Human visual perception. Cognitive ability

In 1910, psychologist Max Wertheimer, observing the flashing of signal lights at a railway crossing, experienced a sudden insight, which later served as the basis for the development of the concept of Gestalt (from the German Gestalt - holistic structure, image, form) and the formulation of the principles of visual perception of objects.

The psychologist’s chain of reasoning was approximately the following: in fact, the light signal does not move left and right - it’s just 2 separate lamps turning on and off sequentially. An even more inclination of the human brain to “complete” the observed object to a completed, “complete” structure is noticeable when looking at the “running lights” created by electric lamps surrounding the perimeter of signs and roof canopies of cinemas.

To the observer, everything looks as if an individual light is moving along a certain trajectory, periodically changing the direction of movement, although in reality there is a sequential switching on and off of individual lamps. It is the human brain that combines individual objects into a holistic image, categorically different from the sum of its parts - like fixed light bulbs qualitatively differ from the “running light” perceived by the observer of this electrical illumination.

Key Ideas Behind Gestalt Theory

“The whole is something other than the sum of its parts,” - Kurt Koffka, German-American psychologist, one of the founders of Gestalt psychology.

The above quote is the shortest summary of the Gestalt theory. In the example of Wertheimer’s sudden guess, a holistic structure (gestalt, perceived image) - a “running light” - in principle cannot be obtained by simply adding up its constituent elements (individual electric lamps).

In other words, people visually perceive a group of objects as a whole before they recognize the individual objects that make up the group. We see the whole as something greater than the sum of its parts, and even when the details of the overall picture are completely separate objects, when we look at them, we group them into a complete spatially visual form (another definition of Gestalt).

There are 4 key ideas that form the principles of Gestalt:

Emergence - the whole is recognized before its components.

Emergence is the process of forming a complex, coherent image from simple visual patterns. When trying to identify an object, we first determine its contour, its outline. We then compare the selected outline with perceptual patterns (familiar shapes and objects) already stored in our visual memory, looking for a match. Only after the outline of the observed whole matches the existing one in memory will we begin to identify the parts that make up the said whole.

When designing your landing page, keep in mind that visitors will first recognize landing page elements in their most basic form. A simple, clearly visible object will quickly involve the user in a conversion action than a complex object consisting of many small details and with a difficult-to-define contour.

Embodiment/socialization (Reification, “concretization”) is an aspect of perception in which an object is perceived as containing more spatial-visual information than is actually present in the sensory stimulus from the observed object.

In order for the observed object to coincide as much as possible with the stereotypes of perception stored in visual memory, the human brain generates additional information to fill in the “gaps” that cause a discrepancy between the contour of the object and the existing pattern of perception. In other words, we select an almost complete match of the perceived image and “add” it to the existing visual stereotype.

Socialization allows the designer not to complete the outline of the object in order for the user to see the object itself. It is enough to leave so many parts of the contour so that the viewer can compare it with existing perception patterns.

Multiple stability (Multi-stability, multistability) is a property that allows you to switch between stable alternative interpretations in case of ambiguous experience of perceiving an object (ambiguous perceptual experience).

Simply put, some objects can be interpreted by consciousness in more than one way. Many spatial illusions are based on this property of visual perception. Below is an example that you are likely already familiar with: In this picture you can see either two faces in profile or a vase (see the left illustration in the "Figure and Ground" section).

You cannot be in two stable states of object perception at the same time, seeing a vase and faces at the same time. Instead, you will quickly move back and forth between two stable alternatives for the semantic interpretation of the image, with one of them being the dominant way of perceiving the object, and the longer you stick with this interpretation, the more difficult it will be for you to see the “alternate reality” available on that one. same picture.

From the point of view of the practical application of the mentioned effect in design: if you want to change someone's perception of a certain object, then do not try to change everything at once. Find a way to provide the viewer with an alternative point of view, and this will automatically strengthen the new interpretation of the visual object while weakening its original perception.

Invariance is a property of perception that allows you to recognize objects regardless of their rotation, movement, scaling, changes in lighting conditions, etc.

Because we most often look at objects in the external world from different visual perspectives, we have developed the ability to recognize these objects regardless of our point of view.

Let's imagine a picture that you could recognize a familiar person strictly when looking at him from the front - turning in profile, he appeared before you as an absolute stranger. However, we can still recognize loved ones and friends - despite the possible diversity of the trajectories of our views on the people we know. :)

You can see these ideas implemented in the principles below. The basic concept of the material presented comes down to the fact that the principles of Gestalt describe mechanisms of perception And visual language core, with which designers work.

Gestalt principles

Most of these principles are relatively easy to understand, especially since they have a common theme that runs through many of them:

“All other things being equal, related elements in perception are grouped into units of higher order,” Stephen Palmer, American psychologist.

“People will perceive and interpret ambiguous and complex images as the simplest possible shape or a combination of the simplest shapes.”

This is the fundamental principle of Gestalt. People prefer to deal with simple, understandable and orderly things, which are instinctively perceived as safer than complex and incomprehensible objects.

Simple things do not require intense mental effort from a person and do not threaten him with unpleasant surprises. This is why, when we perceive complex shapes, we tend to “reorganize” them into a set of simple components or into a simple whole shape.

