The sensory organization of the personality is the level of development of individual systems of sensitivity and the possibility of their association. The sensory systems of a person are his sense organs, as if receivers of his sensations, in which sensation is transformed into perception.

The main feature of the sensory organization of a person is that it develops as a result of his entire life path. The sensitivity of a person is given to him at birth, but its development depends on the circumstances, desire and efforts of the person himself. Feeling - the lower mental process of reflecting the individual properties of objects or phenomena of the inner and outer world with direct contact.

It is obvious that the primary cognitive process takes place in human sensory systems, and already on its basis, cognitive processes that are more complex in their structure arise: perceptions, representations, memory, thinking. No matter how simple the primary cognitive process may be, but it is precisely this that is the basis of mental activity, only through the “entrances” of sensory systems does the world around us penetrate into our consciousness. The physiological mechanism of sensations is the activity of the nervous apparatus - analyzers consisting of 3 parts:

· receptor- the perceiving part of the analyzer (performs the conversion of external energy into a nervous process)

· central analyzer section- afferent or sensory nerves

· cortical parts of the analyzer in which nerve impulses are processed.

Each type of sensation is characterized not only by specificity, but also has common properties with other types: quality, intensity, duration, spatial localization. The minimum amount of stimulus at which a sensation appears is absolute threshold of sensation. The value of this threshold characterizes absolute sensitivity, which is numerically equal to a value inversely proportional to the absolute threshold of sensations. Sensitivity to a change in stimulus is called relative or differential sensitivity. The smallest difference between two stimuli that causes a slight difference in sensation is called difference threshold.

Classification of sensations

The classification according to the modality of sensations (specificity of the sense organs) is widespread - this is the division of sensations into visual, auditory, vestibular, tactile, olfactory, gustatory, motor, visceral. There are intermodal sensations - synesthesia. The main and most significant group of sensations brings information from the outside world to a person and connects him with the external environment. These are exteroceptive - contact and distant sensations, they arise in the presence or absence of direct contact of the receptor with the stimulus. Sight, hearing, smell are distant sensations. These types of sensations provide orientation in the nearest environment. Taste, pain, tactile sensations - contact. According to the location of receptors on the surface of the body, in muscles and tendons, or inside the body, they are distinguished, respectively:

– exteroceptive sensations (arising from the action of external stimuli on receptors located on the surface of the body, outside) visual, auditory, tactile;

– proprioceptive(kinesthetic) sensations (reflecting the movement and relative position of body parts with the help of receptors located in muscles, tendons, articular bags);

– interoceptive(organic) sensations - arising from the reflection of metabolic processes in the body with the help of specialized receptors, hunger and thirst.

In order for a sensation to arise, it is necessary that the stimulus reaches a certain value, which is called threshold of perception.
Relative Threshold- the amount that the stimulus must reach in order for us to feel this change.
Absolute Thresholds are the upper and lower limits of the resolution of the organ. Threshold research methods:

Border method

consists in a gradual increase in the stimulus from subthreshold, then the reverse procedure

Installation method

the subject independently distinguishes the magnitude of the stimulus

Question number 26. Overview of sensory systems.

touch system (analyzer according to I.P. Pavlov) is a part of the nervous system, consisting of perceiving elements - receptors that receive stimuli from the external or internal environment, nerve pathways that transmit information.

Receptor – peripheral specialized part of the analyzer, through which the impact of stimuli from the outside world and the internal environment of the body is transformed into a process of nervous excitation.

The sensory system enters information into the brain and analyzes it.

The work of any sensory system begins with the perception by receptors of physical or chemical energy external to the brain, its transformation into nerve signals and transmits them to the brain through chains of neurons.

The process of transmission of sensory signals is accompanied by their multiple transformation and recoding and ends with higher analysis and synthesis (image recognition), after which the response of the body is formed.

Main general principles for constructing sensory systems higher vertebrates and humans are as follows:

1) layering, that is, the presence of several layers of nerve cells, the first of which is associated with receptors, and the last with neurons in the motor areas of the cerebral cortex. This property makes it possible to specialize neural layers in the processing of different types of sensory information, which allows the body to quickly respond to simple signals analyzed already at the first levels of the sensory system;

2) multi-channel sensory system, that is, the presence in each layer of a multitude (from tens of thousands to millions) of nerve cells associated with a multitude of cells of the next layer;

3) a different number of elements in neighboring layers, which forms "sensor funnels";

4) differentiation of the sensory system vertically and horizontally. Vertical differentiation consists in the formation of departments, each of which consists of several neural layers. Horizontal differentiation consists in different properties of receptors, neurons and connections between them within each of the layers.

The sensor system performs the following main functions, or operations, with signals:

– detection;

- discrimination (the ability to notice differences in the properties of simultaneously or sequentially acting stimuli);

– transmission and transformation;

- coding (transformation of information into a conditional form, performed according to certain rules - a code);

- detection of signs (selective selection by a sensory neuron of one or another sign of an irritant that has behavioral significance);

- recognition of images (consists in assigning the image to a particular class of objects that the organism has previously encountered, that is, in the classification of images).

Detection and primary discrimination of signals is provided by receptors, and detection and recognition of signals - by neurons of the cerebral cortex. Transmission, transformation and encoding of signals is carried out by neurons of all layers of sensory systems.

Types of sensory systems.

