The diversity of the surrounding world to a certain extent becomes accessible to us thanks to the diversity of our sensations.

The feeling is mental process reflection of individual properties of objects and phenomena of the surrounding world, as well as internal states of the body with the direct influence of stimuli on the corresponding analytical systems.

Sensation, their nature, the laws of formation and change are studied in special area psychology, what is called psychophysics. It arose in the second half of the 19th century, and its name is associated with the main question that is posed and resolved in this field of knowledge - the question of the relationship between sensations and the physical characteristics of stimuli affecting the senses.

Evolutionary sensations arose on the basis irritations, which are inherent in living matter, which selectively reacts by changing its internal state to biologically significant environmental influences. The elementary response to irritation appears in the simplest single-celled living organisms, which react to the influence of the environment with movement. Irritation, or excitability of the sense organs, is the most important prerequisite for the body to display the objective properties of the environment, which is the essence of sensibility processes. According to the hypothesis of O. M. Leontyev, sensuality “is genetically nothing more than irritation in relation to this kind of environmental influence that correlates the organism with other influences, i.e., orients the organism in the environment, performing a signaling function.” Thanks to sensuality, the signs of objects (smells, shape, color), in themselves are indifferent (in the sense that they cannot satisfy organic needs), acquire a signaling value. The more developed the senses, the more opportunities to reflect the influence of the external environment. It is necessary to distinguish between stimuli, adequate for a given sense organ and not adequate for it. Specialization of the sense organs to display one or another type of energy, certain properties of objects or phenomena of reality is a product of long evolution, and the sense organs themselves are a product of adaptation to the influences of the external environment. Adequate reflection of reality on the sensory -perceptual level is necessary from an evolutionary-historical point of view, because it is a prerequisite for survival.

The physiological basis of sensation is the nervous process that occurs when a stimulus acts on the corresponding analyzer. When talking about analyzers, two things should be kept in mind. Firstly, this name is not entirely accurate, because the analyzer provides not only analysis, but also the synthesis of stimuli into sensations and images. Secondly, analysis and synthesis can occur outside the conscious control of these processes on the part of a person. She feels and processes most stimuli, but is not aware of them.

The sensation is reflexive in nature; physiologically it is provided by the analyzer system. The analyzer is a nervous apparatus that performs the function of analyzing and synthesizing stimuli that come from the external and internal environment of the body. I introduced the concept to the analyzer. P. Pavlov. The analyzer consists of three parts:

1) peripheral department - receptor, which transforms a certain type of energy into a nervous process;

2) afferent(centripetal) pathways that transmit excitation that arose in the receptor in the higher centers of the nervous system, and efferent (centrifugal) pathways through which impulses from higher centers are transmitted to lower levels;

3) subcortical and cortical projective zones, where the processing of nerve impulses from peripheral parts occurs.

Historically, it so happened that those analyzer systems, the receptor part of which (presented from an anatomical point of view) exists in the form of separate external organs (nose, ear, etc.), are called sense organs. Vision, hearing, smell, touch and taste were highlighted by Aristotle. In reality, there are much more varieties of sensations. A significant part of physical impacts acquires direct vital significance for living beings, or simply not perceived by them. For some influences that occur on Earth in pure form and in quantities that threaten human life, it simply does not have the appropriate sensory organs. Such an irritant is, for example, radiation. A person is also not given the ability to consciously perceive or reflect in the form of sensations ultrasounds and light rays whose wavelengths exceed the permissible range.

The analyzer constitutes the initial and most important part of the entire path of nervous processes, or reflex arc.

Reflex arc = analyzer + effector. The effector is a motor organ (a certain muscle) that receives a nerve impulse from the central nervous system (brain). The interconnection of the elements of the reflex arc provides the basis for the orientation of a complex organism in the environment, the activity of the organism depending on the conditions of its existence.

For a feeling to arise, it is not enough for the organism to be subjected to the appropriate influence of a material stimulus; some work of the organism itself is also necessary. Optimization of the sensation process is carried out through perceptual regulation. The sense organs are closely connected with the organs of movement, which perform not only adaptive and executive functions, but are also directly involved in the processes of obtaining information.

In the first case (I), the muscular apparatus acts as an effector. In the second case (II), the sensory organ itself can be either a receptor or an effector.

Not a single sensory impulse, not a single irritation of a receptor by itself can unambiguously determine an adequate image of sensation and perception without muscular correction (since inevitable errors require feedback). When receiving a sensory image, this feedback is always present, so there is reason to speak not of a reflex arc, but of a closed one reflex ring.

