The 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

4.7 Proprioceptive sensitivity

Bibliography

Introduction

It is known that a personality is realized in activities that are possible due to cognition. environment. In ensuring the interaction of a person with the outside world, the leading role is played by the properties of the personality, its motives, attitudes. However, any mental phenomenon is both a reflection of reality and a link in the regulation of activity. The regulation of activity begins already at the level of sensations and perceptions - from mental cognitive processes. Sensations, perceptions, representations, memory belong to sensory forms of knowledge. Sensual reflection in a person is always associated with logical knowledge, thinking. The individual in human sensory cognition is reflected as a manifestation of the general. In sensory knowledge essential role plays the language, the word, which always performs the function of generalization. In turn, logical cognition (thinking) is based on the data of sensory experience, on sensations, perception and memory representations. In a single process of cognition, a continuous interaction of all cognitive processes is carried out. More complex cognitive processes are based on sensations: perceptions, ideas, memory, thinking, imagination. Otherwise, except through sensations, we cannot learn anything about any forms of movement. Sensation is the simplest, further indecomposable mental process. The sensations reflect the objective qualities of the object (smell, color, taste, temperature, etc.) and the intensity of the stimuli affecting us (for example, higher or more low temperature).

1. Sensory organization of personality

The sensory organization of personality is the level of development individual systems sensitivity and the possibility of their combination. 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 generic sign. For example, bats have developed sensitivity to the perception of short ultrasonic pulses, dogs have olfactory sensitivity. main feature sensory organization of a person is that it develops as a result of all his 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.

2. The concept of sensation

Sensation is a manifestation of the general biological property of living matter - sensitivity. Through the feeling comes psychic connection with external and inner world. Thanks to sensations, information about all the 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 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 in human sensory systems there is a primary cognitive process and already on its basis, cognitive processes that are more complex in their structure arise: perceptions, ideas, memory, thinking. No matter how simple the primary cognitive process, but it is it that is the basis mental activity, only through the “entrances” of sensory systems does the world around us penetrate into our consciousness.

2.1 Processing sensations

After receiving information by the brain, the result of its processing is the development of a response action 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 from the options accessible to man at the time of making the decision. However, it is clear that the number of options available and the quality of choice are different for different people and depend, for example, on: - mental properties of the personality; - Strategies for relationships with others; - partly physical condition; - experience, availability necessary information in memory and the possibility of their retrieval; - 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 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); - the central section 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.

According to certain principles and containing the observer himself as one of the elements under study. Unlike sensation, in perception the image of a holistic object is formed by reflecting the totality of its properties. The process of perception includes such complex mechanisms as memory and thinking. Therefore, perception is called the human perceptual system. Perception is the result...

The human body, the integrity of the sensory reflection of the objective world. An increase in sensitivity as a result of the interaction of analyzers and exercise is called sensitization. The physiological mechanism for the interaction of sensations is the processes of irradiation and concentration of excitation in the cerebral cortex, where the central sections of the analyzers are represented. According to I.P. Pavlova, weak...

Expand the concept of sensation, classify the types of sensations. Reveal the connection of sensations with the work of analyzers as the physiological basis of sensory processes.

Nature endowed every person with the ability to know the world in which he was born, and, in particular, the ability to feel and perceive the world around him - people, nature, culture, various items and phenomena. Path to knowledge of the environment and eigenstates It starts with a person's feelings.

The meaning of feelings:

1. sensations allow a person to navigate in the world of sounds, smells, perceive color schemes, evaluate the weight and dimensions of objects, determine the taste of the product, etc.
2. sensations provide material for other more complex mental processes (for example, deaf people will never be able to comprehend sounds human voice, blind - colors);
3. especially developed senses are a condition for the success of a person in a particular profession (for example, a taster, artist, musician, etc.);
4. depriving a person of sensations leads to sensory deprivation (sensory hunger - a lack of impressions), which can occur both in natural and in laboratory conditions. (according to Lee, sensory deprivation- the main condition for creativity, since 95% of the energy spent on overcoming gravity goes to creative potential);
5. there is the possibility of influencing the human condition through sensations (the sound of the surf, birdsong, aromatherapy, music).

Feeling (lat. sensus- perception) is a mental cognitive process of reflection individual properties of the real external world and internal state person who directly affect the sense organs in this moment .

Sensation does not give a person a complete picture of reflected objects. If, for example, a person is blindfolded and offered to touch an object unfamiliar to him (table, computer, mirror) with his fingertip, then the sensation will give him knowledge of only certain properties of the object (for example, that this object is hard, cold, smooth, etc.). P.).

Feelings are sensory reflection objective reality, as they arise due to the impact various factors(irritants) to the sense organs (vision, hearing, etc.). They are characteristic of all living beings with a nervous system. Moreover, some animals (for example, eagles) have much sharper eyesight than humans, a more subtle sense of smell and hearing (dog). The eyes of ants can distinguish ultra-violet rays inaccessible to the human eye. The bats and dolphins distinguish between ultrasounds that humans cannot hear. Rattlesnake distinguishes between insignificant temperature fluctuations - 0.001 degrees.

Feelings are both objective and subjective. Objectivity lies in the fact that they reflect a real-life external stimulus. Subjectivity is due to the dependence of sensations on individual characteristics and the current mental state of a person. This is what the well-known proverb says: "There are no comrades for the taste and color."

