Physiological basis of sensations. Physiological bases of sensations and perception Physiological bases of classification and types of sensations

Physiological basis of sensations

Introduction

2. The concept of sensation

3. Physiology of sensations

3.1 Analyzers

3.2 Properties of sensations

3.3 Classification of sensations

4. Types of sensations

4.1 Vision

4.3 Vibratory sensations

4.4 Smell

Bibliography

Introduction

It is known that personality is realized in activities that are possible thanks to knowledge of the environment. In ensuring a person’s interaction with the outside world, the leading role is played by the properties of the individual, his motives, and attitudes. However, every mental phenomenon is both a reflection of reality and a link in the regulation of activity. Regulation of activity begins at the level of sensations and perceptions - with mental cognitive processes. Sensations, perceptions, ideas, memory are sensory forms of cognition. Sensory reflection in a person is always associated with logical cognition and thinking. The individual in human sensory cognition is reflected as a manifestation of the general. In sensory cognition, language plays an essential role, the word, which always performs the function of generalization. In turn, logical cognition (thinking) is based on the data of sensory experience, on sensations, perceptions and memory representations. In a single process of cognition, continuous interaction of all cognitive processes takes place. More complex cognitive processes are based on sensations: perceptions, ideas, memory, thinking, imagination. We cannot learn anything about any forms of movement except through sensations. Sensation is the simplest, no longer decomposable mental process. Sensations reflect the objective qualities of an object (smell, color, taste, temperature, etc.) and the intensity of the stimuli affecting us (for example, higher or lower temperature).

1. Sensory organization of personality

The sensory organization of a personality is the level of development of individual sensitivity systems and the possibility of their unification. Human sensory systems are his sense organs, like receivers of his sensations, in which the transformation of sensation into perception occurs. Any receiver has a certain sensitivity. If we turn to the animal world, we will see that the predominant level of sensitivity of any species is a generic characteristic. For example, bats have developed sensitivity to the perception of short ultrasonic pulses, and dogs have olfactory sensitivity. The main feature of a person’s sensory organization is that it develops as a result of his entire life path. A person’s sensitivity is given to him at birth, but its development depends on the circumstances, desires and efforts of the person himself.

2. The concept of sensation

Sensation is a manifestation of a general biological property of living matter - sensitivity. Through sensation there is a psychic connection with the external and internal world. Thanks to sensations, information about all phenomena of the external world is delivered to the brain. In the same way, a loop is closed through sensations to receive feedback about the current physical and partly mental state of the body. Through sensations we learn about taste, smell, color, sound, movement, the state of our internal organs, etc. From these sensations, holistic perceptions of objects and the whole world are formed. It is obvious that the primary cognitive process occurs in the human sensory systems and, on its basis, cognitive processes that are more complex in structure arise: perceptions, ideas, memory, thinking. No matter how simple the primary cognitive process may be, it is precisely it that is the basis of mental activity; only through the “inputs” of sensory systems does the surrounding world penetrate into our consciousness.

2.1 Processing sensations

After the brain receives information, the result of its processing is the development of a response action or strategy aimed, for example, at improving physical tone, focusing more attention on the current activity, or setting up an accelerated involvement in mental activity. Generally speaking, the response or strategy developed at any given time is the best choice of the options available to a person at the time of decision making. However, it is clear that the number of available options and the quality of choice are different for different people and depend, for example, on: - mental properties of the individual; - strategies for relationships with others; - partly physical condition; - experience, availability of necessary information in memory and the ability to retrieve it; - the degree of development and organization of higher nervous processes, etc.

3. Physiology of sensations

3.1 Analyzers

The physiological mechanism of sensations is the activity of nervous apparatus - analyzers, consisting of 3 parts: - receptor - the perceiving part of the analyzer (carries out the transformation of external energy into a nervous process); - central section of the analyzer - afferent or sensory nerves; - cortical sections of the analyzer, in which nerve impulses are processed. Certain receptors correspond to their own areas of cortical cells. The specialization of each sense organ is based not only on the structural features of the analyzer-receptors, but also on the specialization of the neurons that are part of the central nervous apparatus, which receive signals perceived by the peripheral sense organs. The analyzer is not a passive receiver of energy; it reflexively adapts under the influence of stimuli.

3.2 Properties of sensations

Any sensation can be described using several properties inherent to it. The main properties of sensations include: quality, intensity, duration and spatial localization.

Quality- this is a specific feature of a given sensation, distinguishing it from all other types of sensations and varying within a specific modality.

For example, the qualities of the visual modality include

Brightness,

Saturation,

Color tone.

Quality of hearing sensations:

Volume,

Quality of tactile sensations:

Hardness,

Roughness, etc.

3.3 Classification of sensations

The most common, earliest and simplest classification of sensations by modality (type) of stimulus. Modality is a qualitative characteristic in which the specificity of sensation as a simple mental signal is manifested, in contrast to a nervous signal.

Depending on the location of the receptors, all sensations are divided into three groups. The first group includes sensations that are associated with receptors located on the surface of the body: visual, auditory, olfactory, taste and skin sensations. These are exteroceptive sensations. The second group includes interoreceptive sensations associated with receptors located in the internal organs. The third group includes kinesthetic (motor) and static sensations, the receptors of which are located in the muscles, ligaments and tendons - proprioceptive sensations (from the Latin "-own").

Depending on the modality of the analyzer, the following types of sensations are distinguished:

- distant(visual, auditory),

- contact(tactile, gustatory) sensations.

4. Types of sensations

Each receptor responds to a specific type of stimulus. Therefore, the following types of sensations can be distinguished:

Visual - occur under the influence of light rays on the retina of the eye; - auditory - caused by sound waves from speech, music or noise; - vibration - the ability to capture vibrations of an elastic medium (water, air, earth, objects); this is a type of auditory sensitivity, poorly developed in humans, but used by dolphins, bats, etc. (echolocation, ultrasound); - olfactory - reflect the smells of surrounding objects; - taste; - skin: tactile (touch sensation), temperature and pain. The palms, fingertips and lips are very sensitive to touch - we use them to touch. Painful sensations have a strong emotional connotation - they are clearly audible or visible to other people. Temperature sensitivity varies in different parts of the body: the back is most sensitive to cold, the chest is the least sensitive. In special states of the psyche and human body, pseudo-sensations may occur - hallucinations, when the stimulus is absent, but the sensation is present (mirage, visions, “voices”, delusions, etc.).

4.1 Vision

The visual apparatus is the eye, a sensory organ with a complex anatomical structure. Light waves reflected by an object are refracted as they pass through the lens of the eye and are focused on the retina in the form of an image. The eye is a distant receptor, since vision provides knowledge about objects and phenomena located at some distance from the sense organs.

