Sensation is a reflection of the properties of objects of the objective world, arising from their direct impact on the sense organs, this is, firstly, the initial moment of the sensorimotor reaction; secondly, the result of conscious activity.
The emergence of sensation is directly related to the work of human receptors. A receptor is an organ specially adapted for the reception of stimuli; it is more easily irritated than other organs or nerve fibers; its sensitivity is especially high. In addition, each receptor is specialized in relation to a particular stimulus.
In the process of biological evolution, the sense organs themselves were formed in the real relationship of the organism with the environment, under the influence of the outside world. The impact of the outside world forms the receptors themselves. Receptors are, as it were, anatomically fixed in the structure of the nervous system, imprints of the effects of irritation processes.
In sensation, absolute and differential thresholds are distinguished. Not every stimulus causes a sensation, but only one whose intensity has overcome the threshold of sensation. This minimum stimulus intensity at which a sensation occurs is called the lower absolute threshold. Along with the lower, there is also an upper absolute threshold, i.e. the maximum intensity possible to experience a given quality.
The thresholds of sensitivity are significantly shifted depending on the attitude of a person to the task that he solves.
For the sensitivity of an organ, its physiological state is also important. The significance of physiological moments is manifested primarily in the phenomena of adaptation, in the adaptation of an organ to a long-acting stimulus. The phenomenon of contrast is also associated with adaptation, which is associated with a change in sensitivity under the influence of a previous (or accompanying) stimulus.
The differentiation and specialization of receptors does not exclude their interaction, which is expressed in the effect that stimulation of one receptor has on the thresholds of another.
Classification of sensations
organic sensations. Organic sensations include sensations of hunger, thirst, sensations coming from the cardiovascular, respiratory and reproductive systems of the body, and all sensations associated with the state of the human body.
All organic sensations have a number of common features:
They are usually associated with organic needs, which are usually first reflected in consciousness through organic sensations.
All organic sensations are more or less brightly colored.
Organic sensations, reflecting needs, are usually associated with motor impulses and are interconnected in a psychomotor unity.
Static sensations. These are sensations associated with indications of the position of our body in space, its posture, passive and active movements of the body. The central organ that regulates the balance of the body in space is the vestibular apparatus.
kinesthetic sensations. Sensations of movement of various parts of the body are caused by excitations coming from proprioreceptors located in the joints, ligaments and muscles. Through kinesthetic sensations, a person can determine the position and movement of their body parts. Impulses entering the central nervous system from proprioreceptors due to changes that occur during movement in the muscles cause reflex reactions and play a significant role in muscle tone and coordination of movements.
Skin sensitivity. Skin sensitivity is subdivided by the classical physiology of the sense organs into 4 types. These are the receptions of pain, heat, cold and touch (pressure). It is assumed that each of these types of sensitivity also has specific receptors.
Touch. Touch includes sensations of touch and pressure in unity with kinesthetic, muscular-articular sensations. The proprioceptive components of touch come from receptors located in muscles, ligaments, and articular bags. When moving, they are irritated by a change in voltage.
Olfactory sensations. Olfactory sensations arise when molecules of various substances enter the nasal cavity together with the inhaled air and are transmitted to the central nervous system through the olfactory receptor.
Taste sensations. Taste sensations, like olfactory sensations, are due to the chemical properties of substances. Taste sensations play an important role in adjusting the emotional state of a person, their role is determined by the state of the body's need for food. Arise through the taste receptor, the peripheral part of which is located in the oral cavity.
Auditory sensations. Auditory sensations are a reflection of sound waves affecting the auditory receptor, which are generated by the sounding body and represent a variable condensation and rarefaction of air.
visual sensations. Visual sensations are caused by exposure to the visual analyzer of a light wave, which differ in length and frequency of oscillations.
sensations
(receptor)
Here there is a transformation of a certain type of energy into a nervous process.
Through afferent, or centripetal, pathways, excitation is transmitted to the central section of the analyzer
Analyzer- anatomical and physiological apparatus, specialized for receiving the effects of certain stimuli from the external and internal environment and processing them into sensations
The physiological basis of sensations is laid down in the work of special nervous structures, called analyzers by I. Pavlov. Analyzers are channels through which a person receives all the information about the world (both about the external environment and about his own, internal state).