Related emotional sphere a person, sensations can give rise to various feelings in him, cause the simplest emotional experiences. For example, the sensation of the sharp sound of car brakes heard somewhere nearby can cause a person passing by to have unpleasant memories of their own driving practice. Negative experiences are generated by sensations of an unloved smell, color and taste.

The structure of the analyzers:

The physiological basis of sensations is laid down in the work of special nervous structures, called analyzers by I. Pavlov. Analyzers- these are the channels through which a person receives all information about the world (as external environment, and about their own, internal state).

Analyzer – nerve formation which carries out the perception, analysis and synthesis of external and internal stimuli acting on the body.

Each type of analyzer is adapted to isolate a certain property: the eye reacts to light stimuli, the ear to sound stimuli, the olfactory organ to smells, etc.

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. Receptor - a specialized cell designed to receive from external or internal environment a certain stimulus and for converting its energy from physical or chemical form in the form nervous excitement(impulse).

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

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

Feeling is inherently mental process arising from the processing of information received by the brain.

Depending on the type of sensitivity, visual, auditory, olfactory, gustatory, skin, motor and other analyzers are distinguished. Each analyzer from the whole variety of influences allocates incentives of a certain type. For example, the auditory analyzer highlights the waves formed as a result of vibrations of air particles. The taste analyzer generates an impulse as a result of " chemical analysis"molecules dissolved in saliva, and olfactory - in the air. The visual analyzer perceives electromagnetic oscillations, the characteristic of which generates one or another visual image.

8. The concept of sensation. Physiological basis sensations. Types and basic properties, mechanisms for changing sensitivity, the problem of measuring sensation.

Feeling called the mental reflection in the cerebral cortex of individual properties of objects and phenomena that directly affect the sense organs. For the emergence of sensations, it is necessary, first of all, the presence of objects and phenomena affecting the sense organs real world which are called irritants. The effect of stimuli on the sense organs is called irritation. Information about the outside world can enter the brain, that is, the center that processes it, only through 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 the 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 character data system. external influence.

All living beings with a nervous system have the ability to sense, 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 analyzer, and cell systems, the most

complexly organized and being perceiving apparatuses that directly carry out the analysis of stimuli - analyzers.

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

The peripheral (receptor) section of the analyzers consists of all the sense organs - the eye, ear, nose, skin, as well as special receptor apparatus located in the internal environment of the body (in the digestive, respiratory, cardiovascular system, 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 during internal organs and tissues (interoceptors). Receptors located on the surface of the body respond to external stimuli. Visual, auditory, skin, taste, 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 (feeling of hunger, thirst). Organic sensations are associated with the activity of interoceptors. An intermediate position is occupied by proprioceptors located in the muscles and ligaments, which serve to sense the movement and position of the body's 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, external analyzers are distinguished (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 a motor analyzer, the receptors of which are located in the muscles and ligaments. For all analyzers, pain sensations are common, thanks to which the body receives information about the destructive properties of the stimulus for it.

types of sensations

Classifications of sensations: 1) by the presence or absence of direct contact with the stimulus that causes sensation: 2) by the location of the receptors, 3) by the time of occurrence in the course of evolution; 4) according to the modality (kind) of the stimulus.

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

The most ancient is organic (first of all, pain) sensitivity, then contact (tactile) forms appeared. And the most evolutionarily young are 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, and hunger.

Visual sensations arise as a result of exposure to 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. Due to auditory sensations (distant), a person hears speech, communicates with other people. Irritants for these sensations are sound waves - longitudinal vibrations of air particles, propagating in all directions from the sound source. The human hearing organ responds to sounds in the range from 16 to 20,000 vibrations per second. Auditory sensations reflect the pitch of the sound, which depends on the frequency of the vibration. sound waves; loudness, which depends on the amplitude of their oscillations; timbre of sound - forms of vibrations of sound waves. All auditory sensations can be reduced to three types - speech, musical, 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 specific vibration receptors have been found in humans. All body tissues can reflect the vibrations of the external and internal environment. In humans, vibrational sensitivity is subordinated to auditory and visual. Olfactory sensations (distant) reflect the smells of objects around us. Olfactory organs are olfactory cells located in the upper part of the nasal cavity. Taste sensations are caused by the action on taste buds of substances dissolved in saliva or water. Taste buds - taste buds located on the surface of the tongue, pharynx, palate distinguish sensations, sweet, sour, salty, bitter. Skin sensations. In the skin there are several analyzer systems; tactile (sensations of touch), temperature (sensations of cold and heat), pain. The system of tactile sensitivity is unevenly distributed throughout the body. But most of all, the accumulation of tactile cells is observed on the palm, on the fingertips and on the lips. The tactile sensations of the hand, combined with the musculo-articular sensitivity, form the sense of touch. If you touch the surface of the body, then press on the Negro, the pressure can cause pain. Tactile sensitivity gives knowledge about the qualities of an object, and pain sensations signal the body about the need to move away from the stimulus and have a bright emotional tone. The third type of skin sensitivity is temperature sensations - the 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 least - the chest. Static sensations signal the position of the body in space. Static sensitivity receptors are located in the vestibular apparatus of the inner ear. Abrupt changes body positions 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 the feeling of hunger, thirst, satiety, complexes of 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 variety of sensations reflects the infinite variety of forms of motion of matter.

