General characteristics of mental processes of sensation and perception. Physiological mechanisms of sensations

The physiological basis of sensations is the activity of complex complexes of anatomical structures, called Pavlov's analyzers; each analyzer consists of 3 parts. 1. peripheral section - receptors. Receptor – the perceiving part of the analyzer, its main function is to transform external energy into a nerve impulse. 2. conducting nerve pathways - (centripetal, centrifugal, afferent) 3. cortical sections of the analyzer, in which the processing of nerve impulses coming from peripheral sections occurs. For sensation to arise, it is necessary to use all the components of the analyzer. If any part of the analyzer is destroyed, the occurrence of sensation becomes impossible (visual sensation stops if the eye is damaged.) Analyzer- an active organ that reflexively rearranges itself under the influence of stimuli, so sensation is not a passive process, but always includes motor components. Thus, the American psychologist Neff, observing areas of the skin with a microscope, became convinced that when they are irritated with a needle, the moment the sensation occurs is accompanied by a reflex-motor reaction of this area of ​​the skin.

12 Classification of sensations

There are different approaches to the classification of sensations. It has long been customary to distinguish 5 main types (based on the number of sense organs): smell, taste, touch, vision, hearing. This classification according to its main modalities is correct, although not exhaustive. For example, Ananyev spoke about 11 types of sensations. Luria believes that the classification of sensations can be carried out according to at least two basic principles: systematic, genetic (by the principle of modality on the one hand and by the principle of complexity or level of their structure on the other hand). A systematic classification was proposed by English physiologists Sherrington. SYSTEMATIC Classification of the main types of sensations Exteroceptive– are the largest group . sensations. They bring it to people's attention. information from the outside world and are the main group. sensations that connect people. with the external environment. Whole gr. These sensations are conventionally divided into 2 subgroups. contact and remote. Contact – are caused directly by the impact of an object on the senses. Contact are taste and touch. Distant – reflect the quality of an object that is located at a certain distance from the senses. These sensations include hearing and vision. It should be noted that the sense of smell, according to many authors, occupies an intermediate position between contact and distant ones, since formally the olfactory sensation occurs at a distance from the object, but at the same time the molecules characterizing the smell of the object with which the olfactory receptor is in contact , undoubtedly belong to this subject. This is the duality of the position that marks the olfactory sensation. Since sensation arises as a result of the action of a certain physical stimulus on the corresponding receptor, the primary classification of sensations comes, naturally, from the receptor that gives sensations of a given quality or modality. INTEROCEPTIVE– organic (sensation of pain) - combine signals that reach us from the internal processes of the body, arise thanks to receptors that are located on the walls of the stomach and intestines, heart and blood vessels, and other internal organs. Receptors that perceive information about the state of internal organs are called internal receptors. PROPRIOCEPTIVE – transmit signals about the position of the body in space and form the afferent basis of human movements. They play a decisive role in their regulation. The described group of sensations includes the sensation of balance (stomatic sensations) and movement (kinesthetic sensations). Receptors for these sensations are located in muscles, joints, tendons and are called Paccini corpuscles. Peripheral receptors of this group. sensations are located in the semicircular canals of the inner ear, which are responsible for balance. In addition to systematic, there is genetic classification. It was suggested by the English neuropathologist Head. Genetic classification allows us to distinguish 2 types of sensitivity: protatapic– which includes organic feelings: thirst, hunger, etc. epicritic– main types of sensations.

- INTRODUCTION -

All the information that a person receives in the process of cognition is obtained through sensory cognitive processes that arise during the direct interaction of the senses with environmental objects. Understanding the world around us begins with sensations. Sensation is the simplest cognitive process that ensures the functioning of all more complex processes. Sensations arise from the direct action of the properties and qualities of the external and internal environment on the senses. Information about the properties and qualities of objects and phenomena coming from the senses is reflected in our consciousness in the form of sensations and impressions.

Sensation is an elementary sensory cognitive process, reflecting in the form of perceptions the properties and qualities of objects that directly act on the senses. Sensation is a cognitive process, and perception is a form of reflection of a stimulus acting on the sense organs that has arisen in our consciousness. So, sensation is the process of converting information received by the senses into facts of consciousness. This information exists in our consciousness in the form of various perceptions: light, auditory, olfactory, gustatory and tactile.

Sensation as such is a rather complex mental phenomenon, as it seems at first glance. Despite the fact that this is a fairly studied phenomenon, the global nature of its role in the psychology of activity and cognitive processes is underestimated by humans. The sensations are widespread in ordinary life of a person, and in the continuous process of cognitive activity for people is an ordinary, primary form of psychological connection between the organism and the environment.

Partial or complete absence of types of sensation (vision, hearing, taste, smell, touch) in a person prevents or inhibits his development.
Sensations are of great importance on the formation of such cognitive processes as speech, thinking, imagination, memory, attention and perception, as well as on the development of activity as a scientific type of human activity aimed at creating objects of material and spiritual culture, transforming one’s abilities, preserving and improving nature, and building society.

An object research - human sensations.

Item research - types of sensations.

The problem studies are various classifications of sensations in psychology.

Target work - analyze theoretical literature on the research problem, consider different kinds and classification of sensations.

Tasks:

1. Give a general concept of sensations in psychology.

2. Consider the properties and functions of sensations.

3. Consider the classifications of types of sensations that exist in psychological science.

The work consists of an introduction, two chapters, an experimental part, a conclusion and a list of references.

The experimental part is devoted to visual sensations.

1. General concept of sensations and their functions in psychology

1.1 Concept of sensation

Sensations allow a person to perceive signals and reflect the properties and signs of things in the external world and states of the body. They connect a person with the outside world and are both the main source of knowledge and the main condition for his mental development.

Sensation is one of the simplest cognitive mental processes. The human body receives a variety of information about the state of the external and internal environment in the form of sensations through the senses. Sensation is the most important connection between a person and the surrounding reality.

The process of sensation arises as a result of the influence on the sense organs of various material factors, which are called stimuli, and the process of this influence itself is called irritation.

Sensations arise on the basis of irritability. Sensation is a product of development in the phylogenesis of irritability. Irritability is a common property of all living bodies to come into a state of activity under the influence of external influences (pre-psychic level), i.e. directly affecting the life of the organism. Irritation causes excitation, which travels along centripetal, or afferent, nerves to the cerebral cortex, where sensations arise. On early stage In the development of living things, the simplest organisms (for example, the slipper ciliate) do not need to distinguish between specific objects for their life activity - irritability is sufficient. At a more complex stage, when a living person needs to identify any objects that he needs for life, and, consequently, the properties of this object as necessary for life, this is where the transformation of irritability into sensitivity occurs. Sensitivity is the ability to respond to neutral, indirect influences that do not affect the life of the body (example with a frog reacting to a rustle). The totality of feelings creates elementary mental processes, processes of mental reflection.

There are two main forms of sensitivity, of which one depends on environmental conditions and is called adaptation, and the other depends on the conditions of the body’s state, called sensitization.

Adaptation (adjustment, adjustment) is a change in sensitivity in the process of adapting to environmental conditions.

There are three directions:

1) increased sensitivity under the influence of a weak stimulus, for example, dark adaptation of the eye, when within 10-15 minutes. sensitivity increases by more than 200 thousand times (at first we do not see objects, but gradually we begin to distinguish their outlines);

2) a decrease in sensitivity under the influence of a strong stimulus, for example, for hearing this occurs in 20-30 seconds; with continuous and prolonged exposure to the stimulus, the corresponding receptors adapt to it, as a result of which the intensity of nervous excitations transmitted from the receptors to the cortex begins to decrease, which is the basis of adaptation.