1. auditory. The appropriate stimulus is sound. Reception (transduction) of sound is the perception of sound at the level of the auditory receptors of the ear, i.e. the transformation (transformation) of sound vibrations into nervous excitation. Sound receptors are hair cells(more precisely: internal hair cells), they are hidden in the cochlea of ​​the inner ear, sitting on the basement membrane of the organ of Corti.

2. visual. ita set of structures that provide the perception of light energy and the formation of visual sensations (visual images). The appropriate stimulus is light.

3. vestibular. Adequate irritant - gravity, acceleration.

4. Taste. Adequate irritant - taste (bitter, sour, sweet, salty).

5. Olfactory. itneurosystemfor recognition of volatile and water-soluble substances by the configuration of their molecules, creating subjective sensory images in the form of odors. Adequate irritant - smell. Functions of the olfactory sensory system: 1) food detection for attractiveness, edibility and inedibility; 2) motivation and modulation of eating behavior; 3) adjustment of the digestive system to food processing according to the mechanism of unconditioned and conditioned reflexes; 4) initiation of defensive behavior due to the detection of substances harmful to the body or substances associated with danger; 5) motivation and modulation of sexual behavior due to the detection of odorous substances and pheromones.

6. kinesthetic\u003d tactile (tactile) + temperature (heat and cold). An adequate irritant is pressure, vibration, heat (high temperature), cold (low temperature).

7. Motor. Provides a sense of the relative position of body parts in space, a sense of one's body). It is the motor sensory system that allows us to touch, for example, our nose or other parts of the body with our hands, even with our eyes closed.

8. muscular(proprioceptive). Provides a sense of muscle tension. Adequate stimulus - muscle contraction and stretching of the tendons.

9. pain. This is a set of nerve structures that perceive damaging stimuli and form pain sensations, that is, pain. Pain receptors are called nociceptors. These are high-threshold receptors that respond to destructive, damaging or disturbing effects of any process. In general, damage is a signal of a violation of normal life: damage to the integument of the body and organs, cell membranes and cells, the nociceptive nerve endings themselves, a violation of the course of oxidative processes in tissues.

10. Interoceptive. Provides inner sensations. It is poorly controlled by consciousness and, as a rule, gives fuzzy sensations. However, in a number of cases, people can say that they feel in some internal organ not just discomfort, but a state of “pressure”, “heaviness”, “bursting”, etc. The interoceptive sensory system ensures the maintenance of homeostasis, and at the same time it does not necessarily generate any sensations perceived by consciousness, i.e. does not create perceptual sensory images.

To ensure the normal functioning of an organism*, the constancy of its internal environment, connection with the constantly changing external environment and adaptation to it are necessary. The body receives information about the state of the external and internal environments with the help of those who analyze (distinguish) this information, provide the formation of sensations and ideas, as well as specific forms of adaptive.

The concept of sensory systems was formulated by IP Pavlov in the doctrine of analyzers in 1909 during the study of them. Analyzer- a set of central and peripheral formations that perceive and analyze changes in the external and internal environments of the body. The concept of "sensory system", which appeared later, replaced the concept of "analyzer", including the mechanisms of regulation of its various departments with the help of direct and feedback connections. Along with this, there is still the concept of "sense organ" as a peripheral entity that perceives and partially analyzes environmental factors. The main part is equipped with auxiliary structures that provide optimal perception.

With the direct impact of various environmental factors with the participation in the body, there are Feel, which are reflections of the properties of objects of the objective world. The peculiarity of sensations is their modality, those. the totality of sensations provided by any one sensory system. Within each modality, in accordance with the type (quality) of the sensory, different qualities can be distinguished, or valency. Modalities are, for example, sight, hearing, taste. Qualitative types of modality (valency) for vision are various colors, for taste - the sensation of sour, sweet, salty, bitter.

The activity of sensory systems is usually associated with the emergence of five senses - sight, hearing, taste, smell and touch, through which the body is connected with the external environment. However, in reality, there are much more of them.

The classification of sensory systems can be based on various features: the nature of the acting stimulus, the nature of the sensations that arise, the level of sensitivity of receptors, the rate of adaptation, and much more.

The most significant is the classification of sensory systems, which is based on their purpose (role). In this regard, there are several types of sensory systems.

External sensor systems perceive and analyze changes in the external environment. This should include visual, auditory, olfactory, gustatory, tactile and temperature sensory systems, which are perceived subjectively as sensations.

Internal (visceral) sensory systems perceive and analyze changes in the internal environment of the body, indicators of homeostasis. Fluctuations in the indicators of the internal environment within the physiological norm in a healthy person are usually not perceived subjectively in the form of sensations. So, we cannot subjectively determine the value of blood pressure, especially if it is normal, the state of the sphincters, etc. However, information coming from the internal environment plays an important role in regulating the functions of internal organs, ensuring the adaptation of the body to various conditions of its life. The significance of these sensory systems is studied in the course of physiology (adaptive regulation of the activity of internal organs). But at the same time, a change in some constants of the internal environment of the body can be perceived subjectively in the form of sensations (thirst, hunger, sexual desire), which are formed on the basis of biological ones. To meet these needs, behavioral responses are included. For example, when a feeling of thirst arises due to the excitation of osmo- or volumic receptors, it is formed, aimed at finding and receiving water.