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

The duration of sensation is its temporal characteristic. It is also determined by the functional state of the sense organ, but mainly by the duration of the stimulus and its intensity. When a stimulus is exposed to a sensory organ, sensation does not occur immediately, but after some time, the so-called latent (hidden) period of sensation. The sensation does not arise simultaneously with the beginning of the action of the stimulus, it does not disappear simultaneously with the termination of its action. This inertia of sensations is manifested in the so-called aftereffect. A visual sensation, for example, has a certain inertia and does not disappear immediately after the cessation of the action of the stimulus that caused it. The trace from the stimulus remains in the form of a consistent image. Distinguish between positive and negative sequential images. A positive consistent image in terms of lightness and color corresponds to the initial stimulus, consists in the preservation of a trace of light stimulus of the same quality as the acting stimulus. If in complete darkness we light a bright lamp for a while and then turn it off, then after that we see the bright light of the lamp against a dark background for some time. The presence of positive successive images explains why we do not notice the breaks between successive frames of the film: they are filled with traces of previous frames - successive images from them. Sequential image changes in time, positive image is replaced by a negative one. With colored light sources, the sequential image turns into a complementary color.

I. Goethe wrote in his “Essay on the Doctrine of Color”: “When one evening I went into a hotel and a tall girl with a dazzlingly white face, black hair and a bright red bodice came into my room, I looked intently at her standing in the semi-darkness at some distance from me. After she left there, I saw on the light wall opposite me a black face, surrounded by a bright glow, while the clothes of a completely clear figure seemed to me the beautiful color of a sea wave.

The occurrence of negative consecutive images is explained by a decrease in the sensitivity of a given area of ​​the retina to a certain color. AT normal conditions we do not notice successive images, since the eye makes continuous movements and therefore there is no significant fatigue of any one part of the retina.

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

Lesson topic: Psychology as a science

Purpose of the lesson: To form an idea about the subject of psychology, its place among other sciences.

Educational-targeted questions of the lesson:

1. History of psychology.

2. The main stages in the development of psychology.

3. Development of psychology in Russia.

4.Main trends in psychology.

5. Definition of psychology as a science.

6. Branches of psychology.

7. The concept of the psyche.

8. The structure of the human psyche.

9. Basic methods of psychological research.

History of psychology

Psychology as a science has a long period formation and relatively short story. It originated many centuries ago, first as an integral part of philosophy. The word "psychology" is formed from the Greek words "psyche" (soul) and "logos" (doctrine, science). But the term “psychology” itself appeared for the first time only in the 16th century, and referred to a science that was engaged in the study of so-called mental or mental phenomena.

Thus,

Psychology – is the science of the psyche and psychic phenomena.

Also in ancient greece(VI century BC) the first attempts to explain mental phenomena arose. The first Greek philosophers believed that in every person there is something (anima (Latin) - “spirit”, “soul”) that allows him to think, feel, desire, make decisions. According to the ideas Plato(427-347 BC) the spirit, or soul, is an independent substance, it exists on a par with the body and independently of it and controls all living and inanimate objects. Democritus(460-370 BC) believed that the soul is a material substance, it consists of atoms of fire. The materialism of Democritus had a naive mechanistic character.

A much more complex idea of ​​the soul was developed by Aristotle(384-322 BC). His treatise "On the Soul" is the first psychological work, which for many centuries remained the main guide to psychology. Aristotle himself is rightfully considered the founder of psychology. Aristotle rejected the view of the soul as a substance. He put forward the concept of the soul as a function of the body, and not some external phenomenon in relation to it. According to Aristotle's theory, the soul or "psyche" is the engine that allows a living being to realize itself.

The dominant religion in the Middle Ages forbade the study of man. Under the influence of the atmosphere characteristic of the Middle Ages (the strengthening of church influence on all aspects of society, including science), the idea was established that the soul is a divine, supernatural principle, and therefore the study of mental life should be subordinated to the tasks of theology.

R. Descartes(1596-1650) was one of the first to try to explain the behavior of animals and humans on the basis of a mechanical model. It was he who introduced the concept of reflex. R. Descartes opposed the soul and the body: the body can only move, the soul can only think. However, the soul is capable of producing movements in the body. His approach is called dualism. Only at the beginning of the twentieth century, the concept of the soul was replaced first by the concept of “mind”, and then by the concept of “consciousness”.

An attempt to reunite the body and soul of man, separated by the teachings of Descartes, was undertaken by the Dutch philosopher B. Spinoza(1632-1677). There is no special spiritual principle, it is always one of the manifestations of an extended substance (matter). Soul and body are determined by the same material causes.

At the beginning of the nineteenth century. new approaches to the psyche began to take shape, the prerequisites for the formation of psychology as a science arose. These prerequisites include the development of the anatomy and physiology of the nervous system. The attention of scientists is drawn to the study of the brain and its role in mental activity.

The change in the position of psychiatry and attitudes towards the mentally ill was also important. The idea that a mental disorder is a disease and needs to be treated gave rise to comparative studies of the psyche in normal and pathological conditions. Thus, the knowledge accumulated in biology, physiology, and medicine became the basis for the creation of scientific psychology.

The separation of psychology into an independent science occurred in the 60s years XIX in. It was associated with the creation of special research institutions - psychological laboratories and institutes, departments in higher educational institutions, as well as with the introduction of experimental methods into it (until that time, the method of introspection - self-observation was dominant in psychology). AT 1879. German psychologist Wilhelm Wundt(1832-1920) opened the world's first experimental psychology laboratory in Leipzig. Then began a systematic study of sensations, perception, reaction speed, feelings. Wundt's school trained the first generation professional psychologists. Soon, in 1885 V. M. Bekhterev(1857-1927) organized a similar laboratory in Russia.