In the illustration above, you are more likely to see the image on the left as a combination of the simplest shapes - circle, square and triangle - as shown in the image on the right, rather than as a complex and ambiguous whole shape to interpret.

In this case, it is easier for us to see three different objects rather than one complex one. Sometimes it is easier to perceive one object by supplementing it with the help of closure.

“When we look at complex elements, we tend to see them as simple, recognizable forms.”

Like the previous law of content, the principle of closure is based on a person’s desire to simplify perceived images. But isolation is the opposite meaningfulness, which allows - as in the example above - to simplify visual perception by representing one object as a combination of three.

At completion we combine parts to see a simple whole. Our brain fills in the missing information to form a complete figure.

In the left image above you will see a white triangle, although the image is actually made up of three black Pac-Man-like shapes. In the picture on the right you will see a panda in a combination of several random shapes. This happens because seeing the triangle and the panda is easier than trying to understand what each individual part of the picture means.

Closure can be simplistically viewed as a “glue” that connects elements together, although we are talking here about a more global concept - about a person’s tendency to seek and find complete structures.

Key to use principle of closure— provide the user with enough information so that he can “complete” the missing elements in his perception. If there is little information, then the elements will be considered as separate objects, and not parts of the whole; if there is too much of it, then there is no need for it to happen in the process of perception completion.

Symmetry and Order

“People tend to perceive objects as symmetrical shapes formed around conventional centers.”

Symmetry gives people a sense of security and order, which we tend to seek due to the eternal human desire to transform chaos into order. This principle leads us to the concept of balance in the composition of a painting, drawing, or web page, although the composition may not be perfectly symmetrical to be in balance.

In the illustration above you can see three pairs of opening and closing parentheses. Principle of Proximity(The principle of proximity), which will be discussed a little later, allows us to assume that we should see something else. The obvious incompleteness of the image - it seems that one more bracket is missing on both sides - indicates that in human perception symmetry takes precedence over proximity.

Because our eyes are quick to detect symmetry and order, then these principles can be used to effectively disseminate time-sensitive information.

Figure and Ground

“An element is perceived either as a figure/object (the element in the focus of attention) or as a background (the surface on which the figure/object is located).”

The principle of “figure and ground” refers to the relationship between the “positive” (meaningful, contextual) elements of any composition and the “negative” background (lacking context). The perception of any image begins with the eye separating figures (objects) from the background.

The figure-ground relationship can be stable or unstable depending on how easy it is to determine what is a figure and what is a background. A classic example of an unstable relationship is shown in the left figure above. You either see a vase or two faces, depending on whether you perceive black as the object color and white as the background color, or vice versa.

The fact that you move with ease from one image perception to another clearly demonstrates the instability of the figure-ground relationship.

The more stable the figure-to-ground ratio is, the easier it is for us to focus the attention of our target audience on exactly what we want to show them (call to action button, main landing page headline, and other converting elements).

Two interrelated principles of perception can help us increase stability:

• Square- of two overlapping objects, the one whose area is smaller is perceived as a figure (regardless of color).
• Convex- not concave, but convex shapes are usually perceived as figures.

Uniform Connectedness

“Items that are visually connected are perceived as more closely connected than elements that are not.”

In the figure below, lines connect two pairs of elements, which creates the perception that the connected elements are in some kind of relationship.

Of all the principles of designing objects as interconnected uniform connectivity- the strongest. In the image we see 2 squares and 2 circles forming closely interconnected circle-square pairs because they are connected visually.

Please note that the lines may not touch the connected objects in order for the latter to be perceived as interconnected.

“Elements are perceived as part of a group if they are in the same closed region.”

Another way to show the relationship between elements is to arrange them in a specific way. Everything that is inside a closed area is perceived as connected to each other. Everything beyond its limits is considered as a set of separate objects.
The circles in the illustration below are the same, but we see two different groups, and the objects in each group are perceived as connected to each other.

Typical way to show general area— draw a rectangle around elements connected to each other. This method will also work for elements placed on background areas that differ in color.

“Objects that are closer together are perceived as interconnected compared to those that are further apart.”

Principle of Proximity similar the principle of common areas, but uses space like the one we mentioned earlier isolation.

If elements are located close to each other, then they are treated as part of a group rather than as individual elements. This is especially true when elements in a group are located closer to each other than to any elements outside.

Objects should not be similar in any way (for example, color, size, shape) so that they can be located in space close to each other and they are perceived as interrelated.

Continuation

“Elements located on a line or curve are perceived as more closely related than elements not on a line or curve.”

It's an instinct to stick to a certain direction. Once you look or walk in a chosen direction, you will continue to do so until you see something significant or you determine that there is nothing interesting to look at.

Another interpretation of this principle is that we will continue our perception of forms beyond their end points. In the picture above we see a straight line and a curved line intersecting instead of two line segments and two curve segments meeting at one point.

Common Fate/Synchrony

“Items moving in the same direction are perceived as more connected than items that are stationary or moving in different directions.”

No matter how far apart elements are placed or how dissimilar they are, if they appear to be moving or changing in sync, they will be perceived as related to each other.

To implement the principle of common fate, the elements do not even need to move. More importantly, they look as having general purpose. Suppose 4 people are standing motionless next to each other, but two of them are watching something, synchronously turning their heads to the right. These two will be considered as having general purpose.