Sensory systems of body position perceive and analyze changes in the position of the body in space and body parts relative to each other. These include the vestibular and motor (kinesthetic) sensory systems. As we evaluate the position of our body or its parts relative to each other, this impulse reaches our consciousness. This is evidenced, in particular, by the experience of D. Maklosky, which the scientist put on himself. Primary afferent fibers from muscle receptors were irritated by threshold electrical ones. An increase in the frequency of impulses of these nerve fibers evoked subjective sensations in the subject of a change in the position of the corresponding limb, although its position did not actually change.

nociceptive sensory system should be singled out separately in connection with its special significance for the body - it carries information about damaging effects. Pain can occur with irritation of both extero- and interoreceptors. .

Interaction of sensory systems carried out at the spinal, reticular, thalamic and cortical levels. The integration of signals in . In the cerebral cortex, the integration of higher-order signals takes place. As a result of multiple connections with other sensory and non-specific systems, many cortical systems acquire the ability to respond to complex combinations of signals of different modalities. This is especially characteristic of the nerve cells of the associative areas of the cerebral cortex, which have high plasticity, which ensures the restructuring of their properties in the process of continuous learning to recognize new stimuli. Intersensory (cross-modal) interaction at the cortical level creates the conditions for the formation of a "scheme of the world" (or "map of the world") and continuous linking, coordination with it of the body's own "scheme" of a given organism.

With the help of sensory systems, the body learns the properties of objects and phenomena of the environment, the beneficial and negative aspects of their impact on the body. Therefore, violations of the function of external sensory systems, especially visual and auditory, make it extremely difficult to understand the outside world (the surrounding world is very poor for the blind or deaf). However, only analytical processes in the CNS cannot create a real idea of ​​the environment. The ability of sensory systems to interact with each other provides a figurative and holistic view of the objects of the external world. For example, we evaluate the quality of a lemon wedge using visual, olfactory, tactile, and gustatory sensory systems. At the same time, an idea is formed both about individual qualities - color, consistency, taste, and about the properties of the object as a whole, i.e. a certain integral image of the perceived object is created. The interaction of sensory systems in assessing phenomena and objects also underlies the compensation of impaired functions in the event of the loss of one of the sensory systems. For example, in the blind, the sensitivity of the auditory sensory system increases. Such people can determine the location of large objects and bypass them if there is no extraneous noise due to the reflection of sound waves from the object in front. American researchers observed a blind man who accurately determined the location of a large cardboard plate. When the subject's ears were covered with wax, he was unable to determine the location of the cardboard.

Interactions of sensory systems can manifest themselves in the form of the influence of excitation of one system on the state of excitability of another according to the dominant principle. For example, listening to music can cause pain relief during dental procedures (audio analgesia). Noise impairs visual perception, bright light increases the perception of sound volume. The process of interaction of sensory systems can manifest itself at various levels. The reticular formation, the cerebral cortex, plays a particularly important role in this. Many cortical neurons have the ability to respond to complex combinations of signals of different modalities (multisensory convergence), which is very important for learning about the environment and evaluating new stimuli.

General information

Adhering to the cognitive approach to the description of the psyche, we represent a person as a kind of system that processes symbols in solving its problems, then we can imagine the most important feature of a person's personality - the sensory organization of the personality.

Sensory organization of personality

The sensory organization of the personality is the level of development of individual systems of sensitivity and the possibility of their association. The sensory systems of a person are his sense organs, as if receivers of his sensations, in which sensation is transformed into perception.

Every 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 trait. For example, bats have developed sensitivity to the perception of short ultrasonic pulses, dogs have olfactory sensitivity.

The main feature of the sensory organization of a person is that it develops as a result of his entire life path. The sensitivity of a person is given to him at birth, but its development depends on the circumstances, desire and efforts of the person himself.

What do we know about the world and about ourselves? Where do we get this knowledge from? How? The answers to these questions come from the depths of centuries from the cradle of all living things.

Feel

Sensation is a manifestation of the 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 the phenomena of the external world is delivered to the brain. In the same way, a loop closes through sensations to receive feedback about the current physical and, to some extent, mental state of the organism.

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 takes place in human sensory systems, and already on its basis, cognitive processes that are more complex in their structure arise: perceptions, representations, memory, thinking.

No matter how simple the primary cognitive process may be, but it is precisely this that is the basis of mental activity, only through the “entrances” of sensory systems does the world around us penetrate into our consciousness.

Sensation Processing

After the information is received by the brain, the result of its processing is the development of a response or strategy aimed, for example, at improving physical tone, focusing more on current activities, or setting up for accelerated inclusion in mental activity.

Generally speaking, the response or strategy worked out at any given time is the best choice of the options available to the person at the time of the decision. However, it is clear that the number of options available and the quality of choice vary from person to person and depend on, for example:

mental properties of personality,

strategies for interacting with others

some of the physical condition,

experience, the availability of the necessary information in memory and the possibility of retrieving it.

the degree of development and organization of higher nervous processes, etc.

For example, the baby went out naked in the cold, his skin feels cold, perhaps chills appear, he becomes uncomfortable, a signal about this enters the brain and a deafening roar is heard. The reaction to cold (stimulus) in an adult may be different, he will either rush to get dressed, or jump into a warm room, or try to warm himself in another way, for example, by running or jumping.

Improving the higher mental functions of the brain

Over time, children improve their reactions, multiplying the effectiveness of the result achieved. But after growing up, the opportunities for improvement do not disappear, despite the fact that the adult's susceptibility to them decreases. It is in this that "Effekton" sees part of its mission: increasing the efficiency of intellectual activity by training the higher mental functions of the brain.

