Yuri Viktorovich Shcherbatykh general psychology introduction. What is sensation in psychology? Sensation and perception in psychology

Depending on the source of stimulation acting on the receptors, sensations are divided into three groups. Each of these groups, in turn, consists of various specific sensations (Fig. 5.7).

Rice. 5.7.

1. Exteroceptive sensationsreflect the properties of objects and phenomena of the external environment (“five senses”). These include visual, auditory, taste, temperature and tactile sensations. In fact, there are more than five receptors that provide these sensations, and the so-called “sixth sense” has nothing to do with it.
   For example, visual sensations arise when excited chopsticks (“twilight, black and white vision”) and cones (“daytime, color vision”).
   Temperature sensations in humans occur during separate excitationcold and heat receptors.Tactile sensations reflect the impact on the surface of the body, and they arise when excited or sensitivetouch receptorsin the upper layer of the skin, or with stronger exposure topressure receptorsin the deep layers of the skin.
2. Interoreceptivesensations reflect the state of the internal organs. These include sensations of pain, hunger, thirst, nausea, suffocation, etc. Painful sensations signal damage and irritation of human organs and are a unique manifestation of the body’s protective functions. The intensity of pain varies, reaching great strength in some cases, which can even lead to a state of shock.
3. Proprioceptive sensations(muscular-motor). These are sensations that reflect the position and movements of our body. With the help of muscle-motor sensations, a person receives information about the position of the body in space, about the relative positionall its parts, about the movement of the body and its parts, about the contraction, stretching and relaxation of muscles, the condition of joints and ligaments, etc. Muscular-motor sensations are complex. Simultaneous stimulation of receptors of different quality gives sensations of a unique quality:
   • irritation of receptor endings in the muscles creates a feeling of muscle tone when performing a movement;
   • sensations of muscle tension and effort are associated with irritation of the nerve endings of the tendons;
   • irritation of the receptors of the articular surfaces gives a sense of direction, shape and speed of movements.
4. Many authors include in this same group of sensations the sensations of balance and acceleration that arise as a result of stimulation of the receptors of the vestibular analyzer.

4.2. Feel

The concept of sensation. Objects and phenomena of the external world have many different properties and qualities: color, taste, smell, sound, etc. In order for them to be reflected by a person, they must influence him with any of these properties and qualities. Cognition is carried out primarily by the senses - the only channels through which the external world penetrates into human consciousness. Images of objects and phenomena of reality that arise in the process of sensory cognition are called sensations.

Feel - this is the simplest mental cognitive process of reflecting individual properties of objects and phenomena of the surrounding world, as well as internal states of the body, arising from their direct impact on the senses.

Our consciousness exists only due to the presence of sensations. If a person is deprived of the ability to sense and perceive the surrounding reality, he will not be able to navigate the world, he will not be able to do anything. Under conditions of “sensory deprivation” (lack of sensations), in less than a day a person experiences a sharp decrease in attention, a decrease in memory capacity, and serious changes in mental activity occur. It is not without reason that this is one of the most difficult tests for future cosmonauts, polar explorers, and speleologists.

In ordinary life, we are tired not so much by the lack of sensations as by their abundance - sensory overload. That’s why it’s so important to follow basic rules of mental hygiene.

The physiological basis of sensations is activity analyzer – a special nervous apparatus that performs the function of analyzing and synthesizing stimuli emanating from the external and internal environment of the body. Any analyzer consists of three parts.

1. Receptor (peripheral) department- a receptor, the main part of any sensory organ, specialized for receiving the effects of certain stimuli. Here the transformation of the energy of an external stimulus (heat, light, smell, taste, sound) into physiological energy - a nerve impulse - occurs.

2. Wiring department– sensory nerves that can be afferent(centripetal), conducting the resulting excitation to the central section of the analyzer, and efferent(centrifugal, through which the nerve impulse travels to the working organ (effector)).

3. Central department – cortical section of the analyzer, a specialized area of ​​the cerebral cortex, where the transformation of nervous energy into a mental phenomenon - sensation.

The central part of the analyzer consists of a nucleus and nerve cells scattered throughout the cortex, which are called peripheral elements. The bulk of receptor cells is concentrated in the nucleus, due to which the most subtle analysis and synthesis of stimuli is carried out; Due to peripheral elements, a rough analysis is made, for example, light is distinguished from darkness. Scattered elements of the cortical part of the analyzer are involved in establishing communication and interaction between various analyzer systems. Since each analyzer has its own central section, the entire cerebral cortex is a kind of mosaic, an interconnected system of the cortical ends of the analyzers. Despite the common structure of all analyzers, the detailed structure of each of them is very specific.

A sensation always appears in consciousness in the form of an image. The energy of an external stimulus turns into a fact of consciousness when a person, who has an image of the object that caused the irritation, can designate it with a word.

The sensation is always associated with a response like a reflex ring with mandatory feedback. The sense organ is alternately a receptor and an effector (working organ).

Types and classification of sensations. According to the five sense organs known to the ancient Greeks, the following types of sensations are distinguished: visual, auditory, gustatory, olfactory, tactile (tactile). In addition, there are intermediate sensations between tactile and auditory - vibration. There are also complex sensations, consisting of several independent analytical systems: for example, touch is tactile and muscle-articular sensations; skin sensations include tactile, temperature and pain. There are organic sensations (hunger, thirst, nausea, etc.), static, sensations of balance, reflecting the position of the body in space.

