Illusions of perception- These are distorted perceptions of real objects. They can occur in different modalities, but the largest number of them is observed in the field of vision. Visual illusions (optical deception) are extremely numerous and varied. There are a number of illusions caused by the imperfection of the sense organ. The most common types of illusions are:
1. Related, one way or another, to the structural features of the eye. From everyday experience we know that light objects seem larger in comparison with equal dark (black) objects. This illusion is the result of the irradiation effect of excitation in the retina.
2. Conditioned by contrast. The perceived size of figures turns out to depend on the environment in which they are given. Circles of the same size appear different depending on their surroundings: a circle appears larger among small ones and smaller among large ones. Each of us has been in a similar situation, when among small children we seemed like giants, and when we found ourselves in a group of people much taller than ourselves in height, we felt that we had decreased in stature.
3. Revaluation of vertical lines compared to horizontal lines when they are actually equal. Any distance filled with individual objects appears larger than the unfilled distance. Moreover, the distance filled with transverse lines is removed more than the distance filled with longitudinal ones.
4. Related to the transfer of properties of a whole figure to individual parts, which lead to erroneous visual images. This is the largest class of illusions.
5Conditioned by the relationship between “figure” and “ground”. Looking at the drawing, we see first one figure, then another. These could be stairs going up or down, two profiles changing to a drawing of a vase, etc.
6. Portraits. Many have seen “mysterious” portraits that always look at us, watching us, turning their eyes to where we are moving. This is explained by the fact that the pupils of the eyes in the portrait are placed in the middle of the eye section. As we walk away, we see the whole face in the same position and it seems to us that the portrait has turned its head and is watching us.
However, the vast majority of illusions arise not because of the imperfection of the sense organ, but because of a false judgment about the perceived object, so we can say that deception arises when comprehending the image. Such illusions disappear when observing conditions change, comparative measurements are performed, and certain factors that interfere with correct perception are eliminated. There are illusions that arise due to special observation conditions (for example, observation with one eye or with fixed eye axes). They also disappear when unusual viewing conditions are removed.
Sensory knowledge of the world and personality
Sensations and perceptions, despite their simplicity and subordinate, auxiliary position in relation to more complex mental cognitive processes, have a significant impact not only on the characteristics of the course of cognition, but also on the development of the individual as a whole. With the simultaneous absence of vision and hearing (deaf-blindness), the child cannot develop as a person at all without special help from others. The absence of one type of sensation also limits the possibilities of human development and the formation of him as a person. Thus, special studies show that people who are blind and have poor vision are often asthenic and hypochondriacal.
Those who cannot hear or suffer from hearing loss may be touchy and have increased anxiety. In general, people with visual and hearing defects, which are leading in our civilization, very often become indecisive, timid, and dependent on others. Due to the incorrect attitude of those around them to the capabilities of these people to understand the world, they often develop overvalued ideas of inferiority, combined with such qualities as integrity, a high level of moral requirements in relation to themselves and others.
As for violations of other types of sensations that do not belong to the sphere of significance for life in society, here the range of attitudes towards such violations is large - from complete indifference to admiration for their phenomenal characteristics, which also affects the development of the individual. We tolerate the fact that our loved ones cannot smell or have decreased taste sensitivity, we sympathize with those who have increased sensitivity to acceleration and get motion sickness, or those who suffer color blindness(inability to distinguish colors - usually red and green).
Considering the psychophysiological characteristics of sensations, we noted that one of them - synesthesia - has such a feature as individuality, i.e. unlike other characteristics, it is not obligatory for every person and can represent a unique combination of sensations. Visual-auditory synesthesia is usually noted, but it can also be visual-gustatory, olfactory-visual, etc. Such an unusual reflection of the properties of the surrounding reality cannot but influence the characteristics of the individual. For a large number of people with synesthesia, its feature formed the basis of their professional activities.