In the illustration above, the arrows point to general purpose elements. The actual movement or change is not even necessary - most of all common purpose/synchronicity indicate arrows or , only implying movement as such.

Parallelism

“Elements that are parallel to each other are considered more related than elements that are not parallel.”

This principle is similar to the general purpose described above. Lines are often used as a symbol of indicating a direction or moving somewhere.

Parallel lines are perceived as indicating the same direction or moving in the same direction, which is interpreted visually as the relationship of these lines.

It should be noted that the principle of parallelism is also applicable to curves or shapes, although for the latter - with reservations: several parallel lines must be located on them.

Similarity

“Items that share similar general characteristics are perceived as related—in contrast to items that do not share those characteristics.”

Any number of characteristics of objects can be similar: color, shape, size, textures, etc. When the user sees these similar characteristics, he perceives the elements as related due to their shared characteristics.

In the picture below, the red circles are considered to be related to other red circles due to the similarity of color. The same statement is true for black circles. Red and black circles are perceived as different from each other, although they are all circles in shape.

An obvious application of the similarity principle in web design is link color. As a rule, links in page content are designed the same, most often blue and underlined. This helps the visitor, who has empirically determined that there is a link in front of him, to use all words/phrases in a similar way, highlighted with similar characteristics: color and underlining.

Focal Points

“Focus points are elements that, due to their difference from others, can capture and hold the attention of a landing page/site visitor.”

This principle assumes that the visitor's attention will be focused on an element that is somehow different from the others. In the figure below, the focal point is highlighted by shape, color and cast “shadow” (pseudo-volume).

The Principle of Focus Points is based on our ability to quickly identify unknown objects as potential sources of danger.

Principles similarities and points focusing related in the sense that Focal Point must not be similar to any other element on the landing page in order to attract the visitor's attention. On landing pages/sites, conversion-critical elements, such as CTAs, are usually placed at focal points.

Past Experiences

“Items tend to be perceived in accordance with the user's past experiences.”

It is perhaps the weakest Gestalt principle. When compared to any of the previously listed principles, each will dominate the principle of past experience.

Past experience is unique to each individual, so it is difficult to make plausible assumptions about how a new visual element will be perceived by a random user.

Nevertheless, there is a certain universal experience, with certain reservations inherent in every person: when we see a traffic light, we will expect that the red light will indicate the need to stop, and the green light will “allow” us to go. This is how the principle of past experience works.

Many of our interpretations of visual stimuli are determined by the cultural attitudes that dominate society (think of “color psychology”). In some countries, white is the color of purity and innocence, and black is the color of evil and death. In other regions of the world, interpretations of these two colors can be radically different.

And in general, the concept of “generally accepted experience” in itself is very conditional - not all people during their lives can experience similar events to acquire a similar past experience.

Instead of a conclusion

It is important for both marketers and web designers to understand the principles of gestalt, because they form the basis of the graphical display of an offer; they describe how people perceive visual objects, which includes the landing page on the user’s monitor.

The principles outlined above are relatively easy to understand: definitions and illustrations are sufficient to understand most of them. It is much more difficult to understand how exactly the principles of Gestalt in practice affect the visitor’s readiness to convert and the most important business metrics.

In the following, we'll take a closer look at the influence of Gestalt on design: we'll see how symmetry helps us balance the visual and textual content of a landing page, and how the combined application of the principles of similarity and focal points allows us to create a visual hierarchy on a landing page.

“Creativity begins with vision. Vision –

This is already a creative act that requires tension.”

Henri Matisse

The theory of aesthetic perception is based on the fact that perception is basically a cognitive process determined by the forms and type of visual perception.

We will place special emphasis on the fact that aesthetic perception is not a passive, contemplative act, but a creative, active process.

Each act of visual perception, according to Arnheim (author of the most interesting book “Art and Visual Perception”), is an active study of an object, its visual assessment, selection of existing features, comparison of them with memory traces, their analysis and organization of all this into a holistic image.

In the 20s of the last twentieth century, a new direction in psychology appeared, it is called Gestalt. The term Gestalt cannot be unambiguously translated into Russian; it has a number of meanings: holistic, image, structure, form. And it can be used without translation, meaning a holistic unification of elements of mental life, irreducible to the sum of its constituent parts. In their works, Gestalt psychologists paid great attention to problems of perception. They opposed, first of all, the associative theory of perception, which dominated the psychological theories of the 19th century. They sought to prove that perception is holistic in nature and is built on the basis of the creation of integral structures - gestalts. Instead of abstract questions about how we see three dimensions, what sensory elements are, how their unification is possible, Gestalt psychologists put forward real and concrete problems: how we see things as they really are, how a figure is perceived separately from the background, what is surface, what shape is, why you can “change” its weight, dimensions and other parameters without changing anything in an object.

Let's try to figure out how we see and, thereby, help ourselves learn to manage visual perception.

So - any perception is also thinking, any reasoning is at the same time intuition, any observation is also creativity. And each person sees and hears only what he understands and rejects what he does not understand.