The following criteria for classification of sensations are identified.

I.According to the location of the receptors– exteroceptive and interoceptive. Receptors exteroceptive sensations are located on the surface of the body and receive irritations from the outside world, and receptors interoceptive(organic) sensations are located in the internal organs and signal the functioning of the latter. These sensations form the organic feeling (well-being) of a person.

II.By the presence or absence of direct contact With irritant, causing sensations, exteroceptive sensations are divided into contact and distant. Contact sensations involve direct interaction with the stimulus. These include taste, skin, pain, temperature, etc. Distant sensations provide orientation in the immediate environment - these are visual, auditory and olfactory sensations.

A special subclass of interoceptive sensations are sensations proprioceptive, whose receptors are located in ligaments, muscles and tendons and receive irritation from the musculoskeletal system. These sensations also indicate the position of the body in space.

Sensations have a number of characteristics and patterns that manifest themselves in each type of sensitivity. Three groups of patterns of sensations can be distinguished.

1. Time relationships between the beginning (end) of the stimulus and the appearance (disappearance) of sensations:

The onset of the action of the stimulus and the onset of sensations do not coincide - the sensation occurs somewhat later than the onset of the action of the stimulus, since the nerve impulse needs some time to deliver information to the cortical part of the analyzer, and after the analysis and synthesis carried out in it - back to the working organ. This is the so-called hidden (latent) period of the reaction;

The sensations do not disappear immediately with the end of the stimulus, which can be illustrated by successive images - positive and negative. The physiological mechanism for the emergence of a sequential image is associated with the phenomena of the aftereffect of the stimulus on the nervous system. The cessation of the action of the stimulus does not cause an immediate cessation of the process of irritation in the receptor and excitation in the cortical parts of the analyzer.

2. The relationship between sensations and stimulus intensity. Not every stimulus strength can cause a sensation; it occurs when exposed to a stimulus of known intensity. It is customary to distinguish between the threshold of absolute sensitivity and the threshold of sensitivity to discrimination.

The minimum amount of stimulus that causes a barely noticeable sensation is called lower absolute threshold of sensitivity.

There is an inverse relationship between sensitivity and the strength of the stimulus: the greater the force needed to produce a sensation, the lower the sensitivity. There may also be subthreshold stimuli that do not cause sensations because signals about them are not transmitted to the brain.

The maximum magnitude of the stimulus that the analyzer is capable of adequately perceiving (in other words, at which the sensation of a given type is still preserved) is called upper absolute threshold of sensitivity.

The interval between the lower and upper thresholds is called sensitivity range. It has been established that the sensitivity range for color is vibrations of electromagnetic waves with a frequency from 390 (violet) to 780 (red) millimicrons, and for sound – vibrations of sound waves from 20 to 20,000 Hertz. Stimuli of extremely high intensity cause pain instead of sensations of a certain type.

Threshold of sensitivity to discrimination(differential) is the minimum difference between two stimuli that causes a subtle difference in sensation. In other words, this is the smallest amount by which the intensity of the stimulus must be changed (increased or decreased) in order for a change in sensation to occur. German scientists - physiologist E. Weber and physicist G. Fechner - formulated a law that is valid for stimuli of average strength: the ratio of the additional stimulus to the main one is a constant value. This value is specific for each type of sensation: for visual – 1/1000 , For auditory - 1/10, for tactile - 1/30 of the initial value of the stimulus.

III.Changing the sensitivity of the analyzer. This change can be illustrated by the patterns of sensations such as adaptation, sensitization and interaction.

Adaptation(from Latin adaptare - adapt, adjust, get used to) is a change in sensitivity under the influence of a constantly acting stimulus. Adaptation depends on environmental conditions. The general pattern is this: when moving from strong to weak stimuli, sensitivity increases, and vice versa, when moving from weak to strong, it decreases. The biological feasibility of this mechanism is obvious: when the stimuli are strong, fine sensitivity is not needed, but when they are weak, the ability to capture them is important.

There are two types of adaptation: positive and negative. Positive(positive, dark) adaptation is associated with an increase in sensitivity under the influence of a weak stimulus. Thus, when moving from light to darkness, the area of ​​the pupil increases 17 times, a transition occurs from cone vision to rod vision, but mainly the increase in sensitivity occurs due to the conditioned reflex work of the central mechanisms of the analyzer. Negative(negative, light) adaptation can manifest itself as a decrease in sensitivity under the influence of a strong stimulus and as a complete disappearance of sensations during the long-term action of the stimulus.

Another pattern of sensations is interaction of analyzers, which manifests itself in a change in the sensitivity of one analyzing system under the influence of the activity of another. The general pattern of interaction of sensations can be expressed in the following formulation: weak in intensity stimulation of one analyzer increases the sensitivity of the other, and strong stimulation decreases it.

Increasing the sensitivity of the analyzer is called sensitization. It can manifest itself in two areas: either as a result of exercise of the senses, training, or as a need to compensate for sensory defects. A defect in the operation of one analyzer is usually compensated by increased work and improvement of another.

A special case of the interaction of sensations is synesthesia, in which the senses work together; in this case, the qualities of sensations of one type are transferred to another type of sensations and co-sensations arise. In everyday life, synesthesia is used very often: “velvet voice”, “screaming color”, “sweet sounds”, “cold tone”, “sharp taste”, etc.