Yes, composer A.N. Scriabin created musical works, each sound of which was colored for him, which formed the basis of modern color music. He created a color-musical apparatus especially for other people; for him the sound was already in color. While for the artist Mikalojus Ciurlionis the colors made sounds, he painted “musical” pictures. For many perfumers, the scent compositions they create are coupled with visual images, which are often conveyed to consumers either through the name ("Spring Waltz", "Southern Night") or, more recently, through accompanying video clips ("Old Spays" with a cool sea wave). Therefore, many modern methods of influencing people are based on the characteristics of their sensorimotor organization.
The worldview of many peoples includes the phenomenon of synesthesia, which is enshrined in their language. Thus, anthropologists have long known that among the Indians of Central America, the tribes of Southeast Asia, and the blacks of central Africa, there are such associations in language: good things and people are compared with the concepts of “tall” and “light”, bad things - “low” and “dark” "
One experiment tested the connection between attitude and optical illusion. Psychologists divided the subjects into three subgroups according to their perceptions of the world. The first group included people with a positive outlook: completely satisfied with their appearance and health, success in work and family life. The second group consisted of people expressing dissatisfaction. And finally, the third group included subjects with an intermediate worldview. The subjects from the second group were most susceptible to optical illusion, and the least from the first. The subjects included in the third group occupied an intermediate position here too.
Not only sensation and perception influence the development and existence of a personality; the reverse process also takes place. First of all, it concerns the process of perception. It even has a special characteristic - apperception , representing the influence on the image of perception of the past experience of the perceiving subject, his socio-cultural environment, as well as the thinking, emotional state of the subject, etc. factors.
Thus, the accuracy of perception can be determined by:
- past experience perceiver. The influence of the existing practical experience was tested by the Austrian psychologist I. Kohler using prismatic glasses. Wearing them for a long time no longer affected the subjects; they corrected their perception with the help of practice;
- the significance of individual features perceived objects;
- professional training perceiver;
- features of the individual’s attitude to the process of perception. Thus, a large number of perception errors occur in subjects with an increased willingness to accept the opinions of others and reduced criticality;
- preferred style of analyzing the information received. In this case, distinguish different types of perception. Most often they talk about analytical or synthetic type of perception;
- mental level of the subject;
- emotional or physiological states subject at the moment of perception (remember a stressful situation or a state of affect).
Perception gives humanity the first objective way of scientific knowledge of the world - observation . This perception is inherent the presence of a goal, volitional effort in its implementation and independent choice of the object of perception. It is systematic. Observation arises due to the internal activity of the individual. It is preceded by preliminary preparation: setting observation tasks, planning the observation process. Observation is usually accompanied by keeping records of its results and process.
The effectiveness of observation is influenced by the knowledge and skills that a person possesses, the stability of his voluntary attention, as well as the synchronicity in the joint work of speech, perception and thinking. Observation must be learned. A person who masters the observation technique acquires a special personality property called observation skills, by which is meant a property of an individual, manifested in the ability to notice significant, including subtle, features of objects and phenomena. Observation is acquired through life experience and presupposes that a person has such personality traits as curiosity and inquisitiveness.
Report “Illusions of perception”.
People have long been trying to understand how we perceive the world around us. One of the most interesting ways to study is the study of illusions. Many researchers have been studying the causes of their occurrence, not only psychologists, but also artists, since ancient times. Let us remember the parable of King Solomon and the Queen of Sheba. King Solomon, wanting to see the queen’s legs (which for some reason she always hid), made a glass floor in one of the halls of his palace, just beyond the threshold, into which they poured water and let fish swim. The queen, entering, instinctively pulled back from the water surface, lifting her dress so as not to get it wet. And everyone saw that the most beautiful Queen of Sheba’s legs were not as perfect as the rest.
Illusions are a distorted, inadequate reflection of the properties of a perceived object. Translated from Latin, the word “illusion” means “error, delusion.” This suggests that illusions have long been interpreted as some kind of malfunction in the visual system.