The end of the 19th - the beginning of the 20th centuries. characterized by rapid growth of experimental and various branches of applied psychology. Are being developed experimental methods memory research (G. Ebbinghaus, 1850-1909). The first intelligence tests were created by the French psychologist A. Binet (1905).

The main stages in the development of psychology

I stage – psychology as a science of the soul. This definition of psychology was given more than two thousand years ago. The presence of the soul tried to explain all the incomprehensible phenomena in human life.

II stage– psychology as a science of consciousness. It arises in the 17th century in connection with the development of the natural sciences. The ability to think, feel, desire is called consciousness. The main method of study is the observation of a person for himself.

Stage III – psychology as a science of behavior. Arises in the 20th century. Observation and study of what can be directly seen, namely: behavior, actions, reactions of a person. The main method is experiment.

IV stage– psychology as a science, studying objective patterns, processes and mental mechanisms. It has been developing since the second half of the 20th century.

However, there are sensations that cannot be associated with any particular modality. Such sensations are called intermodal. These include, for example, vibration sensitivity, which connects the tactile-motor sphere with the auditory one.

Feeling the vibration is the sensitivity to vibrations caused by a moving body. According to most researchers, the vibrational sense is an intermediate, transitional form between tactile and auditory sensitivity.

In particular, some authors believe that tactile-vibrational sensitivity is one of the forms of sound perception. With normal hearing, it does not particularly protrude, but with damage to the auditory organ, this function of it is clearly manifested. Vibration sensitivity is of particular practical importance in visual and hearing impairments. It plays an important role in the lives of deaf and deaf-blind people. The deaf-blind, due to the high development of vibration sensitivity, learned about the approach of a truck and other modes of transport at a great distance. In the same way, deaf-blind-mute people know by vibrational sense when someone enters their room.

Consequently, sensations, being the simplest kind of mental processes, are in fact very complex and not fully understood.

It should be noted that there are other approaches to the classification of sensations.

Basic properties of sensations

All sensations can be characterized in terms of their properties. Moreover, properties can be not only specific, but also common to all types of sensations. The main properties of sensations include:

• quality,
• intensity,
• duration,
• spatial localization,
• absolute and relative thresholds of sensations

Quality - this is a property that characterizes the basic information displayed by a given sensation, distinguishing it from other types of sensations and varying within this type of sensation. For example, taste sensations provide information about certain chemical characteristics subject: sweet or sour, bitter or salty. The sense of smell also provides information about the chemical characteristics of the object, but of a different kind: the smell of flowers, the smell of almonds, the smell of hydrogen sulfide, etc.

It should be noted that often, when speaking about the quality of sensations, they mean the modality of sensations, since it is the modality that reflects the main quality of the corresponding sensation.

Intensity sensation is its quantitative characteristic and depends on the strength of the acting stimulus and the functional state of the receptor, which determines the degree of readiness of the receptor to perform its functions. For example, with a runny nose, the intensity of perceived odors can be distorted.

Duration Feelings are a temporal characteristic of the sensation that has arisen. It is also determined by the functional state of the sense organ, but mainly by the time of action of the stimulus and its intensity. It should be noted that sensations have a so-called latent (hidden) period. When a stimulus is applied to the sense organ, the sensation does not occur immediately, but after some time. The latent period of different types of sensations is not the same. For example, for tactile sensations it is 130 ms, for pain - 370 ms, and for taste - only 50 ms.

And finally for sensations characteristic spatial localization irritant. The analysis carried out by the receptors gives us information about the localization of the stimulus in space, that is, we can tell where the light comes from, the heat comes from, or which part of the body is affected by the stimulus.

All of the above properties to some extent reflect the qualitative characteristics of sensations. However, the quantitative parameters of the main characteristics of sensations are no less important, in other words, degree sensitivity. The human sense organs are surprisingly fine working apparatuses. For example, the human eye is a very sensitive instrument. He can distinguish about half a million shades and colors. If the air were perfectly clean, we could see the flame of a candle at a distance of 27 km. Water vapor and dust drastically impair visibility, so an ordinary fire is practically visible only 6-8 km away, and a lit match - about 1.5 km away. Each sense organ has its own limits of sensitivity.

The concept of sensitivity thresholds

There are two types of sensitivity: absolute sensitivity and sensitivity to difference. By absolute sensitivity is meant the ability to sense weak stimuli, and by difference sensitivity is the ability to sense subtle differences between stimuli. However, not every irritation causes a sensation. It is not given to a person to hear the ticking of a clock in another room, to see stars of the sixth magnitude. In order for a sensation to arise, the force of irritation must have a certain value. The minimum value of the stimulus at which a sensation first occurs is called absolute threshold of sensation. Stimuli, the strength of which lies below the absolute threshold of sensation, do not give sensations, but this does not mean that they do not have any effect on the body. Thus, studies by the Russian physiologist G. V. Gershuni and his collaborators showed that sound stimuli below the threshold of sensation can cause a change in the electrical activity of the brain and dilation of the pupil. Stimuli that do not cause sensations are called subthreshold.