And the person’s emotions? It is this issue that we decided to devote today’s article. After all, without these components we would not be people, but machines that do not live, but simply exist.

What are the sense organs?

As you know, a person learns all the information about the world around him through his own. These include the following:

• eyes;
• language;
• leather.

Thanks to these organs, people feel and see the objects around them, as well as hear sounds and taste. It should be noted that this is not a complete list. Although it is usually called the main one. So what are the feelings and sensations of a person who has functioning not only of the above organs, but also of other organs? Let's consider the answer to the question posed in more detail.

Eyes

The sensations of vision, or rather color and light, are the most numerous and diverse. Thanks to the presented body, people receive about 70% of information about the environment. Scientists have found that the number of visual sensations (of various qualities) of an adult, on average, reaches 35 thousand. It should also be noted that vision plays a significant role in the perception of space. As for the sensation of color, it completely depends on the length of the light wave that irritates the retina, and the intensity depends on its amplitude or so-called scope.

Ears

Hearing (tones and noises) gives a person approximately 20 thousand different states of consciousness. This sensation is caused by air waves that come from the sounding body. Its quality depends entirely on the magnitude of the wave, its strength on its amplitude, and its timbre (or sound coloring) on ​​its shape.

Nose

The sensations of smell are quite varied and very difficult to classify. They occur when the upper part of the nasal cavity, as well as the mucous membrane of the palate, is irritated. This effect occurs due to the dissolution of the smallest odorous substances.

Language

Thanks to this organ, a person can distinguish different tastes, namely sweet, salty, sour and bitter.

Leather

Tactile sensations are divided into feelings of pressure, pain, temperature, etc. They occur during irritation of nerve endings located in tissues, which have a special structure.

What feelings does a person have? In addition to all of the above, people also have feelings such as:

• Static (body position in space and a sense of its balance). This feeling occurs during irritation of the nerve endings that are located in the semicircular canals of the ear.
• Muscular, joint and tendon. They are very difficult to observe, but they are of the nature of internal pressure, tension and even slip.
• Organic or somatic. Such feelings include hunger, nausea, sensations of breathing, etc.

What are the feelings and emotions?

A person’s emotions and inner feelings reflect his attitude towards any event or situation in life. Moreover, the two named states are quite different from each other. So, emotions are a direct reaction to something. This happens at the animal level. As for feelings, this is a product of thinking, accumulated experience, experiences, etc.

What feelings does a person have? It is quite difficult to answer the question posed unambiguously. After all, people have a lot of feelings and emotions. They give a person information about needs, as well as feedback on what is happening. Thanks to this, people can understand what they are doing right and what they are doing wrong. After realizing the feelings that have arisen, a person gives himself the right to any emotion, and thereby he begins to understand what is happening in reality.

List of basic emotions and feelings

What are the feelings and emotions of a person? It is simply impossible to list them all. In this regard, we decided to name only a few. Moreover, they are all divided into three different groups.

Positive:

• pleasure;
• jubilation;
• joy;
• pride;
• delight;
• confidence;
• confidence;
• Delight;
• sympathy;
• love (or affection);
• love (sexual attraction to a partner);
• respect;
• gratitude (or appreciation);
• tenderness;
• complacency;
• tenderness;
• gloat;
• bliss;
• feeling of satisfied revenge;
• feeling of self-satisfaction;
• feeling of relief;
• anticipation;
• feeling of security.

Negative:

Neutral:

• astonishment;
• curiosity;
• amazement;
• calm and contemplative mood;
• indifference.

Now you know what feelings a person has. Some to a greater extent, some to a lesser extent, but each of us has experienced them at least once in our lives. Negative emotions that are ignored and not recognized by us do not just disappear. After all, the body and soul are one, and if the latter suffers for a long time, then the body takes on some part of its heavy burden. And it’s not for nothing that they say that all diseases are caused by nerves. The influence of negative emotions on human well-being and health has long been a scientific fact. As for positive feelings, the benefits of them are clear to everyone. After all, experiencing joy, happiness and other emotions, a person literally consolidates in his memory the desired types of behavior (feelings of success, well-being, trust in the world, people around him, etc.).

Neutral feelings also help people express their attitude towards what they see, hear, etc. By the way, such emotions can act as a kind of springboard to further positive or negative manifestations.

Thus, by analyzing his behavior and attitude to current events, a person can become better, worse, or remain the same. It is these properties that distinguish people from animals.

PSYCHOLOGY OF SENSATIONS.

Feeling- this is the simplest mental process, consisting of reflecting individual properties of objects and phenomena of the material world, as well as the internal states of the body under the direct influence of material stimuli on the corresponding receptors.

Reflection- a universal property of matter, which consists in the ability of objects to reproduce, with varying degrees of adequacy, the signs, structural characteristics and relationships of other objects.

Receptor- a specialized organic device located on the surface of the body or inside it and designed to perceive stimuli of various nature: physical, chemical, mechanical, etc., and convert them into nerve electrical impulses.

Sensation constitutes that initial area of ​​the sphere of mental cognitive processes, which is located at the border sharply separating mental and pre-psychic phenomena. Mental cognitive processes– dynamically changing mental phenomena, in their totality providing cognition as a process and as a result.

