Psychiatry - O. K. Napryeyenko 2001

General Psychiatry
Disorders of Sensation and Perception

Sensation and perception are the first steps in human cognition of both the self and the world. They are Components of the sensory cognition process. Sensation refers to the process by which the human consciousness reflects individual properties of objects and phenomena occurring in the surrounding world. Perception, on the other hand, is The process of holistic reflection of objects and phenomena in their totality of properties. Closely linked to sensation and perception is mental representation (imagery), which is the reproduction in human consciousness of traces of previously perceived images. Sensations, perceptions, and mental imagery are categorized According to the Sense Organs involved: sight, Hearing, smell, taste, cutaneous (tactile) sensitivity, interoception, and Proprioception (body position in space). The processes of sensation and perception are individual in nature. The external world is felt and perceived as it is, but with varying degrees of completeness depending on a person's motivations, interests, stock of knowledge, and life experience.

Under normal conditions, a decrease or sharpening of sensations is accompanied by anxiety and fear for one's health. In psychotic disorders, the subjectivism of sensation and perception makes it impossible for the patient to distinguish between normal perception and pathological phenomena in a given sphere. Consequently, morbid phenomena acquire a real character for the patient, and the individual lacks critical insight into their mental state.

Classification of Disorders of Sensation and Perception

1. Sensory disorders (quantitative: hyperesthesia, hypesthesia, anesthesia; qualitative: cenestopathy).

2. Perceptual disorders:

a) illusions (affective, verbal, pareidolic);

b) hallucinations. Depending on their complexity, they are classified as elementary (simple) or complex hallucinations; according to the sense organs involved—visual, auditory, olfactory, gustatory, tactile, visceral; in relation to the patient's personality—neutral, commenting, imperative, antagonistic; and by their degree of development—true hallucinations and pseudohallucinations.

3. Psychosensory disorders (macropsia, micropsia, metamorphopsia, autometamorphopsia, derealization, depersonalization).

Hyperesthesia is an acute hypersensitivity to ordinary external stimuli. In this condition, normal daylight is blinding, sounds are deafening, smells are irritating, and the slightest Touch to the body becomes unbearable. Hyperesthesia of the sense organs is observed in asthenia, neuroses, organic Brain lesions, and early manifestations of acute psychosis.

Hypesthesia manifests as a reduced sensitivity to stimuli. In this state, the surrounding environment loses clarity and distinctness for the patient. Sounds become muffled and indistinct, colors grow dull and vague, and objects lose their shape, brightness, and appear static. Hypesthesia is characteristic of neuroses, reactive psychoses, and organic brain damage.

Anesthesia consists of the complete loss of sensitivity to stimuli and is clinically manifested by blindness, hearing impairment, loss of smell, taste, and Skin sensitivity. It frequently occurs in hysterical neurosis (where it is functional in nature) as well as in organic lesions of the central and peripheral nervous systems.

A more complex phenomenon of sensory pathology is cenestopathy. These are diverse, indefinite, diffuse, and extremely unpleasant sensations resembling stretching, squeezing, burning, heat, flushing, twisting, numbness, etc. They occur in various PARTS OF THE body and Internal Organs, and are not caused by any objective pathology therein. They often develop in a bottom-up direction (along the limbs and spinal Column toward the HEAD or Heart). The Emergence of these unusual sensations causes patients anxiety and suspicion regarding a severe, incurable disease. Cenestopathies are observed in neuroses and psychoses, and are particularly characteristic of Schizophrenia.

Perceptual disorders include illusions and hallucinations.

An illusion is defined as a distorted perception of a really existing object or phenomenon. Illusions are divided into physical, physiological, and psychic types. Physical illusions occur in all people and are explained by the laws of physics. For example, at the boundary between two media with different optical densities, a light ray is refracted. As a result, a spoon immersed in a Glass of tea appears bent. Physiological illusions are related to the physiology of our analyzers; for instance, skillfully made-up eyes are perceived as larger.

Psychic illusions occur when the Vision of an object merges with a morbid mental representation. In addition to being classified by analyzers (visual, auditory, olfactory, gustatory, tactile, and general sense of body position in space), psychic illusions are divided into affective, verbal, and pareidolic. Affective illusions arise in patients in states of fear, tension, and anxiety. In such states, a bush in an unlit part of the street is perceived as a criminal lurking and waiting for a victim. Amidst street noise, the patient hears voices of people allegedly making threats. Verbal illusions consist of the distorted meaning of a real conversation, where the patient perceives neutral judgments and remarks as accusations and threats. Pareidolic illusions most commonly arise when mental activity is diminished, and their content is fantastic and imaginative. Instead of cracks and stains on a wall, the patient sees marvelous plants, animals, fairy-tale characters, architectural ensembles, or panoramas.

Illusions can temporarily occur in mentally healthy individuals under adverse conditions (fatigue, starvation, emotional stress, anxiety). However, they are most frequently encountered in patients suffering from infectious, intoxication, alcoholic, and somatogenic psychoses.