In perception, usually each part depends on the environment in which it is given. Numerous observations and experimental studies indicate the effect of color on the apparent size of an object: white and generally light objects appear larger than equal black or dark objects (for example, in a light dress a person appears larger, fuller than in a dark one), the relative intensity of lighting affects to the apparent distance of an object. The distance or viewing angle from which we perceive an image or object affects its apparent color: color changes significantly at a distance. The inclusion of an object in the composition of one or another colored whole affects its perceived color.
One of the most famous optical-geometric illusions is the Muller-Lyer illusion. Looking at this figure, most observers will say that the left segment with arrows pointing outward is longer than the right segment with arrows pointing inward. The impression is so strong that, according to experimental data, subjects claim that the length of the left segment is 25-30% greater than the length of the right. Another example of optical-geometric illusions, the Ponzo illusion, also illustrates distortions in the perception of size. Many theories have been proposed to explain such distortions. One of them assumes that a person interprets both pictures as flat images in perspective. Arrows at the ends of the segments, as well as the convergence of oblique rays at one point, create signs of perspective, and it seems to a person that the segments are located at different depths relative to the observer. Taking into account these signs, as well as the same projection of the segments on the retina, the visual system is forced to conclude that they are of different sizes. Those fragments of the picture that seem more distant are perceived as larger in size. In everyday life, we are surrounded by many rectangular objects: rooms, windows, houses. . Therefore, a picture in which the lines diverge may be perceived as a corner of the building that is further away from the observer, while a picture in which the lines converge is perceived as a corner of the building that is closer. The Ponzo illusion can be explained in a similar way. Oblique lines converging at one point are associated either with a long highway or with a railroad track on which two objects lie. The visual patterns formed by such a “rectangular” environment are what cause us to make mistakes when looking at them. But when landscape elements are introduced into the drawing, the illusion disappears.
Analyzing the proposed explanation, we can assume that, firstly, all parameters of the visual image are interconnected, due to which a holistic perception arises and an adequate picture of the external world is recreated. Secondly, perception is influenced by stereotypes formed by everyday experience, for example, the idea that the world is three-dimensional, which begin to work as soon as signs indicating perspective are introduced into the picture.
An example of how a holistic image of an object can be destroyed is the so-called “impossible”, contradictory figures, paintings with disturbed perspective. The "impossible" Penrose staircase illustrates this well. Let's look at the picture: is the person moving upward? Each individual flight of stairs tells us that he is going up, but after going up four flights, he finds himself in the same place from which he began his journey. The “impossible” staircase is not perceived as a single whole, since there is no consistency between its individual fragments.
We encounter illusions every day. Sitting in a train carriage, looking out the window, it seems that objects located closer to the point of fixation are moving so quickly that sometimes it is not possible to distinguish details. And objects located in the background move together quite slowly. This phenomenon is called motor parallax.
Another dynamic illusion is autokinetic movement. If you look at a luminous point in a dark room, you can observe an amazing phenomenon. The experiment is extremely simple: you need to light a cigarette and put it in an ashtray. The indispensable conditions for the appearance of an illusion are that the room must be so dark that, apart from this spot of light, nothing else can be seen. In this case, the gaze must be carefully fixed on the luminous point for several minutes. Knowing that the cigarette lies motionless in the ashtray, after a while you suddenly discover that its light is moving, making sweeping movements, sharp jumps, and describing circles around the room. The range of motion can be quite large. Moreover, the understanding that this is an illusion does not in any way affect the results of the observation. Hypotheses explaining this phenomenon by eye movements were refuted by experiments in which eye movements and the observer's report of the direction in which the light spot was moving were simultaneously recorded. A comparison of the data obtained showed that there is no correspondence between real eye movements and the apparent movement of the object. Many hypotheses have been proposed attempting to explain the autokinetic illusion. For example, the absence of other visual stimuli in the visual field (I. Rock, 1980) or unusual corrective signals from the eye movement control center to maintain fixation (R.L. Gregory, 1970). However, none of the proposed theories has received general acceptance.
But perhaps the greatest visual is cinema and television, based on one of the most important properties of the visual system - inertia. The observer is presented with a static luminous dot in one place on the screen for several seconds, and after 60-80 ms it is shown in another place. A person does not see two different objects flashing in different places, but an object moving from one position to another. The visual system interprets successive and interconnected changes as movement. It is thanks to this effect that we see on the screens not a series of frames quickly replacing each other, but a single moving picture.