Together, the analyzers form the human sensory system.
The beginning of sensation is given by the physical process of irritation, which occurs when the signals of the external or internal environment act on the human senses: vision, smell, etc. Sensations are provided by the work of the brain. The brain is connected with the sense organs that react to "their" stimuli. In order for the brain to perceive these stimuli, they must be given to it in a certain form, namely in the form of electrical signals. The energy of stimuli of various nature (light, smell, etc.) must be converted into electrical energy. The task of translating signals of various modalities into an electrical form is solved by receptors.
A receptor is a specific neuron that receives physical signals from the external environment and signals from the internal state of a person. The work of the receptor is specialized. Each receptor works with “its own” signals: the visual receptor reacts to light stimuli, the auditory receptor to sound stimuli, and so on. But this is not a simple response. The brain requires information not only about the presence of a stimulus, but also about its characteristics (for example, on scales intense - weak, large - small, sweet - bitter, etc.). Therefore, the receptor must be able to encode these characteristics in order to transmit information about them to the brain. Such coding is implemented through the transformation of physical stimuli into electrical signals with parameters corresponding to the characteristics of the stimulus. So, for example: sensations of a pleasant voice timbre correspond to electrical signals of a sinusoidal shape; sensations of touching the hand - a successive series of rectangular electrical impulses (in this case, a light touch corresponds to a small number of impulses in a series, strong pressure - a large number of).
Encoded electrical signals of a certain form with the appropriate parameters along the nerve pathways (afferent nerves) enter the receptive zones of the cerebral cortex. Each receptor of one or another modality has its own receptive zone. The movement of signals is provided by the physiological process of excitation - the property of nerve cells (neurons) to respond to irritation. When excited, the cell moves from a state of physiological rest to activity. If the amplitude of excitation reaches a threshold value, then it spreads to neighboring parts of the nervous system. In the cerebral cortex, an electrical signal causes the simplest emotional experiences of sensations. The results of experiences in the form of a spreading excitation through the efferent nerves come to the periphery of the body (to the muscles, glands).
1.6.2 Analyzers
Functional diagram analyzer
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The analyzer is not a passive element. His work can be rebuilt under the changing influence of stimuli. In other words, the nature of the analyzer is reflexive, i.e. reflects real changes in the environment. Naturally, the nature of sensations is also reflexive. Sensations are always associated with motor components. This occurs either in the form of a vegetative reaction (narrowing of the pupils, blood vessels, etc.), or in the form of a muscular reaction (twitching of the hand, turning of the eyes, tension of the muscles of the lips, etc.).
Indeed, sensation is not limited to a simple reflection of reality in the human brain. An obligatory element of sensation (without which, in fact, it is impossible) is the body's response. This reaction may take the form of a movement or an internal process, such as a healing one. It has long been known, for example, that the singing of birds, the sound of the surf balance the nervous system; sounds of music such as "hard rock" and "rock music" often cause aggressive nervous system excitement in fans, as well as acute stomach cramps.
The body reacts to the sensations of smells. The Japanese firm "Shieydo" successfully uses "smell therapy" to increase the stress resistance of its employees. The synthesis of aromas is used in production and at home. The result - errors in the work decreased by more than 50%.
The body reacts no less sharply to a prolonged or complete absence of stimuli (sensory hunger or sensory deprivation). Sensory hunger (sensory deprivation) is a phenomenon associated with a sharp decrease in the “range” of sensations (or a complete loss) experienced by a person in situations of physical and psychological isolation.
The results of sensory hunger can be devastating to the human psyche. Having lost his hearing, Ludwig van Beethoven experienced a life drama: he shunned people, suffered deeply from loneliness: “It is not given to me to find inspiration in the company of people, in subtle conversation, in mutual frankness. Alone, completely alone! .. I must live like an outcast.
So that the operator of tracking aerial targets on the radar screen in the mode of a long and continuous review of "empty" space does not dull his vigilance, does not decrease his efficiency, a false target mark from a special imitator is "thrown" on the screen from time to time.