Effekton's software products make it possible to measure various indicators of the human sensorimotor system (in particular, the Jaguar package contains tests of the time of a simple audio and visual-motor reaction, a complex visual-motor reaction, and the accuracy of perception of time intervals). Other packages of the "Effekton" complex evaluate the properties of cognitive processes of higher levels.

Therefore, it is necessary to develop the perception of the child, and the use of the package "Jaguar" can help you with this.

Physiology of sensations

Analyzers

The physiological mechanism of sensations is the activity of the nervous apparatus - analyzers, consisting of 3 parts:

receptor - the perceiving part of the analyzer (carries out the conversion of external energy into a nervous process)

central part of the analyzer - afferent or sensory nerves

cortical sections of the analyzer, in which the processing of nerve impulses takes place.

Certain receptors correspond to their sections of cortical cells.

The specialization of each sense organ is based not only on the structural features of the receptor analyzers, but also on the specialization of the neurons that make up the central nervous apparatus, which receive signals perceived by the peripheral senses. The analyzer is not a passive receiver of energy; it is reflexively rebuilt under the influence of stimuli.

The movement of stimulus from the outer to the inner world

According to the cognitive approach, the movement of a stimulus during its transition from the external world to the internal one occurs as follows:

the stimulus causes certain changes in energy in the receptor,

energy is converted into nerve impulses

information about nerve impulses is transmitted to the corresponding structures of the cerebral cortex.

Sensations depend not only on the capabilities of the brain and sensory systems of a person, but also on the characteristics of the person himself, his development and condition. With illness or fatigue, a person changes sensitivity to certain influences.

There are also cases of pathologies when a person is deprived, for example, of hearing or sight. If this trouble is congenital, then there is a violation of the flow of information, which can lead to mental retardation. If these children were taught special techniques to compensate for their shortcomings, then some redistribution within the sensory systems is possible, thanks to which they will be able to develop normally.

Properties of sensations

Each type of sensation is characterized not only by specificity, but also has common properties with other types:

quality,

intensity,

duration,

spatial localization.

But not every irritation causes a sensation. The minimum value of the stimulus at which a sensation appears is the absolute threshold of sensation. The value of this threshold characterizes the absolute sensitivity, which is numerically equal to the value inversely proportional to the absolute threshold of sensations. And sensitivity to a change in the stimulus is called relative or difference sensitivity. The minimum difference between two stimuli, which causes a slightly noticeable difference in sensations, is called the difference threshold.

Based on this, we can conclude that it is possible to measure sensations. And once again you come to admiration from amazing delicately working devices - human sense organs or human sensory systems.

Effekton's software products allow you to measure various indicators of the human sensory system (for example, the Jaguar package contains tests of the speeds of a simple audio and visual-motor reaction, a complex visual-motor reaction, the accuracy of time perception, the accuracy of space perception, and many others). Other packages of the "Effekton" complex also evaluate the properties of cognitive processes of higher levels.

Classification of sensations

Five basic types of sensations: sight, hearing, touch, smell and taste - were already known to the ancient Greeks. At present, ideas about the types of human sensations have been expanded, about two dozen different analyzer systems can be distinguished, reflecting the impact of the external and internal environment on receptors.

Sensations are classified according to several principles. The main and most significant group of sensations brings information from the outside world to a person and connects him with the external environment. These are exteroceptive - contact and distant sensations, they arise in the presence or absence of direct contact of the receptor with the stimulus. Sight, hearing, smell are distant sensations. These types of sensations provide orientation in the nearest environment. Taste, pain, tactile sensations - contact.

According to the location of receptors on the surface of the body, in muscles and tendons, or inside the body, they are distinguished, respectively:

exteroception - visual, auditory, tactile and others;

proprioception - sensations from muscles, tendons;

interoception - feelings of hunger, thirst.

In the course of the evolution of all living things, sensitivity has undergone changes from the most ancient to the modern. So, distant sensations can be considered more modern than contact ones, but in the structure of the contact analyzers themselves, one can also reveal more ancient and completely new functions. So, for example, pain sensitivity is more ancient than tactile.

Such classification principles help to group all kinds of sensations into systems and see their interaction and connections.

Types of sensations

Vision, hearing

Let us consider various types of sensations, bearing in mind that vision and hearing are the most well studied.

The eye is a completely unusual device that "mother nature" could only invent for our vision, a sensory organ with a very complex anatomical structure. Light waves, reflected from objects, are refracted, pass through the lens of the eye, which provides focusing of light, and appear on the retina in the form of an image.

Clear, sharp vision of equidistant objects is provided by a change in the curvature of the lens, called accommodation. This is the most important regulator of the function of vision. Various disorders can affect accommodation, which affects visual acuity, the level of discrimination of small details.

The retina of the eye is the front edge of the brain, the part of the visual analyzer farthest from the brain, which first perceives light, processes and converts light energy into irritation - a signal in which all information about what the eye sees is encoded. The study of this nerve formation helps to reveal the secrets of the visual mechanism created by nature. Yes, of course, "mother nature" did a great job creating such a perfect instrument of our vision.

The eye itself is a distant receptor, because it makes it possible to recognize objects remote from the sense organs and phenomena occurring around us. Our vision helps to determine the distance to objects and their volume. This is possible due to the pairing of the visual analyzer, on the retina, when moving away or approaching an object, the image size changes, and movement, i.e. convergence and dilution of the axes of the eyes.