It is known that the first steps of cinema were accompanied by an episode when the audience saw an approaching train on the screen, they jumped up and ran away screaming - it seemed to them that it was rushing right at them. This phenomenon is called Luming. If a person is shown a spot of light that suddenly begins to expand in all directions, it will seem to him that it is moving directly towards him, and does not increase its size. Moreover, the illusion will be so strong that it will force you to involuntarily move away from the screen, as if from an object that poses a threat. Something similar can be seen when watching fans of computer games: someone leans to the side, trying to hide from bullets flying at him, someone recoils from a fireball rushing towards him. Obviously, in the case when there is no unambiguous information about a change in the shape of an object, the visual system prefers to interpret an increase in the retinal image as an approximation of the object, and not as an increase in its size.
More complex illusions are those that arise in connection with the processing of incoming information. Such illusions are caused by a higher level of information processing, when the nature of the problem being solved determines what a person perceives in the world around him. The peculiarities of selectivity of perception are interesting. If you tell a person: your name is in this book, then he will be able to very quickly flip through the pages and find a mention of himself. Moreover, there is no talk of any reading of the text. Such skills are possessed by proofreaders who incomprehensibly identify errors in the text that are invisible to the average reader. In this case we are talking about professional skills acquired in the process of activity.
Perception generally works very selectively when it comes to significant events that are too important for us. For example, the human face is perceived in a special way. The perception of an inverted image of a face is paradoxical. If you look at two photographs of faces turned upside down, you create the illusion that they are no different: eyes, nose, lips, hair - everything is identical. But by turning these portraits over, you can see that they are completely different. On one - the calm and sweet smile of Gioconda, on the other - a terrible grimace.
A very interesting question is about the differences in the perception of illusions in different cultures. Psychologists from different countries have conducted many cross-cultural studies using the classic Müller-Lyer illusion. How will illusions be perceived in cultures where the signs of perspective are different from the Western one, where houses and rooms are rectangular, roads are long with parallel markings? Experiments were carried out among the Zulu tribes living in Africa. Their culture is very unique: they build their houses not square, but round, and the doors also have a round shape. They even plow the fields not with rectangular lines, but with rounded ones. It can be said that the Zulus are characterized by a circle culture. They were asked: which of the lines is longer in the Müller-Lyer illusion? It turned out that they see this illusion only to a very small extent - they perceive the segments as almost equal. It also turned out that in other cultures, impoverished in the perspective typical of the West, perception depends on the characteristics of the environment. The studies were carried out in tribes living in a dense forest, where there is no distant perspective, the field of vision is limited, and there are no converging lines on the horizon (and this is one of the rules of perspective). It turned out that when people accustomed to such a limited view were taken into open spaces, they inadequately perceived the size of objects located in the distance. They could exclaim, looking at a herd of cows grazing in the distance: “Look, what little cows there are...” - without taking into account the fact that the size of objects decreases in the distance.
However, the influence of culture on the perception of illusions is a controversial issue. Do animals see illusions? It turns out that they are just as susceptible to their influence as a person. Experiments were conducted to study the perception of the Müller-Lyer illusion by fish and pigeons. Pigeons were first taught to discriminate the length of segments. If they chose the longer one, they were given grain. A conditioned reflex was developed, and of the two options they preferred the one for which they would be fed tasty food. When the birds were presented with a picture with two segments, they, like people, chose the one that seemed longer. It turned out that animals are not only susceptible to the Müller-Lyer illusion. They are capable of perceiving the stroboscopic effect, as well as the phenomenon of luming. When they were placed in front of a screen and shown an expanding spot of light, they reacted differently: crabs squatted to the ground, frogs jumped away, turtles hid their heads in their shells, that is, they all tried to avoid the spot as if it were an impending danger. It can be assumed that the perception of illusions is based on innate visual reactions associated with the physiological mechanisms of the visual systems.
