At the heart of all illusions is a perverted, twisted, and therefore erroneous perception of real-life phenomena or objects. In other words, objects and phenomena are directly perceived, and their actual real essence disappears.
Taste illusions that arise on their own are most often not a sign of the disease, they are rather concomitant phenomena in certain types of mental disorders.
In essence, experts refer to taste illusions as contrasting illusions, for example, sometimes taste sensations from one substance can affect the perception of subsequent taste sensations. So, salt dissolved in pure water can give it a sour taste, and sucrose - bitterness.
To explain the nature of this type of illusion, scientists and doctors have put forward a large number of theories. So, for example, I. Rock argued that the most suitable for this explanation is the science of gestalt psychology, since it reveals the fallacy of the hypothesis of the constancy of taste sensations.
According to this theory, illusions do not represent something abnormal or unexpected, in other words, a person's perception of phenomena or objects does not depend on an individual specific stimulus, but on the interaction of all sensations.
Thus, taste illusions (as well as all illusions) are based on the erroneous perception of real taste sensations and their subconscious replacement with other, completely different, (it does not matter, familiar or unfamiliar before) taste sensations under the influence of unconscious factors hidden for a person.
In psychology and psychiatry, there are special research methods when a person, instead of real familiar food products, is offered visually different ones, but with the latter's characteristic taste or smell.
And often a healthy person clearly and distinctly reveals illusory taste sensations. By the way, oriental cuisine, which is very "fashionable" in Russia today, is famous for its delusions of taste - when serving fish to visitors, the cooks are proud that it tastes like meat, and vice versa.
Taste illusions of a sick person, as a rule, have unpleasant and negatively perceived taste sensations in the mouth, both during the intake of food or liquid, and outside the process of eating. In addition, food can be perceived by a sick person with an unusual taste sensation.
The illusion of taste is one of the most unexplored issues among all varieties, both in sick and healthy people, due to the fact that the line is too thin between gustatory illusions and hallucinations, illusions and phenomena in disorders of the gastrointestinal tract, the phenomena of painful manifestations, etc. suggestibility.
Linda M. Bartoshuk of the University of Wales (School of Medicine, Department of Surgery), in her work Sense of Taste Determined by Contact, tried to derive the theory of deceiving taste sensations. The main provisions of her work are in the role of a person's conscious distinction between smell and taste (these concepts are inextricably linked) of food and liquids taken.
Any food or liquid, penetrating into the oral cavity, turns out, first of all, on the taste buds of the tongue and palate. The designations of sensations for humans are divided into sweet, salty, sour and bitter, while simultaneously with their "recognition" by the receptors of the oral cavity, volatile light substances from food and liquids rise up the nasopharynx cavities, and, in turn, reach the olfactory receptors, which are located under eye area.
All these high-quality olfactory sensations are the main responsible elements for the perception of food, that is, in the process of eating, a person feels both taste concepts and the smell of food, a combination of these phenomena is called taste, while the mouth is considered the main point of its origin.
Linda M. Bartoshuk in her work proves that gustatory sensations arise from touch (contacts). That is, she claims that taste sensations do not occur due to the interaction of food elements with areas of certain specific taste receptors, but depend on their mechanical contact with various zones located in the oral cavity.
In this regard, during eating, taste sensations come from all points and receptors on the surfaces of the oral cavity, despite the fact that the taste receptors themselves are located only in specific zones.
This phenomenon arises due to the fact that the human brain in the process of forming sensations of taste "takes on board" all the information and information from the receptors of touch located in the oral cavity at the moment of direct contact with liquids and food.
At the slightest disturbance of cerebral activity caused not only by mental illness, but also by stress, a state of passion, fear, excitement and other abnormal conditions, the consciousness incorrectly "registers" its sensations, and a gustatory illusion arises.
The general name for all qualitative disturbances and deceptions of taste sensitivity is parageusia (including dysgeusia, taste illusions and hallucinations of taste). When any neurological pathology occurs, symptoms of parageusia appear (as a result of damage to the opercular region of the brain).
The types of violations of smell and taste (which, as a rule, occur simultaneously) and gustatory illusions include:
- loss (both partial and complete) of gustatory or olfactory sensations;
- loss of interconnections between a certain (previously well-known) smell, taste and a typical, familiar to humans, inherent quality for a particular food item;
- change up to the exact opposite (inversion) of familiar and familiar tastes and smells (a person perceives previously pleasant tastes or smells as disgusting and vice versa).
In other words, all gustatory and olfactory illusions take on the character of a subjective change (inversion) of sensation (sometimes sweet takes on the taste of sour, the aroma can be perceived as a stench). Therefore, a taste illusion is very difficult to distinguish from distorted taste sensations caused by a disease, such as the liver (bitterness in the mouth, altered taste perception of food).
In mental illness, taste illusions play a minor role; they accompany some types of mental disorders. In these cases, the illusions of taste can manifest themselves not only as unpleasant sensations, but as sensations of a threatening nature.
The smell and taste of food and liquids can be perceived by a sick person as poison, have the taste of known poisons (especially for well-read and educated people), the smell of carrion.
In terms of content and quality, a sick person almost always has an unpleasant taste illusions, he complains of suffocating gases, the taste of feces, acids, metals, cadaveric odor, etc. It is extremely rare for such patients to have taste illusions or illusions of pleasant smells.
A typical example is the illusion of taste in alcoholics at the time of a delirium tremens attack - taking a solution of chloral hydrate and bromine for medicinal purposes to calm down, they are sure that they are drinking vodka.
The French psychiatrist Eskirol was the first to propose to distinguish between gustatory illusions and gustatory hallucinations, that is, to subdivide all the phenomena of deception of gustatory senses into areas, but to this day this division remains rather arbitrary, since it is far from always possible to determine the border between hallucinations and gustatory illusions.
This is easily explained by their manifestations - when hallucinations occur not only in the area of taste (but also in relation to sight and hearing), for the diagnosis of insufficiently differentiated sensations and perception of smells, taste, touch, because the presence of external stimuli can never be completely excluded. And when gustatory illusions arise, hallucinatory elements are always present.