The optic nerve fibers make up the retina of the eye, which consists of several tens of thousands of endings that are excited under the influence of a light wave. The endings of the optic nerve are different in form and function.

Receptors located in the center of the retina, similar in shape to cones, reflect color and are the apparatus of daytime vision. Rod-shaped nerve endings reflect light. Located around the cones, closer to the edge of the retina, they are the twilight vision apparatus. Cone and rod vision are independent of each other, so if one is impaired, the other remains unchanged.

Two groups of visual sensations can be distinguished:

achromatic, reflecting the transition from white to black, with all shades of gray and

chromatic, reflecting the color gamut with a large number of shades and tones of color.

Without the reflection of color, the human world would become much poorer, and the emotional background is also expressed in color sensations, for example, they often talk about warm and cold color tones. The emotional impact of color is widely used in painting, and in any kind of art craft.

With the help of a visual analyzer, you can distinguish the brightness of the color and highlight the object from the general background. Black on white or white on black is especially visible. Thanks to the law of contrast, it becomes possible to distinguish all planar black and white images. If the object is far away and at the same time poorly lit, then for its unmistakable definition, the contrast should be high enough.

Perhaps, in the life of any person, visual sensations play the greatest role, without them human activity is very limited, and some types of activity are generally impossible, because. the main source of information is vision. The eyes, during long work, for example, on a computer, get tired, they need rest, the exercises of the "Comfort" package will come to their aid.

Hearing

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, different in length and thickness, set in motion at a certain number of vibrations per second, and the received signals are transmitted to the brain. These oscillations occur in elastic bodies and are transmitted by the air medium. We know from physics that sound has a wave nature and is characterized by frequency and amplitude.

The frequency of sound is determined by the number of wave periods per unit of time. So, for example, the auditory range of an adult is in the range of 15 - 20,000 Hz, decreasing with age. Sounds differ not only in frequency, but also in timbre, giving uniqueness and peculiar coloring to the voice and sound of various musical instruments. The loudness of a sound depends on its amplitude and is measured in decibels (logarithmic scale). Normal conversation occurs at 50 - 60 dB, and rock music up to 130 dB, i.e. reaches the pain threshold.

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

force (loud - weak),

height (high - low),

sound duration and tempo-rhythmic pattern of perceived sounds.

Phonemic hearing is called hearing, using which you can distinguish the sounds of speech. It is formed during life and depends on the speech environment. Good knowledge of a foreign language involves the development of a new system of phonemic hearing. The ability to learn foreign languages ​​is determined by phonemic hearing, which also affects the literacy of written speech.

The musical ear of a person is brought up and formed, as well as speech. The ability to enjoy music is a centuries-old result of the development of the musical culture of mankind.

Noises and rustles are less significant for a person, unless they interfere with his life. Noises can cause a pleasant emotional mood, for example, the sound of rain, the roar of the surf, and, one of my acquaintances, a computer network administrator, said that he cannot fall asleep when he does not hear the noise of working fans from three or four computers. Noises can also serve as a danger signal - the hiss of gas, the clatter of feet behind your back, the howl of a siren.

Smell, touch, vibratory and proprioceptive sensations

A person has the most developed vision and hearing, respectively, they are the most studied, although there are other senses that are also important for a person in his daily life.

vibration sensations

Vibrational sensitivity can be associated with auditory sensations, because. they have a common nature of reflected physical phenomena. Vibration sensations reflect vibrations of an elastic medium. This kind of sensitivity can be called "contact hearing". No specific vibration receptors have been found in humans. It is believed that the vibrational sense is one of the most ancient types of sensitivity, and all tissues of the body can reflect the vibrations of the external and internal environment.

In human life, vibrational sensitivity is subordinated to auditory and visual. The cognitive value of vibration sensitivity increases in those activities where vibrations become a signal of malfunctions in the operation of the machine. In the life of the deaf and deaf-blind, vibrational sensitivity compensates for hearing loss. The body of a healthy person is energized by short vibrations, long and intense vibrations tire and cause painful phenomena.

Smell

The olfactory sensation receptor is the end of the olfactory nerve in the nasal cavity, it belongs to the distant ones. Microscopic particles of substances that enter the nasal cavity with air, being irritants, cause olfactory sensations.

In animals, the sense of smell is the main distant receptor, guided by smell, the animal finds food or avoids danger. The sexual behavior of animals depends on the production of special substances - pheromones. There is a theory that in humans, pheromones play an important role in matters of sex.

A person in the modern world does not need to follow olfactory sensations, orienting himself in the environment. The function of smell in humans is suppressed by sight and hearing. The absence in the language of special words for designating olfactory sensations indicates their insufficient development and instability. Usually they say: "the smell of the sea", "the smell of roses", "the smell of the stables".

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

Taste sensations are contact, arising from the contact of the sense organ (tongue) 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 tongue movements 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 are quickly worn out from contact with food and then renewed. Sensory signals then travel along nerves to the hindbrain, thalamus, and gustatory cortex, which processes taste sensations.

Taste sensations, like olfactory ones, increase a person's appetite. By analyzing the quality of food, taste sensations also have a protective function and are important for survival. When fasting, taste sensitivity increases, when saturated or satiety - decreases.