Correction of the sensory image occurs with the help of perceptual actions, in which the image of an object is compared with the real-practical features of this object. The effector components of these actions include hand movements that feel an object, eye movements that track a visible contour, movements of the larynx that reproduce a heard sound, and others. In all these cases, a copy is created that is comparable to the original, and the branching signals, entering the nervous system, can perform a corrective function in relation to the image, and therefore, to practical actions. Thus, perceptual action is a kind of self-regulating model what drives the feedback mechanism and adapts to the characteristics of the object being studied.

All living beings that have a nervous system have the ability to sense sensations. As for conscious sensations (about, the source and quality of which a report is given), only humans have them.

In the evolution of living beings, sensations arose on the basis of primary irritability, which is the property of living matter to respond to biologically significant environmental influences by changing its internal behavior.

By their origin, from the very beginning, sensations were associated with the activity of the body, with the need to satisfy its biological needs. The vital role of sensations is to promptly convey to the central nervous system (as the main organ of control of human activity and behavior) information about the state of the external and internal environment, the presence of biologically significant factors in it.

Sensation, unlike irritability, carries information about certain qualities of external influence. A person’s sensations, in their quality and diversity, reflect the variety of environmental properties that are significant to him.

Potential energy signals are: light, pressure, heat, chemicals, etc.

Human sense organs, or analyzers, from the moment of birth are adapted to perceive and process various types of energy in the form of stimuli - irritants (physical, mechanical, chemical and others).

An irritant is any factor that affects the body and can cause some kind of reaction in it. It is necessary to distinguish between stimuli that are adequate for a given sense organ and those that are adequate for it. This fact indicates a subtle specialization of the senses to reflect one or another type of energy, certain properties of objects and phenomena of reality.

The specialization of the sense organs is a product of long-term evolution, and the sense organs themselves are products of adaptation to the influences of the external environment, therefore, in their structure and properties they are adequate to these influences. In humans, subtle differentiation in the field of sensations is associated with the historical development of human society and with social and labor practice. “Serving” the processes of adaptation of the organism to the environment, the sense organs can successfully perform their function only if they correctly reflect its objective properties. Thus, it is not the specificity of the sense organs that gives rise to the specificity of sensations, but the specific qualities of the external world that give rise to the specificity of the senses.

Sensations are not symbols, hieroglyphs, but reflect the actual properties of objects and phenomena of the material world that affect the sense organs of the subject, existing independently of him. The physiological basis of sensations is the complex activity of the sensory organs, called analyzer activity.

Analyzers are a set of interacting formations of the peripheral and central nervous systems that receive and analyze information about phenomena occurring both inside and outside the body.

The entire human body can be considered as a single and complexly differentiated analyzer of environmental impacts on humans.

The differentiation of analyzers is associated with their specialization in displaying various types of influences. The analyzer consists of three parts:

• 1. The peripheral part of the analyzers consists of receptors in which the primary transformations of external influences into the internal state of a person are carried out.
• 2. Afferent (centripetal) and efferent (centrifugal) nerves, conducting pathways connecting the peripheral part of the analyzer with the central one.
• 3. Subcortical and cortical sections (brain end) of the analyzer, where the processing of nerve impulses coming from peripheral sections occurs. In the cortical section (central) of each analyzer there is the core of the analyzer, i.e., the central part, where the bulk of the receptor cells is concentrated, and the periphery, consisting of scattered cellular elements, which are located in varying quantities in areas of the cortex. The peripheral (receptive) section of the analyzers consists of all sense organs - the eye, ear, nose, skin, as well as special receptor devices located in the internal environment of the body (in the digestive, respiratory, cardiac organs). vascular system, in the genitourinary organs). This section of the analyzer reacts to a specific type of stimulus and processes it into a specific excitation. Receptors can be located on the surface of the body (exteroceptors) and in internal organs and tissues (interoreceptors). 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. Organic sensations are associated with the activity of interoceptors. An intermediate position is occupied by proprioceptors located in muscles and ligaments, which serve to sense the movement and position of body organs, and also participate in determining the properties and qualities of objects, in particular when touching them with the hand. Thus, the peripheral section of the analyzer plays the role of a specialized, perceiving apparatus. Certain cells of the peripheral parts of the analyzer correspond to certain areas of cortical cells. Thus, spatially different points in the cortex represent, for example, different points of the retina of the eye, and the organ of hearing is represented in the cortex by spatially different locations of cells. The same applies to other senses. Numerous experiments carried out using artificial stimulation methods now make it possible to quite definitely establish the localization in the cortex of certain types of sensitivity. Thus, the representation of visual sensitivity is concentrated mainly in the occipital lobes of the cerebral cortex. For sensation to arise, the entire analyzer must work as a whole. The impact of an irritant on a receptor causes irritation. The beginning of this irritation is the transformation of external energy into a nervous process, which is produced by the receptor. From the receptor, this process travels along the centripetal nerve to the nuclear part of the analyzer, located in the spinal cord or brain. When excitation reaches the cortical cells of the analyzer, we feel the qualities of the stimuli, and after this the body’s response to the irritation occurs. If the signal is caused by an irritant that threatens to cause damage to the body, or is addressed to the autonomic nervous system, then it is very likely that it will immediately cause a reflex reaction emanating from the spinal cord or other lower center, and this will happen before we are aware of this impact (a reflex is an automatic response of the body to the action of some internal or external stimulus). Our hand withdraws when burned by a cigarette, our pupil constricts in bright light, our salivary glands begin to secrete saliva if we put a piece of candy in our mouth, and all this happens before our brain deciphers the signal and gives the appropriate order. The survival of an organism often depends on the short neural circuits that make up the reflex arc.