Sensations arise only with the direct impact of objects on the sense organs. The sense organ is an anatomical and physiological apparatus located on the periphery of the body or in the internal organs and specialized for receiving the effects of certain stimuli from the external environment and internal organs. The main part of each sense organ is the nerve endings, which are called receptors. The receptor is a part of the analyzer, the function of which is to transform external energy into a nervous process. Such sense organs as the eye, ear, uniting dozens of receptor endings. A receptor, nerves that conduct information about teasing, and a site in the cerebral cortex, which represent a single morphological structure. IP. Pavlov called the analyzer analyzer.
Each analyzer is a nervous mechanism, which consists of three parts: 1) a peripheral section - a receptor, 2) an afferent or sensory nerve (centripetal), which conducts excitation to nerve centers three (the central section of the analyzer), 3) cortical sections of the analyzer, in which is the processing of nerve impulses coming from the peripheral parts. The cork part of the analyzer includes a single region, which is a projection of the periphery in the cerebral cortex, since certain cells of the periphery (receptors) correspond to certain regions of the cortical cells. For a sensation to arise, the work of the entire analyzer as a whole is necessary.
Objects and phenomena of reality that affect our senses are called stimuli. The influence of stimuli on the sense organs is called irritation. Irritation causes excitation in the nervous tissue. Vi idchuttya arises as a reaction of the nervous system to a particular stimulus and has a reflex character. The action of the stimulus on the receptor leads to the emergence of a nerve impulse, which is transmitted along the afferent nerves to certain parts of the cerebral cortex. Reaction - the response is transmitted along the efferent (motor) nerve to the organ that responds to feelings. So, when a person touches a hot object with his hand, the signal goes to the brain and along the efferent nerves to the muscles, as a result of which they contract.
23 Feelings
Even the ancient Greeks distinguished five sense organs and their corresponding sensations: visual, auditory, tactile, olfactory and gustatory. modern science significantly expanded the concept of the types of sensations. OR. Luria believes that the classification of sensations can be carried out according to less than 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 ab in the level of their construction, on the other).
Systematic classification of sensations
According to the placement of receptors on the surface of the body or inside the body, the following types of sensations are distinguished:
1) exteroceptive;
2) interoceptive;
3) proprioceptive
exteroceptive sensation- This is the largest group of sensations. They provide signals from the outside world and form the basis for our consciousness. Exteroceptive sensations include visual, auditory, olfactory, sensory, tactile (tactile), thermal (temperature) and pain sensations.
interoceptive sensation- these are organic sensations, they signal the state of the internal processes of the body, bring irritation to the brain from the walls of the stomach and intestines, the heart and circulatory system and other internal organs. This is the oldest and most elementary group of sensations. They are among the least conscious and most diffuse forms of sensation and are always closely associated with emotional states.
proprioceptive sensation provide signals about the position of the body in space and form the basis of human movements, playing an important role in their regulation. Peripheral receptors for proprioceptive sensitivity are located in muscles and joints (tendons, ligaments) and have the form of special nerve bodies (bodies. Paccini). The excitation that occurs in these bodies reflects the sensations that occur when calculating muscle tension and changing the position of the joints. This group of sensations includes a specific type of sensitivity called the sense of balance, or static sensation, their peripheral receptors are located in the canals of the inner ear. Kinesthetic and static sensations belong to proprioceptive ones.
exteroceptive sensation is usually divided, depending on the presence or absence of direct contact of the receptor with the stimulus that causes sensation, into:
1) contact;
2) sufficient
Contact sensations are caused by exposure directly applied to the surface of the body of the corresponding organ of perception. Examples of contact sensations are taste, touch
Distant sensations are caused by stimuli acting on the sense organs at some distance. These include smell, hearing and vision.
Genetic classification allows us to distinguish two types of sensitivity:
1) protopathic (more primitive, affective, less differentiated and localized), which includes organic sensations (hunger, thirst, etc.);
2) epicritical (more finely differentiated, objectified and rational), to which the main human senses belong. Epicritical sensitivity is the youngest in the genetic plan, and it exercises control over protopathic sensitivity.
Let us dwell in more detail on the characteristics of certain types of sensations.