The ability to reflect space is provided by the pairing of the visual analyzer, changes in the size of the image on the retina when moving away from or approaching an object, as well as movement (convergence and separation) of the axes of the eyes. The retina of the eye consists of several tens of thousands of optic nerve fiber endings, which become excited under the influence of a light wave. The endings of the optic nerve vary in shape and function. Cone-shaped receptors are adapted to reflect color. They are located in the center of the retina and are a daytime vision device. Rod-shaped nerve endings reflect light. They are located around the cones, closer to the edge of the retina. This is a twilight vision device. Cone vision is not impaired when rods are affected, and vice versa, i.e., the sensations of color and light have their own analyzer systems.

From the above, it is clear that two large groups of visual sensations can be distinguished: achromatic sensations, reflecting the transition from white to black, through a mass of shades of gray, and chromatic sensations, which reflect the color gamut with numerous shades and color transitions.

Auditory sensations are also distant sensations. The sensory endings of the auditory nerve are located in the inner ear, the cochlea with the auditory membrane and sensory hairs. The auricle, the so-called outer ear, collects sound vibrations, and the mechanism of the middle ear transmits them to the cochlea. The sensory endings of the cochlea are excited as a result of resonance, i.e. The endings of the auditory nerve, varying in length and thickness, begin to move at a certain number of vibrations per second, and the resulting signals are transmitted to the brain. These vibrations occur in elastic bodies and are transmitted by the air. From physics we know that sound has a wave nature and is characterized by frequency and amplitude.

There are three types of auditory sensations: speech, music and noise. In these types of sensations, the sound analyzer identifies four sound qualities:

Strength (loud - weak),

Height (high - low),

Duration of sound and tempo-rhythmic pattern of perceived sounds.

Phonemic hearing is the ability to distinguish speech sounds. It is formed throughout life and depends on the speech environment. Good knowledge of a foreign language presupposes the development of a new system of phonemic hearing. The ability to learn foreign languages ​​is determined by phonemic awareness, which also affects the literacy of written speech. A person’s musical ear is nurtured and formed, just like his speech ear. The ability to enjoy music is a centuries-old result of the development of human musical culture. Noises and rustles are less significant for a person, unless they interfere with his life. Noises can evoke a pleasant emotional mood, for example, the sound of rain, the roar of the sea surf, and one computer network administrator I know told me that he cannot sleep when he does not hear the noise of running fans from three or four computers. Noises can also serve as a danger signal - the hiss of gas, the stomping of feet behind you, the howl of a siren.

4.3 Vibratory sensations

Vibration sensitivity is adjacent to auditory sensations. They have a common nature of reflected physical phenomena. Vibration sensations reflect vibrations of an elastic medium. This type of sensitivity is figuratively called “contact hearing.” No special vibration receptors have been found in humans. Currently, it is believed that the vibration sense is one of the most ancient types of sensitivity, and all tissues of the body can reflect vibrations of the external and internal environment.

In human life, vibration sensitivity is subordinated to auditory and visual. The cognitive significance of vibration sensitivity increases in those types of activities where vibrations become a signal of malfunctions in the operation of the machine. In the lives of deaf and deaf-blind people, vibration sensitivity compensates for hearing loss. Short-term vibrations have a tonic effect on the body of a healthy person, while long-term and intense vibrations tire and can cause painful phenomena.

4.4 Smell

Olfactory sensations are distant. The irritants that cause olfactory sensations are microscopic particles of substances that enter the nasal cavity with air, dissolve in the nasal fluid and act on the receptor. In a number of animals, the sense of smell is the main distant receptor: guided by smell, the animal finds food or avoids danger.

In humans, olfactory sensations have little connection with orientation in the environment. This function of smell is suppressed by vision and hearing. The lack of development and instability of olfactory sensations is evidenced by the absence in the language of special words to designate them; the sensations are not abstracted from the object that names it. They say: “the smell of hay”, “the smell of rotten apples”, “the smell of lilies of the valley”.

Olfactory sensitivity is closely related to taste and helps to recognize the quality of food. The sense of smell warns of an air environment that is dangerous to the body and, in some cases, allows one to distinguish the chemical composition of substances.

Taste sensations are contact sensations that arise when a sensory organ (tongue) comes into contact with the object itself. The sense of taste detects molecules dissolved in saliva. There are four main qualities of taste stimuli: sour, sweet, bitter, salty. From the combinations of these four sensations, to which the movements of the tongue are added, a complex of taste sensations arises. Initially, the sensory process occurs in the taste buds, and each of the papillae has from 50 to 150 receptor cells, which quickly wear out from contact with food and are then renewed. The sensory signals then travel along nerves to the hindbrain, thalamus, and gustatory cortex, which processes taste.

Taste sensations, like olfactory sensations, increase a person’s appetite. By analyzing the quality of food, taste also performs a protective function and is important for survival. When fasting, taste sensitivity increases, when saturated or satiated, it decreases.

There are several independent analyzing systems in the skin:

Tactile (touch sensations),

Temperature,

Painful.

All types of skin sensitivity are classified as contact sensitivity. The largest concentration of tactile cells is in the palm of your hand, on your fingertips and on your lips. Cutaneous receptors transmit information to the spinal cord by contacting motor neurons, which makes reflex actions possible, such as withdrawing a hand from a fire. Touch is the tactile sensation of the hand together with muscle-joint sensitivity.

Temperature sensitivity regulates heat exchange between the body and the environment. The distribution of heat and cold receptors across the skin is uneven. The back is most sensitive to cold, the chest is the least sensitive.

Strong pressure on the surface of the body causes pain. The receptor endings of pain sensitivity are located under the skin, deeper than the tactile receptors. Where there are more tactile receptors, there are fewer pain receptors. Tactile sensitivity gives knowledge about the qualities of an object, and pain sensitivity gives a signal about the harm caused by the irritant.

4.7 Proprioceptive sensitivity

Kinesthesia

Kinaesthetic sensations are sensations of movement and position of individual parts of the body. Receptors for kinesthetic sensations are located in muscles and tendons. Irritation in these receptors occurs under the influence of muscle stretching and contraction.

A large number of motor receptors are located in the fingers, tongue and lips, since these organs need to carry out precise and subtle working and speech movements. The activity of the motor analyzer allows a person to coordinate and control his movements.

Speech kinesthesia is formed in the infant and preschool periods of human development. Learning a foreign language requires the development of speech kinesthesia that is not typical for the native language.

Vestibular sense

Static, or gravitational, sensitivity reflects the position of our body in space. Its receptors are located in the vestibular apparatus of the inner ear: the semicircular canals and vestibular sacs convert signals about relative motion and gravity and transmit them to the cerebellum and the temporal cortex. Sudden and frequent changes in body position relative to the plane of the earth, such as swinging on a swing or sea motion, lead to dizziness - “seasickness”.