Psychologists have traditionally used the term “sensation” to designate an elementary perceptual image and the mechanism of its construction. In psychology, they talk about sensation when a person is aware that his senses have received some kind of signal. Any change in the environment that is accessible to vision, hearing and other modalities is psychologically presented as a sensation. Sensation is the primary conscious representation of a formless and objectless fragment of reality of a certain modality: color, light, sound, indefinite touch. In the area of ​​taste and smell, the difference between sensation and perception is much smaller, and sometimes it is virtually non-existent. If we cannot identify a product (sugar, honey) by taste, then we are talking only about sensations. If odors are not identified with their objective sources, then they are presented only in the form of sensations. Pain signals are almost always presented as sensations, since only a person with a very rich imagination can “construct” an image of pain.

The role of sensations in human life is extremely great, since they are the source of our knowledge about the world and about ourselves. We learn about the richness of the surrounding world, about sounds and colors, smells and temperatures, sizes and much more thanks to our senses. With the help of the senses, the human body receives a variety of information in the form of sensations about the state of the external and internal environment.

internal environment.

The sense organs receive, select, accumulate information and transmit it to the brain for processing. The result is an adequate reflection of the surrounding world and the state of the organism itself. On this basis, nerve impulses are formed that arrive to the executive organs responsible for regulating body temperature, the functioning of the digestive organs, organs of movement, endocrine glands, for adjusting the sense organs themselves, etc.

The senses are the only channels through which the external world “penetrates” the human consciousness. The senses give a person the ability to navigate the world around him. If a person lost all his senses, he would not know what was happening around him, would not be able to communicate with people around him, obtain food, or avoid danger.

PHYSIOLOGICAL BASES OF SENSATIONS. CONCEPT ABOUT THE ANALYZER

All living beings that have a nervous system have the ability to sense sensations. As for conscious sensations (about, the source and quality of which a report is given), only humans have them. In the evolution of living beings, sensations arose on the basis of the primary irritability, which is the property of living matter to respond to biologically significant environmental influences by changing its internal state and external behavior.

A person’s sensations, in their quality and diversity, reflect the variety of environmental properties that are significant to him. Human sense organs, or analyzers, from the moment of birth are adapted to perceive and process various types of energy in the form of stimuli-irritants (physical, mechanical, chemical and others).

The sensation arises as a reaction of the nervous system to a particular stimulus and, like any mental phenomenon, has a reflex character. Reaction- the body's response to a specific stimulus.

The physiological basis of sensation is a nervous process that occurs when a stimulus acts on an analyzer adequate to it. Analyzer– a concept (according to Pavlov) denoting a set of afferent and efferent nervous structures involved in the perception, processing and response to stimuli.

Efferent is a process directed from the inside out, from the central nervous system to the periphery of the body.

Afferent- a concept that characterizes the course of the process of nervous excitation through the nervous system in the direction from the periphery of the body to the brain.

The analyzer consists of three parts:

1. Peripheral section (or receptor), which is a special transformer of external energy into the nervous process. There are two types of receptors: contact receptors- receptors that transmit irritation upon direct contact with objects affecting them, and distant receptors - receptors that respond to stimuli emanating from a distant object.

Afferent (centripetal) and efferent (centrifugal) nerves, conducting pathways connecting the peripheral part of the analyzer with the central one.

3. Subcortical and cortical sections (brain end) of the analyzer, where the processing of nerve impulses coming from the peripheral sections occurs.

In the cortical section of each analyzer there is an analyzer core, i.e. the central part, where the bulk of the receptor cells is concentrated, and the periphery, consisting of scattered cellular elements, which are located in varying quantities in various areas of the cortex.

The nuclear part of the analyzer consists of a large mass of cells that are located in the area of ​​the cerebral cortex where the centripetal nerves from the receptor enter.

Scattered (peripheral) elements

of this analyzer are included in areas adjacent to the cores of other analyzers. This ensures the participation of a large part of the entire cerebral cortex in a separate act of sensation. The analyzer core performs the function of fine analysis and synthesis. Scattered elements are associated with the coarse analysis function. Certain cells of the peripheral parts of the analyzer correspond to certain areas of cortical cells.

For sensation to arise, the entire analyzer must work as a whole. The impact of an irritant on the receptor causes irritation. The beginning of this irritation is the transformation of external energy into a nervous process, which is produced by the receptor. From the receptor, this process travels along the centripetal nerve to the nuclear part of the analyzer, located in the spinal cord or brain. When excitation reaches the cortical cells of the analyzer, we feel the qualities of the stimuli, and after this the body’s response to the irritation occurs.

If the signal is caused by an irritant that threatens to cause damage to the body, or is addressed to the autonomic nervous system, then it is very likely that it will immediately cause a reflex emanating from the spinal cord or other lower center, and this will happen before we are aware of this impact (reflex - automatic response " the body's reaction to the action of any internal or external stimulus).

If the signal continues its path along the spinal cord, then it follows two different paths: one leads to the brain cortex through the thalamus, and the other, more diffuse, passes through reticular formation filter, which keeps the cortex awake and decides whether the signal transmitted directly is important enough for the cortex to “take care of it.” If the signal is deemed important, a complex process will begin that will lead to a sensation in the truest sense of the word. This process involves changing the activity of many thousands of cortical neurons, which will have to structure and organize the sensory signal to give

it makes sense to him. (Sensory - associated with the work of the senses).

First, the cortex's attention to the stimulus will now entail a series of movements of the eyes, head, or torso. This will allow you to become more deeply and in detail familiar with the information coming from the sensory organ - the primary source of this signal, and also, possibly, connect other senses. As new information becomes available, it will be associated with traces of similar events stored in memory.