Thus, illusions are not unique to humans. And they are due to different reasons. And the imperfection of human organs, and due to the current situation, mental state, and various cultural attitudes of a person. Illusions can be visual, tactile, auditory, etc. (by sense organs). Illusions are not a sign of any illness, although they may accompany any mental disorders. However, the main difference from them is that a healthy person, perceiving the world around him falsely, realizes that it is an illusion, while a sick person accepts it as reality.
Thus, illusions make our lives brighter and richer, helping us understand our own structure and the structure of the world around us. Rubinshtein S.L. Fundamentals of general psychology. M.1991.P.234.
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What is a perceptual illusion? Scientists are studying this issue not only in our country, but throughout the world. It is worth noting that this topic is of great interest to ordinary people who are not psychologists. In general, the illusion of perception is a not entirely adequate reflection of the properties of an object or itself during perception. This could be some gray object that, when placed on a dark background, turns out to be darker than when placed on a completely black background.
People today know many illusions. This is stroboscopic, autokinetic, induced movement. All this can be classified as a group of illusions of movement. In addition, there are many illusions in the world of temperature, time and even color. However, a theory that would explain all this does not yet exist. Most experts believe that such effects are the result of our perceptual mechanisms operating under unusual conditions.
The illusion of perception, or more precisely, its nature, in most cases is explained by certain features of the structure of the human eye. Many people generally believe that our entire world is one huge illusion. Many books have been written on this topic. Perceptual illusions in psychology are explained as a distorted perception of something from our world or the whole of reality. Illusions make us experience sensations that do not correspond to reality at all.
Probably many people are familiar with the visual illusion of Müller-Lyer perception. For a long time, experts tried to explain this distortion of reality. As a result, this particular illusion has been much better studied than anything else. An excellent example of a perceptual illusion of this type is the distortion of some things or objects when perceiving them through a prism or ordinary water. In addition, examples include numerous mirages that often appear in deserts. It is simply impossible to explain such processes using psychology.
It is worth noting that at the moment there is no generally accepted unified psychological classification of this kind of illusions. In addition, they can be detected in almost all sensory modalities. If we talk about taste illusions of perception, then this is, first of all, an illusion of contrast. That is, as a result of eating any food, one taste sensation is superimposed on another. For example, sucrose often gives water a bitter taste, and salt - sour.
As for the so-called proprioceptive illusion of perception, an example of this type can be the special or, as they say, drunken gait of professional sailors. In their case, the deck seems to be a fairly stable surface to a person. If a sailor walks on a flat surface, then the ground seems to disappear from under his feet.
In order to explain the illusions of perception, scientists have put forward a huge number of different theories. According to one of them, the illusion of perception is not something at all. This process is quite expected. The thing is that human perception itself depends, first of all, on the interaction of several stimuli in the visual field. For example, if you study a neutral color based specifically on the ratio of two or more neighboring areas, you can expect an illusory contrast. That is, in this case everything is predictable.
There is another theory that explains the origin of specific illusions based on the asymmetry effect. It is here that one can include the illusion of perception, which was already mentioned above, called Müller-Lyer.
English illusion; from lat. illudere - to deceive) - distorted perceptions of real objects. The greatest number of them is observed in the field of vision. Especially numerous are visual illusions (“optical illusions”) that arise when reflecting certain spatial properties of objects (lengths of segments, sizes of objects and angles, distances between objects, shape) and movement. You can highlight the following. their types.
1. Illusions associated with the structure of the eye. An example is illusions that are the result of the effect of irradiation of excitation in the retina and are expressed in the fact that light objects seem larger to us compared to dark ones (for example, a white square on a black background seems larger than an identical black square on a light background - see Fig. 3 a). (Cf. Aubert phenomenon.)
2. Overestimation of the length of vertical lines compared to horizontal ones when they are actually equal. The height of the figure in Fig. 3 b, seems larger than its width, although in reality the figure has the shape of a square. If the lengths of the perpendicular and its horizontal base are equal, the first is perceived to be larger in length. Any distance filled with individual objects seems larger than the unfilled one, and the distance filled with transverse lines lengthens more than the distance filled with longitudinal lines.