Questions

Lecture 1.6. Sensations and perception

1. The concept of sensations. Physiological basis of sensations.

2. Types and properties of sensations.

3. Characteristics of the main types of sensations.

4. The concept of perception.

5. Properties and types of perception.

6. Development of the child’s sensory-perceptual sphere.

The world of human mental phenomena is diverse (mental processes, mental properties, mental states). Mental processes are divided into cognitive and emotional-volitional. In this lecture we begin to talk about cognitive processes, thanks to the functioning of which a person understands the reality around him. Cognitive processes include: sensation, perception, representation, attention, memory, imagination, thinking, speech.

Human knowledge of the world begins with the accumulation of information through the senses. To describe sensory cognition in psychology, the concepts of “sensation” and “perception” are used. Do a little experiment: ask a friend to close his eyes and touch his palm with an unfamiliar object, and then ask what he can say about the object. If the subject does not know what it is, he will answer: “Something hard, smooth, cold” or “Soft, warm, rough.” These words express the feelings that a person experiences. Sensations arise as images reflecting the individual properties of objects.

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, having direct significance for their life activities 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 their practical activities, consciousness, and 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.

Sensation is not a simple reflection of the influences of the external world by the senses. An important element of sensation is the body’s response to the impact. This reaction is indirect and active. Sensation is mediated by a person’s consciousness, his life experience, developed skills, etc. Sensation is interconnected with many mental phenomena. For example, information accumulated through the senses is a necessary condition for the development thinking. There is also a direct interdependence of many sensations with emotions person (spring birdsong, sea surf, music often evoke positive emotions in a person). Feelings are always emotionally charged. The fact of different psychophysiological effects of color on a person has been experimentally proven: green calms, red excites. Of two boxes of equal weight, painted white and black, the first seems lighter, the second heavier. Special sensations coming from internal organs determine a person’s well-being and emotional tone. It is no coincidence that in the language the words “sensitivity” (meaning the characteristic of the cognitive function of sensations) and “feeling” (experience) have the same roots.

Conscious sensations are inherent only to living organisms that have a brain and cerebral cortex. In case of disturbances in brain function or temporary shutdown of the cerebral cortex naturally or with the help of biochemical drugs, a person loses the state of consciousness and with it the ability to have sensations, that is, to feel, to consciously perceive the world. This happens during sleep, during anesthesia, and during painful states of consciousness.

Organic sensations are correlated with objects of the external world, give rise to desires, and serve as a source of volitional impulse. Movements and actions aimed at achieving a goal are regulated by sensations that are necessary to construct an action. Thus, sensations ensure human life.

Sensations are not the only form of reflection of the world. Higher forms of sensory reflection ( perception, performance) cannot be reduced to a sum or combination of sensations. Each form of reflection has a qualitative originality, but without sensations as the initial form of reflection, the existence of cognitive activity is impossible.

Without sensations, human mental activity is impossible. Currently, in connection with the task of exploring space and the bottom of the World Ocean, many experiments are being carried out to reveal the effect of sensory isolation (complete or partial absence of stimuli) on the human psyche and body. Experiments have shown that in less than a day, with complete sensory isolation, disturbances of consciousness are observed: hallucinations appear, obsessions arise. Thus, the constant “conversion of the energy of an external stimulus into a fact of consciousness,” carried out in sensations, is a necessary condition for the normal functioning of the psyche.

Physiological bases of sensations. Sensation can only arise 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” of molecules dissolved in saliva, and the olfactory analyzer generates an impulse as a result of “chemical analysis” of molecules dissolved in saliva, and the olfactory analyzer generates an impulse 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.

The doctrine of higher nervous activity reveals the scientific and natural foundations of sensations. I.M. Sechenov and I.P. Pavlov showed through their research that sensations are a kind of reflex actions, the physiological basis of which is the nervous processes that arise as a result of the influence of stimuli on the sense organs, or analyzers.

Analyzers are organs of the human body that analyze the surrounding reality and highlight 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 of substances; skin analyzers - thermal, mechanical properties of objects and phenomena that cause certain sensations.

Each analyzer has its peripheral, analyzing part, or receptor, that is, a sensory organ whose purpose is to isolate 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 core is distinguished, that is, clusters of sensitive cells, and cells are scattered outside of it.

The core of the analyzer, as noted by I.P. Pavlov, carries out 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 crude analysis, for example, they distinguish only musical sounds from noise, and 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 damaged. If only the central part of the analyzer is disturbed, a misunderstanding of what was heard or seen occurs, although there is no sensation of light or sound.

Simple feelings and sensitivity in the first stages of human life have their physiological basis in the innate unconditional reflex activity of the nervous system. Complex sensations are caused by conditioned reflex analytical-synthetic activity, in which properties reinforced by life conditions are highlighted, and those not reinforced are inhibited.

Classification of sensations

There are various classifications of the sensory 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, sensitivity is distinguished between contact (tangential, gustatory, pain) and distant (visual, auditory, olfactory).

Based on 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 (feelings of hunger, thirst, fatigue) and proprioceptive, reflecting the movements of the body organs and the state of the body (kinesthetic and static).

Independent sensations include temperature, which is the function of a special temperature analyzer that carries out thermoregulation and heat exchange between the body and the environment.

Temperature sensations are also part of tactile sensations.

According to the analyzer system, there are the following types of sensations: visual, auditory, tactile, pain, temperature, gustatory, olfactory, hunger and thirst, sexual, kinesthetic and static. Each of these types of sensation has its own organ (analyzer), its own patterns of occurrence and functions.

The organ of visual sensation is the eye. It distinguishes parts - the world-receptive (cornea, pupil, vitreous body) and the light-sensitive (retina with its cones sensitive to daylight colored light and rods sensitive to darkness).

There are chromatic and achromatic colors. Chromatic are characterized by their color tone, lightness and saturation. Hue is the property that distinguishes a certain color from any other at the same lightness and saturation. Color tone depends on the wavelength of light. Lightness of color is a measure of the difference of a particular color from black.

The smallest lightness is characteristic of black, and the greatest lightness is characteristic of white. The brightness of a color depends on the intensity of the light wave, that is, on the amplitude of its vibration.

Color saturation is a measure of the identification of color tone, that is, the difference between a certain color and gray, the same 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 - 0.04-0.003 (the paper in which photographic film is wrapped is black velvet).

The sensitivity of the eye to color varies. The sensitivity to blue is 40 times less than to yellow. The brightest part of the spectrum is the yellow-green part. The light color is yellow, from which the lightness decreases towards red and violet.

