In psychopathology, sensory disorders are identified, which include: hyperesthesia, hyposthesia, anesthesia, paresthesia and senestopathy, as well as a phantom symptom.
Hyperesthesia is a violation of sensitivity, which is expressed in superstrong perception of light, sound, smell. It is typical for conditions after suffering somatic diseases, traumatic brain injury. Patients may perceive the rustling of leaves in the wind as like a thundering iron, and natural light as very bright.
Hyposthesia is a decrease in sensitivity to sensory stimuli. The environment is perceived as faded, dull, indistinguishable. This phenomenon is typical of depressive disorders.
Anesthesia is a loss of most often tactile sensitivity, or functional loss of the ability to perceive taste, smell, individual objects, typical of dissociative (hysterical) disorders.
Paresthesia is a tingling sensation, burning sensation, crawling creeps. Usually in the zones corresponding to the Zakharyin-Ged zones. Typical for somatoform mental disorders and somatic diseases. Paresthesias are caused by the peculiarities of blood supply and innervation, which differ from senestopathies.
Senestopathy – complex unusual sensations in the body with experiences of movement, transfusion, overflow. Often fanciful and expressed in unusual metaphorical language, for example, patients talk about tickling movement inside the brain, transfusion of fluid from the throat to the genitals, stretching and compression of the esophagus.
Phantom syndrome occurs in individuals with loss of limbs. The patient displaces the absence of a limb and, as it were, feels pain or movement in the missing limb. Often such experiences arise after awakening and are supplemented by dreams in which the patient sees himself with a missing limb.
The main disorders of perception are illusions and hallucinations. Patients may be reluctant to talk about these phenomena or hide them.
Indirect signs of perceptual disorders are:
- a person’s conversation with himself (alone or in the presence of others),
- unreasonable and sudden change in attitude towards others,
- the emergence of new words (neologisms) in speech,
- facial expressions,
- a tendency to solitude, mood changes,
- contraction of the masticatory muscles and sternocleidomastoid muscles,
- stress of the orbital area with a half-open mouth,
- sudden glance to the side while talking,
- dissociation of facial expressions, posture and gesture,
- unfocused unexpected gestures with relatively motionless facial expressions.
Illusions are a distorted perception of real-life objects – a voice (illusory image) is heard in the sound of falling water (real stimulus). The main characteristics of illusions are:
- the presence of an object or phenomenon that is subject to distortion, for example, a visual, auditory or other sensory image,
- the sensory nature of the phenomenon, that is, its connection with a specific modality of perception,
- distorted assessment of the object,
- assessment of the distorted sensation as real,
- the disappearance of an illusion after an assessment by thinking or the inclusion of another modality, for example, with a visual illusion, an attempt to touch an object allows you to exclude an illusory perception.
In terms of complexity, illusions are divided into elementary, simple, complex, panoramic and paraidolic, an example of which are the images that we can see in a series of clouds or a carpet pattern. According to the sense organs, they are divided into: tactile, visual, visual, olfactory, auditory, proprioceptive and kinesthetic. For reasons of occurrence, illusions are divided into: physical, due to the objective properties of the environment, for example, due to the peculiarities of light refraction or sound reflection; physiological, associated with peripheral analyzers, for example, the illusion of a luminous gallo – the glow around the lanterns in patients with glaucoma; mental, in particular, associated with the expectation of a person whom we, mistakenly, suddenly see in the crowd; eidetic, associated with the imagination. Illusions are characteristic of neurotic disorders, as well as for the first stages of development of disorders of consciousness, such as delirium. Some illusions arise in mentally healthy individuals in special stressful environmental conditions. For example, when landing on the moon, astronaut Armstrong felt being tracked, which was associated with an illusory perception of the oscillation of the space shuttle antenna.
Hallucination is the perception of an object or sensory image that occurs without the presence of a real object, but is accompanied by the belief that this object exists. The term “hallucination” was first introduced by J.-E.D. Esquirol in 1838. According to the degree of complexity, they are divided into elementary ones, the most typical for epilepsy. These include audible from the outside simple sounds of hum, ringing, the whistle of a locomotive (akufeny), flashes of light or simple luminous figures that can be modeled with closed eyes by pressing on the eyeballs (phosphenes), smoldering smells or pleasant smells, usually accompanied by salivation (parosmia) …
Simple hallucinations are typical of organic brain damage. For example, with local lesions of the occipital region of the left hemisphere, the patient can observe a complete and objective image of a fish, a human face, or a hanging ax, which is observed in a specific place in space, for example, lying on a table (hallucinations of Charles Bonnet). The patient can feel the movement of insects under the skin in a specific area of the body, which is characteristic of organic lesions of the legs of the brain (Lermitt’s peduncular hallucinosis).
Complex hallucinatory images resemble dynamic phenomena. For example, an audible voice can comment on the events of others, and a visible image can move, smile or cry.
According to the sense organs, hallucinations are divided in the same way as illusions.
According to the conditions of occurrence, hallucinations preceding falling asleep (hypnagogic) are distinguished, these are usually sequential images resembling film shots, and hypnopompic hallucinations noted at the moment of awakening.
Hallucinations are also divided according to the space of their occurrence into true hallucinations and pseudo-hallucinations. True hallucinations are projected in natural space, for example, voices are heard on the street or in a room, the image is visible directly in front of the patient. In terms of content, true auditory hallucinations can be commentary (voices explain the patient’s behavior), imperative (voices force something to be done), conversational (voices talk to each other). In true visual hallucinations, the objectivity of the images is so high that patients communicate with them as with living people, in addition, the patient is convinced that those around him also see these images. True hallucinations tend to occur more often in the evening, especially visual images.
With pseudo-hallucinations, visual images are transparent and non-corporeal, they are closely related to thinking and can be associated with a specific idea. V. Khlebnikov defined this connection as “thought-form”. Pseudo-hallucinatory images invade the psyche forcibly, therefore they are explained by the patient as a result of the influence of someone else’s will, energy or force. An idea may arise that they speak with the patient’s own voice, controlling his speech apparatus, and thus the expressed thoughts do not belong to the person himself (Segl’s speech-motor hallucinations). They can also be combined with ideas of control, for example, experiences that the mood is associated with an alien force, it controls body movements, thoughts and intentions, This phenomenon is called mental automatism.
Auditory pseudo-hallucinations are projected into a conceivable space, for example, voices can be heard from another room that is well isolated, and even from other planets or emanating from the body. They are often heard inside the head as sounding or conflicting thoughts. Pseudo-hallucinatory object images inside the body are called somatic hallucinations. It can be the experience of a specific, often moving foreign body inside the abdomen, child, animal, or machinery. The internal image may have pseudo-hallucinatory thoughts that it exchanges with the patient. Pseudo-hallucination is most typical for schizophrenia.
Psychosensory disorders are sometimes considered intermediate between disorders of consciousness and perception. These include experiences of depersonalization and derealization, as well as special syndromes described in the corresponding section.
Depersonalization is expressed in the following symptoms:
- changes of “I”, a kind of feeling of transformation, often negative, of one’s own personality, accompanied by the fear of going crazy, the experience of one’s own uselessness, the emptiness of the meaning of life and the loss of desires. This condition is characteristic of affective disorders and some neuroses.
- splitting “I”, typical for schizophrenia and dissociative disorders, is expressed in the feeling of having two or more personalities in oneself, each of which has its own intentions and desires.
- a change in the body scheme, expressed in an abnormal perception of the length of the limbs, shortening or stretching of the arms and legs, changes in the shape of the face, head. A condition observed as a result of organic disorders.