The basic human knowledge about illusions is based on the fact that it is a subjective phenomenon, different from real perception. At the same time, psychologists argue that a person's perception of the real world practically consists of illusions.
The simplest example is the perception of a three-dimensional image - each person associates a drawing depending on the angle of view, everything else is perceived at the stage of conjecture, with the help of additional senses, by touch, or depending on the location of the light source.
The formation of illusions in the human brain is based on the rethinking of the events that are taking place, and this is due to the fact that the human brain is not just working at full strength, but only by 10%.
And it is the emergence of illusions that is the brain's reaction, which is realized through the senses (as an auxiliary function), which perceive not everything that happens, and only that which seems to be the main thing at each specific moment of life. Some psychologists call this the function of "survival", that is, the brain perceives only those phenomena that it needs for conditional survival at this very moment (feeling of hunger, thirst, etc.). These moments are subdivided into different segments and directions.
The appearance in the mind of visual illusions is provoked by the peculiarity of the work of the human eye. Theoretically, the eyes perform the function of a scanner, that is, they simply "read" information, and then transmit it to the brain, which combines the received data into one integral picture. If the brain receives unreliable information, or incomplete information, then it independently "thinks out" based on previous experience. In such cases, there is a mismatch between reality and the picture created by the brain.
Sometimes a phenomenon or an object is supplemented by the brain with such details that do not exist, but which a person subconsciously wants to see. The experience of psychologists can serve as a striking example of such a phenomenon - they have repeatedly come across a situation where people of different professions, education and age interpret the same picture in different ways.
Visual illusions are subdivided into separate groups, depending on the reasons that can create an illusory perception of a particular event, phenomenon or object. These include physiological reasons associated with the retinal perception of what is happening.
Well-known illusions such as the perception of the size of vertical lines larger than horizontal (at the same length), the Ebbinghaus illusion, called the illusion of contrast. It consists in the fact that among small objects a large object seems larger, and vice versa.
No less well-known is the Zellner illusion, which is a hatching made in a special way, in which all parallel lines are perceived as not parallel. The illusion of an autokinetic nature also belongs to visual illusions that change a person's life depending on perception - with a certain look at the drawings, some objects begin to move and rotate. There are a lot of such examples, and they are well known not only to psychologists, but also to architects, artists and fashion designers, who often use them in their works.
All this is easy to explain - all the senses and the brain are not able to instantly accept, analyze, process, and, most importantly, keep in memory all the information they receive about an object, object, phenomenon. Therefore, they "snatch" familiar features, considering them key, and on the basis of them "finish" the overall picture.
As a rule, all the differences from reality lie in the difference in the data that they did not receive, but "invented". The most interesting thing is that in different situations, one and the same object or phenomenon can be interpreted in completely different ways.
The second most important factor contributing to the appearance of an illusory perception of reality in a person is auditory illusions. This is due to the fact that when receiving a signal about the arrival of someone a sound, the brain, first of all, tries to "establish" its source, for which it also uses the previously obtained experience. And the first thing that the brain "specifies" is the distance to the sound source.
With erroneous conclusions, a person perceives a strong noise from afar, as a whisper in the ear, and vice versa. Almost every person at least once in his life took the murmur of water in the kitchen, or the "wheezing" of the tap, for the conversation of unknown people. This illusion appears especially brightly at night, in the dark, when a person is relaxed and has no visual orientation to the sound source.
Cognitive or psychological illusions play a much larger role in a person's life than he knows about it. The fact is that illusions of this type are created on erroneous thinking and templates, with the participation of an element of previous knowledge, that is, the effect of prejudice, and the role of such illusions is purely adaptive. In other words, a person is unable to think when perceiving events, this process occurs automatically.
In addition, a person who has an illusion decides that a similar situation has already happened and acts in a similar way. Cognitive illusions include several types of illusory perception, the main of which can be called the effect of a behavioral stereotype.
It can be attributed to the effect of "general opinion" - that is, the stereotype of thinking of others. Also, psychological illusions include the erroneous opinion of confirmation from the series "everyone thinks so." Psychological illusory perceptions of reality psychologists call an erroneous assessment of the situation, for example, according to the type "I will not survive this." In such cases, the psychology of illusion also intervenes, that is, the expectation of the unknown, which is always frightening, so a person sets up an illusory barrier in advance.
The effect of acquaintance is very common, not without reason in the old days, it was customary to communicate only with a person whom someone, well known, introduced. That is, regardless of his personal qualities, this person is immediately perceived favorably.