Under normal conditions, a person is able to distinguish up to 150 colors by hue, 20 shades by saturation, and about 200 by lightness. Under the influence of exercise, color sensitivity increases.

The eye's sensitivity to color can be weakened as a result of injury or disease. 5-7 percent of men and 1-1.5 percent of women experience color blindness, that is, the inability to distinguish colors.

Color blindness is a phenomenon of hereditary origin. It is transmitted primarily 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, there are sound-conducting and sound-sensitive parts. The sound-conducting part of the ear is the outer ear, eardrum, incus, malleus and stapes, which are located in the middle ear. They conduct vibrations of the sound wave into the central part of the ear, which contains the 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 with 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 area of ​​the cerebral cortex (temporal lobe).

The function of the hearing organ is to analyze sounds ranging from 16 to 20,000 hertz and differentiate them into noise and tones. Among the tones, musical tones stand out. In music, tones range from 27.5 to +4224 vibrations.

Sound waves are distinguished by their height, volume (intensity) and timbre. High-altitude sensitivity to sounds is determined by the oscillation frequency of the sound wave. Sounds with a sound wave oscillating between 1000-4000 hertz are better felt.

The volume, or intensity, of a sound depends on the amplitude of the vibration of the sound wave - it is usually defined in bels, or decibels (a decibel is 10 times less than a bel). The smallest increase or decrease in sound intensity that the human ear can experience is 1 decibel.

Timbre reflects the vibrational shape of sound. Typically, the oscillations of a sound wave (the sound of a tuning fork) have the shape of a sinusoid. Musical sounds (singing, sounds of a musical instrument) are complex sounds consisting of a main and partial tones.

Partial tones are sounds from the vibration of half, quarter, 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, and intonation of speech, 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 degree of equality and relief of the surface of objects, felt when touching them. More organs of tactile sensation are located on the fascicles, the tip of the tongue. When there is 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, and their location in space. They are especially developed in the blind, compensating for the lack of vision when perceiving certain spatial phenomena. This is the basis for the Braille alphabet for the blind, in which letters are depicted using raised dots.

Painful 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 defensive reaction in a person. Directing attention to pain enhances it, and distraction weakens pain. Pain, recorded in the central part of the pain analyzer (in the cerebral cortex), causes the illusion of pain in amputated limbs (so-called phantom pain). Temperature sense - a feeling of cold, warmth - is caused by contact with objects that have a temperature higher or lower than body temperature. Paradoxical sensations of heat and cold can be evoked: touching something cold causes a sensation of warmth, and touching something warm causes a sensation of cold.

Temperature sensations are caused by both organic processes (blood circulation) and mental states (emotional experiences). These states have fixed figurative expressions in the language: “threw into the heat,” “threw into the cold.” Temperature sensations signal the degree to which the environment is favorable for life and the state of health of the body.

The vibration sense is clearly manifested in the deaf and blind. Deaf and blind people react to the vibration of objects and feel its rhythm. The vibration sense organ has not yet been found. This feeling is largely associated with visual and auditory sensitivity. The vibration sense 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 odors. Olfactory sensations signal the body about the state of suitability of products for consumption, whether the air is clean or polluted.

The human olfactory organ is very sensitive to odors. A person can smell the presence of very small parts of an odorous substance in the air, for example, rose oil, hydrogen sulphide, musk. In dogs, for example, their 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, the extent of a chemical reaction or the suitability of products is determined by smell.

The sense of taste is through special cones, sensitive to chemical stimuli, located on the tongue and palate. The middle and lower parts of the tongue do not have taste organs. There are sensitivity to bitter, sour, salty and - the least - to sweet.

Flavors can mix, so it tastes sweet and sour and bittersweet. This allows you to combine different taste properties of products in the food industry. Taste sensations, like olfactory sensations, are important for life - they signal the degree of suitability of food products for consumption. This sensitivity is professionally necessary in culinary specialties and 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, balance, 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, on 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, or for working 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. Pressure on these organs during movement causes a sense of the position of the body organs. Kinesthetic sensations, giving knowledge about strength, speed, degree of movements, contribute to the regulation of a number of actions.

In many professions and in physical culture, these sensations contribute to coordination of movements.

Language kinesthesia is the basis for articulation.

Thus, the formation of kinesthetic sensations in the process of teaching and upbringing is an important task of educational, physical education institutions, labor education and training institutions.

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 the degree of sufficiency of nutrients and oxygen in the body or to the presence of decay products in the organs of the body, in the nervous system, occurs during working hours, consumption of poor quality products, alcohol, etc.

Organic sensations cause various emotional states that a person tries to maintain or eliminate through his actions. The expediency of these actions (consumption 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 medications, food, and smoking temporarily slow down and dull unpleasant sensations, but at the same time cause significant harm to the body.

8. The concept of sensation. Physiological bases of sensations. Types and basic properties, mechanisms of changes in sensitivity, the problem of measuring sensation.

Feeling is called the mental reflection in the cerebral cortex of individual properties of objects and phenomena that directly affect the senses. For sensations to arise, it is necessary, first of all, to have objects and phenomena in the real world that affect the senses, which are called stimuli. The effect of stimuli on the sense organs is called irritation. Information about the external world can enter the brain, that is, the center that processes it, only through the sensory system, which can therefore be considered the gateway of consciousness. Sensory cell - receptor- converts the stimulus (impact) into short rhythmic electrochemical impulses. Then their flow is transmitted along nerve pathways to various switching stations of the central nervous system, where these impulses, passing from one neuron to another, are synthesized and “decoded” into a system of data about the nature of the external influence.

All living beings with a nervous system have the ability to sense sensations, but only those who have a brain with a highly developed cortex can be aware of their sensations. If the cerebral cortex is temporarily turned off (with the help of anesthesia or drugs), then a person cannot consciously respond even to severe pain.

The physiological basis of sensations is the complex activity of the sense organs. I.P. Pavlov called this activity analytical, and cell systems, the most

complexly organized and being perceptive apparatuses that directly carry out the analysis of irritations - analyzers.

The analyzer is characterized by the presence of three specific sections: peripheral (receptor), transmitting (conducting) and central (brain).

The peripheral (receptor) section of the analyzers consists of all sense organs - the eye, ear, nose, skin, as well as special receptor devices located in the internal environment of the body (in the digestive and respiratory organs, in the cardiovascular system, in the genitourinary organs). This section of the analyzer reacts to a specific type of stimulus and processes it into a specific excitation. Receptors can be located on the surface of the body (exteroceptors) and in internal organs and tissues (interoceptors). Receptors located on the surface of the body respond to external stimuli. Visual, auditory, skin, gustatory, and olfactory analyzers have such receptors. Receptors located on the surface of the internal organs of the body respond to changes occurring inside the body (feelings of hunger, thirst). Organic sensations are associated with the activity of interoceptors. An intermediate position is occupied by proprioceptors, located in muscles and ligaments, which serve to sense the movement and position of body organs, and are involved in determining the properties and qualities of objects, i.e. the peripheral section of the analyzer plays the role of a specialized, perceiving apparatus.