3) complete disappearance of sensation as a result of prolonged exposure to the irritant, for example, after 1-1.5 minutes, a person stops feeling any smell in the room.

Adaptation is especially manifested in the spheres of vision, hearing, smell, touch, taste and indicates greater plasticity of the organism, its adaptation to environmental conditions.

Sensitization is an aggravation of sensitivity as a result of a change in the internal state of the body under the influence of stimuli that arrive at the same time to other sense organs (for example, an increase in visual acuity under the influence of weak auditory or olfactory stimuli).

1.2 Properties of sensations

All sensations can be characterized in terms of their properties. Moreover, the properties can be not only scientific, but also common to all types of sensations. The main properties of sensations include: quality, intensity, duration and spatial localization, absolute and relative thresholds of sensations (Fig. 1).

Rice. 1. General properties sensations

It should be borne in mind that very often, when they talk about the quality of sensations, they mean the modality of sensations, since it is the modality that reflects the main quality of the corresponding sensation.

The intensity of the sensation is its quantitative characteristic and depends on the strength of the current stimulus and the functional state of the receptor, which determines the degree of readiness of the receptor to perform its functions. For example, if you have a runny nose, the intensity of perceived odors may be distorted.

The duration of a sensation is a temporary characteristic of the sensation that has arisen. 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. It should be noted that sensations have a so-called latent (hidden) period. When a stimulus acts on a sense organ, the sensation does not occur immediately, but after some time. The latent period of different types of sensations is not the same. For example, for tactile sensations it is 130 ms, for pain - 370 ms, and for taste - only 50 ms.

The sensation does not appear simultaneously with the onset of the stimulus and does not disappear simultaneously with the cessation of its effect. This inertia of sensations manifests itself in the so-called aftereffect. A visual sensation, for example, has some inertia and does not disappear immediately after the cessation of the action of the stimulus that caused it. (C) Information published on the site
The trace of the stimulus remains in the form of a consistent image. There are positive and negative sequential images. A positive sequential image corresponds to the initial irritation and consists in maintaining a trace of irritation of the same quality as the actual stimulus.

A negative sequential image consists in the emergence of a quality of sensation that is opposite to the quality of the stimulus that influenced it. (C) Information published on the site
For example, light-darkness, heaviness-lightness, warmth-cold, etc. The emergence of negative sequential images is explained by a decrease in the sensitivity of a given receptor to a certain influence.

And finally, sensations are characterized by the spatial localization of the stimulus. (C) Information published on the site
The analysis carried out by receptors gives us information about the localization of the stimulus in space, i.e. we can tell where the light is coming from, where the heat is coming from, or what part of the body the stimulus is affecting.

All the properties described above, to one degree or another, reflect the qualitative characteristics of sensations. However, no less important are the quantitative parameters of the main characteristics of sensations - the degree (thresholds) of sensitivity (Fig. 2).

Rice. 2. Sensitivity thresholds

It should be remembered that the same stimulus for one person may be lower, and for another – higher than the threshold of sensation. The weaker the stimuli that a person is able to sense, the higher his sensitivity. In other words, the lower the absolute threshold of sensations, the higher the absolute sensitivity, and vice versa.

So, sensation is the simplest mental process of reflecting a separate quality (property) of an object under the direct influence of stimuli on the perceiving part of the analyzer.

1. 3 Physiological mechanisms of sensations

The physiological basis of sensations is the activity of complex complexes of anatomical structures called analyzers. The concept of an analyzer (a device that performs the function of distinguishing external stimuli) was introduced by Academician I.P. Pavlov. He also examined the structure of the analyzers and came to the conclusion that they consist of three parts:

1) Regional department, called a receptor (a receptor is the perceiving part of the analyzer, a socialized nerve ending, its main function is the transformation of external energy into a nervous process);

2) nerve pathways(afferent department - transmits excitation to the central department; efferent department - along it transmits the response from the center to the peripheral);

3) analyzer core- cortical sections of the analyzer (they are also called the central sections of the analyzers), in which the processing of nerve impulses coming from the peripheral sections occurs. The cortical part of each analyzer includes an area that represents a projection of the peripheral region (i.e., a projection of the sensory organ) in the cerebral cortex, since certain receptors correspond to certain areas of the cortex.

So, the organ of sensation is the central section of the analyzer.

For sensation to occur, all components of the analyzer must be used. If any part of the analyzer is destroyed, the occurrence of the corresponding sensations becomes impossible. Thus, visual sensations cease when the eyes are damaged, when the integrity of the optic nerves is damaged, and when the occipital lobes of both hemispheres are destroyed. In addition, for sensations to arise, 2 more conditions must be present:

· Sources of irritation (irritants).

· Medium or energy that is distributed in the environment from the source to the subject.

For example, in a vacuum there are no auditory sensations. In addition, the energy emitted by the source may be so small that a person does not feel it, but it can be registered by instruments. That. Energy, in order to become perceptible, must reach a certain threshold value of the analyzer system.

Also, the subject may be awake or asleep. This should also be taken into account. During sleep, the thresholds of analyzers increase significantly.

So, sensation is a mental phenomenon that is the result of the interaction of an energy source with the corresponding human analyzer. In this case, we mean an elementary single source of energy that creates a homogeneous sensation (of light, sound, etc.).

Five conditions must exist for sensations to occur:

· Receptors.

· Analyzer nucleus (in the cerebral cortex).

· Conducting pathways (with directions of impulse flows).

· Source of irritation.

· Environment or energy (from source to subject).

It should be noted that human sensations are a product of historical development, and in this regard they are qualitatively different from the sensations of animals. In animals, the development of sensations is entirely limited by their biological, instinctive needs. In humans, the ability to feel is not limited by biological needs. Labor created in him an incomparably wider range of needs than in animals, and in activities aimed at satisfying these needs, human abilities were constantly developing, including the ability to feel. In this regard, a person can sense a much larger number of properties of the objects around him than an animal.

Sensations are not only the source of our knowledge about the world, but also our feelings and emotions. The simplest form of emotional expression is the so-called sensual, or emotional, tone of sensation, i.e. a feeling directly related to a sensation. For example, it is well known that some colors, sounds, smells can themselves, regardless of their meaning, memories and thoughts associated with them, cause us a pleasant or unpleasant feeling. The sound of a beautiful voice, the taste of alsina, the smell of roses are pleasant and have a positive emotional tone.
The creaking of a knife on glass, the smell of hydrogen sulfide, the taste of quinine are unpleasant and have a negative emotional tone.
This kind of simplest emotional conditions play a relatively insignificant role in the life of an adult, but from the point of view of the origin and development of emotions, their significance is very great.

The following functions of sensations are distinguished.

Signaling - notifying the body about vital objects or properties of the surrounding world.

Reflective (figurative) - construction of a subjective image of a property necessary for orientation in the world.

Regulatory - adaptation in the surrounding world, regulation of behavior and activity.

There are several theories of sensations.

Receptive. According to this theory, the sensory organ (receptor) passively responds to influencing stimuli. This passive response is the corresponding sensations, that is, the sensation is a purely mechanical imprint external influence in the corresponding sense organ. Currently, this theory is recognized as untenable, since the active nature of sensations is denied.

Dialectical-materialistic.
According to this theory, “sensation is a real direct connection between consciousness and the external world, it is the transformation of the energy of external stimulation into a fact of consciousness” (V.L. Lenin).

Reflex.
Within the framework of the reflex concept of I.M. Sechenov and I.P. Pavlov conducted studies that showed that, according to its physiological mechanisms, sensation is an integral reflex that unites the peripheral and central sections of the analyzer through direct and feedback connections.