A lot of psychological illusions are based on probabilities and faith (for example, in omens). Psychologists are well aware of the observation factor, in which a person begins to behave somewhat differently than he would do on his own. This effect is called Hawthorne, and the most striking example is the behavior of children in the presence of parents, employees in the presence of a boss, participants in any experiments.
The Hawthorne effect is a situation in which interest in an experiment, event, or increased attention to some issue leads to an erroneous, distorted, overly favorable result. Participants in the event behave differently, more diligently than they usually do, only through the realization that they are involved in the event, or by observing them.
A very interesting psychological illusion of correlation, an erroneous connection that arises between specific events, phenomena and results. Almost all folk signs refer to this effect - almost every person knows what to do if a black cat crosses the road so that there is no misfortune.
Also, students and schoolchildren are confident in many signs (eat a lilac flower with 5 petals, put a penny under the heel, etc.). Interestingly, if a person does not know what he is "threatened" with, for example, a meeting with a woman carrying an empty bucket, then nothing will happen to him.
Illusions of memory (cryptomnesia), which are confusion in their own memories and eyewitness accounts, are of great importance for creating illusions in ordinary human life. For example, adults often confuse their childhood memories with the mother's story, mistaking it for their own memory. A variation of this phenomenon is the effect of retrospective distortion - when an event occurs, a person often thinks that he foresaw it.
The proverb that there is nothing worse than waiting and catching up is based on the illusion of time. This phenomenon is known to everyone, time flies by when a person is doing well, and it drags on endlessly when he is bored and uninteresting. This can be interpreted as the fact that with active pastime, all thoughts are focused on the events that are taking place, and vice versa.
The placebo phenomenon can be imagined as focusing a person's perception on confidence in what is happening, for example, patients take harmless vitamins, knowing that it is an antibiotic, and begin to recover. Almost all doctors and psychologists know that the effectiveness of such a phenomenon (in fact, an illusion) is very high.
Nocebo is a phenomenon in which a person's consciousness, analyzing what is happening, "gives out" a definition of this situation. For example, if a person feels nauseous and dizzy, remembers that he had eaten mushrooms before, then he immediately assures himself that he was poisoned. But, most interestingly, this is the opposite phenomenon - if a person is convinced that he has eaten a poisoned substance, he immediately begins to feel all the signs accompanying this state.
The phenomenon of "imaginary" pregnancy, widely known in medicine, also refers to nocebo. There are cases when suspicious people pushed themselves to a real disease, finding in themselves signs of certain diseases that do not exist in their reality.
The effect of psychogenic purpura, or, more simply, Munchausen's syndrome, occurs very often in life - the desire to attract attention by any means. People deliberately induce symptoms of diseases known to them, and constantly demand more and more powerful drugs from doctors.
This type of illusion is almost always caused by self-doubt, lack of self-sufficiency and disorder in life. Most often, people with an unstable psyche suffer from it, and the line between pathology and an ordinary illusion in these cases is very thin.
The well-known "Stockholm Syndrome" is unusually interesting from the point of view of illusions. For a long time, psychologists did not correlate it with illusory perception, and considered it a consequence of traumatic psychological stress. And only recently, the experiments of many scientists have confirmed the direct connection of this phenomenon with the psychological illusion of perception.
The sympathy that arises between the victim and the attacker is caused by a misjudgment of the situation, when, after prolonged communication, both discard the reasons that brought them together and begin to sympathize with each other.
Also, phantom pains belong to illusions - after amputation of a limb, a person continues to feel it. At the same time, he feels her in the state in which she was before the amputation, that is, all the pain and discomfort in this limb.
Another illusory phenomenon that is quite common in life is synesthesia. This phenomenon is a combination of feelings, in the absence of one of them. For example, the sight of a picture with birds can cause the sound of their singing, after which, with the sounds of singing, a previously seen picture may appear in front of a person's eyes. At the sound of the surf, many people get the taste of the sea in their mouths.
Some especially impressionable people see numbers or letters in different colors. And musical notes can be associated with a particular color. Psychologists believe that the concept of "goosebumps" when frightened or when watching a scary movie, a book read, also refers to synesthesia.
Joint experiments of doctors and psychologists allowed to give a more precise definition of the causes of such illusions of sensation and imagination. This is due to the presence of physiological connections (bridges) between the auditory and optic nerves. Today it is called "color hearing". In literature and life, this is expressed by well-established metaphors - crimson ringing, green melancholy, warm meeting, etc.
The opinion that illusions are harmful and far-fetched phenomena that negatively affect a person's life is wrong. Just like the opinion that illusions are characteristic of unhealthy or very impressionable people. Most of the illusions are based on completely logical features of the human body, they must be treated like any psychological manifestation of character. The only thing you need to know is that they exist and be prepared for their manifestations.