There is no clear connection between receptors and the functions they perform. A set of hierarchical mechanisms that solve perceptual tasks of varying complexity is called a perceptual system.

The physiological basis of sensations is the activity of complex complexes of anatomical structures, named by I.P. Pavlov analyzers . Each analyzer consists of three parts:

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

2) nerve pathways;

3) the cortical sections of the analyzer (they are also called the central sections of the analyzers), in which the processing of nerve impulses coming from the peripheral sections occurs.

The cortical part of each analyzer includes an area that represents a projection of the periphery (i.e., a projection of the sensory organ) in the cerebral cortex, since certain receptors correspond to certain areas of the cortex. For sensation to occur, all components of the analyzer must be used. If any part of the analyzer is destroyed, the occurrence of the corresponding sensations becomes impossible. Thus, visual sensations cease when the eyes are damaged, when the integrity of the optic nerves is damaged, and when the occipital lobes of both hemispheres are destroyed.

Analyzer - this is an active organ, reflexively rearranged under the influence of stimuli, therefore sensation is not a passive process, it always includes motor components. Thus, the American psychologist D. Neff, observing an area of ​​skin with a microscope, became convinced that when it is irritated by a needle, the moment the sensation occurs is accompanied by reflexive motor reactions of this area of ​​the skin. Subsequently, numerous studies have established that sensation is closely related to movement, which sometimes manifests itself in the form of a vegetative reaction (vasoconstriction, galvanic skin reflex), sometimes in the form of muscle reactions (turning the eyes, tension in the neck muscles, motor reactions of the hand, etc.) .d.). Thus, sensations are not at all passive processes - they are active, or reflexive, in nature.

3. Classification of types of sensations.

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

Let's consider systematic classification sensations (Fig. 1). This classification was proposed by the English physiologist C. Sherrington. Considering the largest and most significant groups of sensations, he divided them into three main types: interoceptive, proprioceptive and exteroceptive Feel. The first combine signals reaching us from the internal environment of the body; the latter transmit information about the position of the body in space and the position of the musculoskeletal system, and ensure the regulation of our movements; finally, still others provide signals from the external world and create the basis for our conscious behavior. Let's consider the main types of sensations separately.

Interoceptive sensations signaling the state of the internal processes of the body arise due to receptors located on the walls of the stomach and intestines, the heart and circulatory system and other internal organs. This is the most ancient and most elementary group of sensations. Receptors that perceive information about the state of internal organs, muscles, etc. are called internal receptors. Interoceptive sensations are among the least conscious and most diffuse forms of sensations and always retain their proximity to emotional states. It should also be noted that interoceptive sensations are often called organic.

Proprioceptive sensations transmit signals about the position of the body in space and form the afferent basis of human movements, playing a decisive role in their regulation. The described group of sensations includes a sense of balance, or static sensation, as well as a motor, or kinesthetic, sensation.

Peripheral receptors of proprioceptive sensitivity are located in muscles and joints (tendons, ligaments) and are called Paccini corpuscles.

In modern physiology and psychophysiology, the role of proprioception as the afferent basis of movements in animals was studied in detail by A.A. Orbeli, P.K. Anokhin, and in humans - by N.A. Bernstein.

Peripheral receptors for the sensation of balance are located in the semicircular canals of the inner ear.

The third and largest group of sensations are exteroceptive Feel. They bring information from the outside world to a person and are the main group of sensations that connect a person with the external environment. The entire group of exteroceptive sensations is conventionally divided into two subgroups: contact and distant sensations.