Sensations begin to develop immediately after birth. However, not all types of sensitivity develop equally. Immediately after birth, the child develops tactile, gustatory and olfactory sensitivity (the child reacts to the temperature of the environment, touch, pain; identifies the mother by the smell of mother's milk; distinguishes mother's milk from cow's milk or water). However, the development of these sensations continues for quite a long time (they are little developed at 4-5 years).

Visual and auditory sensations are less mature at the time of birth. Auditory sensations begin to develop faster (reacts to sound - in the first weeks of life, to direction - after two to three months, and to sound and music - in the third or fourth month). Speech hearing develops gradually. First, the child responds to the intonation of speech (in the second month), then to the rhythm, and the ability to distinguish sounds (first vowels, and then consonants) appears by the end of the first year of life.

Absolute sensitivity to light in an infant is low, but increases markedly in the first days of life. Color differentiation begins only in the fifth month.

In general, absolute sensitivity of all species reaches a high level of development in the first year of life. Relative sensitivity develops more slowly (rapid development occurs at school age).

Sensations, within certain limits, can be developed through constant training. Thanks to the possibility of developing sensations, for example, children learn (music, drawing).

Among sensory disturbances, quantitative and qualitative changes are distinguished.

Quantitative disorders include: loss or decrease in the ability to perceive various types of stimuli and an increase in this ability. Loss of sensitivity usually extends to tactile, pain, and temperature sensitivity, but can also cover all types of sensitivity.

This is usually associated with various diseases of the individual. Synesthesia is a qualitative disorder of sensations. Another type of pathology of sensations manifests itself in various unpleasant sensations: numbness, tingling, burning, crawling, etc. With various pathological diseases there may be changes in pain sensitivity. They consist of different pain sensitivity and pain tolerance.

Individual differences in sensations are a little-studied area of ​​psychology. It is known that the sensitivity of different sense organs depends on many factors. The characteristics of the central nervous system influence (individuals with a strong nervous system have lower sensitivity); emotionality (emotional people have a more developed sense of smell); age (hearing acuity is greatest at 13 years old, visual acuity at 20-30 years old, old people hear low-frequency sounds quite well, and high-frequency sounds worse); gender (women are more sensitive to high sounds, and men - to low sounds); the nature of the activity (steelworkers distinguish the subtlest shades of a red-hot flow of metal, etc.).

2. Classification of types of sensations

There are different approaches to classifying sensations. It has long been customary to distinguish between five (based on the number of sense organs) main types of sensations: smell, taste, touch, vision and hearing. This classification of sensations according to the main modalities is correct, although not exhaustive. B.G. Ananyev spoke about eleven types of sensations. A.R. Luria believed that the classification of sensations can be carried out according to at least two basic principles - systematic and genetic (in other words, according to the principle of modality, on the one hand, and according to the principle of complexity or level of their construction, on the other).

Let's consider a systematic classification of sensations (Fig. 3). This classification was proposed by the English physiologist C. Sherrington. Considering the largest and most significant groups of sensations, he divided them into three main types: interoceptive, proprioceptive and exteroceptive sensations. The first combine signals reaching us from the internal environment of the body; the latter provide information about the position of the body in space and the position of the musculoskeletal system, ensuring the regulation of our movements; finally, still others ensure the receipt of signals from the external world and create the basis for our conscious behavior. Let's consider the main types of sensations separately.

The basis of perception are exteroceptors, since they provide an objective view of the external world.

As you know, a person has five senses. There are one more types of external sensations, since motor skills do not have a separate sensory organ, but they also cause sensations. Consequently, a person can experience six types of external sensations: visual, auditory, olfactory, tactile (tactile), gustatory and kinesthetic sensations.