Depending on the location of the receptor, there are external analyzers (in which the receptors are located on the surface of the body) and internal (in which the receptors are located in the internal organs and tissues). An intermediate position is occupied by the motor analyzer, the receptors of which are located in the muscles and ligaments. Common to all analyzers are pain sensations, through which the body receives information about the destructive properties of the stimulus.

types of sensations

Classification of sensations: 1) according to the presence or absence of direct contact with the stimulus causing the sensation: 2) according to the location of the receptors, 3) according to the time of occurrence during evolution; 4) by modality (type) of stimulus.

Based on the presence or absence of direct contact of the receptor with the stimulus that causes sensation, distant (vision, hearing, smell - orientation in the immediate environment) and contact (taste, pain, tactile sensations) reception are distinguished.

The most ancient is organic (primarily pain) sensitivity, then contact (tactile) forms appeared. And the youngest evolutionarily are the auditory and visual receptor systems.

According to the modality of the stimulus, sensations are divided into visual (85% of information), auditory, olfactory, gustatory, tactile, static and kinesthetic, temperature, pain, thirst, hunger.

Visual sensations arise as a result of the influence of light rays (electromagnetic waves) on the sensitive part of the eye - the retina, which is the receptor of the visual analyzer. Light affects two types of light-sensitive cells in the retina - rods and cones. Thanks to auditory sensations (distant), a person hears speech and communicates with other people. The irritants for these sensations are sound waves - longitudinal vibrations of air particles, spreading in all directions from the sound source. The human hearing organ responds to sounds ranging from 16 to 20,000 vibrations per second. Auditory sensations reflect the pitch of sound, which depends on the frequency of vibration of sound waves; volume, which depends on the amplitude of their vibrations; timbre of sound - vibrational shapes of sound waves. All auditory sensations can be reduced to three types - speech, music, noise. Vibration sensitivity is adjacent to auditory sensations. Vibration sensations reflect vibrations of an elastic medium. This type of sensitivity is called “contact hearing.” No special vibration receptors have been found in humans. All tissues of the body can reflect vibrations of the external and internal environment. In humans, vibration sensitivity is subordinated to auditory and visual. Olfactory sensations (distant) reflect the smells of objects around us. The olfactory organs are the olfactory cells located in the upper part of the nasal cavity. Taste sensations are caused by the action of substances dissolved in saliva or water on the taste buds. Taste buds—taste buds located on the surface of the tongue, pharynx, and palate—distinguish sensations of sweet, sour, salty, and bitter. Skin sensations. There are several analyzer systems in the skin; tactile (touch sensations), temperature (cold and warm sensations), pain. The tactile sensitivity system is unevenly distributed throughout the body. But most of all, the accumulation of tactile cells is observed in the palm of the hand, on the tips of the fingers and on the lips. Tactile sensations of the hand, combining with muscle-joint sensitivity, form the sense of touch. If you touch the surface of the body and then press on it, the pressure can cause pain. Tactile sensitivity provides knowledge about the qualities of an object, and painful sensations signal the body about the need to move away from the stimulus and have a strong emotional tone. The third type of skin sensitivity is temperature sensations - regulation of heat exchange between the body and the environment. The distribution of heat and cold receptors on the skin is uneven. The back is most sensitive to cold, the chest is the least sensitive. The position of the body in space is signaled by static sensations. Static sensitivity receptors are located in the vestibular apparatus of the inner ear. Sudden changes in body position relative to the ground can lead to dizziness. A special place is occupied by interoceptive (organic) sensations that arise from receptors located in the internal organs and signal their functioning. These sensations form the organic feeling (well-being) of a person. These include feelings of hunger, thirst, satiety, pain and sexual sensations.

General properties of sensations

Different types of sensations are characterized not only by specificity, but also by properties common to them. These properties include: quality, intensity, duration and spatial localization.

Quality is the main feature of a given sensation, distinguishing it from other types of sensations and varying within a given type of sensation. The qualitative diversity of sensations reflects the infinite variety of forms of matter movement.

The intensity of sensation is its quantitative characteristic and is determined by the strength of the current stimulus and the functional state of the receptor.

The duration of a sensation is its temporal characteristic. 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. When a stimulus acts on a sense organ, the sensation does not arise immediately, but after some time the so-called latent (hidden) period of sensation. The sensation does not arise simultaneously with the onset of the stimulus, nor does it 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. 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 in lightness and color to the initial stimulus and consists in preserving a trace of light stimulation of the same quality as the actual stimulus. If you light a bright lamp in complete darkness for a while and then turn it off, then after that for some time we see the bright light of the lamp against a dark background. The presence of positive sequential images explains why we do not notice breaks between successive frames of a film: they are filled with traces of the frames that acted before - sequential images from them. The consistent image changes over time, the positive image is replaced by a negative one. With colored light sources, the sequential image turns into a complementary color.

I. Goethe in his “Essay on the Doctrine of Color” wrote: “When I walked into a hotel one evening and a tall girl with a dazzling white face, black hair and a bright red bodice entered my room, I looked intently at her standing in the twilight at some distance from me. After she left there, I saw on the light wall opposite me a black face, surrounded by a light radiance, and the clothes of a completely clear figure seemed to me to be a beautiful sea green color.”

The appearance of negative sequential images is explained by a decrease in the sensitivity of a given area of ​​the retina to a certain color. Under normal conditions, we do not notice successive images, since the eye makes continuous movements and therefore significant fatigue of any one area of ​​​​the retina is not observed.

And finally, sensations are characterized by the spatial localization of the stimulus. Analysis carried out by spatial receptors gives us information about the localization of the stimulus in space. Contact sensations correspond to the part of the body that is affected by the stimulus.

State budgetary educational institution

Higher professional education

"Yaroslavl State Medical Academy"

Ministry of Health of the Russian Federation

Department of Pedagogy and Psychology with EITI course

COGNITIVE MENTAL PROCESSES

(SENSATION, PERCEPTION, ATTENTION, MEMORY, THINKING, IMAGINATION)

Textbook for 1st year students of medical, pediatric, dental, pharmaceutical faculties

Yaroslavl

UDC 15

Vasilyeva L.N., senior teacher of the department of pedagogy and psychology with the EITI course of the Yaroslavl State Medical Academy, candidate of psychological sciences, Misiyuk Yu.V., senior teacher of the department of pedagogy and psychology with the EITI course of the Yaroslavl State Medical Academy, Odintsova O.Yu., Lecturer at the Department of Pedagogy and Psychology with the EITI course at the Yaroslavl State Medical Academy.