Visual sensations play an important role in human interaction with the environment. The apparatus of vision is the eye - a sensory organ with a complex anatomical structure. The physical cause of visual sensations?. The human eye perceives only a small part of electromagnetic vibrations. Light waves that are reflected by an object are refracted as they pass through the lens and are focused on the retina in the form of an image. The retina is connected via the optic nerve to the cerebral hemispheres. The retina has a complex structure. One of the layers included in its composition is the layer of rods and cones, which are the final formations of the optic nerve. Rods and cones perform different functions. Rods are the organ of vision in the dark, and since under such conditions a person does not feel spectral colors, they are called non-color vision organ. Cones are the organ of "daytime" vision, they are characterized by less sensitivity to light. Since during the day?
The visual sensations include the sensation of light and color
Auditory sensations, reflecting a wide variety of properties of sounding objects and phenomena, help a person to navigate in the environment and regulate their actions. They are caused by sounds we, acting on the auditory analyzer at a distance through air vibrations and sound waves. Therefore, auditory sensations are classified as distant sensations.
The sensory endings of the auditory nerve are located in the inner ear. The outer ear (pinna) collects sound vibrations and transmits them to the inner ear on the cochlea. The excitation of the nerve endings in the curls occurs according to the principle of resonance, the endings of the auditory nerve, different in length and thickness, begin to move along a certain number of oscillations per second.
Auditory sensations include the sense of language, music, and noise. With the help of auditory sensations, the following qualities of sound are distinguished: strength (loud - quiet), height (high - low), timbre (the peculiarity of a voice or a musical instrument), duration (sounding time), as well as a dark rhythmic pattern of sounds, are consistently perceived.
Auditory sensations are great importance and in perception oral speech. phonemic hearing, or sensitivity to the sounds of speech, is formed in the process of mastering the language and using it. Its development affects without zpomilkovist writing especially in elementary grades.
Vibration sensitivity is closely related to auditory sensitivity. It is believed that in the human body there are no special receptors designed to sense vibration, and all organs and tissues of the human body are capable of reflecting vibrations.
Olfactory sensations do not have the same significance in human life as visual and auditory ones, since they are not associated with orientation in the environment, their role is that they signal to a person about the freshness of food, the purity of the air, etc. In those cases, when their development is stimulated by the conditions of professional activity, they achieve considerable perfection (perfumers, firefighters, etc.).
Irritants that cause olfactory sensations are microscopic particles of odorous substances that enter the nasal cavity with air, dissolve in the nasal fluid and affect the receptor. Olfactory sensations are very often combined with other senses - taste, tactile, temperature, etc. and become complex. The connection of the olfactory sensation with others can be conditioned reflex in nature (the sight of a rose can enhance our sense of its smell).
Taste sensations are closely related to olfactory ones, they are united by a common role in nutrition processes. The organ of taste is the tongue. Taste sensations include the sensation of sour, sweet, bitter and salty. Other tastes of ki are the result of mixing basic flavors. Taste sensations increase a person's appetite, and also perform a protective function, signaling poor-quality food. The dynamics of taste sensations is closely related to the body's need for food. In a state of hunger, sensitivity increases, when saturated, it decreases.
Skin sensation includes tactile, temperature and pain sensations
Tactile sensations arise due to the impact of mechanical stimuli on the surface of the skin. The condition for their occurrence is contact with an irritant that causes deformation of the skin, tactile sensitivity is unevenly distributed throughout the body. The largest accumulation of tactile receptors on the palms, fingertips and lips.
Tactile sensations are sensations of touch and pressure. They signal the presence of a particular stimulus that collides with the surface of the body. Tactile sensations reflect important properties subject matter of the objective world: equality, roughness, hardness, softness, dryness, thinness of moisture.
Temperature sensations are divided into sensations of cold and heat. They signal changes in the temperature environment, the danger of cooling the body or overheating, and help regulate the exchange between the body and the environment. In addition, temperature sensations give a person information about the thermal properties of objects and phenomena in the environment.
The nature of temperature sensations depends on the nature of the acting stimulus. If the temperature of the object is lower than body temperature, then there is a feeling of cold, if it is higher - a feeling of warmth. Temperature sensations are local in nature, since we attribute them to a specific area of the skin, which is affected by irritants.