Between the receptor and the brain there is not only a direct (centripetal) connection, but also a feedback (centrifugal) connection .

Thus, sensation is not only the result of a centripetal process, it is based on a complete and complex reflex act, subject in its formation and course to the general laws of reflex activity. In this case, the analyzer constitutes the initial and most important part of the entire path of nervous processes, or reflex arc.

CLASSIFICATION OF SENSATIONS

The classification of sensations is based on the properties of the stimuli that cause them and the receptors that are affected by these stimuli. So, by the nature of reflection and location of sensation receptors divided into three groups:

1 Interoceptive sensations, having receptors located in the internal organs and tissues of the body and reflecting the state of the internal organs. Signals coming from the internal organs are in most cases not noticeable, with the exception of painful symptoms. Information from interoceptors informs the brain about the states of the internal environment of the body, such as the presence of biologically useful or harmful substances in it, body temperature, the chemical composition of fluids present in it, pressure and much more.

2. Proprioceptive sensations, whose receptors are located in ligaments and muscles, they provide information about the movement and position of our body. The subclass of proprioception, which is the sensitivity to movement, is called kinesthesia, and the corresponding receptors are called kinesthetic or kinesthetic.

3. Exteroceptive sensations, reflecting the properties of objects and phenomena of the external environment and having receptors on the surface of the body. Exteroceptors can be divided into two groups: contact and remote. Contact receptors transmit irritation upon direct contact with objects affecting them; These are the tactile and taste buds. Distant receptors respond to stimulation emanating from a distant object; they are visual, auditory, and olfactory receptors.

From the point of view of the data of modern science, the accepted division of sensations into external (exteroceptors) and internal (interoceptors) is not enough. Some types of sensations can be considered external-internal. These include, for example, temperature, pain, taste, vibration, muscle-articular and static-dynamic.

According to sense organs, sensations are divided into gustatory, visual, olfactory, tactile, and auditory.

Touch(or skin sensitivity) is the most widely represented type of sensitivity. The sense of touch, along with tactile sensations (touch sensations: pressure, pain), includes an independent type of sensation - temperature sensations (heat and cold). They are a function of a special temperature analyzer. Temperature sensations are not only part of the sense of touch, but also have an independent, more general significance for the entire process of thermoregulation and heat exchange between the body and the environment.

Unlike other exteroceptors, which are localized in narrowly limited areas of the surface of the predominantly head end of the body, the receptors of the skin-mechanical analyzer, like other skin receptors, are located over the entire surface of the body, in areas bordering the external environment. However, the specialization of skin receptors has not yet been accurately established. It is unclear whether there are receptors exclusively designed to perceive one stimulus, generating differentiated sensations of pressure, pain, cold or heat, or whether the quality of the resulting sensation may vary depending on the specific property affecting it.

The function of tactile receptors, like all others, is to receive the process of irritation and transform its energy into the corresponding nervous process. Irritation of nerve receptors is the process of mechanical contact of the stimulus with the area of ​​the skin surface in which this receptor is located. With significant intensity of the stimulus, contact turns into pressure. With the relative movement of the stimulus and a section of the skin surface, contact and pressure are carried out under changing conditions of mechanical friction. Here irritation is carried out not by stationary, but by fluid, changing contact.

Research shows that touch or pressure sensations only occur when a mechanical stimulus causes deformation of the skin surface. When pressure is applied to a very small area of ​​skin, the greatest deformation occurs precisely at the site of direct application of the stimulus. If the pressure is applied to a sufficiently large surface, then it is distributed unevenly - its lowest intensity is felt in the depressed parts of the surface, and the highest is felt along the edges of the depressed area. G. Meissner's experiment shows that when a hand is immersed in water or mercury, the temperature of which is approximately equal to the temperature of the hand, pressure is felt only at the boundary of the part of the surface immersed in the liquid, i.e. precisely where the curvature of this surface and its deformation are most significant.

The intensity of the sensation of pressure depends on the speed with which the deformation of the skin surface occurs: the stronger the sensation, the faster the deformation occurs.

Smell- a type of sensitivity that generates specific sensations of smell. This is one of the most ancient and vital sensations. Anatomically, the organ of smell is located in most living creatures in the most advantageous place - in front, in a prominent part of the body. The path from the olfactory receptors to those brain structures where the impulses received from them are received and processed is the shortest. Nerve fibers extending from the olfactory receptors directly enter the brain without intermediate switches.

The part of the brain called the olfactory region is also the most ancient; The lower the level of the evolutionary ladder a living creature is, the more space it occupies in the mass of the brain. In many ways, the sense of smell is the most mysterious. Many have noticed that although smell helps to recall an event, it is almost impossible to remember the smell itself, just as we mentally recall an image or sound. The reason why smell serves memory so well is because the mechanism of smell is closely connected to the part of the brain that controls memory and emotions, although we do not know exactly how this connection works and works.

Taste sensations have four main modalities: sweet, salty, sour and bitter. All other sensations of taste are various combinations of these four basic ones. Modality is a qualitative characteristic of sensations that arise under the influence of certain stimuli and reflect the properties of objective reality in a specifically encoded form.

Smell and taste are called chemical senses because their receptors respond to molecular signals. When molecules dissolved in a liquid, such as saliva, excite the taste buds on the tongue, we experience taste. When molecules in the air strike the olfactory receptors in the nose, we smell. Although in humans and most animals taste and smell, having developed from a common chemical sense, have become independent, they remain interconnected. In some cases, for example, when we smell chloroform, we think we smell it, but in fact it is a taste.