It is often believed that the eye is like a camera. However, there are signs of perception that are completely different from the camera. The eye supplies the brain with information that is encoded into neural activity - a chain of electrical impulses, which in turn, with the help of its code and a certain structure of brain activity, reproduces objects. It's like letters when reading, symbols are not pictures. There is no internal picture! For the brain, this structural excitation is the object.

A very interesting tendency of our brain is to group objects and simple shapes and continue (complete) unfinished lines. A few lines are what the eye needs, the rest will be completed by the brain as it develops and understands. (Caricatures, visions in flames or in the clouds - faces and figures, fortune telling on coffee grounds, etc.)

We can say with complete confidence that the process of visual perception also includes knowledge about an object, obtained from past experience, and this experience is not limited to vision, there is also touch and taste, color, olfactory, auditory, and perhaps even temperature, pain and other sensory characteristics of this item.

Perception goes beyond the sensations directly given to us. Perception and thinking do not exist independently of each other. The phrase: “I see what I understand” indicates a connection that really exists.

When describing objects and things, we constantly point out their relationship with the environment. No object is perceived in isolation. Perceiving something means attributing to this “something” a certain place in the system: location in space, degree of brightness, color, size, size, distance, etc. Changing our hairstyle, we suddenly notice that our face has become a little rounder. When choosing a dress style, we dream of “stretching” our legs and neck and “reducing” our waist size. We can say with complete confidence that we see more than what hits the retina. And this is not an action of the intellect!

It seems incredible, but any line drawn on paper or applied to the surface of an object (in our case, on clothing or on the face) is like a stone thrown into the calm water of a pond. All this is a disturbance of peace, mobilization of space, action, movement. And vision perceives this movement, this action.

This is where perceptual powers come into play. Are these forces real? Perceptual objects naturally don't have them (of course, you didn't grow up wearing vertical stripes or expanding from horizontal stripes), but they can be thought of as psychological counterparts or equivalents to the physiological forces operating in the visual area of ​​the brain. There is no reason to call these forces illusions; they are no more illusory than the colors inherent in the objects themselves, although colors from a physiological point of view are just a reaction of the nervous system to light with a certain wavelength (but more on that later).

MENTAL AND PHYSICAL BALANCE.

When discussing the influence of the location of an object on its perception, we inevitably encounter the factor of balance. From the point of view of physics, equilibrium is a state of a body in which the forces acting on it compensate each other. This definition also applies to perceptual powers. Like any physical body, each visual model that has boundaries has a fulcrum or center of gravity. Why do you need balance in creating an image? An unbalanced composition, be it a drawing, furniture arrangement, selection of clothes or colors and lines of makeup and hairstyle, looks random and temporary. When there is a lack of calm and clarity, we have the impression of destruction or sloppiness. For example, the clown's clothes are red and blue, dividing the body in half - and the figure seems ridiculous, although both halves of the body and their physical weight are equal. We can say with complete confidence that the lack of balance leads to the impossibility of perceiving a single whole.

WEIGHT. When creating a visual composition, one should not forget about apparent weight. Weight depends on the location of the part or item. An element located in the center of the composition or close to it weighs less than others. The part at the top seems heavier than the one at the bottom, and the one on the right side has more weight than the one on the left. Weight also depends on size; naturally, a larger object will look heavier. Now, regarding the “weight” of color, red (warm) color is heavier than blue (cold), and bright and light colors are heavier than dark ones. For example, in order to mutually balance black and white, it is necessary to make the area of ​​black space slightly larger than white. Weight is also influenced by the shape of the object and the direction of perceived objects. A correct geometric shape always looks heavier than an irregular one. For example, when comparing a ball, square and triangle of the same weight and color, the ball seems to be the heaviest.

DIRECTION. Direction, like weight, affects balance, i.e. to create a general impression of the subject. It is very important to understand and remember that in elongated forms, the spatial orientation of which deviates from the horizontal or vertical by a small angle, this direction becomes dominant. The simplest and most accessible example of this rule is the slightly offset seam on the once fashionable seamed stockings!

RIGHT AND LEFT SIDE. A difficult problem arises from the asymmetry of right and left. Any object located on the right looks heavier than the left. Experts believe that everything that is located on the left has more meaning for the observer than what is located in the center or on the right. Remember where the speaker's podium is, where the main action on stage takes place: in the middle, and more often on the left. This phenomenon is associated with the dominance of the left hemisphere of the cerebral cortex, which contains the higher brain centers - speech, reading and writing.

OUTLINE. In essence, vision is a means of practical orientation in space. The visual process means “grasping,” the rapid awareness of several characteristic features of an object. (A poorly printed photograph has turned the face into several gray spots, but we recognize it) We can say that the human gaze is, to some extent, an insight into the essence of the subject. And the outline is just one of the essential characteristics of an object, captured and perceived by the human eye. The outline is the boundary of the mass. But here’s an interesting example: we don’t see the hidden side of the ball, but we know for sure that the ball is round. What is familiar to us appears as knowledge that is added to direct observation.

Gestalt psychologists believe that any stimulating model is perceived as the simplest, i.e. the object we see consists of a small number of characteristic structural features. And the farther an object is from us, the simpler the shape we see. Upon closer inspection, we begin to see details.