Rice. 1. Systematic classification of the main types of sensations

Contact sensations are caused by the direct impact of an object on the senses. Examples of contact sensation are taste and touch. Distant Feel reflect the qualities of objects located at some distance from the senses. Such sensations include hearing and vision. It should be noted that the sense of smell, according to many authors, occupies an intermediate position between contact and distant sensations, since formally olfactory sensations occur at a distance from the object, but, at the same time, the molecules characterizing the smell of the object, with which the olfactory receptor contacts, undoubtedly belong to this subject. This is the duality of the position occupied by the sense of smell in the classification of sensations.

Since sensation arises as a result of the action of a certain physical stimulus on the corresponding receptor, the primary classification of sensations considered by us proceeds, naturally, from the type of receptor that gives the sensation of a given quality, or “modality”. However, there are sensations that cannot be associated with any specific modality. Such sensations are called intermodal. These include, for example, vibration sensitivity, which connects the tactile-motor sphere with the auditory sphere.

The sensation of vibration is the sensitivity to vibrations caused by a moving body. According to most researchers, the vibration sense is an intermediate, transitional form between tactile and auditory sensitivity. In particular, the school of L. E. Komendantov believes that tactile-vibration sensitivity is one of the forms of sound perception. With normal hearing, it does not appear particularly prominent, but with damage to the auditory organ, this function is clearly manifested. The main position of the “auditory” theory is that tactile perception of sound vibration is understood as diffuse sound sensitivity.

Vibration sensitivity acquires particular practical significance in cases of damage to vision and hearing. It plays a big role in the lives of deaf and deaf-blind people. Deaf-blind people, thanks to the high development of vibration sensitivity, learned about the approach of a truck and other types of transport at a great distance. In the same way, through the vibrational sense, deaf-blind people know when someone enters their room. Consequently, sensations, being the simplest type of mental processes, are actually very complex and have not been fully studied.

It should be noted that there are other approaches to the classification of sensations. For example, the genetic approach proposed by the English neurologist H. Head. Genetic classification allows us to distinguish two types of sensitivity: 1) protopathic (more primitive, affective, less differentiated and localized), which includes organic feelings (hunger, thirst, etc.); 2) epicritic (more subtly differentiating, objectified and rational), which includes the main types of human sensations. Epicritic sensitivity is younger in genetic terms, and it controls protopathic sensitivity.

The famous Russian psychologist B.M. Teplov, considering the types of sensations, divided all receptors into two large groups: exteroceptors (external receptors), located on or close to the surface of the body and accessible to external stimuli, and interoceptors (internal receptors), located deep in tissues, such as muscles, or on surfaces of internal organs. The group of sensations that we called “proprioceptive sensations” was considered by B.M. Teplov as internal sensations.

All sensations can be characterized in terms of their properties. Moreover, the properties can be not only specific, but also common to all types of sensation. 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, distinguishes it from other types of sensations and varies within a given type of sensation. For example, taste sensations provide information about certain chemical characteristics of an object: sweet or sour, bitter or salty. The sense of smell also provides us with information about the chemical characteristics of an object, but of a different kind: flower smell, almond smell, hydrogen sulfide smell, etc.

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

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

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

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

Negative sequential image consists in the emergence of a quality of sensation opposite to the quality of the stimulus that acts. For example, light-darkness, heaviness-lightness, warmth-cold, etc. The emergence of negative sequential images is explained by a decrease in the sensitivity of a given receptor to a certain influence.

And finally, sensations are characterized by 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 what part of the body the stimulus affects.

All the properties described above, to one degree or another, reflect the qualitative characteristics of sensations. However, no less important are the quantitative parameters of the main characteristics of sensations, in other words, the degree sensitivity .

4. Patterns of sensations.

So far we have been talking about the qualitative difference in types of sensations. However, quantitative research, in other words, their measurement, is no less important.

Sensitivity and its measurement. Various sense organs that give us information about the state of the external world around us may be more or less sensitive to the phenomena they display, i.e. can reflect these phenomena with greater or less accuracy. Sensitivity The sensory organ is determined by the minimum stimulus that, under given conditions, is capable of causing sensation. The minimum strength of the stimulus that causes a barely noticeable sensation is called lower absolute threshold sensitivity .

Stimuli of lesser strength, so-called subthreshold, do not cause sensations, and signals about them are not transmitted to the cerebral cortex. At each individual moment, from an infinite number of impulses, the cortex perceives only vitally relevant ones, delaying all others, including impulses from internal organs. This position is biologically expedient. It is impossible to imagine the life of an organism in which the cerebral cortex would equally perceive all impulses and provide reactions to them. This would lead the body to inevitable death. It is the cerebral cortex that guards the vital interests of the body and, raising the threshold of its excitability, transforms irrelevant impulses into subthreshold ones, thereby relieving the body of unnecessary reactions.