On the other hand, what we call the taste of a substance is often its smell. If you close your eyes and pinch your nose, you may not be able to distinguish a potato from an apple or wine from coffee. By holding your nose, you will lose 80 percent of your ability to smell the aromas of most foods. This is why people whose noses cannot breathe (runny nose) have difficulty tasting food.

Although our olfactory system is amazingly sensitive, humans and other primates smell much less well than most other animal species. Some scientists suggest that our distant ancestors lost their sense of smell when they climbed trees. Since visual acuity was more important during that period, the balance between different types of senses was disrupted. During this process, the shape of the nose changed and the size of the olfactory organ decreased. It became less subtle and was not restored even when human ancestors descended from the trees.

However, in many animal species the sense of smell is still one of the main means of communication. It is likely that smells are also more important for humans than previously thought.

Substances have an odor only if they are volatile, that is, they easily pass from a solid or liquid state to a gaseous state. However, the strength of the smell is not determined by volatility alone: ​​some less volatile substances, such as those found in pepper, smell stronger than more volatile substances, such as alcohol. Salt and sugar have almost no odor, since their molecules are so tightly linked to each other by electrostatic forces that they hardly evaporate.

Although we are very good at detecting odors, we are poor at recognizing them in the absence of a visual cue. This is the property of our perception mechanism.

Smell and smell are much more complex phenomena and influence our lives to a greater extent than we believed until recently, and it seems that scientists working on these problems are on the verge of many amazing discoveries.

Visual sensations- a type of sensation caused by exposure to electromagnetic waves on the visual system in the range from 380 to 780 billionths of a meter. This range occupies only part of the electromagnetic spectrum. Waves that are within this range and differ in length give rise to sensations of different colors. The visual apparatus is the eye. Light waves reflected by an object are refracted as they pass through the lens of the eye and are formed on the retina in the form of an image - an image. Visual sensations are divided into:

Achromatic, reflecting the transition from darkness to light (from black to white) through a mass of shades of gray;

Chromatic, reflecting a color spectrum with numerous shades and color transitions - red, orange, yellow, green, blue, indigo, violet.

The emotional impact of color is related to its physiological, psychological and social meaning.

Auditory sensations are the result of mechanical action on the receptors of sound waves with an oscillation frequency from 16 to 20,000 Hz. Hertz is a physical unit by which the frequency of air vibrations per second is measured, numerically equal to one vibration performed per second. Fluctuations in air pressure, following with a certain frequency and characterized by the periodic appearance of areas of high and low pressure, are perceived by us as sounds of a certain height and volume. The higher the frequency of air pressure fluctuations, the higher the sound we perceive.

There are 3 types of sound sensations:

Noises and other sounds (occurring in nature and in the artificial environment);

Speech (related to communication and mass media);

Musical (artificially created by man for artificial experiences).

In these types of sensations, the auditory analyzer identifies four sound qualities:

Strength (loudness, measured in decibels);

Height (high and low frequency of oscillations per unit time);

Timbre (original coloring of sound - speech and music);

Duration (sounding time plus tempo-rhythmic pattern).

BASIC PROPERTIES OF SENSATIONS.

Different types of sensations are characterized not only by specificity, but also by properties common to them. These properties include:

Spatial localization– display of the location of the stimulus in space. For example, contact sensations (tactile, pain, taste) are correlated with the part of the body that is affected by the stimulus. At the same time, the localization of pain sensations can be more diffuse and less accurate than tactile ones. Spatial threshold- the minimum size of a barely perceptible stimulus, as well as the minimum distance between stimuli when this distance is still felt.

Intensity of sensation- a quantitative characteristic that reflects the subjective magnitude of the sensation and is determined by the strength of the stimulus and the functional state of the analyzer.

Emotional tone of sensations- the quality of sensation, manifested in its ability to evoke certain positive or negative emotions.

Speed ​​of sensation(or time threshold) - the minimum time required to reflect external influence.

Differentiation, subtlety of sensations- an indicator of discriminative sensitivity, the ability to distinguish between two or more stimuli.

Adequacy, accuracy of sensation- correspondence of the resulting sensation to the characteristics of the stimulus.

Quality (sensations of a given modality)- this is the main feature of a given sensation, distinguishing it from other types of sensation and varying within a given type of sensation (a given modality). Thus, auditory sensations differ in pitch, timbre, and volume; visual - by saturation, color tone, etc. The qualitative diversity of sensations reflects the infinite variety of forms of matter movement.

Sensitivity level stability- duration of maintaining the required intensity of sensations.

Duration of sensation- its time characteristics. It is also determined by the functional state of the sensory organ, but mainly by the time of action of the stimulus and its intensity. The latent period for different types of sensations is not the same: for tactile sensations, for example, it is 130 milliseconds, for painful sensations - 370 milliseconds. The sensation of taste occurs 50 milliseconds after applying a chemical irritant to the surface of the tongue.

Just as a sensation does not arise simultaneously with the onset of the stimulus, it does not disappear simultaneously with the cessation of the latter. This inertia of sensations manifests itself in the so-called aftereffect.