Rice. 3. Systematic classification of the main types of sensations The main source of information about the external world is the visual analyzer. With its help, a person receives up to 80% of the total amount of information. The organ of visual sensation is the eye. At the level of sensations, he perceives information about light and color. Colors perceived by humans are divided into chromatic and achromatic. The first ones include the colors that make up the spectrum of the rainbow (i.e., the splitting of light - the well-known “Every hunter wants to know where the pheasant sits”). The second ones are black, white and gray colors. Color shades, containing about 150 smooth transitions from one to another, are perceived by the eye depending on the parameters of the light wave. Visual sensations have a great influence on a person. All warm colors have a positive effect on a person’s performance, excite him and cause a good mood. Cool colors calm a person. Dark colors have a depressing effect on the psyche. Colors can carry warning information: red indicates danger, yellow warns, green signals safety, etc. The next most important in receiving information is the auditory analyzer. The sensations of sounds are usually divided into musical and noise. Their difference is that musical sounds are created by periodic rhythmic vibrations of sound waves, and noises are created by non-rhythmic and irregular vibrations. Auditory sensations are also of great importance in human life. The source of auditory sensations is a variety of sounds acting on the organ of hearing. Auditory sensations reflect noise, musical and speech sounds. Sensations of noise and rustling signal the presence of objects and phenomena that produce sounds, their location, approach or distance. They can warn of danger and cause a certain emotional distress. Musical sensations are characterized by emotional tone and melody. These sensations are formed in a person on the basis of the education and development of musical ear and are associated with the general musical culture of human society. Speech sensations are the sensory basis of human speech activity. On the basis of speech sensations, phonemic hearing is formed, thanks to which a person can distinguish and pronounce speech sounds. Phonemic hearing influences not only the development of oral and written speech, but also the acquisition of a foreign language. Many people have interesting feature- a combination of sound and visual sensations into one overall sensation. In psychology, this phenomenon is called synesthesia. These are stable associations that arise between objects of auditory perception, such as melodies, and color sensations. Often people can tell “what color” a given melody or word is. Synesthesia, based on the association of color and smell, is somewhat less common. It is often characteristic of people with a developed sense of smell. Such people can be found among perfume tasters - not only a developed olfactory analyzer is important for them, but also synesthetic associations that allow Difficult language scents should be transformed into a more universal language of color. In general, the olfactory analyzer, unfortunately, is most often not very well developed in people. People like the hero of Patrick Suskind's novel “Perfume” are a rare and unique phenomenon. The sense of smell is a type of sensitivity that gives rise to the scientific sensations of smell. This is one of the most ancient, simple, but vital sensations. Anatomically, the organ of smell is located in most living creatures in the most advantageous place - in the middle, 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, without intermediate connections, enter the brain. The part of the brain, which is called the olfactory part, is also the most ancient, and the lower a living creature is on the evolutionary ladder, the more space in the mass of the brain it occupies. In fish, for example, the olfactory brain covers almost the entire surface of the hemispheres, in dogs - about one third, in humans its relative share in the volume of all brain structures is approximately one twentieth. These differences correspond to the development of other sense organs and the vital importance that this type has sensations for living beings. For some animal species, the importance of smell goes beyond the perception of smells. In insects and great apes, the sense of smell also serves as a means of intraspecific communication. The odor classification system known as the “Henning Prism” (floral, fruity, spicy, resinous, burnt, putrid) forms the corners of a prism with intermediate qualities located on the planes (Fig. 4 ).Rice. 4. “Henning Prism” There are other classifications. In practice, a comparison of a given smell with a known standard (lilac, hay, etc.) is often used. Taste sensations are a reflection of the quality of food, providing the individual with information about whether a given substance can be ingested. The sense of taste (often together with the sense of smell) is caused by the action chemical properties substances dissolved in saliva or water, on taste buds (taste buds) located on the surface of the tongue, the back of the pharynx, the palate and the epiglottis. The taste classification system is represented by the “Hanning Tetrahedron” (Fig. 5), in which there are four main tastes (sweet , sour, salty, bitter).SweetSaltyFig. 5. “Hanning Tetrahedron” They are located in the corners of the tetrahedron (quadrangular pyramid), and all other taste sensations are located on the planes of the Tetrahedron and represent them as combinations of two or more basic taste sensations. Cutaneous sensitivity, or touch, is the most widely represented and widespread type of sensitivity. The familiar sensation that occurs when an object touches the surface of the skin is not an elementary tactile sensation. It is the result of a complex combination of four other, simpler types of sensations: pressure, pain, heat and cold, and for each of them there is a specific type of receptors, unevenly located in different parts of the skin surface. The presence of such receptors can be found in almost all areas of the skin. However, the specialization of skin receptors has not yet been accurately established. It is unclear whether there are receptors exclusively designed to perceive one influence, generating differentiated sensations of pressure, pain, cold or heat, or whether the quality of the resulting sensation may vary depending on the state of the same receptor, as well as on the nature of the property affecting it. It is only known that the strength and quality of skin sensations themselves are relative. For example, when the surface of one area of ​​skin is simultaneously exposed to warm water, its temperature is perceived differently depending on what kind of water we act on the adjacent area of ​​skin. If it is cold, then on the first part of the skin there is a feeling of warmth, if it is hot, then a feeling of cold. Temperature receptors, as a rule, have two threshold values: they respond to high and low magnitude impacts, but do not respond to medium ones. Using the examples of kinesthetic sensations and feelings of balance, we can confirm the fact that not all sensations are conscious. In everyday speech that we use, there is no word that denotes sensations coming, for example, from receptors located in the muscles and working when they contract or stretch. Nevertheless, these sensations still exist, providing control of movements, assessment of the direction and speed of movement, and the magnitude of the distance. They are formed automatically, enter the brain and regulate movements at a subconscious level. To designate them in science, a word has been adopted that comes from the concept of “movement” - kinetics, and in this regard they are called kinesthetic. Without sensations of this kind, we would experience great difficulties associated with the simultaneous coordination of movements various parts body, maintaining posture, balance, controlling various involuntary movements (unconditioned reflex reactions, skills, etc.), because they all include motor moments that are performed automatically and very quickly. In addition to muscles, receptors for kinesthetic sensations are located in other organs. For example, the formation of sensations that help maintain and maintain balance occurs due to the presence of special balance receptors present in the inner ear. The feeling of acceleration or deceleration of movements depends on the work of these receptors. There is evidence that with the help of ordinary senses a person perceives stimuli that are beyond the lower threshold of his sensitivity. These stimuli (they are called subsensory) can even influence conscious sensations. This proves the existence of human sensitivity to stimuli that are not consciously felt. With the help of such sensitivity, we clarify, for example, the localization of sound. Physiologist G.V. Gershuni, in particular, writes that “immediately after a concussion, when auditory sensations are either completely absent or appear only when exposed to very strong sounds, the body’s responses occur such as a change in the spontaneous electrical activity of the cerebral cortex - the appearance of rhythms of higher frequencies... a change in the potential difference of the skin (galvanic skin reaction) and the cochlear-pupillary reflex - a change in the diameter of the pupil under the influence of sound.” The zone of inaudible sounds that cause the cochlear-pupillary reflex was called by Gershuni the “subsensory region.” During the stages of gradual hearing restoration, this zone increases, and with complete normalization it decreases. Other involuntary reactions recorded during the pathological process behave in a similar way. Normally, the limits of the subsensory area significantly depend on the state of the person and for the cochlear-pupillary reflex range from 5 to 12 dB. The entire group of exteroceptive sensations is conventionally divided into two subgroups: contact and distant sensations. Contact sensations are caused by the direct impact of an object on the sense organs . Examples of contact sensations are taste and touch. Distant sensations reflect the qualities of objects located at some distance from the sense organs. These senses include hearing and vision. It should be noted that the sense of smell, according to many authors, occupies an intermediate position between contact and distant sensations, since formally olfactory sensations arise at a distance from the object, but at the same time, the molecules characterizing the smell of the object, with which the olfactory receptor comes into contact, undoubtedly belong to this item. This is the duality of the position occupied by the sense of smell in the classification of sensations. Since a sensation arises as a result of the influence of a certain physical stimulus on the corresponding receptor, the primary classification of sensations, which we have considered, proceeds, naturally, from the type of receptor that gives the sensation of a given quality, or “ modality." However, there are sensations that cannot be associated with any specific modality. Such sensations are called intermodal. These include, for example, vibration sensitivity, which connects the tactile-motor sphere with the auditory sphere. The sensation of vibration is sensitivity to vibrations caused by a moving body. According to most researchers, the vibration sense is an intermediate, transitional form between tactile and auditory sensitivity. In particular, some authors believe that tactile-vibration sensitivity is one of the forms of sound perception. With normal hearing, it does not appear particularly prominent, but with damage to the auditory organ, this function is clearly manifested. Vibration sensitivity acquires particular practical importance in cases of damage to vision and hearing. It plays a big role in the lives of deaf and deaf-blind people. Deaf-blind people, thanks to the high development of vibration sensitivity, learned about the approach of a truck and other types of transport at a great distance. In the same way, through the vibration sense, deaf-blind people recognize when someone enters their room. Consequently, sensations, being the simplest type of mental processes, are in fact very complex and have not been fully studied. Interoceptive sensations - combine signals reaching us from the internal environment of the body, sensitivity to its own metabolic processes (hunger, thirst, suffocation, etc.). Usually they are isolated at the subsensory (unconscious) subcortical level and are realized only in the case of a significant violation normal condition organism, violation of the necessary constancy of its internal environment (homeostasis). They arise due to receptors located on the walls of the stomach and intestines, heart and circulatory system and other internal organs. Interoceptive sensations are among the least conscious and most diffuse forms of sensations and always retain their proximity to emotional states. It should also be noted that interoceptive sensations are often called organic. Proprioceptive sensations (“deep sensitivity”) are sensations that convey information about the position of the body in space and the position of the musculoskeletal system, ensure the regulation of our movements. These sensations create the basis of human movements, playing a decisive role in their regulation. This group of sensations includes the feeling of balance, or static sensation, as well as motor, or kinesthetic, sensation. Peripheral receptors for this sensitivity are located in muscles and joints (tendons, ligaments) and are called Paccini corpuscles. Peripheral receptors for the sensation of balance are located in the semicircular canals of the inner ear. It should be noted that there are other approaches to the classification of sensations. An attempt to create a genetic classification of sensations was made by the English neurologist H. Head, who identified the more ancient - protopathic and younger - epicritic sensitivity. Protopathic sensations (Greek protos - first, primary, pathos - illness, suffering) - phylogenetically these are more ancient sensations, primitive and undifferentiated, mixed with emotions and localized. More often this concept is used in relation to skin sensitivity. This includes organic sensations (hunger, thirst, etc.). Epicritic sensations (Greek Epikrisis - judgment, decision) - phylogenetically new sensations. They are characterized by a lower threshold of irritation, the ability to sense light touches, precise localization of external irritation, and more perfect recognition of the quality of the external stimulus. (C) Information published on the site
These include all the main types of human sensations. Types of sensations are classified according to modality, location of receptors, and contact with the stimulus. - Conclusion -

The vital role of sensations is to promptly and quickly convey to the central nervous system, as the main organ of activity control, information about the state of the external and internal environment, the presence of biologically significant factors in it.

The life of every person is complex and multifaceted. It is revealed through a number of important processes. They can be conditionally divided into social and business activity of the individual, culture, medicine, sports, communication, interpersonal relationships, scientific and research activities, entertainment and recreation.