Illusions must be distinguished from intellectual interpretations (such as glass artificially processed by a jeweler being perceived as a diamond) and functional hallucinations, which arise under METABOLISM/18.html">The Influence of a real stimulus acting on the analyzer associated with the hallucination. In this case, the real stimulus is perceived alongside the imaginary one. For example, a patient hears voices in the noise of a motor, but when the noise stops, the voices disappear.

Particularly relevant to psychopathology are hallucinations—perceptions occurring without a really existing object. They become just as real to the patient as the objective world and exert a tremendous influence on their actions and behavior. "Patients may recognize the subjective origin of hallucinations and still believe in their reality" (W. Griesinger, 1886).

The Doctrine of hallucinations is associated with the names of prominent psychiatrists of the past: J. Esquirol, J. Baillarger, G. de Clérambault, and V. Kh. Kandinsky. Modern scientists define hallucinations as false, imaginary perceptions that arise on a pathological basis and have the character of genuine sensory reflection of objective reality for the patient.

Hallucinations, in turn, are divided into visual, auditory, olfactory, gustatory, tactile, general bodily sensations, and complex hallucinations (involving multiple analyzers). Visual hallucinations may take the form of visions of individual objects of varying degrees of clarity (ranging from vague to sharper than reality), varying sizes (micro- or macroptic), and either colorless or saturated with vivid colors. Visual hallucinations are sometimes multiple, where the patient sees groups of people, animals, insects, or fantastic creatures that are either stationary or moving, transforming or remaining unchanged. The content of visual hallucinations causes terror or, conversely, fascination and attraction in patients.

Auditory hallucinations are characterized by extreme diversity. They can include ringing, noise, calls by name, or elaborate monologues (verbal hallucinations), dialogues, and narratives sounding from above, below, afar, or nearby. The content of verbal hallucinations can be neutral to the patient, pleasant, soothing, or threatening and ominous. A distinction is made between commenting hallucinations (voices discussing the patient's actions, feelings, and thoughts, mocking and criticizing them) and imperative voices (giving commands, often compelling the performance of a dangerous act). Voices can be male or female, familiar or unfamiliar, differing in intensity and timbre, appearing temporarily or remaining constant.

Olfactory hallucinations manifest as various imaginary odors of differing intensity, sometimes pleasant, but more often unpleasant in nature (smoke, gas, decay). Gustatory hallucinations are practically difficult to distinguish from olfactory ones. The patient experiences a taste uncharacteristic of the food consumed, often extremely unpleasant or poisonous.

Tactile hallucinations involve the sensation of insects crawling over the body or the feeling that objects are appearing on or under the skin.

Visceral hallucinations include sensations within the body, most commonly in the abdomen, of foreign objects or living creatures—either stationary or moving—causing unpleasant sensations.

Tactile and visceral hallucinations must be distinguished from cenestopathies, which are more elementary morbid sensations devoid of objective form.

Depending on their complexity, hallucinations are divided into elementary (simple) and complex. In elementary auditory hallucinations (akoasms), the patient hears isolated, undefined sounds, noise, or whistling, while in visual ones (photopsias), they see sparks, streaks, smoke, or fog. Simple hallucinations present the patient with a complete image or clearly articulated phrases. Complex hallucinations involve multiple analyzers and manifest as the simultaneous occurrence of Different types of hallucinations (visual, auditory, tactile, gustatory, olfactory, and visceral).

Hallucinatory images, regardless of the analyzer involved, may possess the traits of realistically existing, concrete, and sensuously colored representations. Such hallucinations are called true; the hallucinatory image is projected outward, meaning it is perceived as an object or phenomenon genuinely existing in external space, outside the patient's body. In contrast, pseudohallucinations, although perceived as quite concrete and sensuously defined, are not associated with actually existing objects and phenomena; they are perceived not in the outside world, but within one's own body, most commonly inside the head. The patient speaks of peculiar, unreal voices, images, or odors contained within themselves ("nesting in the brain," "in The Stomach," "in the intestines"). Despite the subjective nature of pseudohallucinatory images, patients harbor no doubt about their existence and believe in their reality. Unlike patients with true hallucinations, those with pseudohallucinations claim that their voices and images are the result of external influence (having been "put" there by someone). Visual pseudohallucinations are characterized by the sensation that they have been "hexed." They occur against the Background of a clear consciousness within the subjective space of one's own body, taking the form of single or multiple images, or scene-like pictures of varying degrees of clarity.

Auditory pseudohallucinations are identical in content to true ones, manifesting as "implanted" thoughts or voices sounding inside the head.

Unlike true ones, olfactory, gustatory, tactile, and visceral pseudohallucinations are accompanied by the sensation of being "hexed" or subjected to external intrusiveness.

In kinesthetic (motor, proprioceptive) pseudohallucinations, patients feel that they cannot control their own body. Movements occur against their will, imposed from the outside. Speech-motor pseudohallucinations occur when a patient has the sensation that someone is moving their Tongue, forcing them to pronounce words and phrases.

Psychiatric practice also encounters patients with antagonistic, or contrast, hallucinations—a hallucinatory sensation of a comparative nature. The "voices" argue with one another, defending opposing viewpoints.

Autoscopic hallucinations occur when a patient sees their own double next to them.