The beginning of the study of the thresholds of sensations was laid by the German physicist, psychologist and philosopher G. T. Fechner, who believed that the material and the ideal are two sides of a single whole. In his opinion, the process of creating a mental image can be represented by the following scheme:

Irritation -->	Excitation -->	Feeling -->	Judgment
(physics)	(physiology)	(psychology)	(logics)

The most important thing in Fechner's idea was that for the first time he included elementary sensations in the circle of interests of psychology. The magnitude of the stimulus at which sensation begins, Fechner called the lower absolute threshold. Upper absolute threshold sensitivity is called maximum strength stimulus, in which there is still an adequate sensation to the acting stimulus. A further increase in the strength of stimuli acting on our receptors causes only pain in them. The upper absolute threshold is sometimes called pain threshold. Absolute Thresholds- upper and lower - define the boundaries of the world around us accessible to our perception.

The concept of sensory adaptation

Studies show that absolute and relative sensitivity can vary within very large limits. For example, in the dark, vision becomes sharper, and in strong light, its sensitivity decreases. This can be observed when moving from a dark room to light or from a brightly lit room to darkness: at first nothing is visible, but after a few minutes the eyes get used to it, and it becomes possible to distinguish the objects located there. In both cases, the person is temporarily "blind", it takes some time for the eyes to adjust to bright light or darkness. This example sensitivity changes associated with the phenomenon of sensory adaptation.

Sensory adaptation - a change in sensitivity that occurs as a result of the adaptation of the sense organ to the stimuli acting on it. As a rule, adaptation is expressed in the fact that when sufficiently strong (or long-acting) stimuli act on the sense organs, sensitivity decreases (example with a glove on the hand), and when weak stimuli or in the absence of a stimulus act, sensitivity increases.

Especially quickly and easily a person adapts to the smell. Worst of all, a person adapts to pain, because pain protects the body from destruction. Imagine what would happen if we did not feel pain when touching a hot or piercing, cutting object.

Thus, the following can be distinguished types of adaptation:

Complete disappearance of sensation in the process of prolonged action of the stimulus.

Dullness of sensation under the influence of a strong stimulus.

Increased sensitivity under the influence of the action of a weak stimulus.

The increase in sensitivity as a result of the interaction of analyzers and training (exercises) is called sensitization. Studies have shown that the acuteness of the sensitivity of the sense organs increases with age, reaching a maximum by the age of 20-30, and then gradually decreases.

The concept of sensory deprivation

Sensory deprivation is observed when an individual is in a situation where there is no effect of any stimuli on his body. In 1956, a group of psychologists at McGill University conducted the following experiment. The researchers suggested that the volunteers stay as long as possible in a special chamber, where they were protected as much as possible from external stimuli of the world. It turned out that most of the subjects were unable to withstand such conditions for more than 2-3 days. It was concluded that the body needs a constant supply of stimuli from the changing environment. The most enduring subjects had hallucinations, and this, according to scientists, indicated that without external stimuli, intellectual functions and the personality itself would inevitably degrade. Another scientist, J. Lilly, in the same period tested the effect of sensory isolation on himself. He did this in an impenetrable chamber, where he was immersed in a salt solution with a temperature close to body temperature, so that he was almost devoid of even the sensations associated with the weight of his own body. And only after several years of research (1977) did he comment on his experiments. According to Lilly, the conditions of isolation in the chamber increase the sensory experience, and this happens without the participation of external stimuli. Lilly noted that after a period of internal tension, which he himself felt, and felt most of the subjects at McGill University, and which becomes almost unbearable, a new state of consciousness gradually sets in, accompanied by many visual images - all kinds of hallucinations and illusions. When a person perceives these phenomena calmly and does not consider them as pathological, they allow him to experience a peculiar sensation of an “ocean wave”, which reaches such intensity that a few hours later, at the moment of leaving the isolated chamber, he feels reborn. In contrast to the experience of the Eastern masters of meditation, in the experience in an isolated chamber there is a sharp break with the reality that is constantly acting on the body. And then the body is faced with its inner world and with all the visions that develop and manifest outside of reality.

The concept of representational systems

Each person has at his disposal different ways of representing (reflecting) our experience of the world. Man has five known senses: sees, hears, feels, tastes and smells. In addition, he has a system of language (speech) with which he can represent his experience. A person comprehends the world around him, first of all, in the representational system that is most developed in him. If the primary representational system visual , - the world is comprehended in pictures; if kinesthetic - in feelings; if auditory - in sounds. For example, people sometimes imagine the world in terms of smells and tastes.

Sensory typology

visual type. All perceived information is presented to this type of people in the form of vivid pictures, visual images, telling something, these people often gesticulate, as if drawing images in the air. In a conversation, the phrases are often used: “Look, look ...”, “Let's imagine ...”, “I clearly see that ...”, “The solution is already looming ...” At the moment of remembering, these people look as if straight ahead, up, left up or right up.

Auditory type. These people mainly use the following words: “I hear what you are saying”, “Then the bell rang”, “I am in tune with this”, “Here, listen ...”, “It sounds like this ...”, etc. that a person of this type remembers, as if slandering him his inner voice or he hears the speech, the words of another. When remembering, the gaze is directed to the right, left or left down.

kinesthetic type. These people remember sensations and movements well. Remembering, these people, as it were, first recreate, repeat the movements and sensations of the body. Remembering, they look down or down to the right. In a conversation, kinesthetic words are mainly used: "take, grab, feel, heavy", "I feel that ...", "It's hard for me", "I can't grasp the thought ...", etc.

Naturally, each person owns all types of remembering, but one of the three systems for providing information to consciousness is usually developed better than others. When remembering images, a person usually relies on a more developed, leading one.