In the skin there are several independent analyzer systems:

tactile (sensation of touch),

temperature,

All types of skin sensitivity are referred to as contact sensitivity. The largest accumulation of tactile cells is in the palm, on the fingertips and on the lips. Skin receptors transmit information to the spinal cord by contacting motor neurons, which makes possible reflex actions, such as, for example, pulling a hand away from a fire. The sense of touch is the tactile sensations of the hand along with the musculo-articular sensitivity.

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

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 the object, and pain sensitivity gives a signal about the harm caused by the stimulus.

proprioceptive sensitivity

Kinesthesia

Kinesthetic sensations are sensations of movement and position of individual parts of the body. Kinesthetic sensation receptors 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. The exercises for the hands of the "Comfort" package improve blood circulation, reduce tension and fatigue, promoting better coordination of movements and increasing mental performance.

It is clear that the development of kinesthetic sensations is one of the most important tasks of education.

Speech kinesthesias are formed in the infantile and preschool periods of human development. Teaching a foreign language requires the development of such speech kinesthesias that are 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: semicircular canals and vestibular sacs convert signals about relative motion and gravity and transmit them to the cerebellum and the cortex of the temporal region. Sudden and frequent changes in the position of the body relative to the plane of the earth, such as swinging on a swing or sea rolling, lead to dizziness - "seasickness".

Do humans have enough sense organs?

Sensations provide the body with adequate orientation in the environment. Could a person get to know the world around him more deeply if he had more sense organs?

Philosophers-idealists made a conclusion about the limited cognitive capabilities of a person, linking this with the limitedness of the sense organs and the variety of phenomena in the surrounding world.

Materialists believed that the existing sense organs are sufficient for a complete knowledge of the world. Cognition goes deeper, the cognitive power of a person lies in the fact that the activity of his sense organs is added to the activity of thinking, which pushes the limits of cognitive possibilities.

sensory systems- these are specialized parts of the nervous system, including peripheral receptors (sensory organs, or sense organs), nerve fibers extending from them (pathways) and cells of the central nervous system grouped together (sensory centers). Each area of ​​the brain that contains touch center (nucleus) and switching of nerve fibers is carried out, forms level sensory system. In the sensory organs, the energy of an external stimulus is converted into a nerve signal - reception. nerve signal (receptor potential) transforms into impulse activity or action potentials neurons (coding). Action potentials reach the sensory nuclei along the conductive pathways, on the cells of which the switching of nerve fibers and the transformation of the nerve signal take place. (transcoding). At all levels of the sensory system, simultaneously with the coding and analysis of stimuli, decoding signals, i.e. reading the touch code. Decoding is based on the connections of sensory nuclei with the motor and associative parts of the brain. Nerve impulses of axons of sensory neurons in the cells of motor systems cause excitation (or inhibition). The result of these processes is traffic- act or stop movement - inaction. The final manifestation of the activation of associative functions is also movement.

The main functions of sensory systems are:

1. signal reception;
2. conversion of the receptor potential into impulse activity of the nerve pathways;
3. transmission of nervous activity to sensory nuclei;
4. transformation of nervous activity in sensory nuclei at each level;
5. signal properties analysis;
6. identification of signal properties;
7. signal classification and identification (decision making).

12. Definition, properties and types of receptors.

Receptors are special cells or special nerve endings designed to transform the energy (transformation) of various types of stimuli into a specific activity of the nervous system (into a nerve impulse).

Signals entering the CNS from receptors cause either new reactions or change the course of ongoing activity.

Most receptors are represented by a cell equipped with hairs or cilia, which are such formations that act like amplifiers in relation to stimuli.

Either mechanical or biochemical interaction of the stimulus with receptors occurs. Thresholds for stimulus perception are very low.

According to the action of stimuli, receptors are divided into:

1. Interoreceptors

2. Exteroreceptors

3. Proprioreceptors: muscle spindles and Golgi tendon organs (discovered by I.M. Sechenov a new type of sensitivity - articular-muscular feeling).

There are 3 types of receptors:

1. Phase - these are receptors that are excited in the initial and final period of the stimulus.

2. Tonic - act during the entire period of the stimulus.

3. Phasno-tonic - in which impulses occur all the time, but more at the beginning and at the end.

The quality of perceived energy is called modality.

Receptors can be:

1. Monomodal (perceive 1 type of stimulus).

2. Polymodal (can perceive several stimuli).

The transfer of information from the peripheral organs occurs along sensory pathways, which can be specific and nonspecific.

Specific are monomodal.

Nonspecific are polymodal

Properties

Selectivity - sensitivity to adequate stimuli

Excitability - the minimum amount of energy of an adequate stimulus, which is necessary for the onset of excitation, i.e. arousal threshold.

Low threshold value for adequate stimuli

Adaptation (may be accompanied by both a decrease and an increase in the excitability of receptors. So, when moving from a bright room to a dark one, a gradual increase in the excitability of the photoreceptors of the eye occurs, and a person begins to distinguish dimly lit objects - this is the so-called dark adaptation.)

13. Mechanisms of excitation of primary-sensing and secondary-sensing receptors.

Primary sensory receptors: the stimulus acts on the dendrite of the sensory neuron, the permeability of the cell membrane to ions (mainly to Na +) changes, a local electrical potential (receptor potential) is formed, which electrotonically propagates along the membrane to the axon. An action potential is formed on the axon membrane, which is transmitted further to the CNS.

A sensory neuron with a primary sensory receptor is a bipolar neuron, on one pole of which there is a dendrite with a ciliary, and on the other - an axon that transmits excitation to the CNS. Examples: proprioceptors, thermoreceptors, olfactory cells.