The full course of all the above processes is problematic, and sometimes even impossible to imagine without the involvement of all our senses. In this regard, it is necessary to evaluate the role of sensations in a person’s life, since sometimes this knowledge helps in organizing the prosperous existence of an individual in society and achieving success in a business environment.

So, sensation is the process of reflecting individual properties of objects in the objective world, both the external environment and one’s own body, arising from their direct impact on receptors (sense organs). This is a process of primary information processing, characteristic of both animals and humans. With the help of sensations, the subject reflects light, color, sounds, noises, heat, cold, smells, tastes. Sensations are a prerequisite for the creation of images and their cognition.

There are several classifications of types of sensations. According to modality (types of analyzers), sensations are distinguished: visual, auditory, tactile (tactile, temperature and pain), olfactory and gustatory. Intermodal sensations are also distinguished.

The classification of sensations based on the nature of reflection and location of receptors was presented by the English physiologist C. Sherrington. Based on the anatomical location of the receptors, sensations are divided into three classes: interoceptive (receptors are located in the internal environment of the body), proprioceptive (receptors are located in the muscles, tendons and joint capsules) and exteroceptive (receptors are located on the surface of the body). Exteroceptive ones include: contact (taste, touch) and distant (smell, hearing, vision). A.R. Luria supplements the final series with two categories: intermodal (intermediate) and non-digital types of sensations.

By origin (genetic classification by X. Head) they distinguish: protopathic and epicritic sensations.

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The physiological basis of sensations is the activity of complex complexes of anatomical structures called analyzers. The concept of an analyzer (a device that performs the function of distinguishing external stimuli) was introduced by Academician I.P. Pavlov. He also examined the structure of the analyzers and came to the conclusion that they consist of three parts:

1) peripheral section, called a receptor (a receptor is the perceiving part of the analyzer, a specialized nerve ending, its main function is the transformation of external energy into a nervous process);

2) nerve pathways(afferent department - transmits excitation to the central department; efferent department - it transmits a response from the center to the periphery);

3) analyzer core- cortical sections of the analyzer (they are also called the central sections of the analyzers), in which the processing of nerve impulses coming from the peripheral sections occurs. The cortical part of each analyzer includes an area that represents a projection of the periphery (i.e., a projection of the sensory organ) in the cerebral cortex, since certain receptors correspond to certain areas of the cortex.

The feeling is psychological process reflections of individual properties and qualities of environmental objects. peace.

They provide sensory knowledge of the world. More complex cognitive processes are based on the process of sensation. Sensations are constantly mediated by knowledge. Sensations reflect the objective qualities of objects (t°, taste, smell), their intensity and duration. Sensations provide the collection of sensory material, on the basis of which mental images are built.

1. exteroceptive (on the surface of the body) - visual, auditory, olfactory, gustatory and skin;

2. interoreceptive (in internal organs) - internal pain, vibration;

3. proprioceptive (in muscles, ligaments and tendons) - static, motor.

Perception is the mental process of reflecting objects of the external world in a holistic form. It is caused by complex stimuli acting simultaneously, is carried out by the simultaneous and coordinated activity of several analyzers and occurs with the participation of the associative parts of the cerebral cortex and speech centers.

The process of forming a mental image during perception is a combination of recognition, understanding and comprehension, as well as attributing an object to a certain category. Perception is influenced by past experience, knowledge, and attitudes. Perception is characterized by: 1) meaningfulness; 2) integrity; 3) structure (objectivity); 4) selectivity; 5) constancy; 6) apperception (past experience).

Perception and its influence on learning.

Perception, perception(from lat. perceptio) is a cognitive process that forms a subjective picture of the world. This is a mental process consisting of the reflection of an object or phenomenon as a whole with its direct impact on the receptor surfaces of the sense organs. Perception is one of the biological mental functions, defining the complex process of receiving and transforming information received through the senses, forming a subjective holistic image of an object that affects analyzers through a set of sensations initiated by this object. As a form of sensory reflection of an object, perception includes the detection of the object as a whole, the discrimination of individual features in the object, the identification of informative content in it that is adequate to the purpose of the action, and the formation of a sensory image.

Perception is much more than the transmission of neural impulses by the nervous system to certain areas of the brain. Perception also presupposes the subject’s awareness of the very fact of stimulation and certain ideas about it, and for this to happen, it is first necessary to sense the “input” of sensory information, that is, to experience a sensation. In other words, perception is the process of comprehending the stimulation of sensory receptors. There are reasons to view perception as a task that involves focusing on a sensory signal, analyzing and interpreting it to create a meaningful representation of the world around us.

Feeling- a cognitive process in which, as a result of the direct influence of stimuli on the senses, the reflection of individual properties of objects in the objective world occurs.

Sensations are considered the simplest and primary form of orientation of the body in the surrounding world. All living beings with a nervous system have the ability to sense sensations.. Lowly organized animals reflect only individual that have direct significance for their life properties of objects and phenomena. The same for a newborn. In the first weeks of life, he reacts only to individual properties of objects. These facts indicate that sensation is the initial form of development of cognitive activity.

Unlike animals, human sensations are influenced by socio-historical development. People’s feelings are mediated by the practical activities they carry out, consciousness, individual characteristics. In sensation we can roughly distinguish objective And subjective side. The objective side is associated with the characteristics of the influences of the external world, with the peculiarities of the properties of reflected objects and phenomena. The subjective side of sensations is determined by the individual characteristics of the sense organs, which are determined by both genetic and factors acquired during life. It has been proven that the nature of sensations can change under the influence of the activity being performed, illness, special exercises, etc.

Physiological basis of sensations. Sensation can only occur when an object impacts a sensory organ. A sense organ is an anatomical and physiological apparatus located on the periphery of the body or in internal organs and designed to receive the effects of certain stimuli from the external and internal environment.

The physiological basis of sensation has been deeply and systematically studied within the framework of the reflex concept of I. M. Sechenov and I. P. Pavlov. It is shown that in essence sensation is a holistic reflex, uniting the peripheral and central parts of the nervous system. I. P. Pavlov introduced the concept "analyzer" and showed that the activity of analyzers reveals the physiological mechanism of the occurrence of sensations. Analyzer– a nervous formation that carries out the perception, analysis and synthesis of external and internal stimuli acting on the body.

The analyzer consists of 3 blocks:

1). Receptor– the peripheral part of the analyzer, which performs the function of receiving information from stimuli acting on the body. The receptor is designed to perceive a certain stimulus from the external or internal environment and to convert its energy from a physical or chemical form into the form of nervous excitation (impulse).

2). Afferent(conductive) and efferent(outgoing) paths. Afferent pathways are areas of the nervous system through which the resulting excitation enters the central nervous system. Efferent pathways are areas along which the response impulse (based on information processed in the central nervous system) is transmitted to the receptors, determining their motor activity (reaction to the stimulus).

3). Cortical projection zones(central section of the analyzer) - areas of the cerebral cortex in which nerve impulses received from receptors are processed. Each analyzer in the cerebral cortex has its own “representation” (projection), where the analysis and synthesis of information of a certain sensitivity (sensory modality) occurs.

Thus, sensation is essentially a mental process that occurs when processing information received by the brain.

Depending on the type of sensitivity, there are visual, auditory, olfactory, gustatory, cutaneous, motor and others analyzers. Each analyzer singles out stimuli of only a certain type from the entire variety of influences. For example, a hearing analyzer identifies waves generated by vibrations of air particles. The taste analyzer generates an impulse as a result of " chemical analysis» molecules dissolved in saliva, and olfactory molecules in the air. The visual analyzer perceives electromagnetic waves, the characteristics of which give rise to a particular visual image.