SIMILARITY. When creating any composition, it is necessary to remember the principle of similarity: the more similar the parts of any perceived model are to each other, the more strongly they will unite into a whole. Elements related by similar shape, color, size, etc. tend to be located in the same plane. Similarity creates a strong visual effect by shaping and forming visual patterns. And the simpler the models obtained in this way, the more striking they are, often breaking the composition or creating a new one.

Further development of the principle of similarity of parts finds its expression in a pattern that deals with the internal similarity of a visually perceived object: when there is a choice between several possibilities for the continuation of curves (and the human body, I want to remind you, consists only of them), then preference is given to the one that is most consistently preserves the internal structure. And yet, we always mentally fill in the intervals between curved segments and build them up to a full circle. It has also been proven that the similarity of figures or color spots is expressed not in a strict repetition of the previous one, but in a gradual change in shape. And the viewer's eye, forced to follow this perceptual movement, sees a new form!

Advertising as a marketing communications tool is largely based on the characteristics of consumer behavior and psychology. Therefore, it is advisable to begin the analysis of the issue of the role of communication in advertising by identifying the psychophysiological characteristics of human perception of information as such.

In the natural sciences, it is customary to distinguish three main types of perception:

• 1. Auditory perception. It is a way of perceiving information through hearing and auditory impressions (for example, through communication, noise, music).
• 2. Visual perception. It involves the perception of information by activating the visual channel and its subsequent storage in memory in the form of images.
• 3. Kinesthetic perception. It involves the perception of information through the creation of direct physical contact with an object through tactile (touch), olfactory (smell) and taste sensations.

The most informative channel of perception of the above is visual. According to the results of scientific research, it has been established that a person receives about 80% of information coming from outside through visual receptors. Through this channel, a person is able to determine many properties of the observed object: its type, color, shape, size, texture, etc. The visual channel plays a key role in a person’s understanding of the reality around him.

Visual perception (visual perception) The concepts of “visual perception” and “visual perception” are equivalent (derived from the Latin words “visualis” and “perceptio”), however, Latin transliteration entered Russian professional use relatively recently, and began to be widely used only in the last decades of the existence of the USSR. defined as:

• - “a set of processes for constructing a visual image of the world based on sensory information obtained using the visual system” Meshcheryakov B.G., Zinchenko V.P. Large psychological dictionary. - M.: Olma-Press, 2004. - P. 124.;
• - “a system of sequential perceptual actions aimed at reflecting phenomena of the surrounding world in visual images” Khilko. N.F. Audiovisual culture. Dictionary. - Omsk: Omsk Publishing House. state University, 2000. - C. 20..

In the framework of this study, the second definition will be adopted as a working one, since it emphasizes the stage-by-stage process of fixing the image of the surrounding world in the human mind. So, first we see the big picture, and only after that our perception begins to capture the details. As a result, a certain established visual image of the surrounding reality is deposited in the consciousness.

Visual perception is a complex multi-level process consisting of two key stages:

• 1) obtaining information at the physiological level (along the chain: light stimulus - retina of the eye - electrical impulses in the neurons of the brain);
• 2) decoding of visual signals (analysis of the electrical signal and awareness of the presence of a particular visual image in the field of view).

However, vision is not a purely automatic response to external stimuli, but is an essential tool for understanding the world around us. Visual perception involves multiple sources of information beyond those perceived by the eye when a person looks at an object. Visual perception is the result of a complex interaction of a visual stimulus with a complex of knowledge, associations, experience, etc. already existing in the brain. Having received information about an object seen, our brain compares it with existing patterns, templates, expectations in order to understand what to do and how to react to this object. Therefore, visual perception is a complex two-way process. On the one hand, seeing the details of the environment, we interpret them into a general whole. On the other hand, we turn to our memory, where all the patterns of our understanding of the world are collected, and, depending on current goals, we interpret the data we see.

There is no single template for the visual perception of a particular object - the assessment of what is seen is always formed on the basis of personal attitudes and principles. Each person has his own vision of the world, which largely depends on the sociocultural environment around him. The system of subconscious decoding of information is based on a person’s life experience and his environment, which means that it can be different for people of different origins, upbringing, and education. In other words, “external sociocultural settings are refracted in individual consciousness” Dmitrieva L.M. and others. Philosophy of advertising activities: textbook. - M.: Master: NIC Infra-M, 2013. - P. 44..

Thus, visual perception is one of the most important human tools for orientation in reality and obtaining information about surrounding objects. This complex multi-level process includes not only a chain of neural reactions to stimuli, but also the entire variety of ideas already existing in the brain, thanks to which a person, through vision, continuously expands his library of knowledge about the outside world.

The ability to read text seems to be a simple process: we direct our eyes to the letters, see them, and know what they say. But in fact, it is an extremely complex process that relies on a series of brain structures that specialize in visual perception, as well as in recognizing the various subcomponents of vision.