3. Illusions due to contrast. The perceived size of figures turns out to depend on the environment in which they are given (Fig. 3 c). The same circle appears larger among small circles and smaller among large circles (Ebbinghaus illusion).
4. Transferring the properties of the whole figure to its individual parts. We perceive a visible figure, each individual part of it, not in isolation, but always in a certain whole. In the Müller-Lyer illusion, straight lines ending in differently directed angles appear to be unequal in length (Fig. 3d).
The opposite cases of visual illusions are also possible, when, due to the greater difference between 2 adjacent parts, the impression of a secondary difference in the figures as a whole arises. Shown in Fig. d figures are the same, although the upper one seems smaller than the lower one, since the lower side of the upper figure is clearly smaller than the upper side of the lower figure adjacent to it (Yastrov illusion).
5. Apparent distortion of the direction of lines due to shading and intersections with other lines. Parallel lines appear to be curved under the influence of other lines intersecting them (Zellner illusion; Fig. 3 f). The illusion of non-collinearity, or a break in a straight line, is well known (Fig. g): segments of a straight line intersecting 2 vertical rectangles are perceived not as belonging to 1 straight line, but as separate segments located at different levels (Poggendorff illusion).
6. There are a number of I.V. known, which are based on an overestimation of the values of acute angles. In Fig. Figure 3 h shows parallel lines that make acute angles with other lines. Due to the illusory exaggeration of the latter, parallel lines do not appear as such. For the same reason, the circle seems to be drawn in at the corners of the square inscribed in it (Fig. 3g).
The reasons causing I. v. are diverse and not clear enough. Some theories explain visual illusions by the action of peripheral factors (irradiation, accommodation, eye movements, etc.), others by the influence of some central factors. Sometimes illusions appear due to special viewing conditions (for example, with one eye or with fixed eye axes). A number of illusions are caused by the optics of the eye. Of great importance in the occurrence of visual I. v. has a systemic effect of temporary connections formed in past experience, which, for example, explains the illusion of likening a part to a whole: usually if the whole is larger, then its parts are larger (compared to similar parts of another, smaller whole), and, conversely, if to .-l. of these parts is less, then the whole is less. Illusions of contrast may. explained by inductive relationships of excitation and inhibition in the cerebral cortex. Visual I.v. widely used in painting and architecture.
I.v. can be observed not only in the field of vision, but also in other areas of perception. Thus, the illusion of gravity by A. Charpentier is well known: if you lift 2 objects that are identical in weight and appearance, but different in volume, then the smaller one is perceived as heavier (and vice versa). The basis of this illusion is the connection formed in life between weight (volume) and the size of objects: the greater the size, volume, the greater the weight. And when this expectation does not correspond to reality, a contrasting illusion arises.
In the field of touch, Aristotle's illusion is known. If we cross our index and middle fingers and simultaneously touch a ball or pea with them (roll them), we will perceive not 1 ball, but 2.
Illusions can also arise under the influence of immediately previous perceptions. Such, for example, are the contrasting illusions observed when developing an “attitude” according to the method of D. N. Uznadze. After repeated perception of very different objects (in weight, size, volume, etc.), objects that are equal in the same respect are perceived by a person as unequal: an object located in the place of a previously perceived smaller object appears larger, etc. Contrast illusions often are also observed in the area of temperature and taste sensations: after a cold stimulus, a thermal stimulus seems hot; after the sensation of sour or salty, sensitivity to sweets increases, etc. See: Directionless field (autokinetic illusion), Moon illusion, Induced movement, Induced (Fechner) colors, Apparent movement, Mach bands, Oculogravic illusion, Optical-geometric illusions , Pulfrich stereo effect.
Illusions of perception
Word formation. Comes from Lat. illusere - to deceive.