The transformation of the energy of external influence into a nerve impulse, its conduction into the brain, the formation of sensation and response - all this unfolds in time. The period of time from the application of irritation to the occurrence of a response is called latent(hidden) period. It is different for different sensations. Thus, the latent period of tactile sensations is 130 milliseconds, pain – 370.

A brief excursion into the development of the concept of sensations

Feel- “the law of specific energy of the sensory organ,” that is, the sensation does not depend on the nature of the stimulus, but on the organ or nerve in which the process of irritation occurs. The eye sees, the ear hears. The eye cannot see, but the ear cannot see. 1827

The objective world is fundamentally unknowable. The result of the sensation process is a partial, that is, partial image of the world. Everything we perceive is a process of specificity of influence on the senses. “Mental processes” Wekker L.M.

Power-law dependence of changes in sensations when the intensity of stimuli changes (Stevens' law)

The lower and upper absolute thresholds of sensation (absolute sensitivity) and thresholds of discrimination (relative sensitivity) characterize the limits of human sensitivity. Along with this, there is a distinction operational sensation thresholds— the magnitude of the difference between the signals at which the accuracy and speed of their discrimination reaches a maximum. (This value is an order of magnitude greater than the discrimination threshold.)

2. Adaptation. The sensitivity of the analyzer is not stable, it varies depending on different conditions.

Thus, when entering a poorly lit room, we initially do not distinguish objects, but gradually the sensitivity of the analyzer increases; being in a room with any odors, after a while we stop noticing these odors (the sensitivity of the analyzer decreases); when we move from a poorly lit space to a brightly lit one, the sensitivity of the visual analyzer gradually decreases.

A change in the sensitivity of the analyzer as a result of its adaptation to the strength and duration of the current stimulus is called adaptation(from lat. adaptatio- device).

Different analyzers have different speed and range of adaptation. Adaptation to some stimuli occurs quickly, to others - more slowly. The olfactory and tactile senses adapt faster (from the Greek. taktilos- touch) analyzers. The auditory, gustatory and visual analyzers adapt more slowly.

Full adaptation to the smell of iodine occurs in a minute. After three seconds, the pressure sensation reflects only 1/5 of the force of the stimulus. (Searching for glasses pushed onto the forehead is one example of tactile adaptation.) For complete dark adaptation of the visual analyzer, 45 minutes are needed. However, visual sensitivity has the largest range of adaptation - it changes 200,000 times.

The phenomenon of adaptation has expedient biological significance. It helps to reflect weak stimuli and protects analyzers from excessive exposure to strong ones. Adaptation, as getting used to constant conditions, provides an increased orientation to all new influences. Sensitivity depends not only on the strength of external stimuli, but also on internal states.

3. Sensitization. Increasing the sensitivity of analyzers under the influence of internal (mental) factors is called sensitization(from lat. sensibilis- sensitive). It can be caused by: 1) the interaction of sensations (for example, weak taste sensations increase visual sensitivity. This is explained by the interconnection of analyzers, their systemic work); 2) physiological factors (the state of the body, the introduction of certain substances into the body; for example, vitamin “A” is essential to increase visual sensitivity); 3) the expectation of a particular influence, its significance, a special attitude towards distinguishing between stimuli; 4) exercise, experience (thus, tasters, by specially exercising their taste and olfactory sensitivity, distinguish between different types of wines and teas and can even determine when and where the product was made).

In people deprived of any type of sensitivity, this deficiency is compensated (compensated) by increasing the sensitivity of other organs (for example, increasing auditory and olfactory sensitivity in the blind). This is the so-called compensatory sensitization.

Strong stimulation of some analyzers always reduces the sensitivity of others. This phenomenon is called desensitization. Thus, increased noise levels in “loud workshops” reduce visual sensitivity; desensitization of visual sensitivity occurs.

Rice. 4. . The inner squares produce sensations of varying intensities of gray. In reality they are the same. Sensitivity to the properties of phenomena depends on adjacent and sequential contrasting influences.

4. . One of the manifestations of the interaction of sensations is their contrast(from lat. contrast- sharp contrast) - increased sensitivity to some properties under the influence of other, opposite, properties of reality. Thus, the same gray figure appears dark on a white background, but white on a black background (Fig. 4).

5. Synesthesia. An associative (phantom) foreign-modal sensation that accompanies a real one (the sight of a lemon causes a sour sensation) is called synesthesia(from Greek synaisthesis- shared feeling).

Rice. 5.

Features of certain types of sensations.

Visual sensations. Colors perceived by humans are divided into chromatic (from the Greek. chroma- color) and achromatic - colorless (black, white and intermediate shades of gray).

For visual sensations to occur, electromagnetic waves must act on the visual receptor—the retina (a collection of photosensitive nerve cells located at the bottom of the eyeball). The central part of the retina is dominated by nerve cells called cones, which provide the sense of color. At the edges of the retina, rods, sensitive to changes in brightness, predominate (Fig. 5, 6).

Rice. 6. . Light penetrates the light-sensitive receptors - rods (reacting to changes in brightness) and cones (reacting to different lengths of electromagnetic waves, i.e. chromatic (color) influences), bypassing the ganglion and bipolar cells, which carry out the primary elementary analysis of nerve impulses traveling already from the retina. For visual stimulation to occur, it is necessary that the electromagnetic energy falling on the retina be absorbed by its visual pigment: rod pigment - rhodopsin and cone pigment - iodopsin. Photochemical transformations in these pigments give rise to the visual process. At all levels of the visual system, this process: manifests itself in the form of electrical potentials, which are recorded by special devices - an electroretinograph.

Light (electromagnetic) rays of different lengths cause different color sensations. Color is a mental phenomenon - human sensations caused by different frequencies of electromagnetic radiation (Fig. 7). The eye is sensitive to the region of the electromagnetic spectrum from 380 to 780 nm (Fig. 8). The 680 nm wavelength gives the sensation of red; 580 - yellow; 520 - green; 430 - blue; 390 - purple flowers.

Electromagnetic radiation.

Rice. 7. Electromagnetic spectrum and its visible part (NM - nanometer - one billionth of a meter)

Rice. 8. .

Rice. 9. . Opposite colors are called complementary colors - when mixed they form White color. Any color can be obtained by mixing two bordering colors. For example: red - a mixture of orange and purple).

The mixing of all perceived electromagnetic waves gives the sensation of white color.

There is a three-component theory of color vision, according to which the entire variety of color sensations arises as a result of the work of only three color-perceiving receptors - red, green and blue. Cones are divided into groups of these three colors. Depending on the degree of excitation of these color receptors, different color sensations arise. If all three receptors are excited to the same extent, the sensation of white color occurs.

Rice. 10. .

Our eye is sensitive to different parts of the electromagnetic spectrum unequal sensitivity. It is most sensitive to light rays with a wavelength of 555 - 565 nm (light green color tone). The sensitivity of the visual analyzer in twilight conditions moves towards more short waves— 500 nm (blue color). These rays begin to appear lighter (Purkinje phenomenon). The rod apparatus is more sensitive to ultraviolet color.

In conditions of sufficiently bright lighting, the cones are turned on and the rod apparatus is turned off. In low light conditions, only the sticks are activated. Therefore, in twilight lighting, we do not distinguish chromatic color, the coloring of objects.

Rice. eleven. . Information about events in the right half of the visual field enters the left occipital lobe from the left side of each retina; information about the right half of the visual field is sent to the left occipital lobe from the right parts of both retinas. Redistribution of information from each eye occurs as a result of the crossing of part of the optic nerve fibers in the chiasm.