To perceive means to interpret information about the environment received through the senses. This interpretation depends on our cognitive processes and existing knowledge. Visual or visual perception can be defined as the ability to interpret information reaching the eyes through light in the visible region of the spectrum. The result of the interpretation our brain makes based on this information is what is known as visual perception or vision. Thus, visual perception is a process that begins in our eyes:

• Photoreception: Light rays pass through the pupils of the eyes and excite cellular receptors in the retina.
• Transfer and basic processing: The signals these cells create are transmitted through the optic nerve to the brain. The signal first passes through the optical chiasmata (where information from the right visual field is sent to the left hemisphere, and from the left visual field to the right hemisphere), then the information travels to the lateral geniculate body and the thalamus.
• Information processing and perception: Visual information received through the eyes is then sent to the visual cortex in the occipital lobe of the brain. These brain structures process information and send it to the rest of the brain so we can use it.

Characteristics that shape visual perception

To get an idea of ​​how complex this function is, let's try to imagine what our brain does when we see a simple soccer ball. How many factors does he have to determine? For example:

• lighting and contrast: we see that there is a concentration of lines, more or less illuminated and having its own diameter, which distinguishes it from other objects in the environment and background.
• Size: This is a circle about 70 cm in diameter.
• Form: Shaped like a circle.
• Location: located three meters from me, to the right. I can reach it easily.
• Color: white with black pentagons. In addition, if the lighting suddenly changed, we would know that its colors were black and white.
• Measurements: Exists in three dimensions as it is a sphere.
• Movement: currently without movement, but can be given movement.
• Unit: There is one, and it is different from the environment.
• Usage: used for playing football, intended for kicking.
• Personal relationship with the object: Similar to the one we use in training.
• Name: soccer ball. This last process is also known as .

If this seems like a lot of steps, consider that our brains perform this process constantly and at incredible speed. Additionally, our brains do not passively perceive information, but rather use existing knowledge to "package" information about what it perceives (which is why we know that a ball is a sphere even when we see it as flat in a photo). IN occipital lobe brain and adjacent parts ( temporal and parietal lobes) there are several areas specializing in each of the previously described processes. Correct perception requires coordinated work of all these departments.

When we look at our desktop, our brain instantly identifies all the objects on it, allowing us to quickly interact with them. Knowing this, it is easy to understand the enormous importance of this process in our daily lives and how important it is for normal functioning in any life situation.

Examples of visual perception

• Driving is one of the most complex everyday tasks involving multiple cognitive functions. Visual perception is one of the fundamentals of driving. If one of the processes of visual perception is disrupted, the driver puts his life and the lives of other people at risk. It is important to quickly determine the position of the car relative to the road and other vehicles, the speed at which they are moving, etc.
• When a child is in a lesson, his visual acuity and perception must be optimal so as not to lose sight of the details of the material being explained. Violations of this ability can lead to a decrease in the child's academic performance.
• In visual arts, such as painting, visual perception is everything. When we want to paint a picture and dream of making it realistic and attractive, we must test our visual perception and work out every detail, shade of color, perspective... Of course, to appreciate works of art, we also need good visual perception, it is not enough just to see.
• Visual perception is essential for any monitoring or surveillance activity. A security guard who, due to impaired perception, cannot correctly assess what is happening on surveillance cameras will not be able to properly perform his job.
• Of course, in everyday life we ​​constantly use visual perception. If we see an approaching bus on the road, its image becomes larger in our mind. However, our brains are capable of interpreting changes that are not real. We continue to see a regular-sized bus no matter how close or far it is from us. We also need visual perception to move through space, not to mix up medications, prepare food, clean the house, etc.

Pathologies and disorders associated with problems in visual perception

Visual perception disorders can be accompanied by various problems and difficulties at different levels.

Complete or partial loss of vision as a result of damage to the sensory organs leads to inability to perceive (blindness). This may be caused damage to the eye itself(for example, eye injury), damage to information transmission paths from the eyes to the brain (eg glaucoma) or damage to parts of the brain responsible for analyzing this information (for example, as a result of stroke or traumatic brain injury).

However, perception is not a unitary process. There are specific damages that can disrupt each of the above processes. Disorders of this type are characterized by damage to areas of the brain responsible for certain processes. These disorders are known as visual agnosia. Visual agnosia is defined as inability to recognize known objects despite maintaining visual acuity. Classically, agnosia is divided into two types: perceptual agnosia (the patient can see parts of an object, but is not able to understand the object as a whole) and associative agnosia (the patient can recognize the object as a whole, but cannot understand which object is being referred to). It is difficult to imagine how perception functions in people with these disorders. Even though they can see, their sensations are similar to those experienced by those suffering from blindness. In addition, there are even more specific disorders, such as, for example, akinetopsia (inability to see movement), color blindness (inability to distinguish colors), prosopagnosia (inability to recognize familiar faces), alexia (acquired inability to read), etc.

In addition to these disorders, in which the ability to perceive visual information (or part of it) is lost, disorders are also possible in which the received information is distorted or does not exist at all. This may be the case hallucinations in schizophrenia or other syndromes. In addition, scientists have described a type of visual illusion in people who have lost their sight: Charles Bonnet syndrome. In this case, a person who has lost his vision, after a long period during which his brain does not receive visual activity, experiences self-activation of the brain, provoking visual illusions in which the patient sees geometric figures or people. However, unlike the hallucinations of schizophrenia, people with this syndrome know that the things they see are not real.

How to measure and evaluate visual perception?