Kinds. The most numerous are spatial visual illusions. It is customary to distinguish the following types of visual illusions:
Illusions based on physiological phenomena, such as the irradiation of excitation in the retina, due to the action of which the perception of light objects on a black background is determined as larger than objectively equal black objects on a light background;
The length of vertical lines is perceived as greater in comparison with horizontal ones, which are objectively equal to them;
The illusion of contrast (G. Ebbinghaus illusion), in which the same object is perceived as larger among small background objects and smaller among large background objects;
The distribution of signs of a whole figure to its parts, as for example, in the Müller-Lyer illusion, in which identical straight lines are perceived as unequal, depending on their completion;
Illusions caused by the use of shading, when parallel lines are perceived as curved (Zellner illusion);
Illusions based on overestimation of acute angles.
ILLUSIONS OF PERCEPTION
from Greek illusio - error.) - distorted perceptions of real objects. I.v. can occur in different modalities. They most often occur in the visual area. Visual I.v. (optical illusions) - errors of perception that arise when reflecting certain spatial properties of objects (lengths of segments, sizes of objects and angles, distances between objects) and movement. Illusions in the field of vision are very diverse. The following types of visual I. can be distinguished. 1. I. v. associated with structural features of the eye. An example is I. v., which are the result of the irradiation effect - excitation in the retina and are expressed in the fact that light objects seem larger to us compared to equal dark objects. Thus, a white square on a black background appears larger than an identical black square on a light background (Fig. 3a). 2. Revaluation of vertical lines compared to horizontal ones when they are actually equal to each other. The height of the figure (Fig. 3 b) seems greater than its width, although in reality the figure has the shape of a square. In the same way, a perpendicular is perceived to be greater in length than its horizontal base, although in reality they are equal. 3. Illusions due to contrast. The perceived size of figures turns out to depend on the environment in which they are given (Fig. 3v). Circles of the same size appear different depending on their environment. The circle appears large among small ones and smaller among large ones. 4. Transferring the properties of the whole figure to its individual parts. A person perceives a visible figure, each of its parts, not in isolation, but always in a certain whole. For example, straight lines ending in angles with different directions appear to be unequal in length (Fig. 3d). The opposite cases of visual I.V. are also possible. 5. Apparent distortion of the direction of lines due to the influence of other lines. Parallel lines appear to be bent under the influence of other lines intersecting them. The illusion of a break in a straight line is also known: segments of a straight line intersecting two vertical rectangles are not perceived as segments of the same straight line, but seem reduced in comparison with how they should go (Fig. 3 d-g). 6. There are a number of I.V., which are based on an overestimation of the size of acute angles. In Fig. Figure 3 h shows parallel lines that make acute angles with other lines. Due to the illusory exaggeration of the latter, parallel lines do not appear parallel. For the same reason, the circle seems to be drawn in at the corners of the square inscribed in it. The illusions considered are also called optical-geometric illusions. They are widely used in painting and architecture; their consideration is also necessary when displaying graphic and symbolic information. Here it is important to prevent the operator from experiencing certain I.V. when perceiving information from indicators. I.v. can occur not only in the field of vision, but also in other types of perception. For example, of two objects of equal weight but different sizes, the smaller one seems heavier. The so-called contrasting i.v., which consists in the fact that after repeated perception of very different objects (in weight, volume, size, volume, etc.), objects that are equal in the same respect are perceived by a person as unequal: an object in place seems larger a previously perceived smaller object, etc. Contrasting I. v. often observed also in the area of temperature and taste sensations: after a cold stimulus, a warm stimulus seems hot; after feeling sour or salty, sensitivity to sweets increases, etc. Causes of I. v. are not yet clear enough.
Refers to “On systems neurophysiology”Illusions of perception
What can be said about illusions, except that they exist and everyone is guilty of them? Common opinions are very different, ranging from the fact that there are no illusions at all to the fact that the whole world is a complete illusion. Is there a chance to understand how things really stand with this :) and how this can be practically taken into account?
Yes, I have! To do this, you just need to understand the mechanisms of perception and how what is perceived is realized. For this purpose, About Systems Neurophysiology was written. So that I will not be considered a sadist who sends a normal person to these jungles, I will make some kind of summary.