Pain sensations arise when exposed to various kinds of stimuli (mechanical, thermal, chemical, electrical, etc.), which cause damage or destruction of body tissues. They play an important role as components of protective reflexes, signal the harm of the stimulus to the body and the need to break contact with it, and have a pronounced negative emotional coloring. Pain sensations carry certain information about the stimulus, they reflect its intensity, quality (stabbing, cutting, burning pain), location. The spatial localization of pain is not always accurate, which is explained by the irradiation of excitation processes.
Static sensations reflect the position of the body in space, its balance. Static sensation receptors are located in the vestibular apparatus of the inner ear. This type of sensation is of great importance for the vitality of the organism, since it ensures the balance of the organism. The regulation of the balance of the body has a reflex character. The normal operation of a static analyzer is necessary to display space with the help of other types of sensations, in particular visual and rukovogovogo.
kinesthetic sensation (from the Greek "kinesis" - movement and "aistesis" - sensation) is the sensation of movements and the position of parts own body. Kinesthetic sensation receptors are found in muscles and tendons. Irritation in these receptors occurs during contraction and stretching of muscles and ligaments, friction of the joints. The result of these sensations is knowledge about the strength, speed, trajectory of movement of parts of the body of parts of the body.
In combination with other senses, kinesthetic sensations become definite and differentiated; in combination with visual sensations, they become important in a person's cognition of the spatial property of things. The combination of kinesthetic sensation with tactile acts in the form of groping.
In the course of training, it is necessary to pay attention to the development of kinesthetic sensations, which are aimed at the lessons of labor, drawing, physical education, as well as dancing, rhythmic gymnastics and other sports. At the same time, it is important to take into account the peculiarities of the development of this type of sensations in certain age periods.
Organic sensations are sensations associated with the activity of internal organs. These sensations, merging, form an organic feeling (well-being) of a person. This is the so-called senesthesia ( general feeling), which reflects the general state of the body based on signals from various organs of the body. An example is the feeling of general malaise that occurs in the patient. Organic sensations include feelings of hunger, thirst, satiety, nausea, changes in the activity of the heart, stomach, and pain sensations.
Organic sensations are caused by impulses from internal states, as well as by a change in the chemical formula of the blood. They are characterized by lack of clarity, fuzziness and uncertainty of localization. feature th organic sensations is their emotional coloring (positive or negative).
The doctrine of higher nervous activity reveals the scientific and natural foundations of sensations. I. M. Sechenov and I. P. Pavlov showed in their studies that sensations are a kind of reflex actions, the physiological basis of which are nervous processes resulting from the action of stimuli on the sense organs, or analyzers.
Analyzers are the organs of the human body that analyze the surrounding reality and release certain types of energy and information in it.
The visual analyzer emits light energy, or vibrations of electromagnetic waves; auditory - sounds, that is, air vibrations; gustatory, olfactory Chemical properties substances; skin analyzers - thermal, mechanical properties objects and phenomena that cause certain sensations.
In each analyzer there is its peripheral, analyzing part, or receptor, that is, the sense organ, the purpose of which is to extract light, sound, smell and other properties from the surrounding reality. Another part of it is the path from the receptor to the central part of the analyzer located in the brain. In the central part of the analyzer, its nucleus is distinguished, that is, clusters of sensitive cells, and scattered outside its cells.
The core of the analyzer, as I. P. Pavlov noted, performs a subtle analysis and synthesis of excitations coming from the receptor. With its help, stimuli are differentiated by their characteristics, quality and intensity. Scattered cells carry out a more rough analysis, for example, they distinguish only musical sounds from noises, perform a fuzzy distinction between colors and smells.
Organic disorders of any part of the analyzer - peripheral, leading or central - cause blindness or deafness, loss of smell, taste, etc., depending on which analyzer is impaired. If only the central part of the analyzer is disturbed, there is a misunderstanding of what is heard, seen, although there is no sensation of light or sound.
Simple feelings and sensitivity in the first stages of a person's life have their physiological basis in the innate unconditional reflex activity of the nervous system. Complicated sensations are due to conditioned reflex analytic-synthetic activity, in which properties supported by life conditions stand out, and if not supported, they are inhibited.