Secondary sensory receptors: in them, the stimulus acts on the receptor cell, excitation occurs in it (receptor potential). On the axon membrane, the receptor potential activates the release of the neurotransmitter into the synapse, as a result of which a generator potential is formed on the postsynaptic membrane of the second neuron (most often bipolar), which leads to the formation of an action potential on neighboring sections of the postsynaptic membrane. This action potential is then transmitted to the CNS. Examples: hair cells in the ear, taste buds, photoreceptors in the eye.

!fourteen. Organs of smell and taste (localization of receptors, first switching, repeated switching, projection zone).

The organs of smell and taste are excited by chemical stimuli. Receptors of the olfactory analyzer are excited by gaseous, and taste - by dissolved chemicals. The development of the olfactory organs also depends on the way of life of animals. The olfactory epithelium is located away from the main respiratory tract and the inhaled air enters there by vortex movements or diffusion. Such vortex motions occur during “sniffing”, i.e. with short breaths through the nose and expansion of the nostrils, which facilitates the penetration of the analyzed air into these areas.

Olfactory cells are represented by bipolar neurons, the axons of which form the olfactory nerve, ending in the olfactory bulb, which is the olfactory center, and then paths go from it to other overlying brain structures. On the surface of the olfactory cells there are a large number of cilia, which significantly increase the olfactory surface.

Taste Analyzer serves to determine the nature, palatability of the feed, its suitability for eating. Taste and olfactory analyzers help animals living in water to navigate in the environment, determine the presence of food, females. With the transition to life in the air, the value of the taste analyzer decreases. In herbivores, the taste analyzer is well developed, which can be seen in the pasture and in the feeder, when the animals do not eat grass and hay all in a row.

The peripheral part of the taste analyzer is represented by taste buds located on the tongue, soft palate, posterior pharyngeal wall, tonsils and epiglottis. Taste buds are located on the surface of fungiform, foliate and trough papillae.

15. Skin analyzer (localization of receptors, first switching, repeated switching, projection zone).

Various receptor formations are located in the skin. The simplest type of sensory receptor is free nerve endings. Morphologically differentiated formations have a more complex organization, such as tactile discs (Merkel discs), tactile bodies (Meissner bodies), lamellar bodies (Pacini bodies) - pressure and vibration receptors, Krause flasks, Ruffini bodies, etc.

Most specialized terminal formations are characterized by preferential sensitivity to certain types of stimulation, and only free nerve endings are polymodal receptors.

16. Visual analyzer (localization of receptors, first switching, repeated switching, projection zone).

A person receives the greatest amount of information (up to 90%) about the outside world with the help of the organ of vision. The organ of vision - the eye - consists of the eyeball and an auxiliary apparatus. The auxiliary apparatus includes eyelids, eyelashes, lacrimal glands and muscles of the eyeball. The eyelids are formed by folds of skin lined from the inside with a mucous membrane - the conjunctiva. The lacrimal glands are located in the outer upper corner of the eye. Tears wash the anterior part of the eyeball and enter the nasal cavity through the nasolacrimal canal. The muscles of the eyeball set it in motion and direct it towards the object in question
17. Visual analyzer. The structure of the retina. Formation of color perception. Conductor department. Information processing .

The retina has a very complex structure. It contains light-receiving cells - rods and cones. Rods (130 million) are more sensitive to light. They are called the apparatus of twilight vision. Cones (7 million) are a device for day and color vision. When these cells are stimulated by light rays, excitation occurs, which is carried through the optic nerve to the visual centers located in the occipital zone of the cerebral cortex. The area of ​​the retina from which the optic nerve exits is devoid of rods and cones and therefore is not capable of perceiving light. It's called the blind spot. Almost next to it is a yellow spot formed by a cluster of cones - the place of the best vision.

The structure of the optical, or refractive, system of the eye includes: the cornea, aqueous humor, lens and vitreous body. In people with normal vision, the rays of light passing through each of these media are refracted and then enter the retina, where they form a reduced and inverted image of objects visible to the eye. Of these transparent media, only the lens is able to actively change its curvature, increasing it when looking at close objects and decreasing it when looking at distant objects. This ability of the eye to clearly see objects at different distances is called accommodation. If the rays are refracted too much when passing through transparent media, they are focused in front of the retina, resulting in myopia. In such people, the eyeball is either elongated or the curvature of the lens is increased. The weak refraction of these media leads to focusing of the rays behind the retina, which causes farsightedness. It occurs due to the shortening of the eyeball or flattening of the lens. Properly selected glasses can correct these Conducting paths of the visual analyzer. First, the second and third neurons of the visual analyzer pathway are located in the retina. The fibers of the third (ganglion) neurons in the optic nerve partially cross to form the optic chiasm (chiasm). After the decussation, the right and left visual tracts are formed. The fibers of the optic tract terminate in the diencephalon (the nucleus of the lateral geniculate body and the thalamus cushion), where the fourth neurons of the optic pathway are located. A small number of fibers reach the midbrain in the region of the superior colliculi of the quadrigemina. The axons of the fourth neurons pass through the posterior leg of the internal capsule and are projected onto the cortex of the occipital lobe of the cerebral hemispheres, where the cortical center of the visual analyzer is located.

18. Auditory analyzer (localization of receptors, first switching, repeated switching, projection zone). Conductor department. Information processing. auditory adaptation.