Reviewer:

Baraboshin Alexander Timofeevich, head of the course of the Department of Pedagogy and Psychology with the EITI course of the Yaroslavl State Medical Academy, associate professor, candidate of medical sciences.

Cognitive mental processes (sensation, perception, attention, memory, imagination). Yaroslavl, Yaroslavl State Medical Academy, 2013, 60 p.

Mental processes: sensation, perception, attention, memory, imagination in real life are inseparable and inextricably linked and influence successful activity. It is cognitive mental processes that provide a person with knowledge about the world around him and about himself. The textbook reveals the concept, properties, types and main characteristics of cognitive mental processes, their development in ontogenesis.

Addressed to 1st year students of medical, pediatric, dental, pharmaceutical faculties.

Authorized for publication by the Central Coordination Methodological Council (protocol No. 7 of June 18, 2013).

© Vasilyeva L.N., Misiyuk Yu.V., Odintsova O.Yu.

© Yaroslavl State Medical Academy, 2013.

INTRODUCTION

The unprecedented growth of science and technology, the complication of professional activity have increased the dependence of a specialist’s success in work on the professionalization of his cognitive processes: thinking, speech, imagination, attention, memory, thinking. The reason for the incorrect actions of a medical specialist can be inaccuracy of perception, inattention, inertia of his thinking, etc. The professional preparedness of a specialist is formed along with the improvement of the sensitivity of his senses, attention, ideas, memory, imagination and other mental processes. For example, the more accurately a specialist distinguishes between similar influences, identifies subtle changes in perceived phenomena, remembers and reproduces the necessary data, the better he performs his duties. Conversely, insufficiently sharp vision, inertia of attention (inability to switch and distribute it), too strong a tendency towards automaticity of actions, and poor memory can lead to mistakes and inaccurate task completion.

The direction of development of sensations, perceptions and attention in students must correspond to the requirements that their future profession places on them. Sensations, perceptions and attention develop in active and personally significant activities. The future doctor needs evenly developed basic properties of attention. He will not be able to correctly diagnose or carry out treatment without being attentive to the objective and subjective indicators of the disease, to the condition and personality of the patient. The formation of attention and its properties in students involves influencing the direction of their personality, will, and attitude to work. To do this, you need to explain to them their upcoming professional responsibilities, exercise them in solving problems that require correct perception and quick comprehension of future work situations (identifying the main and secondary in these situations). Attention and attentiveness are formed in students in the process of active learning activities, thanks to maintaining discipline and organization in all classes.

There is not a single profession in which a specialist could do without imagination. It is especially important in the medical profession. One of the main functions of the imagination is penetration into the inner world of another person, which forms the basis of such a professionally important quality of a doctor as empathy. Imagination is not an innate and permanent quality of a person, like other mental processes and properties, it develops and improves.

The medical profession places high demands on the thinking of a specialist. It must be purposeful, flexible, deep, mobile, fast and accurate. To develop professional clinical thinking in students, it is necessary, first of all, to equip them with a system of concepts and knowledge necessary to perform the tasks of future work. But this weapon must be special: simply memorizing concepts and knowledge is not enough, since thinking presupposes a targeted relationship between existing knowledge and information perceived at the moment.

The formation of thinking includes the ability to compare, analyze, carry out operations of synthesis, abstraction, concretization, classification, systematization, widely mobilize knowledge, avoid templates, creatively take into account specific data. To form thinking means, on the basis of certain knowledge, scientific facts with the help of a certain form of their assimilation and application, which ensures the active activity of students, to improve operations, processes, types and forms of thinking, as well as the qualities of the mind in accordance with the tasks and conditions of professional medical practice.

The development of independent thinking is one of the most important tasks of higher education. When solving it, it is necessary to take into account the various manifestations of a person’s independent thinking, in particular, not only the ability to solve some new problems, but also the ability to see these problems on their own. The inability to see problems is the result of formalism in the assimilation of educational information, which consists in the fact that the student only remembers the specific content of the problem of various sciences, but does not see what they are. If a problem discovered by the student himself is solved, then this is associated with a high level of mental activity; knowledge is acquired in a creative way and ensures a higher quality.

Professional speech development helps a student acquire knowledge, improve his thinking, memory and other qualities. A specialist without a sufficiently high level of professional speech will not be able to successfully perform his duties. It is very important that students expand their general and professional vocabulary, develop the skills of fluent and correct proficiency in professional language, learn to express their thoughts briefly, clearly and logically in class, and develop fast reading skills.

A person’s choice of one of many decisions and actions at each moment in time is determined by his needs and picture of the world, i.e. his knowledge and ideas about the world in general and about a specific situation in particular. All knowledge about the clearly observable and hidden from direct view structure of things, the patterns of relationships between them, about people and their qualities, about oneself and, finally, knowledge about the general structure of the world is the result of the integration of knowledge obtained through cognitive processes of different levels of complexity.

Each of these processes has its own characteristics and structure and makes its own special contribution to the formation of an internally connected, dynamic, but at the same time holistic image of the world. Taking place simultaneously, mental processes interact with each other so smoothly and imperceptibly for us that at any given moment in time we perceive and understand the world not as a pile of colors, shades, shapes, sounds, smells that need to be understood, but precisely as a world located outside of us, filled with light, sounds, smells, objects, inhabited by people. Thanks to these processes, the world does not appear to us frozen, but in a temporal perspective, as something that develops and exists not only in the present, but also has a past and a future. The mental processes by which ideas about the world around us, as well as about the organism itself and its internal environment, are formed are called cognitive mental processes.

Images of the surrounding world are complex mental formations; various mental processes take part in their formation, the significance of which in the structure of the whole picture can be revealed by artificially (experimentally or logically) dividing this image into its component parts, as well as in the event of disturbances in the course of these processes. The division of a single mental process into separate cognitive processes (sensation, perception, attention, memory, imagination), accepted in psychology, is thus conditional. At the same time, this division is based on the objective specific features of each of these processes, distinguishing them from each other by the contribution they make to the construction of a holistic image.

Let us consider in more detail those basic cognitive mental processes that are involved in constructing images of the surrounding world.

FEEL

The simplest cognitive process is sensation, which represents a certain primary source of a completed image of the world. In the course of practical activity, a person equally relies on both the data of sensory experience and thinking; they are intimately intertwined. The primacy of sensations does not mean that the entire image is a simple sum of them. Sensations provide only the raw material on the basis of which a holistic image is built. At the same time, sensation as a reflection in a person’s consciousness of individual aspects and properties of an object, perception as a holistic image of an object created on the basis of a complex of sensations, and representation as a sensory-visual image of an object are traditionally referred to as forms of sensory cognition.