The leading sensory (representative) system of a person exerts its influence on the compatibility and effectiveness of communication with other people. This should be taken into account when establishing contact with the patient. You can determine another person's leading sensory system by paying attention to the process words (verbs, adverbs, and adjectives) that the other person uses to describe their inner experience. To establish effective interaction with a person, it is better to use the same process words as he does. If you want to establish a distance, then you can intentionally use words from a different system of representations, different from the system of the interlocutor. One of the factors of insufficient understanding of each other by people is the mismatch of the leading sensory (representative) systems.

Pronounced visuals, kinesthetics, auditory have their own specific features in behavior and movements, in speech, breathing, etc.

Control questions

1. What is a “feeling”? What are the main characteristics of this mental process?

2. What is the physiological mechanism of sensations? What is an "analyzer"?

3. What classifications of sensations do you know?

4. What is the “modality” of sensations?

5. Describe the main types of sensations.

6. Tell us about the main properties of sensations.

7. What do you know about the absolute and relative thresholds of sensations?

8. Tell us about sensory adaptation.

9. Tell us about sensory deprivation.

10. What is sensitization?

Lesson topic: Perception as a mental process

Purpose of the lesson : The study of the psychological characteristics of the process of perception, its place and role in human life.

Educational-targeted questions of the lesson

1.general characteristics the process of perception.

2. Phases of perception.

3. Types of perception.

4.Basic properties perception.

5.Phenomena of perception.

6. The relationship of the whole and the part in perception.

7. Violations of perception.

General characteristics of perception

Perception - this is a mental process that reflects a holistic image of objects and phenomena in the human mind with their direct impact on the senses.

The essence of this process, as well as the process of sensation, is to reflect the real existing world. The concepts of “sensation” and “perception” are closely interconnected, there is no clear boundary between these processes - they overlap each other. However, there are fundamental differences between them. The content of sensations does not go beyond the elementary forms of reflection and consists in reflecting only individual properties of objects and phenomena of the surrounding world. However, a person does not live in the world of isolated light or color spots, sounds or touches, he lives in the world of things, objects and forms, in the world difficult situations. Everything that a person perceives, invariably appears before him in the form of integral images.

Perception includes sensation and is based on it. But it is not reduced to a simple sum of sensations. It is something whole included and reproduced past experience, and processes of comprehension of what is perceived, and other mental processes. In other words, perception differs from sensation in that it active process, as a result of which the image of the object is formed.

Perception is often called human perceptual system.

Phases of perception

Research by psychophysiologists shows that perception is a complex process that requires significant analytical and synthetic work. It is known that the human brain has mechanisms that streamline the processes of perception. From the first minutes of life, a newborn is exposed to a huge number of stimuli, which, having reached the brain, are sorted into categories before being deposited in memory.

Always included in the process of perception motor components nets (feeling objects and eye movement during perception specific items; singing or pronouncing the corresponding sounds when perceiving speech). Therefore, perception is most correctly designated as an active perceptual activity of the subject. The result of this activity is holistic view about a subject that we encounter in real life.

Thinking takes part in the formation of a perceptual image. The process of perception requires the unification of a group of basic essential features and the comparison of the perceived set of features with previous knowledge about the subject, i.e., memory is involved in the process of perception. In other words, the way in which perceived phenomena are classified is closely related to the previous one. life experience.

Thus, perception is the result of a complex analytical-synthetic activity. It consists of the following perceptual phases:

1.Detection(the initial phase at which the object is distinguished from the general background of stimuli).

2.distinction(selection in the object of the most characteristic features by which it can be identified).

3.Identification(identification of an object with samples in memory).

4.Object identification(matching it with the sample in memory, assigning it to a certain category of objects, “naming the object”).

At the first stage of the perception process, a complex of stimuli is isolated from the information flow and a decision is made that they refer to the same certain object. At the second stage, there is a search in the memory of a complex of signs that is similar or close in composition of sensations, by which the object can be identified. At the third stage, the perceived object is assigned to a certain category, followed by a search for additional signs that confirm or refute the correctness of the decision. And, finally, at the fourth stage, a final conclusion is formed about what kind of object it is, with attribution to it of yet unperceived properties characteristic of objects of the same class with it.

An important role in perception is played by the desire of a person to perceive this or that object, the consciousness of the need or obligation to perceive it, as well as volitional efforts aimed at achieving a better perception, the persistence that he shows in doing so. Thus, in the perception of the subject of the real world, the attention and orientation of the individual are involved.

Types of perception

Based on modern psychological literature, there are several options for classifying perception (Fig. 4). One of the classifications of perception, as well as sensations, is based on differences in the analyzers involved in perception. In accordance with which analyzer (or which modality) plays a predominant role in perception , distinguish visual, auditory, tactile, kineaesthetic, olfactory and taste perception.

The basis of another type of classification of types of perception are the forms of existence of matter : space, time and movement. In accordance with this classification, space perception, time perception and motion perception are distinguished.

Perception of space and time

The perception of space and time occupies a special place among all that a person perceives. All objects are in space, and every phenomenon exists in time. The human perception of space is whole line features. This is due to the fact that space is three-dimensional, and therefore for its perception it is necessary to use a number of collaborating analyzers. Wherein perception of space can take place at different levels. The spatial properties of an object include: size, shape, position in space. In perception three-dimensional space First of all, the functions of a special vestibular apparatus located in the inner ear, as well as the apparatus of binocular vision, are involved.