Classification of sensations
There are various classifications of the sense organs and the body's sensitivity to stimuli entering the analyzers from the outside world or from within the body. Depending on the degree of contact of the sense organs with stimuli, contact (tangential, gustatory, pain) and distant (visual, auditory, olfactory) sensitivity are distinguished.
Behind the placement of receptors in the body - on the surface, inside the body, in muscles and tendons - exteroceptive sensations are distinguished, reflecting the properties of objects and phenomena of the external world (visual, auditory, olfactory, gustatory), interoceptive, carrying information about the state of internal organs (hunger, thirst, fatigue) and proprioceptive, reflecting the movements of the organs of the body and the state of the body (kinesthetic and static).
Independent sensations include temperature, which is a function of a special temperature analyzer that performs thermoregulation and heat exchange of the body with the environment.
Temperature sensations are also part of the tactile sensations.
According to the system of analyzers, there are such types of sensations: visual, auditory, tactile, pain, temperature, taste, olfactory, hunger and thirst, sexual, kinesthetic and static. Each of these varieties of sensation has its own organ (analyzer), its own patterns of occurrence and function.
The organ of visual sensations is the eye. It distinguishes between parts - the world-losal-luminous (cornea, pupil, vitreous body) and light-sensitive (the retina with its cones sensitive to daylight colored light and rods sensitive to darkness).
There are chromatic and achromatic colors. Chromatic colors are characterized by their hue, lightness and saturation. Hue is a property that distinguishes a certain color from any other with the same lightness and saturation. The color tone depends on the wavelength of the light. The lightness of a color is a measure of the difference between a particular color and black.
The least lightness is characteristic of black, and the greatest - white. The brightness of the color depends on the intensity of the light wave, that is, on the amplitude of its oscillation.
Color saturation is a measure of revealing a color tone, that is, the difference between a certain color and gray, which is the same with it in lightness.
Achromatic colors differ only in the degree of lightness, which depends on the light reflectance. White paper has a reflectance from 0.60 to 0.85, and black paper has a reflectance of 0.04-0.003 (paper in which film is wrapped, black velvet).
The sensitivity of the eye to color is different. The sensitivity to blue is 40 times less than to yellow. The brightest is the yellow-green part of the spectrum. Light yellow, from which lightness decreases towards red and purple.
Under normal conditions, a person is able to distinguish up to 150 colors by hue, 20 shades by saturation, about 200 by lightness. Under the influence of exercise, color sensitivity increases.
The sensitivity of the eye to color can be weakened as a result of injuries, diseases. In 5-7 percent of men and 1-1.5 percent of women, color blindness is observed, that is, the inability to distinguish colors.
Color blindness is a phenomenon of hereditary origin. It is transmitted mainly through the male line - from father through daughter to grandchildren. Color blindness is a contraindication for professional activities that require color discrimination - for example, in color signaling, painting, etc.
The ear is the organ of perception of auditory sensations. In its structure, sound-conducting and sound-sensitive parts are distinguished. The sound-conducting part of the ear is the outer ear, the tympanic membrane, the anvil, the malleus, and the stirrup, which are located in the middle ear. They conduct sound wave vibrations to the central part of the ear, which contains its sound-sensitive part - the organ of Corti. It consists of an auditory membrane, the transverse fibers of which - from 0.04 to 0.5 mm long - resonate on sound waves coming from the middle ear, causing excitation of the sensitive cells of the organ of Corti.
Excitation is transmitted by the auditory nerve in the auditory region of the cerebral cortex (temporal lobe).
The function of the organ of hearing is to analyze sounds with fluctuations from 16 to 20,000 hertz and differentiate them into noises and tones. Musical tones stand out among the tones. In music, they take tones from 27.5 to +4224 vibrations.
Sound waves are distinguished by their height, loudness (intensity) and timbre. Altitude sensitivity to sounds is determined by the frequency of vibration of the sound wave. Sounds with a sound wave oscillation between 1000-4000 hertz are better felt.
The loudness, or intensity, of a sound depends on the amplitude of the vibration of the sound wave - it is customary to determine it in bels, or decibels (decibels are 10 times less than bels). The smallest increase or decrease in sound intensity that the human ear can experience is 1 decibel.