Auditory and vestibular analyzers. The organ of hearing and balance includes three sections: the outer, middle and inner ear. The outer ear consists of the auricle and the external auditory meatus. The auricle is represented by elastic cartilage, covered with skin, and serves to capture sound. The external auditory meatus is a canal 3.5 cm long, which begins with the external auditory opening and ends blindly with the tympanic membrane. It is lined with skin and has glands that secrete earwax.

Behind the tympanic membrane is the middle ear cavity, which consists of the air-filled tympanic cavity, the auditory ossicles, and the auditory (Eustachian) tube. The auditory tube connects the tympanic cavity with the nasopharyngeal cavity, which helps to equalize pressure on both sides of the tympanic membrane. The auditory ossicles - the hammer, anvil and stirrup are movably connected to each other. The malleus is fused with the tympanic membrane with a handle, the head of the malleus is adjacent to the anvil, which is connected to the stirrup at the other end. The stirrup with a wide base is connected to the membrane of the oval window leading to the inner ear. The inner ear is located in the thickness of the pyramid of the temporal bone; consists of a bony labyrinth and a membranous labyrinth located in it. The space between them is filled with fluid - perilymph, the cavity of the membranous labyrinth - endolymph. The bony labyrinth contains three sections: the vestibule, the cochlea, and the semicircular canals. The cochlea belongs to the organ of hearing, the rest of its parts - to the organ of balance.

The cochlea is a bony canal, twisted in the form of a spiral. Its cavity is divided by a thin membranous septum - the main membrane. It consists of numerous (about 24 thousand) connective tissue fibers of different lengths. The receptor hair cells of the organ of Corti, the peripheral part of the auditory analyzer, are placed on the main membrane.

Sound waves through the external auditory meatus reach the tympanic membrane and cause its vibrations, which are amplified (almost 50 times) by the auditory ossicles and transmitted to the perilymph and endolymph, then perceived by the fibers of the main membrane. High sounds cause oscillations of short fibers, low sounds - longer, located at the top of the cochlea. These vibrations excite the receptor hair cells of the organ of Corti. Further, the excitation is transmitted along the auditory nerve to the temporal lobe of the cerebral cortex, where the final analysis and synthesis of sound signals take place. The human ear perceives sounds with a frequency of 16 to 20 thousand Hz.

Conducting paths of the auditory analyzer. First neuron of the auditory analyzer pathways - the bipolar cells mentioned above. Their axons form the cochlear nerve, the fibers of which enter the medulla oblongata and terminate in the nuclei, where the cells of the second neuron of the pathways are located. The axons of the cells of the second neuron reach the internal geniculate body, mainly on the opposite side. Here begins the third neuron, through which impulses reach the auditory region of the cerebral cortex.

In addition to the main pathway connecting the peripheral part of the auditory analyzer with its central, cortical part, there are other ways through which reflex reactions to irritation of the hearing organ in the animal can occur even after removal of the cerebral hemispheres. Of particular importance are orienting reactions to sound. They are carried out with the participation of the quadrigemina, to the posterior and partly anterior tubercles of which there are collaterals of fibers heading to the internal geniculate body.

19. Vestibular analyzer (localization of receptors, first switching, repeated switching, projection zone). Conductor department. Information processing .

vestibular apparatus. It is represented by the vestibule and semicircular canals and is an organ of balance. In the vestibule there are two sacs filled with endolymph. At the bottom and in the inner wall of the sacs are receptor hair cells, which are adjacent to the otolith membrane with special crystals - otoliths containing calcium ions. Three semicircular canals are located in three mutually perpendicular planes. The bases of the channels at the points of their connection with the vestibule form extensions - ampoules in which hair cells are located.

Receptors of the otolithic apparatus are excited by accelerating or decelerating rectilinear movements. The receptors of the semicircular canals are irritated by accelerated or slow rotational movements due to the movement of the endolymph. Excitation of the receptors of the vestibular apparatus is accompanied by a number of reflex reactions: a change in muscle tone, contributing to the straightening of the body and maintaining the posture. Impulses from the receptors of the vestibular apparatus through the vestibular nerve enter the central nervous system. The vestibular analyzer is connected to the cerebellum, which regulates its activity.

Conductive pathways of the vestibular apparatus. the path of the statokinetic apparatus carries out the transmission of impulses when the position of the head and body changes, participating together with other analyzers in the orientation reactions of the body relative to the surrounding space. The first neuron of the statokinetic apparatus is located in the vestibular ganglion, which lies at the bottom of the internal auditory canal. The dendrites of the bipolar cells of the vestibular ganglion form the vestibular nerve, formed by 6 branches: superior, inferior, lateral and posterior ampullar, utricular and saccular. They contact with sensitive cells of the auditory spots and scallops located in the ampullae of the semicircular canals, in the sac and uterine vestibule of the membranous labyrinth.

20. Vestibular analyzer. Building a sense of balance. Automatic and conscious control of body balance. Participation of the vestibular apparatus in the regulation of reflexes .

The vestibular apparatus performs the functions of perceiving the position of the body in space, maintaining balance. With any change in the position of the head, the receptors of the vestibular apparatus are irritated. The impulses are transmitted to the brain, from which nerve impulses are sent to the skeletal muscles in order to correct body position and movements. The vestibular apparatus consists of two parts: vestibule and semicircular canals, in which the receptors of the statokinetic analyzer are located.