Perception of time, despite the importance of this problem, much less has been studied than the question of the perception of space. Difficulty of learning this issue is that time is not perceived as a phenomenon of the material world. Its course can be judged only by certain signs.

The most elementary forms are the processes of perception, which are based on elementary rhythmic phenomena known as “ biological clock". In general, there are two main aspects to consider when studying the perception of time: perception temporal duration and perception of temporal sequence.

Estimation of the duration of a time interval largely depends on what events it was filled with. If there were a lot of events, and they were interesting, then time goes faster. And vice versa, if there were few events or they were not interesting, then time drags on slowly. A time span filled with various events seems to be longer, and vice versa.

Estimation of the length of time also depends on emotional experiences.. If events cause a positive attitude towards oneself, then time seems to go quickly. Conversely, negative experiences lengthen the time period.

Except internal mechanisms time perception a person also enjoys certain valuestime intervals. Such intervals can be a day, a week, a month, a year, a century, etc. The existence of these intervals is possible because a certain change of events alternates in them, for example, sunset and sunrise. So, by the number of sunrises, we can judge how many days, weeks, months, years have passed.

Thus, in the perception of time by a person, it is necessary to distinguish two aspects: subjective and objective-conditional. The subjective aspect is connected with our personal assessment of passing events, which, in turn, depends on the occupancy of a given time period with events, as well as their emotional coloring. The objectively conditional aspect is associated with the objective course of events and a series of conditionally contractual reference points, or time intervals. If the first aspect reflects inner feeling time, the second aspect helps a person to navigate in time.

Basic properties of perception

The main properties of perception include the following:

· objectivity,

· integrity,

· structure,

· constancy,

· meaningfulness,

· selectivity.

Objectivity of perception - is the ability to reflect objects and phenomena of the real world not in the form of a set of bound friend with other sensations, but in the form of individual objects. It should be noted that objectivity is not an innate property of perception. The emergence and improvement of this property occurs in the process of ontogenesis, starting from the first year of a child's life. I. M. Sechenov believed that objectivity is formed on the basis of movements that ensure the contact of the child with the object. Without the participation of movement, the images of perception would not have the quality of objectivity, that is, of being related to objects in the external world. In other words, objectivity is the correlation of an image with an object. Thus, the possibility of object perception is largely due to the presence in the process of perception of the motor component (hand movements, micro- and macro-eye movements).

Another property of perception is integrity . Unlike sensation, which reflects the individual properties of an object, perception gives a holistic image of the object. The components of sensation are so strongly interconnected that a single complex image object arises even when only individual properties or individual parts of the object act directly on a person. This image arises as a conditioned reflex due to the connection between various sensations. In other words, the integrity of perception is expressed in the fact that even with an incomplete reflection of the individual properties of the perceived object, the received information is mentally completed to a holistic image of a particular object.

The integrity of perception is also related to its structure (property opposite to integrity) - the ability to distinguish parts in the image of an object or phenomenon, as a result of which a person can establish relationships between parts. For example, if a person listens to some melody, then the previously heard notes still continue to sound in his mind when information about the sound of a new note arrives. Usually the listener understands the melody, that is, perceives its structure as a whole. It is obvious that the last of the heard notes in itself cannot be the basis for such an understanding - in the mind of the listener, the whole melody continues to sound with various interconnections of its elements. Thus, perception brings to our consciousness the structure of an object or phenomenon that we encounter in the real world.

The next property of perception is constancy . Constancy is the relative constancy of the reflection of certain properties of objects when the physical conditions of their perception change. For example, a truck moving in the distance will be perceived as a large object, although its image on the retina will be much smaller than its image, as if it were nearby.

Due to the property of constancy, which is manifested in the ability of the perceptual system to compensate for changes in the conditions of perception, a person perceives the surrounding objects as relatively constant. Constancy, thus, reduces the diversity of the external world, saves memory space, reducing the description of images. To the greatest extent, constancy is observed in the visual perception of the color, size and shape of objects.

Thus, the property of constancy is explained by the fact that perception is a kind of self-regulating action that has a feedback mechanism and adapts to the characteristics of the perceived object and the conditions of its existence. Without the constancy of perception, a person would not be able to navigate in an infinitely diverse and changeable world.

The next property of perception is its meaningfulness. Perceptual images always have a certain meaning. As mentioned above, human perception is closely related to thinking. The connection between thinking and perception is primarily expressed in the fact that to consciously perceive an object means to mentally name it, that is, to attribute it to a certain group, class, to associate it with a certain word.

Another property of perception is selectivity. It lies in the fact that at any time a person can perceive only one object or a specific group of objects, while the rest of the objects of the real world are the background of perception, that is, they are not reflected in consciousness. For example, a student, listening to a lecture or reading a book, does not pay attention at all to what is happening behind him.

The content of perception is also determined by the personal characteristics of a person, namely: the motives of his activity, his interests and orientation. For example, someone who has little interest in technology most often sees only gross differences in cars of different designs and does not notice many others. design features. The QCD inspector at the production site easily finds defective parts, not only because he knows how to do it well, but because as a result of his professional activity he has developed a mindset for the perception of the products he checks from this side. We observe a similar picture in relation to the emotional coloring of perceived information. So, the mother of a sleeping child may not hear the noise of the street, but instantly reacts to any sound coming from the side of the child.

Phenomena of perception

Perceptual phenomena have been best described and analyzed by the school of Gestalt psychology.

