Illusion: what is it in simple words, types, examples, causes

What is an illusion?

An illusion is a distortion of the perception of reality.

• So, many herbivores are red-green color blind and do not distinguish these colors among themselves, which allows predators such as tigers to blend into the vegetation of the jungle and prey on roe deer and wild boars.
• The structure of human eyes does not allow to perceive a number of colors that are called impossible or forbidden — reddish-green and yellow-blue colors.

But sometimes it’s not just the senses themselves. The processing of information received by the senses by the brain can modify what we see or hear. Take, for example, saccades — rapid eye movements that people make while reading or driving a car.

The brain, receiving a blurry and jumping picture from the eyes, sort of aligns the image, making it static. It seems to us that during saccades we saw everything, but in fact the brain skips a few milliseconds to simplify its work.

Sometimes the paths along which information flows from the sense organ to the brain seem to intersect and Shereshevsky’s syndrome or synesthesia occurs. Irritation in one system leads to involuntary irritation in the other, and the person suddenly begins to hear colors or feel letters.

What is an illusion?

Sometimes people mistakenly believe that optical phenomena are also illusions. However, optical phenomena can be captured by cameras and other devices and are usually caused by light scattering. One of the most common such phenomena is the blue of the sky and the rainbow.

Due to the peculiarities of the Russian language, we can call illusions those things that are not. Take, for example, the illusion of others’ success. This is an illusion in name only, in fact it is one of the many cognitive errors.

Cognitive errors or distortions arise from dysfunctional beliefs. You can notice the presence of such in yourself by analyzing your automatic thoughts. The most common cognitive error is the generalization of particular cases.

That is why it may seem to you that everything around you is more successful than you. Having seen several examples of success, you transfer them to all of humanity. However, cognitive distortions are not illusions, as they are errors of thought, not of perception.

So, how do you know that what you are experiencing is an illusion? As a rule, all illusions are short-term, it is enough to wait until the brain completely processes the information received, focus your attention and you will most likely immediately understand what happened.

Types of illusions

Mentally healthy people may have the following illusions associated with the work of the organs of perception and information processing:

1. visual
2. auditory
3. kinesthetic and tactile
4. olfactory
5. interoceptive;
6. associated with the passage of time.
7. The appearance of visual, auditory and tactile illusions is usually due to the fact that the incoming information is incomplete or we are distracted and do not pay enough attention to what is happening.

Tactile, kinesthetic and interoceptive illusions

One of the rarest (tactile hallucinations are almost as rare). The reason is that the sense of ownership of the body is formed through the mechanisms of multisensory integration. Perception as a whole is a multisensory process, which means that we perceive information about the world around us in its entirety, and not through separate channels.

The brain constantly combines all kinds of information. However, the time window between stimuli plays an important role, which is why information from the dominant organ of our perception, the eye, sometimes outstrips the rest, and we see illusions that quickly pass when information from other organs reaches the brain.

Olfactory illusions

Often associated with memories. For example, if as a child in kindergarten you loved to drink only cocoa, then in the future, visiting kindergarten with your child, you will most likely smell cocoa.

Illusions related to the perception of time

Usually observed in situations where we have nothing to do and need to wait for something for a long time. Time seems to slow down, it seems to us that an hour has already passed, but in reality it is only five minutes. People with depression are less likely to experience such illusions; as a rule, they develop an accurate sense of the passage of time.

There are multi-sensory illusions

For example, visual-tactile and visual-kinesthetic. But as a rule, such illusions do not arise by themselves. They can appear under special conditions, usually during perceptual studies methods are used that can trigger such perceptual errors.

Causes of illusions

The structure of all living organisms is imperfect and prone to error. In addition to errors of a physiological nature, errors of a cognitive, psychological nature may also appear in a person.

Society

Our brain always seeks to supplement what is perceived by the senses, to create a complete and simplified picture of the world around us. Sometimes such an addition to reality becomes completely free and we begin to see, for example, human faces in scattered spots.

The human brain, as an extremely social being, is very sensitive to the faces of other people. We are tuned to notice the slightest mimic changes and decode them to find out how the interlocutor feels now. Therefore, there are social reasons for the emergence of illusions.

Interiorization

The internalization of our culture means that our brains will mistake a long-haired person standing in the distance for a woman rather than a man, music in minor tones is sure to seem sad, and avoidance of eye contact will be perceived as dishonesty of the interlocutor.

Past experience

It happens that the cause of distortions of perception is past experience. After all, it is not in vain that they say “burnt in milk, they blow on the water.” If we suddenly find ourselves in a neutral situation similar to the previous negative one, we are more likely to extrapolate past unsatisfactory experience to a new situation.

Emotional condition

Our emotional state at the moment determines how we interpret what we see. Stress causes the nervous system to become agitated, so during times of stress, people may feel like they see colors brighter than usual, their hearing becomes sharper, the world seems to slow down, and so on. This is a normal adaptive reaction of the body to adverse environmental factors.

Such an emotion as fear makes us see danger even in harmless things. In Buddhism, there is one famous allegory that says that in the dark you can mistake even a piece of rope for a hidden snake. This is exactly what happens, due to an already excited state of the nervous system or a lack of information, a perceptual error can occur.

Thought patterns

Another reason for the appearance of illusions is that the brain, so to speak, prefers familiar images, as this saves the energy needed to process information. Therefore, the brain interprets a fuzzy, blurry image as something that we see often. So sometimes it seems to us that we see in the distance the figure of a person or animal, which, upon closer examination, turns out to be rubbish, beams, or any other objects whose outlines reminded us of something else.

cognitive failures

Of course, there are reasons for the occurrence of perceptual errors associated with various mental disorders. But many absolutely healthy people, both mentally and physically and psychologically, see illusions, and as a rule these are illusions common to all.

Illusion or hallucination?

Hallucination is an image that arises in the human mind in the absence of an external stimulus. Pseudo-hallucinations are also images that appear without an external stimulus, but they are distinguished from true hallucinations by the fact that the person experiencing them perceives them not with the senses, but with the word “we see with the inner eye” or “hears from the inside”.

Pseudohallucinations are much more common than true hallucinations. There are kinesthetic pseudo-hallucinations — the feeling that someone else is controlling your body. Hence the expressions “the hand seemed to reach out by itself”, etc.

Olfactory and gustatory pseudo-hallucinations are usually unpleasant for the one who experiences them and are also characterized by deliberateness, “made-up”. odHe of the more common types are auditory pseudohallucinations, in which a person «hears» that he is being called by name.

• Fatigue, alcohol, and the use of psychotropic substances are all causes of hallucinations.
• People with migraines sometimes experience visual, olfactory, and rarely tactile hallucinations that precede or accompany an episode.

So, the main difference is that the illusion occurs in the presence of an external stimulus, and hallucinations and pseudo-hallucinations — in its absence.

So, illusions are a normal phenomenon, although sometimes unpleasant or annoying.

The human nervous system and sense organs are very complex structures that operate on a large amount of information and manage thousands of complex processes, sometimes in milliseconds, so periodic errors are quite expected.