Feeling –This is a mental cognitive process of sensory reflection of individual properties of objects and phenomena of objective reality with their direct impact on the senses. The need for constant sensation is clearly demonstrated when the sense organs are completely deprived of external influence. As experiments have shown, if a person is placed in an environment isolated from any sensations, the psyche ceases to function normally. Similar results were observed in the 1950s. John Lill, neuroscientist who developed the hyperbaric chamber . It looked like a dark, soundproof tank, isolated from sounds, light and smells. The reservoir was filled with a high-density solution, the temperature of which corresponded to the temperature of the human body. The person placed in the tank seemed to be in weightlessness. However, the subject quite soon asked to end the experiment due to the occurrence of hallucinations, thinking disorders, distorted perception of time, space, his body, etc. Specific problems of a psychological nature arise during sensory deprivation, that is, when the influx of external influences is limited, which is well known from the example of the development of people who are blind or deaf, as well as those with poor vision and hearing. Numerous observations have shown that disruption of the flow of information in early childhood, associated with deafness and blindness, causes sharp delays in mental development. If children born blind-deaf or deprived of hearing and vision at an early age are not taught special techniques that compensate for these defects through the sense of touch, their mental development will become impossible and they will not develop independently. Thus, sensations are necessary for normal human functioning. They are the main source of knowledge about the outside world. To this, perhaps, we can only add that sensations also reflect the state of the human body with the help of receptors located in his body.

Physiological basis of sensations

Phenomena of the external world and the state of the body that affect our senses (for example, sound waves, photons of light, temperature, etc.) are called irritants. The process of exposure of stimuli to the sense organs is called irritation. Irritation, in turn, causes in the nervous tissue excitation. The sensation occurs as a reaction of the nervous system to a particular stimulus. and, like any mental phenomenon, has a reflex character. Sensations are provided by the activity of special nervous apparatuses called analyzers. Each analyzer consists of three parts:

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

2)Afferent or sensitive nerves (centripetal), conducting excitation to the nerve centers;

3) Central section of the analyzer- these are the sections of the analyzer in which nerve impulses are processed.

For sensation to arise, the entire analyzer as a whole must work.

Physiological research shows that sensation is not a passive process. As a result of the sensation, motor reactions arise, sometimes in the form of a vegetative reaction (vasoconstriction, galvanic skin reflex), sometimes in the form of muscle reactions (turning the eyes, tensing the neck muscles, motor reactions of the hand, etc.). Motor reactions are provided by efferent neurons that carry nerve impulses to the executive organs.

Human sensations are a product of historical development, qualitatively different from the sensations of animals. In animals, the development of sensations is entirely limited by their biological, instinctive needs. A person is able to sense a much larger number of properties of the objects around him. This is due to the fact that in the process of historical development, a person has formed an incomparably wider range of needs.

Classification of sensations

There are different approaches to classifying sensations:

1. According to the main modalities there are:

- sense of smell;

- taste;

- touch

- vision;

- hearing.

2. Systematic classification of Ch. Sherrington sensations are divided into 3 types:

- interoceptive– these are sensations that signal the state of the internal processes of the body. They arise due to receptors located on the walls of the stomach and intestines, heart and circulatory system and other internal organs. This is the most ancient and elementary group of sensations. They are little realized and have the most diffuse form, most often close to emotional states.

- proprioceptive- these are sensations that transmit signals about the position of the body in space and form the basis of human movements. They play a decisive role in their regulation. These are a sense of balance (static) and a motor (kinesthetic) sensation. Receptors for proprioceptive sensitivity are located in muscles and joints (tendons, ligaments) and are called Paccini corpuscles. Excitation occurs in these receptors when muscles are stretched and the position of joints changes. Proprioceptive sensations also include a specific type of sensitivity called the sense of balance, or static sensation. Receptors for the sense of balance are located in the semicircular canals of the inner ear.

- exteroceptive- these are sensations that ensure the receipt of signals from the outside world. Exteroceptive sensations are the main group of sensations that connect a person with the external environment. Exteroceptive sensations are usually divided into two subgroups:

a) contact sensations are caused by a stimulus directly applied to the surface of the corresponding receptor. Examples of contact sensation are taste and touch.

b) distant sensations are caused by stimuli acting on the sense organs at some distance. These senses include smell, hearing and vision.

3. Genetic classification by H. Head allows us to distinguish two types of sensitivity:

- protopathic sensitivity - more primitive, less differentiated and localized, which includes organic feelings (hunger, thirst, etc.);

- epicritic sensitivity - finely differentiated, rational, genetically younger. This type of sensitivity includes the main types of human sensations.

Properties of sensations

The main properties of sensations include: quality, intensity, duration, spatial localization, absolute and relative thresholds.

1. Quality - this is the main feature of this sensation, distinguishing it from other types of sensations (visual sensation is qualitatively different from auditory sensation, etc.).

2. Intensity – this is a quantitative characteristic that 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.

3. Duration(or duration) Feel - This is a temporary characteristic of the sensation that has arisen. It is determined by the functional state of the sensory organ, the time and intensity of the stimulus. When a stimulus acts on a sense organ, the sensation does not arise immediately, but after some time - the so-called latent (hidden) period Feel. The latent period of different types of sensations is not the same: for example, for tactile sensations it is 130 ms, for pain - 370, and for taste - only 50 ms. Likewise, the sensation does not disappear simultaneously with the cessation of the stimulus. This inertia of sensations manifests itself in the so-called aftereffect. For example, a visual sensation is stored as a sequential image. So, for example, if in complete darkness we light a bright lamp for a while and then turn it off, then after that for some time we “see” the bright light of the lamp against a dark background. The aftereffect also explains why we do not notice breaks between successive frames of an animated film: they are filled with traces of the frames that were in effect before - successive images from them.

4. Spatial localization stimulus allows you to localize it in space. Contact sensations correspond to the part of the body that is affected by the stimulus.

So far we have been talking about the qualitative difference in types of sensations. However, no less important is the quantitative analysis of the intensity of sensations. Not every irritation causes a sensation. For a sensation to arise, the stimulus must reach a certain magnitude. The minimum magnitude of the stimulus at which sensation first occurs is called absolute lower threshold of sensation (or the threshold for the appearance of sensation). Stimuli that do not reach it lie below the threshold of sensation. For example, we do not feel individual specks of dust and small particles falling on our skin. Light stimuli below a certain brightness limit do not cause visual sensations in us. The value of the lower absolute threshold characterizes absolute sensitivity sense organs. The weaker the stimuli that cause sensations (i.e., the lower the absolute threshold), the higher the absolute sensitivity of the senses.