However, subthreshold impulses are not indifferent to the body. This is confirmed by numerous facts obtained in the clinic of nervous diseases, when it is weak, subcortical stimuli from the external environment that create a dominant focus in the cerebral cortex and contribute to the occurrence of hallucinations and “deception of the senses.” Subthreshold sounds can be perceived by the patient as a host of intrusive voices with simultaneous complete indifference to real human speech; a weak, barely noticeable ray of light can cause hallucinatory visual sensations of various contents; barely noticeable tactile sensations - from contact of skin with clothing - a series of perverted acute skin sensations.

The lower threshold of sensations determines the level of absolute sensitivity of this analyzer. There is an inverse relationship between absolute sensitivity and the threshold value: the lower the threshold value, the higher the sensitivity of a given analyzer. This relationship can be expressed by the formula:

where E is sensitivity, and P is the threshold value of the stimulus.

Our analyzers have different sensitivities. The threshold of one human olfactory cell for the corresponding odorous substances does not exceed 8 molecules. It takes at least 25,000 times more molecules to produce the sensation of taste than to create the sensation of smell.

The sensitivity of the visual and auditory analyzer is very high. The human eye, as shown by the experiments of S.I. Vavilov (1891-1951), is capable of seeing light when only 2-8 quanta of radiant energy hit the retina. This means that we would be able to see a burning candle in complete darkness at a distance of up to 27 kilometers. At the same time, in order for us to feel touch, we need 100-10,000,000 times more energy than for visual or auditory sensations.

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

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

With the help of our senses, we can not only ascertain the presence or absence of a particular stimulus, but also distinguish between stimuli by their strength and quality. The minimum difference between two stimuli that causes a barely noticeable difference in sensation is called discrimination threshold or difference threshold . The German physiologist E. Weber (1795-1878), testing a person’s ability to determine the heavier of two objects in the right and left hand, established that difference sensitivity is relative, not absolute. This means that the ratio of the additional stimulus to the main one must be a constant value. So, if there is a load of 100 grams on your hand, then for a barely noticeable sensation of weight gain to occur, you need to add about 3.4 grams. If the weight of the load is 1000 grams, then to create the feeling of a barely noticeable difference you need to add about 33.3 grams. Thus, the greater the magnitude of the initial stimulus, the greater the increase should be to it.

The discrimination threshold is characterized by a relative value that is constant for a given analyzer. For a visual analyzer this ratio is approximately 1/100, for an auditory analyzer - 1/10, for a tactile analyzer - 1/30. Experimental testing of this position showed that it is valid only for stimuli of average strength.

Based on Weber's experimental data, the German physicist G. Fechner (1801-1887) expressed the dependence of the intensity of sensations on the strength of the stimulus with the following formula:

where S is the intensity of sensations, J is the strength of the stimulus, K and C are constants. According to this position, which is called the basic psychophysical law, the intensity of sensation is proportional to the logarithm of the strength of the stimulus. In other words, as the strength of the stimulus increases in geometric progression, the intensity of the sensation increases in arithmetic progression (Weber-Fechner law).

Difference sensitivity, or sensitivity to discrimination, is also inversely related to the value of the discrimination threshold: the greater the discrimination threshold, the lower the difference sensitivity.

The concept of difference sensitivity is used not only to characterize the discrimination of stimuli by intensity, but also in relation to other features of certain types of sensitivity. For example, they talk about sensitivity to distinguishing shapes, sizes and colors of visually perceived objects or to sound-pitch sensitivity.

Adaptation . The sensitivity of analyzers, determined by the value of absolute thresholds, is not constant and changes under the influence of a number of physiological and psychological conditions, among which the phenomenon of adaptation occupies a special place.

Adaptation, or adaptation, is a change in the sensitivity of the senses under the influence of a stimulus.

Three types of this phenomenon can be distinguished.

1. Adaptation as the complete disappearance of sensation during the prolonged action of a stimulus. We mentioned this phenomenon at the beginning of this chapter, talking about the peculiar mood of the analyzers to changes in stimuli. In the case of constant stimuli, the sensation tends to fade. For example, a light weight resting on the skin soon ceases to be felt. A common fact is the distinct disappearance of olfactory sensations soon after we enter an atmosphere with an unpleasant odor. The intensity of the taste sensation weakens if the corresponding substance is kept in the mouth for some time and, finally, the sensation may fade away completely.

Full adaptation of the visual analyzer does not occur under the influence of a constant and motionless stimulus. This is explained by compensation for the immobility of the stimulus due to movements of the receptor apparatus itself. Constant voluntary and involuntary eye movements ensure continuity of visual sensation. Experiments in which conditions were artificially created to stabilize the image relative to the retina showed that the visual sensation disappears 2-3 seconds after its occurrence, i.e. complete adaptation occurs.