Timbre reflects the shape of the vibration of sound. Usually, the oscillation of a sound wave (the sound of a tuning fork) has the shape of a sinusoid. Musical sounds (singing, sounds of a musical instrument) are complex sounds consisting of the main and partial or partial tones.
Partial tones are sounds from vibrations of a half, a quarter, an eighth, etc. parts of a whole tone. A complex sound of a certain height and strength is formed, which is characterized by its timbre, that is, a peculiar combination of the main and partial tones.
Timbre develops in children with the development of speech. Children already in the first half of their life are able to respond to singing, music, intonation of speech, they distinguish the rhythmic side of speech, and at the end of the first year of life they distinguish the sounds of speech.
Tactile, temperature and pain sensitivity is a function of organs located in the skin.
Tactile sensations provide knowledge about the measure of equality and relief of the surface of objects, felt when they are felt. More organs of tactile sensation are located on the bundles, the tip of the tongue. With strong pressure on the organs of tactile sensations, pain is felt. Tactile sensations, like vision, play a large role in the perception of the shape, size of objects, their location in space. They are especially developed in the blind, compensating for the lack of vision in the perception of certain spatial phenomena. Braille for the blind is built on this, in which the letters are depicted using raised dots.
Pain sensations coming from organs, which are more numerous on the outer and inner surfaces of the body, signal a violation of the integrity of the tissue, which, of course, causes a protective reaction in a person. Direction of attention to pain increases it, and distraction - weakens pain. Pain, fixed in the central part of the pain analyzer (in the cerebral cortex), causes the illusion of pain in amputated limbs (the so-called phantom pain). Temperature sensation - a feeling of cold, heat - is caused by contact with objects that have a temperature higher or lower than body temperature. You can cause paradoxical sensations of heat and cold: touching the cold causes a feeling of warmth, and touching the warm - a feeling of cold.
Temperature sensations are due to organic processes(blood circulation), and mental states (emotional experiences). These states fixed figurative expressions in the language: "thrown into the heat", "thrown into the cold." Temperature sensations signal the degree of favorable environment for life, about the state of health of the body.
Vibrational feeling is vividly manifested in the deaf and blind. The deaf and blind react to the vibration of objects, feel its rhythm. The organ of vibrational sense has not yet been found. This feeling is largely associated with visual and auditory sensitivity. The vibrational feeling is professionally important for those specialties in which the vibration of an object indicates the qualitative features of the activity.
Olfactory sensations are carried out by special olfactory vesicles located on the inner surface of the nose. Not only animals, but also humans are very sensitive to smells. Olfactory sensations signal the body about the state of the suitability of products for consumption, about clean or polluted air.
The human olfactory organ is very sensitive to smells. A person can smell the presence in the air of very small parts of an odorous substance, such as rose oil, hydrogen sulfide, musk. In dogs, for example, the sense of smell is so developed that they can smell one molecule of an odorous substance dissolved in one cubic centimeter of water.
Olfactory sensations are important not only for life, but also for a number of professions: in some specialties, to a lesser extent chemical reaction or the suitability of products is determined by smell.
Taste sensations with their body have special cones sensitive to chemical irritants located on the tongue and palate. The middle and lower parts of the tongue do not have taste organs. Distinguish sensitivity to bitter, sour, salty and - the smallest - to sweet.
Tastes can mix, so sour-sweet and bittersweet are perceived. This allows you to combine different taste properties of products in Food Industry. Taste sensations, like olfactory ones, are important for life - they signal the degree of suitability of foods for consumption. This sensitivity is professionally necessary in culinary specialties, in the food industry - tasting products requires high taste sensitivity and the ability to differentiate the presence of certain flavoring substances in products in order to regulate the preparation of these products.
Taste sensations develop under the influence of exercise and life practice, or weaken if they are not supported by anything.
Static, or gravitational, sensations reflect the position of our body in space - lying, standing, sitting, balancing, falling. The receptors for these sensations are contained in the vestibular apparatus of the inner ear (vestibule, semicircular canals). When the body changes relative to the plane of the earth, as happens when driving, on water, in an airplane and with a disease of the vestibular apparatus, dizziness occurs, balance and orientation in space are lost.