Hypnagogic hallucinations occur during the process of falling asleep.

Hypnopompic hallucinations are observed during awakening.

Charles Bonnet syndrome-type hallucinations are hallucinatory sensations that arise in damaged analyzers. A blind person thus "sees," a deaf person "hears," and so forth.

Extracampine hallucinations are disorders where an image arises outside the field of vision—for example, seeing a spirit behind one's back that "moves" when the patient turns around.

Due to their impact on behavior in severe mental pathology, hallucinations are of particular significance during the clinical assessment of a patient's condition. Although patients in most cases tend to conceal (dissimulate) or deny existing perceptual deceptions, their behavior changes in accordance with their hallucinatory experiences. Regardless of the type of hallucination, patients become extremely focused and absorbed in their inner world, seeming to disconnect from real life. In the presence of visual hallucinations, the patient's eyes are usually wide open and fixed on the source of the perceptual deception. The pupils are dilated, the eyeballs are immobile, and the head—and sometimes the torso—is inclined toward the hallucinatory image. In true auditory hallucinations, the patient's head and body also turn toward the "source of the sounds," with a concentrated facial expression. Auditory pseudohallucinations are typically characterized by closed eyes and a head thoughtfully tilted upward or to the side; the patient listens to something of vital importance to themselves and whispers. When hallucinatory experiences are threatening in nature, patients exhibit a corresponding facial expression and tendencies toward aggression, self-defense, or flight. A peculiar mimicry is also inherent in patients with olfactory and gustatory deceptions: they periodically pinch their Nose to shut out an unpleasant odor, may spit out food in disgust during meals, or refuse to eat altogether.

Persistent hallucinations are always indicative of impaired mental activity, necessitating the intervention of a psychiatrist. Different mental illnesses are characterized by specific types of hallucinatory experiences. True visual hallucinations are most frequently observed in exogenous psychosis, intoxications, infections, delirium tremens, head trauma, Brain Tumors, and Epilepsy. In epilepsy, visual hallucinations are particularly vivid and terrifying. Verbal, olfactory, and gustatory pseudohallucinations are more common in schizophrenia. Alcoholic delirium is more frequently accompanied by true microzoopsias.

The perception of signals from various sense organs serves as the material for sensory synthesis—the cognitive reflection of the surrounding world and one's own body. The disintegration of this synthesis results in psychosensory disorders: distorted perceptions of one's own body, space, life realities, and personal identity. Psychosensory disorders include metamorphopsias, which are distortions of the size or shape of objects and space. All objects may appear to the patient reduced (micropsia), enlarged (macropsia), elongated, widened, or twisted (dysmegalopsia). Distorted perception of object size is usually accompanied by a perceived alteration of space, which may seem compressed, bringing all objects closer, or infinitely elongated (poropsia). Objects surrounding the patient may appear to move unnaturally in their imagination (mental allesthesia). Metamorphopsia is frequently accompanied by autometamorphopsia—the sensation that the shape and size of one's own body are distorted. This produces a morbid sensation of an increase or decrease in the size and mass of one's body, or the distortion and displacement of its individual parts (Disorders of the "body schema"). Occasionally, body schema disorders manifest as notions of duplication or disappearance.

Derealization. The entire environment appears alien, distant, unreal, blurred, frozen, stripped of color, or unnaturally vivid. The sense of time and space is altered, and patients doubt the reality of the existing world. Derealization encompasses phenomena such as déjà vu—where, in an unfamiliar situation, There is a sensation that everything has happened before. Also related to derealization are jamais vu (alienation of perception), déjà entendu (something heard for the first time seems familiar), déjà vécu, and jamais vécu. Derealization is accompanied by bewilderment, anxiety, and fear, although critical judgment remains intact and the patient is aware of having this disorder, attempting to shake it off and overcome it.

Derealization is frequently combined with depersonalization (alienation from oneself), which belongs to disorders of the perceptual sphere involving a disturbance of consciousness (self-awareness). Characteristic of depersonalization are sensations of a changed "I," altered and lost feelings, thoughts, and memories that are perceived as "alien," "implanted," or artificially induced from without. In mild cases, depersonalization manifests as an awareness of oneself as lifeless, muted, faded—in a word, having lost reality.

Also associated with derealization are the sensation of an unwelcome stranger's presence nearby (personified awareness); an altered perception of the flow of time—either stopping or rushing too fast; disorientation regarding the past and future (disorder of time awareness); and the inability to connect individual phenomena or adequately perceive ongoing events (aperception disorder).

The aforementioned disorders may be persistent or assume a paroxysmal character. Most commonly, they indicate an organic brain disease, such as encephalitis or traumatic brain injury.

CONTROL QUESTIONS

1. Structure/97.html">Definitions of The concepts of "sensation" and "perception."

2. Psychosensory disorders. Disturbances of the "body schema."

3. Derealization.

4. Depersonalization.

5. Definitions of THE CONCEPT OF "illusions" and their classification. Affective, verbal, and pareidolic illusions.

6. Definitions of the concept of "hallucinations" and their classification.

7. The distinction between true hallucinations and pseudohallucinations.

8. The Specificity of hallucinations in certain disorders.