The visual sensation has some inertia and does not disappear immediately after the stimulus that caused it ceases to act. The trace of the stimulus remains in the form consistent image. There are positive and negative sequential images. A positive, consistent image in lightness and color corresponds to the initial irritation. The principle of cinema is based on the inertia of vision, on the preservation of the visual impression for a certain period of time in the form of a positive consistent image. The sequential image changes over time, with the positive image being replaced by a negative one. With colored light sources, a transition of a consistent image into an additional color occurs.

SENSITIVITY AND ITS MEASUREMENT

Various sense organs that give us information about the state of the external world around us may be more or less sensitive to the phenomena they display, that is, they can display these phenomena with greater or less accuracy. In order for a sensation to arise as a result of the action of a stimulus on the sense organs, it is necessary that the stimulus causing it reach a certain value. This value is called the lower absolute threshold of sensitivity. Lower absolute sensitivity threshold- minimal stimulus strength, causing a barely noticeable sensation. This is the threshold for conscious recognition of the stimulus.

However, there is a "lower" threshold - physiological. This threshold reflects the sensitivity limit of each receptor, beyond which excitation can no longer occur. This threshold is determined genetically and can only change depending on age or other physiological factors. The threshold of perception (conscious recognition) is much less stable and depends, among other things, on the level of wakefulness of the brain, on the brain’s attention to the signal that has crossed the physiological threshold. Between these two thresholds there is a zone of sensitivity in which the stimulation of receptors entails the transmission of a message, but it does not reach consciousness. Despite the fact that the environment sends us thousands of different signals at any moment, we can only perceive a small part of them.

At the same time, being unconscious, being below the lower threshold of sensitivity, these stimuli (subsensory) are capable of influencing conscious sensations. With the help of such sensitivity, for example, our mood can change, in some cases they influence a person’s desires and interest in certain objects of reality.

Currently, there is a hypothesis that in the zone* below the level of consciousness - in the subthreshold zone - signals perceived by the senses are possibly processed by the lower centers of our brain. If this is so, then every second there must be hundreds of signals that pass by our consciousness, but are nevertheless registered at lower levels.

This hypothesis allows us to find an explanation for many controversial phenomena. Especially when it comes to perceptual protection, subliminal and extrasensory perception, and awareness of inner reality in conditions, for example, of sensory isolation or in a state of meditation.

The fact that stimuli of lesser strength (subthreshold) do not cause sensations is biologically appropriate. At each individual moment, from an infinite number of impulses, the cortex perceives only vital ones, delaying all others, including impulses from internal organs. It is impossible to imagine the life of an organism in which the cerebral cortex would equally perceive all impulses and provide reactions to them. This would lead the body to inevitable death. It is the cerebral cortex that “stands guard” over the vital interests of the body and, raising the threshold of its excitability, transforms irrelevant impulses into subthreshold ones, thereby relieving the body of unnecessary reactions.

Sensation is the simplest mental process that arises as a result of the impact on the senses of objects or phenomena of the material world and consists in reflecting the individual properties of these objects or phenomena.

With the help of sensations, we recognize the properties of things around us: their hardness or softness, roughness or smoothness, their heaviness, temperature, smell and taste, the colors of these things, the sounds they make. In addition, sensations give us information about changes in our own body: we feel the movement and position of individual parts of our body, disturbances in the functioning of internal organs, etc.

Sensations, being a reflection of the properties of the external world, provide material for other, more complex cognitive processes: perceptions, ideas, memories, thinking processes. “Otherwise, as through sensations,” Lenin wrote, “we cannot learn anything about any forms of matter or any forms of motion.”

Material things and processes that affect the senses are called stimuli, and the process of this impact is called irritation. The process that occurs in nervous tissue as a result of irritation is called excitation. When excitation along the centripetal nerves reaches the cerebral cortex, a sensation arises.

I. P. Pavlov proposed calling the entire anatomical and physiological apparatus necessary to obtain sensation an analyzer. Every analyzer consists of three parts: a sensory organ (receptor), centripetal nerves and corresponding parts of the brain. If any part of the analyzer is destroyed, the occurrence of the corresponding sensations becomes impossible. For example, visual sensations cease when the eyes are damaged, when the optic nerves are cut, and when the corresponding areas of the cortex are destroyed.

It is necessary to pay attention to the fact that the term “sense organs” has a conditional meaning. It became widespread at a time when science had not yet made a clear distinction between sensations and feelings. Now, as we know, the word “feeling” denotes a special mental process that is significantly different from sensations. It would therefore be more correct to call receptors not sense organs, but sensory organs.

In the same conventional sense, the word “sense” is used in the expressions: “sense of vision”, “sense of taste”, “vibrational sense”, etc., denoting the ability to have visual, gustatory, vibrational sensations, etc. When encountering such designations, we must remember that they do not refer to “feelings” in the real sense of the word, but to sensations.

The cerebral hemispheres represent the central ends of analyzers that distinguish between external influences and internal states of the body. “In the highest floor of the central nervous system,” notes I. P. Pavlov, “we have the ends of the finest and infinitely varied analyzers.” The brain end of the visual analyzer is located mainly in the occipital lobe of the cortex, the auditory analyzer - mainly in the temporal lobe.

Types of sensations

All sensations can be divided into two groups:

1) Sensations that reflect the properties of things or phenomena located outside of us. The organs of these sensations are located on the surface of the body or close to it.

2) Sensations that reflect the movements of individual parts of our body and the state of our internal organs. The organs of these sensations are located deep in the tissues (for example, muscles) or on the surface of internal organs (for example, in the walls of the stomach, respiratory tract).