Violation of the activity of the vestibular apparatus is contraindicated for the specialties of a pilot, astronaut, for work on a ship.
Kinesthetic sensations reflect the movements and states of individual parts of the body - arms, legs, head, body. The receptors for these sensations are special organs located in the muscles and tendons. The pressure on these organs during movement causes a sensation of the position of the organs of the body. Kinesthetic sensations, giving knowledge about the strength, speed, degree of movement, contribute to the regulation of a number of actions.
In many professions, physical culture these sensations contribute to the coordination of movements.
Linguistic kinesthesia is the basis for articulation.
Thus, the formation of kinesthetic sensations in the process of education and upbringing is an important task of educational, sports institutions, institutions of labor education and training.
Organic sensations signal such states of the body as hunger, thirst, well-being, fatigue, pain, their analyzers are located inside the body and respond to a measure of sufficiency in the body of nutrients, oxygen, or to the presence in the organs of the body, in nervous system decay products, occurs during work, the use of poor-quality products, alcohol, etc.
Organic sensations cause various emotional states that a person tries to maintain or eliminate by his actions. The expediency of these actions (the use of food, drinks, medicines, rest, work) requires awareness of the nature of organic sensations, their causes and knowledge of measures to eliminate them or pleasure.
Some drugs, food, smoking slow down for a while, dull the discomfort, but at the same time cause significant harm to the body.
Feelingcalled the simplest mental process of reflecting the individual properties of external objects, as well as the internal states of the body, resulting from the direct impact of material stimuli on the corresponding receptors.
For example, we feel the color of objects (red, green), their surface properties (smoothness, roughness), muscle tension when performing movements, the state of internal organs (pain), etc.
Sensation is the source of knowledge of the objective world. Due to their reflective essence, sensations are for a person a source of knowledge of the external world around him.
Feeling is a product of the activity of the thinking brain. A person has sensations like everyone else mental processes, is a "function of the brain", they arise as a product of the activity of the brain, caused by the action of matter on the senses.
Feeling is a reflection of the material world. Our sensations are secondary in relation to matter, they are only internal, subjective images of things and phenomena of the external world.
The physiological basis of sensations is the processes of nervous excitation, which take place in special nervous mechanisms called analyzers.
The function of the analyzers is to decompose into separate elements complex influences emanating from the external or internal environment. With their help, the “highest, most subtle analysis” (Pavlov) is carried out, which is necessary for the differentiated adaptation of the organism to environmental conditions. The analyzers have a complex structure, in which receptors, pathways and central sections of the analyzers are distinguished.
Receptors are nervous devices very different in their structure (see the figure below), adapted to the perception of certain stimuli, which are transformed by them into special nerve excitations. In the receptors, the initial, or lower, analysis of the influences of the environment is carried out.
The conductive parts of the analyzers serve only as transmitters of nervous excitations.
The brain ends, or central (cortical) sections, analyzers consist of cells of the cerebral cortex of the cerebral hemispheres with a specific structure. They carry out the highest analysis, which provides the most accurate adaptive reactions of the body. The centripetal nerve impulses that come here cause nervous processes in the corresponding parts of the cortex that make up physiological basis sensations.
With all its diversity morphological structure analyzers in their totality represent a certain integral system, and not the sum of isolated nervous devices.
The physiological basis of sensations is made up of complex diverse conditioned reflex processes. Analyzers are "self-regulating" neural devices operating on the principle feedback. Thus, a better adaptation of the receptors to the perception of stimuli is achieved (for example, turning towards the stimulus), strengthening or weakening of the processes of excitation and inhibition in peripheral nerve devices, etc. Thus, the function of the analyzers cannot be considered as simply conducting nervous excitation from receptors to cerebral cortex. A large role in their activity is played by various reflex connections that regulate in a certain way both the work of receptors and involve other analyzers in the overall activity. So, for example, a light stimulus causes not only a reaction of the light-sensing organ itself (decomposition of the visual purple of the rods and cones of the retina), but at the same time, constriction or expansion of the pupil and accommodation of the lens: a strong sound stimulus causes not only the corresponding auditory sensation, but also the expansion of the pupil and increased light sensitivity of the retina.