Visual perception helps us perform many daily activities. Our ability to move and interact with an environment full of obstacles depends directly on the quality of our visual perception. Thus, perceptual assessment can be useful in various areas of life: in education (to know whether a child can see a blackboard or read books), in the medical field (to know that a patient may have mixed up medications or needs constant supervision), in professional circles (almost any job requires reading, observation or control skills).

With it, we can effectively and reliably assess various cognitive abilities, including visual perception. The test that CogniFit offers to assess visual perception is based on the classic NEPSY test (Corkman, Kirk and Kemp, 1998). Through this task, one can be able to decode the elements presented in the exercise and the amount of cognitive resources the user has to understand and complete the task in the most efficient manner. In addition to visual perception, the test also measures memory for names, response time and processing speed.

• : Images of objects appear on the screen for a short period of time and then disappear. Following this, four letters appear, and only one of them corresponds to the first letter of the object's name. The task is to choose this letter correctly. You need to complete the test as quickly as possible.

How to restore or improve visual perception?

Visual perception, like other cognitive abilities, can be trained and improved. CogniFit makes it possible to do this professionally.

Restoration of visual perception is based on. CogniFit offers a series of exercises and clinical games aimed at the rehabilitation of visual perception and other cognitive functions. The brain and its neural connections are strengthened by the use of functions that depend on them. Thus, if we regularly train visual perception, the connections of brain structures involved in perception are strengthened. Therefore, when our eyes send information to the brain, the neural connections will work faster and more efficiently, improving our visual perception.

CogniFit consists of an experienced team of professionals specializing in the study of synaptic plasticity and neurogenesis. This made it possible to create personalized cognitive stimulation programs, which adapts to the needs of each user. The program begins with an accurate assessment of visual perception and other basic cognitive functions. Based on the assessment results, the CogniFit cognitive stimulation program automatically suggests a personal cognitive training regimen to strengthen visual perception and other cognitive functions that the assessment shows need improvement.

To improve visual perception, it is extremely important to exercise regularly and correctly. CogniFit offers assessment and rehabilitation tools to improve cognitive function. For correct stimulation, you need to spend 15 minutes a day, two or three times a week..

CogniFit cognitive stimulation program is available online. The program contains a variety of interactive exercises in the form of exciting brain games that can be played using a computer. At the end of each session CogniFit will show a detailed improvement chart cognitive state.

Insects

The visual apparatus of birds has features that are not preserved in human vision. Thus, bird receptors contain microspheres containing lipids and carotenoids. It is believed that these microspheres - colorless, and also colored yellow or orange - act as specific light filters that form a “visibility curve”.

Human eye

Stereoscopic vision

In many species whose lifestyle requires a good estimate of the distance to an object, the eyes look forward rather than to the sides. Thus, mountain sheep, leopards, and monkeys have better stereoscopic vision, which helps assess the distance before jumping. Humans also have good stereoscopic vision (see below, section ).

An alternative mechanism for estimating the distance to an object is implemented in some birds, whose eyes are located on different sides of the head and the field of three-dimensional vision is small. Thus, chickens make constant oscillatory movements with their heads, while the image on the retina quickly shifts, inversely proportional to the distance to the object. The brain processes the signal, which allows it to catch small prey with its beak with high accuracy.

Each person's eyes appear identical, but are still somewhat different, so they distinguish between the leading and trailing eyes. Determining the dominant eye is important for hunters, videographers and other professions. If you look through a hole in an opaque screen (a hole in a sheet of paper at a distance of 20-30 cm) at a distant object, and then, without moving your head, alternately close your right and left eyes, then for the dominant eye the image will not shift.

Physiology of human vision

Color vision

The human eye contains two types of light-sensitive cells (receptors): highly sensitive rods, responsible for twilight (night) vision, and less sensitive cones, responsible for color vision.

Uniform stimulation of all three elements, corresponding to the weighted average daylight, also causes the sensation of white (See Psychology of color perception). The three-component theory of color vision was first expressed in 1756 by M. V. Lomonosov, when he wrote “about the three matters of the bottom of the eye.” A hundred years later, it was developed by the German scientist G. Helmholtz, who does not mention Lomonosov’s famous work “On the Origin of Light,” although it was published and summarized in German.

At the same time, there was an opposing color theory by Ewald Goering. It was developed by David H. Hubel and Torsten N. Wiesel. They received the 1981 Nobel Prize for their discovery. They suggested that the information that enters the brain is not about red (R), green (G) and blue (B) colors (Jung-Helmholtz color theory). The brain receives information about the difference in brightness - about the difference in brightness of white (Y max) and black (Y min), about the difference between green and red colors (G-R), about the difference between blue and yellow colors (B-yellow), and yellow color (yellow = R+G) is the sum of red and green colors, where R, G and B are the brightness of the color components - red, R, green, G, and blue, B.

Despite the apparent contradiction of the two theories, according to modern ideas, both are correct. At the level of the retina, the three-stimulus theory operates; however, the information is processed and data that is already consistent with the opponent theory arrives in the brain.

Three genes encoding light-sensitive opsin proteins are responsible for color vision in humans and monkeys. The presence of three different proteins that respond to different wavelengths is sufficient for color perception. Most mammals have only two of these genes, which is why they have non-color vision. If a person has two proteins encoded by different genes that are too similar, color blindness develops.