Visual stimulation is characterized by some inertia. This is the reason for the persistence of a trace of light stimulation after the cessation of exposure to the stimulus. (This is why we do not notice the breaks between frames of the film, which turn out to be filled with traces from the previous frame.)

People with weakened cone apparatus have difficulty distinguishing chromatic colors. (This disadvantage, described by the English physicist D. Dalton, is called color blindness). Weakening of the rod apparatus makes it difficult to see objects in dim light (this deficiency is called “night blindness.”)

For the visual analyzer, the difference in brightness is essential - contrast. The visual analyzer is capable of distinguishing contrast within certain limits (optimum 1:30). Strengthening and weakening of contrasts is possible through the use of various means. (To identify subtle relief, shadow contrast is enhanced by lateral lighting and the use of light filters.)

The color of each object is characterized by those rays of the light spectrum that the object reflects. (A red object, for example, absorbs all rays of the light spectrum except red, which are reflected by it.) The color of transparent objects is characterized by the rays that they transmit. Thus, the color of any object depends on what rays it reflects, absorbs and transmits.

Rice. 12.: 1 - chiasmus; 2 - visual thalamus; 3 - occipital lobe of the cerebral cortex.

In most cases, objects reflect electromagnetic waves of different lengths. But the visual analyzer does not perceive them separately, but collectively. For example, exposure to red and yellow flowers perceived as Orange color, colors are mixed.

Signals from photoreceptors - light-sensitive formations (130 million cones and rods) arrive to 1 million larger (ganglionic) neurons of the retina. Each ganglion cell sends its process (axon) to the optic nerve. Impulses traveling to the brain along the optic nerve receive primary processing in the diencephalon. Here the contrast characteristics of the signals and their time sequence are enhanced. And from here, nerve impulses enter the primary visual cortex, localized in the occipital region of the cerebral hemispheres (Brodmann fields 17 - 19) (Fig. 11, 12). Here, individual elements of the visual image are highlighted - points, angles, lines, directions of these lines. (Established by Boston researchers and 1981 Nobel Prize winners Hubel and Wiesel.)

Rice. 13. Optograph, taken from the retina of a dog's eye after its death. This indicates the screen principle of the functioning of the retina.

The visual image is formed in the secondary visual cortex, where sensory material is compared (associated) with previously formed visual standards - the image of the object is recognized. (0.2 seconds pass from the beginning of the stimulus to the appearance of the visual image.) However, already at the level of the retina, a screen display of the perceived object occurs (Fig. 13).

Auditory sensations. There is an opinion that we receive 90% of information about the world around us through vision. This can hardly be calculated. After all, what we see with the eye must be covered by our conceptual system, which is formed integratively, as a synthesis of all sensory activity.

Rice. 14. Deviations from normal vision - myopia and farsightedness. These deviations can usually be compensated for by wearing glasses with specially selected lenses.

The work of the auditory analyzer is no less complex and important than the work of the visual analyzer. The main flow of speech information goes through this channel. A person perceives sound 35 - 175 ms after it reaches the auricle. Another 200 - 500 ms is necessary for maximum sensitivity to a given sound to occur. It also takes time to turn the head and appropriately orient the auricle in relation to the source of the weak sound.

From the tragus of the auricle, the oval auditory canal deepens into the temporal bone (its length is 2.7 cm). Already in the oval passage, the sound is significantly enhanced (due to resonant properties). The oval passage is closed by the tympanic membrane (its thickness is 0.1 mm and its length is 1 cm), which constantly vibrates under the influence of sound. The eardrum separates the outer ear from the middle ear - a small chamber with a volume of 1 cm³ (Fig. 15).

The middle ear cavity is connected to the inner ear and the nasopharynx. (The air coming from the nasopharynx balances the external and internal pressure on the eardrum.) In the middle ear, sound is amplified many times over by a system of ossicles (the malleus, incus and stapes). These ossicles are supported by two muscles that tighten when sounds are too loud and weaken the ossicles, protecting the hearing aid from injury. With weak sounds, the muscles increase the work of the bones. The sound intensity in the middle ear increases 30 times due to the difference between the area of ​​the eardrum (90 mm2), to which the malleus is attached, and the area of ​​the base of the stapes (3 mm2).

Rice. 15. . Sound vibrations from the external environment pass through the ear canal to the eardrum, located between the outer and middle ear. The eardrum transmits vibrations and the bony mechanism of the middle ear, which, acting on a lever principle, amplifies the sound by about 30 times. As a result, slight changes in pressure at the eardrum are transmitted in a piston-like motion to the oval window of the inner ear, which causes fluid movement in the cochlea. Acting on the elastic walls of the cochlear canal, the movement of the fluid causes an oscillatory movement of the auditory membrane, or more precisely, a certain part of it that resonates at the corresponding frequencies. At the same time, thousands of hair-like neurons transform the oscillatory movement into electrical impulses of a certain frequency. Round window and the Eustachian tube coming from it serves to equalize the pressure with the external environment; entering the nasopharynx area, the Eustachian tube opens slightly during swallowing movements.

The purpose of the auditory analyzer is to receive and analyze signals transmitted by vibrations of an elastic medium in the range of 16-20,000 Hz (sound range).

The receptor section of the auditory system is the inner ear, the so-called cochlea. It has 2.5 turns and is divided transversely by a membrane into two isolated channels filled with fluid (perilymph). Along the membrane, which narrows from the lower curl of the cochlea to its upper curl, there are 30 thousand sensitive formations - cilia - they are sound receptors, forming the so-called organ of Corti. The primary separation of sound vibrations occurs in the cochlea. Low sounds affect long cilia, high sounds affect short ones. The vibrations of the corresponding sound cilia create nerve impulses that enter the temporal part of the brain, where complex analytical and synthetic activity is carried out. The most important verbal signals for humans are encoded in neural ensembles.

The intensity of the auditory sensation—loudness—depends on the intensity of the sound, that is, on the amplitude of vibrations of the sound source and on the pitch of the sound. The pitch of the sound is determined by the frequency of vibrations of the sound wave, the timbre of the sound is determined by overtones (additional vibrations in each main phase) (Fig. 16).

The pitch of a sound is determined by the number of vibrations of the sound source in 1 second (1 vibration per second is called a hertz). The organ of hearing is sensitive to sounds in the range from 20 to 20,000 Hz, but the greatest sensitivity lies in the range of 2000 - 3000 Hz (this is the pitch corresponding to the cry of a frightened woman). A person does not feel the sounds of the lowest frequencies (infrasounds). The sound sensitivity of the ear begins at 16 Hz.

Rice. 16. . The intensity of a sound is determined by the amplitude of the vibration of its source. Height - vibration frequency. Timbre - additional vibrations (overtones) in each “time” (middle picture).
However, subthreshold low-frequency sounds affect a person’s mental state. Thus, sounds with a frequency of 6 Hz cause dizziness, a feeling of fatigue, depression in a person, and sounds with a frequency of 7 Hz can even cause cardiac arrest. Getting into the natural resonance of the work of internal organs, infrasounds can disrupt their activity. Other infrasounds also selectively affect the human psyche, increasing suggestibility, learning ability, etc.

Sensitivity to high-frequency sounds in humans is limited to 20,000 Hz. Sounds lying beyond the upper threshold of sound sensitivity (i.e. above 20,000 Hz) are called ultrasounds. (Animals have access to ultrasonic frequencies of 60 and even 100,000 Hz.) However, since sounds up to 140,000 Hz are found in our speech, it can be assumed that they are perceived by us at a subconscious level and carry emotionally significant information.

The thresholds for distinguishing sounds by their height are 1/20 of a semitone (that is, up to 20 intermediate steps differ between the sounds produced by two adjacent piano keys).