2. Adaptation is also called another phenomenon, close to the one described, which is expressed in a dulling of sensation under the influence of a strong stimulus. For example, when you immerse your hand in cold water, the intensity of the sensation caused by the cold stimulus decreases. When we move from a dimly lit room into a brightly lit space, we are initially blinded and unable to discern any details around us. After some time, the sensitivity of the visual analyzer decreases sharply, and we begin to see normally. This decrease in eye sensitivity under intense light stimulation is called light adaptation.

The two types of adaptation described can be combined with the term negative adaptation, since as a result they reduce the sensitivity of the analyzers.

3. Finally, adaptation is an increase in sensitivity under the influence of a weak stimulus. This type of adaptation, characteristic of certain types of sensations, can be defined as positive adaptation.

In the visual analyzer, this is a dark adaptation, when the sensitivity of the eye increases under the influence of being in the dark. A similar form of auditory adaptation is adaptation to silence. In temperature sensations, positive adaptation is detected when a pre-cooled hand feels warm, and a pre-heated hand feels cold when immersed in water of the same temperature. The existence of negative pain adaptation has long been controversial. It is known that repeated application of a painful stimulus does not reveal negative adaptation, but, on the contrary, has an increasingly stronger effect over time. However, new facts indicate the presence of complete negative adaptation to needle pricks and intense hot irradiation.

Studies have shown that some analyzers detect fast adaptation, while others detect slow adaptation. For example, tactile receptors adapt very quickly. When any prolonged stimulation is applied, only a small volley of impulses runs along their sensory nerve at the beginning of the action of the stimulus. The visual receptor adapts relatively slowly (dark adaptation time reaches several tens of minutes), olfactory and gustatory.

Adaptive regulation of the level of sensitivity depending on what stimuli (weak or strong) affects the receptors is of great biological importance. Adaptation helps the sensory organs to detect weak stimuli and protects the sensory organs from excessive irritation in the event of unusually strong influences.

The phenomenon of adaptation can be explained by those peripheral changes that occur in the functioning of the receptor during prolonged exposure to a stimulus. Thus, it is known that under the influence of light, the visual purple located in the rods of the retina decomposes (fades). In the dark, on the contrary, visual purple is restored, which leads to increased sensitivity. In relation to other sense organs, it has not yet been proven that their receptor apparatus contains any substances that chemically decompose when exposed to a stimulus and are restored in the absence of such exposure. The phenomenon of adaptation is also explained by the processes occurring in the central sections of the analyzers. With prolonged stimulation, the cerebral cortex responds with internal protective inhibition, reducing sensitivity. The development of inhibition causes increased excitation of other foci, which contributes to an increase in sensitivity in new conditions (the phenomenon of sequential mutual induction).

Interaction of sensations . The intensity of sensations depends not only on the strength of the stimulus and the level of adaptation of the receptor, but also on the stimuli acting in this moment to other senses. A change in the sensitivity of the analyzer under the influence of irritation of other senses is called the interaction of sensations.

The literature describes numerous facts of changes in sensitivity caused by the interaction of sensations. Thus, the sensitivity of the visual analyzer changes under the influence of auditory stimulation. S.V. Kravkov (1893-1951) showed that this change depends on the volume of auditory stimuli. Weak sound stimuli increase the color sensitivity of the visual analyzer. At the same time, there is a sharp deterioration in the distinctive sensitivity of the eye when, for example, the loud noise of an aircraft engine is used as an auditory stimulus.

Visual sensitivity also increases under the influence of certain olfactory stimuli. However, with a pronounced negative emotional connotation of the smell, a decrease in visual sensitivity is observed. Similarly, with weak light stimuli, auditory sensations increase, and exposure to intense light stimuli worsens auditory sensitivity. There are known facts of increased visual, auditory, tactile and olfactory sensitivity under the influence of weak painful stimuli.

A change in the sensitivity of any analyzer is also observed with subthreshold stimulation of other analyzers. Thus, P.I. Lazarev (1878-1942) obtained evidence of a decrease in visual sensitivity under the influence of skin irradiation with ultraviolet rays.

Thus, all our analyzing systems are capable of influencing each other to a greater or lesser extent. In this case, the interaction of sensations, like adaptation, manifests itself in two opposite processes: an increase and decrease in sensitivity. The general pattern here is that weak stimuli increase, and strong ones decrease, the sensitivity of the analyzers during their interaction.

Sensitization . Increased 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. Pavlov, a weak stimulus causes an excitation process in the cerebral cortex, which easily irradiates (spreads). As a result of the irradiation of the excitation process, the sensitivity of the other analyzer increases. When exposed to a strong stimulus, a process of excitation occurs, which, on the contrary, tends to concentrate. According to the law of mutual induction, this leads to inhibition in the central sections of other analyzers and a decrease in the sensitivity of the latter.