Binocular and stereoscopic vision

• - data from different authors

Most features of human binocular vision are determined by the characteristics of neurons and neural connections. Using neurophysiological methods, it has been shown that binocular neurons of the primary visual cortex begin to decode the depth of the image, specified on the retinas by a set of disparities. It has been shown that the most important requirement for stereoscopic vision is differences in the retinal images of the two eyes.

Due to the fact that the visual fields of both eyes of humans and higher primates overlap to a large extent, humans are better able than many mammals to determine the appearance and distance (the accommodation mechanism also helps here) to close objects, mainly due to the effect of stereoscopic vision. The stereoscopic effect remains at a distance of approximately 0.1-100 meters. In humans, spatial-visual abilities and three-dimensional imagination are closely related to stereoscopy and ipsi-connections.

Properties of vision

Light sensitivity of the human eye

Light sensitivity is assessed by the threshold value of the light stimulus.

A person with good eyesight can see the light from a candle at a distance of several kilometers at night. However, the light sensitivity of vision of many nocturnal animals (owls, rodents) is much higher.

The maximum light sensitivity of the rods of the eye is achieved after a sufficiently long dark adaptation. It is determined under the influence of light flux in a solid angle of 50° at a wavelength of 500 nm (maximum sensitivity of the eye). Under these conditions, the threshold light energy is on the order of 10 -9 erg/s, which is equivalent to the flux of several quanta of the optical range per second through the pupil.

The sensitivity of the eye depends on the completeness of adaptation, on the intensity of the light source, the wavelength and angular dimensions of the source, as well as on the duration of the stimulus. The sensitivity of the eye decreases with age due to the deterioration of the optical properties of the sclera and pupil, as well as the receptor component of perception.

Visual acuity

The ability of different people to see larger or smaller details of an object from the same distance with the same shape of the eyeball and the same refractive power of the dioptric eye system is determined by the difference in the distance between the cylinders and cones of the retina and is called visual acuity. The Snellen chart is used to test visual acuity.

Binocularity

Looking at an object with both eyes, we see it only when the axes of vision of the eyes form such an angle of convergence (convergence), at which symmetrical, clear images on the retinas are obtained in certain corresponding places of the sensitive macula (fovea centralis). Thanks to this binocular vision, we not only judge the relative position and distance of objects, but also perceive impressions of relief and volume.

The main characteristics of binocular vision are the presence of elementary binocular, depth and stereoscopic vision, stereo visual acuity and fusional reserves.

The presence of elementary binocular vision is checked by dividing a certain image into fragments, some of which are presented to the left eye, and some to the right eye. An observer has elementary binocular vision if he is able to compose a single original image from fragments.

The presence of depth vision is tested by presenting silhouette vision, and stereoscopic vision - random dot stereograms, which should evoke in the observer a specific experience of depth, different from the impression of spatiality based on monocular features.

Stereo visual acuity is the reciprocal of the stereoscopic perception threshold. The stereoscopic threshold is the minimum detectable disparity (angular displacement) between parts of the stereogram. To measure it, the following principle is used. Three pairs of figures are presented separately to the observer's left and right eyes. In one of the pairs the position of the figures coincides, in the other two one of the figures is displaced horizontally by a certain distance. The subject is asked to indicate figures arranged in increasing order of relative distance. If the figures are indicated in the correct sequence, then the test level increases (disparity decreases); if not, the disparity increases.

Fusion reserves are conditions under which motor fusion of the stereogram is possible. Fusion reserves are determined by the maximum disparity between parts of the stereogram, at which it is still perceived as a three-dimensional image. To measure fusion reserves, the principle opposite to that used in the study of stereo visual acuity is used. For example, a subject is asked to combine (fuse) two vertical stripes into one image, one of which is visible to the left eye and the other to the right eye. At the same time, the experimenter begins to slowly separate the stripes, first with convergent and then with divergent disparity. The image begins to “fall apart” at the disparity value , which characterizes the fusion reserve of the observer.

Binocularity may be impaired with strabismus and some other eye diseases. If you are very tired, you may experience temporary strabismus caused by the non-dominant eye switching off.

• See also Binocular, Stereoscope.

Contrast sensitivity

Contrast sensitivity is a person’s ability to see objects that differ slightly in brightness from the background. Contrast sensitivity is assessed using sinusoidal gratings. An increase in the contrast sensitivity threshold can be a sign of a number of eye diseases, and therefore its study can be used in diagnosis.

Vision adaptation

The above properties of vision are closely related to the ability of the eye to adapt. Adaptation occurs to changes in illumination (dark adaptation), color characteristics of lighting (the ability to perceive white objects as white even with a significant change in the spectrum of incident light, see also White Balance).

Adaptation is also manifested in the ability of vision to partially compensate for defects in the visual apparatus itself (optical defects of the lens, retinal defects, scotomas, etc.)

Vision defects

The most widespread drawback is fuzzy, unclear visibility of close or distant objects.

Lens defects

Retinal defects

Literature

• A. Nagel “Anomalies, refraction and accommodation of the eye” (1881, translation from German by Dr. Dobrovolsky);
• Longmore, “Guide to the study of vision for military doctors” (revised by Lavrentiev, 1894);
• A. Imbert, “Les anomalies de la vision” (1889).