The first group includes visual, vocal, olfactory, gustatory and skin sensations.

1. Visual sensations.

The irritant for the organ of vision is light, i.e. electromagnetic waves having a length from 390 to 800 millimicrons (a millimicron is a millionth of a millimeter).

Everything we see has some color. Only an object that is completely transparent and, therefore, invisible can be colorless. Therefore we can say that visual sensations are sensations of colors.

All colors are divided into two large groups: achromatic colors and chromatic colors. Achromatic colors include white, black and all grays, chromatic colors include all the rest, i.e. red, yellow, green, blue with all sorts of shades.

2. Auditory sensations.

The irritant for the organ of hearing is sound waves, i.e. longitudinal vibrations of air particles propagating in all directions from the sound source.

Sound waves are divided into: frequency of vibrations, amplitude, or range, of vibrations and shape of vibrations. Accordingly, auditory sensations have the following three sides: pitch, which is a reflection of the frequency of vibrations, volume - a reflection of the amplitude of vibrations, and timbre - a reflection of the shape of vibrations. Our hearing organ is sensitive to vibrations ranging from 16 vibrations per second to 20,000 vibrations per second. Vibrations with a frequency of more than 20,000 vibrations per second, inaccessible to our hearing, are called ultrasound.

Sounds, according to the nature of the sensations they cause, are divided into musical sounds (sounds of singing, musical instruments, tuning forks) and noises (all kinds of creaks, rustles, knocks, crackling, rumble, etc.). Speech consists of both musical sounds (mainly vowels) and noises (mainly consonants).

3. Olfactory sensations.

The olfactory organs are the olfactory cells located in the upper part of the nasal cavity. The olfactory organ is irritated by particles of odorous substances that enter the nose along with the air.

4. Taste sensations.

The irritants for the taste organ - taste buds - are dissolved (in water or saliva) flavoring substances.

The sense of taste has four different qualities: sweet, sour, salty and bitter. The variety of tastes of various foods largely depends on the addition of olfactory sensations to the taste sensations. If the sense of smell is completely excluded, the taste of tea, coffee and quinine in the corresponding solutions becomes the same.

5. Skin sensations.

The skin, as well as the mucous membrane of the mouth and nose, can give sensations of four types: a) sensations of touch, or tactile sensations, b) sensations of cold, c) sensations of warmth and d) sensations of pain. Some points of the skin give only tactile sensations (touch points), others - only sensations of cold (cold points), others - only sensations of warmth (heat points), and fourth - only sensations of pain (pain points). It is easy to verify by simple experiment the existence of cold spots. To do this, you need to slowly draw the tip of a pencil, lightly touching the skin, over your closed eyelids; From time to time you will get a momentary feeling of cold.

The sensitivity of different areas of the skin to each of these four types of sensations is different. Sensitivity to touch is greatest at the tip of the tongue and at the tips of the fingers, that is, on the most mobile organs; the back, for example, is very little sensitive to touch. Pain sensitivity is distributed completely differently: the skin of the back and cheeks is most sensitive to pain, and the least sensitive is the skin on the fingertips and palms. Thus, those areas of the skin that we use most to feel are the least painful; they are most “hardened” against pain. As for the sensations of heat and cold, those parts of the skin that are usually covered by clothing are most sensitive to them: the skin of the lower back, abdomen, and chest.

The second group includes motor sensations, sensations of balance and organic sensations.

1. Motor sensations.

Their receptors are located in muscles, tendons and on articular surfaces. Motor sensations provide signals about the degree of muscle contraction and the position of our limbs, for example, how much the arm is bent at the shoulder, elbow or wrist joint.

The combination of skin and motor sensations obtained by feeling objects, that is, by touching them with a moving hand, is called touch. The organ of touch is the hand with all its skin, muscle and joint receptors. The hand as an organ of touch first appears in monkeys, but reaches full development only in humans, becoming a tool for him.

Skin sensations themselves signal only the fact of an object touching the body and the location of this touch. When a fly lands on our forehead, we easily notice it, but we can just as easily be misled and mistake the touch of a straw, brush, blade of grass or piece of paper for a fly. To more accurately determine the properties of an object touching the skin, its hardness, softness, roughness, smoothness, shape, outline, etc., you need to feel it. For example, the sensations of hardness and softness depend mainly on how much resistance the body provides when pressure is applied to it; therefore, it is impossible to determine the degree of hardness or softness of objects without the participation of motor sensations.

2. Feelings of balance.

Their receptors are located in the inner ear and provide signals about the movement and position of the head. These sensations play an extremely important role in flying; Therefore, when determining a pilot’s suitability for work, the activity of these organs is always tested.

3. Organic feel.

Their receptors are located in the walls of most internal organs: the esophagus, stomach, intestines, blood vessels, lungs, etc. Organic include the sensations that we have during hunger, thirst, satiety, nausea, internal pain, etc. So far we are completely healthy, well-fed, in general, when the internal organs work normally, we do not notice almost any organic sensations; they mainly give signals about disturbances in the functioning of internal organs. Research by the Pavlovian school, primarily the work of K. M. Bykov, showed that impulses directed to the cortex from the internal organs, without being clearly conscious, underlie the general “well-being” of a person. Internal analyzers monitor, check the chemical composition and blood pressure, the condition of organs and their functioning; at the same time, they can enter into temporary communication with analyzers that bring information about external objects.