A change in the sensitivity of analyzers can be caused by exposure to second-signal stimuli. Thus, evidence was obtained of changes in the electrical sensitivity of the eyes and tongue in response to the presentation of the words “sour as lemon” to the test subjects. These changes were similar to those observed when the tongue was actually irritated with lemon juice.

Knowing the patterns of changes in the sensitivity of the sensory organs, it is possible, by using specially selected side stimuli, to sensitize one or another receptor, i.e. increase its sensitivity.

Sensitivity and exercise . Sensitization of the senses is possible not only through the use of side stimuli, but also through exercise. The possibilities for training the senses and improving them are very great. There are two areas that determine increased sensitivity of the senses:

1) sensitization, which spontaneously results from the need to compensate for sensory defects (blindness, deafness);

2) sensitization caused by the activity and specific requirements of the subject’s profession.

The loss of vision or hearing is to a certain extent compensated by the development of other types of sensitivity.

There are cases when people deprived of vision engage in sculpture; their sense of touch is highly developed. The development of vibration sensations in the deaf also belongs to this group of phenomena. Some people who are deaf develop vibration sensitivity so strongly that they can even listen to music. To do this, they place their hand on the instrument or turn their back to the orchestra. Deaf-blind O. Skorokhodova, holding her hand at the throat of the speaking interlocutor, can thus recognize him by his voice and understand what he is talking about. The deaf-blind mute Helen Keller has such a highly developed olfactory sensitivity that she can associate many friends and visitors with the smells emanating from them, and memories of acquaintances are as well associated with her sense of smell as most people are associated with the voice.

Of particular interest is the emergence in humans of sensitivity to stimuli for which there is no adequate receptor. This is, for example, remote sensitivity to obstacles in the blind.

The phenomena of sensitization of the sense organs are observed in people who have been engaged in certain special professions for a long time.

Grinders are known to have extraordinary visual acuity. They see gaps from 0.0005 millimeters, while untrained people see only up to 0.1 millimeters. Fabric dyeing specialists distinguish between 40 and 60 shades of black. To the untrained eye they appear exactly the same. Experienced steelmakers are able to quite accurately determine its temperature and the amount of impurities in it by the faint color shades of molten steel.

The olfactory and gustatory sensations of tasters of tea, cheese, wine, and tobacco reach a high degree of perfection. Tasters can pinpoint not only what type of grape a wine is made from, but also where those grapes grew.

Painting places special demands on the perception of shapes, proportions and color relationships when depicting objects. Experiments show that the artist's eye is extremely sensitive to assessing proportions. It distinguishes changes equal to 1/60-1/150 of the size of the object. The subtlety of color sensations can be judged by the mosaic workshop in Rome - it contains more than 20,000 shades of primary colors created by man.

The possibilities for developing auditory sensitivity are also quite large. Thus, playing the violin requires special development of pitch hearing, and violinists have it more developed than pianists. Experienced pilots can easily determine the number of engine revolutions by ear. They freely distinguish 1300 from 1340 rpm. Untrained people only notice the difference between 1300 and 1400 rpm.

All this is proof that our sensations develop under the influence of living conditions and practical requirements. labor activity.

Despite the large number of similar facts, the problem of exercising the senses has not yet been sufficiently studied. What underlies the exercise of the senses? It is not yet possible to give a comprehensive answer to this question. An attempt has been made to explain the increased tactile sensitivity in blind people. It was possible to isolate tactile receptors - special bodies found in the skin of the fingers of blind people. For comparison, the same study was conducted on the skin of sighted people of various professions. It turned out that blind people have an increased number of tactile receptors. Thus, if in the skin of the nail phalanx of the first finger in sighted people the number of corpuscles on average reached 186, then in those born blind it was 270.

Thus, the structure of receptors is not constant, it is plastic, mobile, constantly changing, adapting to the best performance of a given receptor function. Together with the receptors and inseparably from them, the structure of the analyzer as a whole is being rebuilt in accordance with new conditions and requirements of practical activity.

Synesthesia . The interaction of sensations manifests itself in another type of phenomenon called synesthesia. Synesthesia is the occurrence, under the influence of stimulation of one sensation analyzer, of sensations characteristic of another analyzer. Synesthesia is observed in a wide variety of sensations. The most common is visual-auditory synesthesia, when the subject experiences visual images when exposed to sound stimuli. U different people There is no overlap in these synesthesias, but they are fairly consistent across individuals. It is known that some composers (N.A. Rimsky-Korsakov, A.M. Scriabin, etc.) possessed the ability of color hearing. We find a striking manifestation of this kind of synesthesia in the work of the Lithuanian artist M.K. Churlionis - in his symphonies of colors.