1. The law of figure and background.

The most important of the principles of Gestal psychology is that any image or object is perceived as figure, which stands out on some background. In accordance with these distinguish item, or object, perceptiontiya, i.e., what perception is currently focused on, and background, which is formed by all other objects acting on the individual at the same time, but receding, in comparison with the object of perception, “into the background”. The human brain has a (apparently innate) tendency to structure signals in such a way that everything that is smaller or more regular, and most importantly that which has some meaning, is perceived as a figure: it stands out against some background, and the background itself is perceived as much less structured.

The selection of an object from the background is associated with the peculiarities of our perception, namely with the objectivity of perception. Easier to stand out what really is separate subject well known from past experience. Selecting an object from the background makes it easier to know what needs to be found, especially if it is a specific image of the object, as well as highlighting the object from the background, which makes it possible to trace the contours of the object or sort through the objects with your hands, i.e. the possibility of manipulating objects.

It should be noted that the subject-to-background ratio is the dyne ratiomic. What at the moment belongs to the background may become the subject after a while, and vice versa, what was the subject may become the background. This is confirmed by the following example. Figure 5. shows a white vase against a black circle, but if you look closely at this picture, you can see that the background also has a certain semantic meaning. In this case, one can see that it is not a vase that is depicted, but profiles of human faces.

Rice. five. Ruby vase

2. The law of filling gaps.

The second important principle of Gestalt psychology is the principle of gap filling. It manifests itself in the fact that our brain is always trying to reduce a fragmented image into a figure with a simple and complete outline. Therefore, when an object, image, melody, word or phrase is represented by only disparate elements, the brain will automatically try to put them together and add the missing parts. For example, when the performance of a famous song or an advertisement heard a thousand times is suddenly interrupted on the radio, the human brain automatically restores the missing one.

3. Paradoxes of perception

The organization of perceptual processes and the features of constancy (constancy) provide a consistent and coherent perception of the environment. However, there are cases when perception is distorted:
8 when conflicting signals come from the objects themselves- in this case it is ambiguous pictures, which at first glance seem "normal" but soon become incomprehensible, because they give rise to two conflicting perceptions, and there is no sign of depth that would allow one to determine what is a figure and what is a background.

8 when an individual misinterprets monocular signals received from objects: some signs of perspective, depth, shape or size, conflicting with each other, give rise to visual illusions.

One explanation for a number of illusions is based on the tendency to perceive as larger what is further away, taking into account the effect of perspective. This causes the human brain to erroneously exaggerate the size of the one that is more distant from two equal objects (this, for example, occurs in the case of the Muller-Lyer illusion).

Control questions

1. Describe perception as a cognitive mental process.

2. What is the relationship between sensation and perception? What do you know about pattern recognition theories?

3. What is the reflex essence of perception?

4. Describe the main properties of perception.

5. What classifications of types of perception do you know?

6. What phenomena of perception do you recognize?

# Modality – quality characteristic sensations, indicating belonging to certain sense organs.

Questions

Lecture 1.6. Feelings and perception

1. The concept of sensations. The 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 sensory-perceptual sphere of the child.

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 start talking about cognitive processes, thanks to the functioning of which a person cognizes the reality surrounding him. Learning processes include: sensation, perception, representation, attention, memory, imagination, thinking, speech.

Human knowledge of the world begins with the accumulation of information with the help of 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, then 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 individual properties of objects.

Feeling- a cognitive process in which, as a result of the direct impact of stimuli on the sensory organs, individual properties of objects of the objective world are reflected.

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

Unlike animals, a person's feelings are influenced by socio-historical development. People's feelings are mediated by the way they practical activities, consciousness, individual features. In sensation, it is conditionally possible to distinguish objective and subjective side. The objective side is connected 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 life-acquired factors. It is proved that the nature of sensations can change under the influence of ongoing activities, diseases, special exercises, etc.

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

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

Organic sensations are correlated with the objects of the external world, give rise to desires, serve as a source of volitional impulse. Movements and actions aimed at achieving the goal are regulated by the sensations that are necessary to build the action. Thus, sensations provide the vital activity of a person.

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

Impossible without feelings mental activity person. At present, in connection with the task of space exploration 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, there are obsessions. Thus, the constant "transformation of energy external stimulus into the fact of consciousness”, carried out in sensations, is a necessary condition for the normal functioning of the psyche.

Physiological basis of sensations. Sensation can arise only when an object acts on the sense 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 foundations of sensation are deeply and systematically studied within the framework of the reflex concept of I. M. Sechenov and I. P. Pavlov. It is shown that its 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 the analyzers reveals the physiological mechanism of the emergence 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 a form of nervous excitation (impulse).

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

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

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

Depending on the type of sensitivity, there are visual, auditory, olfactory, taste, cutaneous, motor other analyzers. Each analyzer from the whole variety of influences allocates incentives only a certain kind. For example, the auditory analyzer highlights the waves formed as a result of vibrations of air particles. The gustatory analyzer generates an impulse as a result of the “chemical analysis” of molecules dissolved in saliva, and the olfactory analyzer generates an impulse in the air. The visual analyzer perceives electromagnetic oscillations, the characteristic of which generates one or another visual image.

Converting the energy of external influence into nerve impulse, its conduction to the brain, the formation of sensation and response - all this is deployed in time. The period of time from the application of irritation to the occurrence of a response is called latent(hidden) period. It is not the same for different sensations. So, the latent period of tactile sensations is 130 milliseconds, pain - 370.