Different analyzers have different sensitivities. The threshold of one human olfactory cell for some odorous substances does not exceed 8 molecules. It takes at least 25,000 times more molecules to produce the sensation of taste than to produce the sensation of smell. A person has a very high sensitivity of visual and auditory analyzers.

The absolute sensitivity of the analyzer is limited not only by the lower, but also by the upper threshold of sensation. Upper absolute threshold Feel is called the maximum strength of the stimulus, at which a sensation adequate to the current stimulus still arises. A further increase in the strength of stimuli acting on our receptors causes a painful sensation (for example, with an extremely loud sound, blinding brightness of light, etc.).

The value of absolute thresholds, both lower and upper, varies depending on various conditions: the age of the person, the functional state of the receptor, the strength and duration of the stimulus, etc.

It is necessary to distinguish from absolute sensitivity relative, or difference, sensitivity, i.e. . sensitivity to change in stimulus, discovered by the German scientist M. Weber. Difference sensitivity is a relative value, not an absolute one. This means that the greater the magnitude of the initial stimulus, the greater must be the addition to it in order for a change in sensation to occur. For example, we notice changes in the illumination of a room depending on the initial illumination level. If the initial illumination is 100 lux (lux), then the increase in illumination that we first notice should be at least 1 lux. The same applies to auditory, motor, and other sensations. The minimal difference between two stimuli, causing barely h noticeable difference in sensations is called threshold of discrimination , or difference threshold. The discrimination threshold is characterized by a relative value that is constant for a given analyzer. For a visual analyzer, this ratio is approximately 1/100 of the intensity of the initial stimulus, for an auditory one - 1/10, for a tactile one - 1/30.

Phenomena of sensations

1. Sensory adaptation. Both the absolute and relative sensitivity of our sense organs can vary within very large limits. For example, in the dark our vision becomes sharper, and in strong light its sensitivity decreases. This can be observed when a person moves from a dark room to a brightly lit one. In this case, the person’s eyes begin to experience pain; it takes some time for the analyzer to adapt to the bright lighting. In the opposite case, when a person moves from a brightly lit room to a dark room, he also does not see anything at first (he temporarily “goes blind”), and it takes 20-30 minutes for him to be able to navigate well enough in the dark. Studies have shown that the sensitivity of the eye increases 200,000 times when moving from bright light to darkness. The described changes in sensitivity are called adaptation sense organs to environmental conditions. Adaptation is a change in the absolute and relative sensitivity of the senses under the influence of external influences. Adaptation phenomena are characteristic of both the auditory sphere and the sense of smell, touch, and taste. The change in sensitivity that occurs according to the type of adaptation does not occur immediately; it has its own temporary characteristics. These temporal characteristics are different for different sense organs. So, in order for vision in a dark room to acquire the required sensitivity, about 30 minutes should pass. Adaptation of the auditory organs occurs much faster. Human hearing adapts to the surrounding background within 15 s. There is also a rapid change in sensitivity in the sense of touch (weak contact with the skin of our clothing ceases to be perceived after just a few seconds). The phenomena of thermal adaptation (getting used to temperature changes) are well known. However, these phenomena are clearly expressed only in the average range, and adaptation to extreme cold or extreme heat, as well as to painful stimuli, almost does not take place. The phenomena of adaptation to odors are also known. Thus, there are three types of adaptation phenomena:

1. Adaptation as the complete disappearance of sensation during prolonged exposure to the stimulus;

2. Adaptation as a dulling of sensation under the influence of a strong stimulus. (These two types of adaptation refer to negative adaptation, since as a result it reduces the sensitivity of the analyzers.)

3. Adaptation is also called an increase in sensitivity under the influence of a weak stimulus. This type of adaptation is defined as positive adaptation. For example, in the visual analyzer, dark adaptation of the eye, when its sensitivity increases under the influence of darkness, is a positive adaptation. A similar form of auditory adaptation is adaptation to silence.

The physiological mechanism of the adaptation phenomenon consists of changes in the functioning of receptors. For example, it is known that under the influence of light, visual purple, located in the rods of the retina, decomposes. In the dark, on the contrary, visual purple is restored, which leads to increased sensitivity. The phenomenon of adaptation is also explained by the processes occurring in the central sections of the analyzers. With prolonged stimulation, the cerebral cortex responds with internal protective inhibition, reducing sensitivity.

2. Interaction and mutual influence of sensations Each other . A change in the sensitivity of the analyzer under the influence of irritation of other sense organs is called interaction of sensations. All our analyzing systems are capable of influencing each other. At the same time, the interaction of sensations, like adaptation, manifests itself in two opposite processes - an increase and decrease in sensitivity. The general pattern is that weak stimuli increase, and strong stimuli decrease, the sensitivity of analyzers when they interact. An increase in sensitivity as a result of the interaction of analyzers is called sensitization. A.R. Luria identified two options for increasing sensitivity (sensitization):

Based on sustainable changes occurring in the body;

Based on temporary physiological and psychological changes in the state of the body (for example, under the influence of psychoactive substances, mental disorders, etc.).

Sensitization of the senses is easy to notice in the following cases: when compensating for sensory defects (blindness, deafness) and the specific requirements of certain professions. Thus, the loss of vision or hearing is to a certain extent compensated by the development of other types of sensitivity. Blindness causes increased tactile sensitivity, and people can read books with a special Broglie alphabet using their fingers. There are cases when people with limited vision engaged in sculpture, which indicates a highly developed sense of touch. Deafness causes the development of vibration sensations. Some people who are deaf develop vibration sensitivity so strongly that they can even hear music - to do this, they put their hand on the instrument. Deaf-blind people, holding their hand at the throat of the speaking interlocutor, can thus recognize him by his voice and understand what he is talking about.

The phenomena of sensitization of the sense organs are also observed in persons of certain professions. Dyers can distinguish up to 50-60 shades of black. The ability of musicians to detect differences in tones that are not perceived by an ordinary listener, or the sensitivity of the taste analyzer of tasters is known.

The interaction of sensations is also manifested in a phenomenon called synesthesia- the occurrence, under the influence of irritation of one analyzer, of a sensation characteristic of other analyzers. In psychology, the facts of “colored hearing” are well known, which occurs in many people, and especially in many musicians (for example, Scriabin). For example, it is widely known that we evaluate high-pitched sounds as “light” and low-pitched sounds as “dark”. It is characteristic that the phenomenon of synesthesia is not distributed equally in all people.

All these facts show that the acuity of absolute and differential sensitivity can vary significantly and that human participation in various forms of conscious activity can change the acuity of this sensitivity.