There are no illusions in the world, they exist in our perception of the world.
If we call an illusion in perception something that does not correspond to what is perceived in some part or in its entirety, which makes expectations in this part unjustified and reactions inadequate, then we can say that illusions accompany any perception without exception. Simply because our senses are not adapted to respond to all existing manifestations of reality, but are limited only by what the evolution of these mechanisms has optimized for the purposes of the survival of the species. Thus, visual receptors are maximally sensitive to only three colors, and intermediate ones are perceived at once by two neighboring receptors in color perception, i.e. all of them are an illusion by which it is impossible to judge the wavelength of visible color - their perception is inadequate.
Moreover, only a negligible part of our visual retina is capable of perceiving a sharply focused image. Our eye makes various scanning movements in order to consistently read the important elements of the image sharply (this is in addition to the constant rapid jitter of the visual field). But there is a complete picture in the head (it really “stands”, represented by the self-sustaining activity of parts of the nervous network responsible for all the observed elements of the image), it seems all sharp to us (as soon as the attention wants to see additional detail in it, the eye will immediately complete missing new details). This picture is an illusion: a purely subjective representation of what is objectively observed, and this picture is very individual for everyone.
But the brain, constantly faced with the task of conveying the properties of the external as accurately as possible, compensates for everything that interferes with the accurate transmission of these properties after each encounter with a discrepancy: the reversal of the image by the lens of the lens is compensated, the distortion of geometric proportions due to the imperfection of the lens, color rendition, age-related clouding of the lens, any retinal defects. This is how an increasingly reliable reflection of the properties of reality arises. But many of the distortions are never confronted with reality and remain uncompensated.
For illusions that arise due to the structure and function of vision, see the articles Visual illusions, Color illusions and the brain.
The situation is approximately the same with all other receptors.
Many inadequacies in the perception of reality arise when the functioning conditions of the brain change, which become different from those when adequate experience was acquired. This may be a general decrease in the threshold for firing neurons, which occurs when taking many hallucinogens and psychedelics, during brain hypoxia (holotropic breathing), with any change in the balance of neurotransmitters, and in many other cases. Here is an example from the article Obsessive thoughts are inherited:
People who have family members with similar problems are nine times more likely to suffer from obsessive-compulsive disorder. New research has shed light on one of the genetic factors that leads to the disease.
Obsessive-compulsive disorder (OCD) is a chronic and very severe mental disorder characterized by obsessions, obsessions and obsessions. These are usually recurring thoughts, images or painful urges that the patient considers wrong and which he tries to ignore or suppress.
At the same time, information about the connection of the disease with the SLC1A1 gene came to the journal Archives of General Psychiatry (USA) from two sources. The gene encodes the EAAC1 protein, which regulates the appearance and release of glutamate from brain cells, the role of which was previously discovered.
Affects the degree of adequacy and many other conditions of perception. In the article: Confidence in the correctness of erroneous decisions grows with the complexity of the problem:
A group of psychologists from the University of Florence, having conducted a series of experiments on people, found that in certain situations, as the task becomes more complex, not only the number of errors increases, but also the self-confidence of those who make these mistakes. ... It turned out that as the task became more complex, the subjects’ confidence in the correctness of the answer given increased. Moreover, this confidence, oddly enough, did not depend at all on whether the subject was right or wrong. ... One way or another, the results of the study show that confidence in one’s own rightness is a deceptive thing. We can easily “see” something that did not actually happen, especially if something distracted us, and the degree of conviction of an eyewitness cannot in any way serve as a criterion for the authenticity of his testimony.
IN list of illusions, generated by the inadequacy of personal life experience, it is especially interesting to highlight the following:
So, illusions are an integral feature of any perception, which is only concerned with comparing them with the extent to which they are consistent with reality (sometimes you are asked to pinch for this:) Accordingly, the loss of life experience of compliance with reality (physiological disorders or the establishment of false, inappropriate reality, connections) leads to illusions and aphasia: see