In addition to high-frequency and low-frequency sensitivity, there are lower and upper thresholds of sensitivity to sound intensity. With age, sound sensitivity decreases. Thus, to perceive speech at the age of 30, a sound volume of 40 dB is required, and to perceive speech at the age of 70, its volume must be at least 65 dB. The upper threshold of hearing sensitivity (in terms of volume) is 130 dB. Noise above 90 dB is harmful to humans. Sudden loud sounds that hit the autonomic nervous system and lead to a sharp narrowing of the lumen of blood vessels, increased heart rate and an increase in the level of adrenaline in the blood are also dangerous. The optimal level is 40 - 50 dB.

Tactile sensation(from Greek taktilos- touch) - sensation of touch. Tactile receptors (Fig. 17) are most numerous on the tips of the fingers and tongue. If on the back two points of contact are perceived separately only at a distance of 67 mm, then at the tip of the fingers and tongue - at a distance of 1 mm (see table).
Spatial thresholds of tactile sensitivity.

Rice. 17. .

High sensitivity zone	Low sensitivity zone
Tip of the tongue - 1 mm	Sacrum - 40.4 mm
Terminal phalanges of fingers - 2.2 mm	Buttock - 40.5 mm
Red part of lips - 4.5 mm	Forearm and lower leg - 40.5 mm
Palmar side of the hand - 6.7 mm	Sternum - 45.5 mm
Terminal phalanx of the big toe - 11.2 mm	Neck below the back of the head - 54.1 mm
The back side of the second phalanges of the toes is 11.2 mm	Lumbar - 54.1 mm
The back side of the first phalanx of the big toe is 15.7 mm	Back and middle of neck - 67.6 mm
	Shoulder and hip - 67.7 mm

The threshold of spatial tactile sensitivity is the minimum distance between two point touches at which these impacts are perceived separately. The range of tactile discrimination sensitivity is from 1 to 68 mm. High sensitivity zone - from 1 to 20 mm. Low sensitivity zone - from 41 to 68 mm.

Tactile sensations combined with motor ones form tactile sensitivity, which underlies objective actions. Tactile sensations are a type of skin sensation, which also includes temperature and pain sensations.

Kinaesthetic (motor) sensations.

Rice. 18. (according to Penfield)

Actions are associated with kinesthetic sensations (from the Greek. kineo- movement and aesthesia- sensitivity) - sensation of the position and movement of parts of one’s own body. Labor movements of the hand were of decisive importance in the formation of the brain and the human psyche.

Based on muscle-joint sensations, a person determines compliance or non-compliance
their movements to external circumstances. Kinaesthetic sensations perform an integrating function throughout the human sensory system. Well-differentiated voluntary movements are the result of the analytical and synthetic activity of a large cortical zone located in the parietal region of the brain. The motor area of ​​the cerebral cortex is especially closely connected with the frontal lobes of the brain, which perform intellectual and speech functions, and with the visual areas of the brain.

Rice. 19. .

Muscle spindle receptors are especially numerous in the fingers and toes. When moving various parts of the body, arms, fingers, the brain constantly receives information about their current spatial position (Fig. 18), compares this information with the image of the final result of the action and carries out appropriate correction of movement. As a result of training, images of intermediate positions of various parts of the body are generalized into a single general model of a specific action - the action is stereotyped. All movements are regulated based on motor sensations, based on feedback.

Motor physical activity of the body is essential for optimizing brain function: proprioceptors of skeletal muscles send stimulating impulses to the brain and increase the tone of the cerebral cortex.

Rice. 20.: 1. Limits of permissible vibrations for individual parts of the body. 2. Limits of permissible vibrations acting on the entire human body. 3. Boundaries of weakly felt vibrations.

Static sensations- sensations of the position of the body in space relative to the direction of gravity, a sense of balance. The receptors for these sensations (gravitoreceptors) are located in the inner ear.

Receptor rotational body movements are cells with hair endings located in semicircular canals inner ear, located in three mutually perpendicular planes. When the rotational movement accelerates or decelerates, the fluid filling the semicircular canals exerts pressure (according to the law of inertia) on the sensitive hairs, in which a corresponding excitation is caused.

Moving into space in a straight line reflected in otolithic apparatus. It consists of sensitive cells with hairs, above which are located otoliths (pads with crystalline inclusions). Changing the position of the crystals signals the brain the direction of the rectilinear movement of the body. The semicircular canals and otolithic apparatus are called vestibular apparatus. It is connected to the temporal region of the cortex and to the cerebellum through the vestibular branch of the auditory nerve (Fig. 19). (Strong overexcitation of the vestibular apparatus causes nausea, since this apparatus is also connected with internal organs.)

Vibration sensations arise as a result of reflection of vibrations from 15 to 1500 Hz in an elastic medium. These vibrations are reflected by all parts of the body. Vibrations are tiring and even painful for humans. Many of them are unacceptable (Fig. 20).

Rice. 21. . The olfactory bulb is the brain center of smell.

Olfactory sensations arise as a result of irritation by particles of odorous substances in the air of the mucous membrane of the nasal cavity, where the olfactory cells are located.
Substances that irritate the olfactory receptors penetrate into the nasopharyngeal cavity from the nose and nasopharynx (Fig. 21). This allows you to determine the smell of a substance both from a distance and if it is in the mouth.

Rice. 22. . Relative concentration of taste receptors on the surface of the tongue.

Taste sensations. The entire variety of taste sensations consists of a combination of four tastes: bitter, salty, sour and sweet. Taste sensations are caused by chemicals dissolved in saliva or water. Taste receptors are nerve endings located on the surface of the tongue - taste buds. They are located unevenly on the surface of the tongue. Certain areas of the surface of the tongue are most sensitive to individual taste influences: the tip of the tongue is more sensitive to sweet, the back to bitter, and the edges to sour (Fig. 22).

The surface of the tongue is sensitive to touch, that is, it participates in the formation of tactile sensations (the consistency of food affects the taste sensations).

Temperature sensations arise from irritation of skin thermoreceptors. There are separate receptors for the sensation of heat and cold. On the surface of the body they are located in some places more, in others - less. For example, the skin of the back and neck is most sensitive to cold, and the tips of the fingers and tongue are most sensitive to hot. Different areas of the skin themselves have different temperatures(Fig. 23).

Painful sensations are caused by mechanical, temperature and chemical influences that have reached above-threshold intensity. Pain sensations are largely associated with subcortical centers, which are regulated by the cerebral cortex. Therefore, they can be inhibited to some extent through a second signaling system.

Rice. 23. (according to A.L. Slonim)

Expectations and fears, fatigue and insomnia increase a person’s sensitivity to pain; with deep fatigue, the pain dulls. Cold intensifies and warmth reduces pain. Pain, temperature, tactile sensations and pressure sensations are skin sensations.

Organic sensations- sensations associated with interoceptors located in the internal organs. These include feelings of satiety, hunger, suffocation, nausea, etc.

This classification of sensations was introduced by the famous English physiologist C.S. Sherrington (1906);

There are three types of visual sensations: 1) photopic - daytime, 2) scotopic - nighttime and 3) mesopic - twilight. The greatest photopic visual acuity is located in the central visual field; it corresponds to the central, foveal region of the retina. In scotopic vision, maximum light sensitivity is provided by the paramolecular regions of the retina, which are characterized by the greatest concentration of rods. They provide the greatest light sensitivity.

Sources and literature

• Enikeev M.I. Psychological encyclopedic dictionary. M., 2010.
• Zinchenko T.P., Kondakov I.M. Psychology. Illustrated Dictionary. M. 2003.