentioned do not, as a rule, come into consciousness independently; but, taken together in health, they constitute our feeling of well-being: our sense of self. In disease we may become, at times, acutely conscious of some or all of them. The development of the personality is extremely interesting.

The child at first is unconscious of its own existence, of its own individuality. It refers to itself in the third person: "Johnnie wants it," "Mamie wants it." The Ego^ — I — is not present. The child inspects its fingers and toes, as it docs that which is held before it, as something foreign to itself. Later, organic sensations proceeding from the fingers and toes and impressing themselves upon the consciousness give to the child the recognition of proprietorship. The organs become part of the child's body. The existence of the child at first seems to be of a dual character. Later, the Ego is formed — the personality — through sensations proceeding from all the organs and tissues of the body and registered in the organic memory.

The Personality is of great interest to those studying insanity, for in disease of the mind it is frequently found that alteration in organic sensations has given to the individual an impression of bodily loss or of change in constitution. Disturbance of sensation, m the foot, may lead to the illusion i that this member is lost or dead, checking or hindrance of mental operations may lead to the delusion^ that the mind is under the control of another. Defective elimination from the torpor of the stomach and bowels, causing a metallic taste in the mouth, may occasion the morbid belief that poison has been administered; inadequacy or impotence in the sexual sphere arising from over-indulgence or indiscretions may be attributed to a "charm" or hypnotic influence exerted by another who has given real or fancied ground for jealousy.^ Change in the action of the nerves of the skin may occasion the delusion that electricity or some harmful agency is at work upon the body. Sensations, indeed, may be so altered in insanity as to lead to the belief in a double personality.

This is not diflicult to understand when we call to mind the clod-like, heavy, foreign feeling of a frozen foot, or that of an extremity which has been separated from vascular and nervous connection with the trunk by a tightly constricting elastic band. Here the sensory nerves are blunted, and sensations proceed from the tissues above the affected point. The organic memory may be so vivid in its reproductions as to convey to the soldier the consciousness of the presence of an amputated extremity.

1 See definitions of "illusion" and delusion, pages 45 and 46.

2 Here wise discrimination is necessary on the part of the examiner. An insane delusion is no less a delusion because there may be fundamentally good reason for criticism or distrust of the one toward whom it is directed. It is the character or quality of the belief — its reasonableness — which is significant.

Impressions taken cognizance of, or perceived by, the mind are hoarded by Memory.

The process of grouping percepts together {Re-presentation— Re-collection) by the aid of Memory, to form concepts or ideas, is called Ideation.

Through impress 'ons coming into consciousness, primitive notions of size, consistency, odor, taste, etc., are formed. Grouped together, these form a percept of the object in its entirety, and these primitive percepts associated by the aid of memory form concepts or ideas.

Illustration : Take an object in the hand ; receive all the impressions possible from it through the medium of common sensation and the special senses. There is here a group of impressions coming into consciousness, constituting a percept of the object (Presentation). Remove the object, and associate the different individual percepts together through the aid of memory. It may still be seen, or heard, or felt. Thus is constituted a concept, or idea, which is a group of percepts reproduced in memory (Re-presentation — Re-collection).

On contact with the flame of the candle the child's finger is immediately withdrawn. This, a simple reflex act, is carried on through the sensory nerves, the conducting paths of the cord, the ganglia at the base of the brain, and the motor nerves. With this experience of the candle, however, there is registered in perceptive centers the memory of disagreeable sensation. Next confronted with the flame, the child draws back in terror. Associated with the sensory memory are others of a visual character which enable the child to identify the lighted candle as the cause "of the previous painful experience (Perception, Ideation). Later on, as its