The phenomenon of synesthesia is the basis for the creation in recent years of color music devices that transform sound images into light images, and intensive research into color music. Less common are cases of auditory sensations arising when exposed to visual stimuli, gustatory sensations in response to auditory stimuli, etc. Not all people have synesthesia, although it is quite widespread. No one doubts the possibility of using such expressions as “sharp taste”, “flashy color”, “sweet sounds”, etc. The phenomena of synesthesia are another evidence of the constant interconnection of the analytical systems of the human body, the integrity of the sensory reflection of the objective world.

Thus, the structure of receptors is not constant, it is plastic, mobile, constantly changing, adapting to the best performance of a given receptor function. Together with the receptors and inseparably from them, the structure of analysis as a whole is being rebuilt in accordance with the new conditions and requirements of practical activity.

The physiological basis of sensations is the activity of complex complexes of anatomical structures, called analyzers by I. P. Pavlov. An analyzer is an anatomical and physiological apparatus for receiving influences from the external and internal environment and processing them into sensations. Each analyzer consists of three parts:

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

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

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

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

Physiology of attention

Physiological basis perception.

The physiological basis of perception is the processes taking place in the sensory organs, nerve fibers and the central nervous system. Thus, under the influence of stimuli at the endings of the nerves present in the sensory organs, nervous excitation arises, which is transmitted along pathways to the nerve centers and, ultimately, to the cerebral cortex. Here it enters the projection (sensory) zones of the cortex, which represent, as it were, the central projection of the nerve endings present in the sense organs. Depending on which organ the projection zone is connected to, certain sensory information is generated.

The mechanism described above is the mechanism by which sensations arise. Consequently, sensations can be considered as a structural element of the process of perception. Own physiological mechanisms of perception are included in the process of forming a holistic image at subsequent stages, when excitation from the projection zones is transferred to the integrative zones of the cerebral cortex, where the formation of images of phenomena is completed real world. Therefore, the integrative zones of the cerebral cortex, which complete the process of perception, are often called perceptual zones. Their function differs significantly from the function of projection zones.

The physiological basis of perception is further complicated by the fact that it is closely related to motor activity, with emotional experiences, various thought processes. Consequently, having begun in the sense organs, nervous excitations caused by external stimuli pass to the nerve centers, where they cover various zones of the cortex and interact with other nervous excitations. This entire network of excitations, interacting with each other and widely covering different zones of the cortex, constitutes the physiological basis of perception.

From a practical point of view, the main function of perception is to ensure recognition of objects, i.e. assigning them to one category or another. Essentially, when we recognize objects, we make inferences about many hidden properties of the object. Any object has a certain shape, size, color, etc. All these properties are important for its recognition.

Currently, it is customary to distinguish several stages in the process of object recognition, some of which are preliminary, others are final. In the preliminary stages, the perceptual system uses information from the retina and describes the object in terms of elementary components such as lines, edges and corners. At the final stages, the system compares this description with descriptions of the shapes of various kinds of objects stored in visual memory, and selects the best match. Moreover, during recognition, most of the information processing, both at the preliminary and final stages of recognition, is inaccessible to consciousness.

THINKING ACTIVITY

Mental activity is an executive

apparatus of functional systems of the mental level. Due to mental

activities are carried out using information

processes in the brain, a kind of “behavior” at the information level.

Nodal mechanisms of mental activity. From a general perspective

theory of functional systems, the thinking process includes universal

system node components:

Result as the leading system-forming factor of thinking

human activity;

Assessing the result of mental activity using feedback

afferentation;

The system-organizing role of the original biological and social

needs and the dominant ones formed on their basis

motivations in constructing mental activity;

Programming mental activity using the device

acceptor of the result of action based on the mechanisms of afferent

synthesis and decision making;

Effective expression of thought processes through behavior,

somatovegetative components and through specially

organized apparatus of speech.

Information equivalents of mental activity.

The operational architectonics of mental activity is built on the basis

emotional and verbal equivalents of reality. This is in

in a certain sense in accordance with the teachings of I.P. Pavlova about the first and second signal

systems of reality. However, if the representations of I.P. Pavlova

were based on information assessment of signals (conditioned stimuli

physical and verbal nature), then from the standpoint of the systemic organization of mental activity, the information content

functional systems of the mental level determine the corresponding adaptive

results for human activity. In case the results

activities have only physical parameters, then the corresponding

the functional systems of mental activity they organize are built

on information equivalent physical properties of these

results. If the results of the activity have speech, verbal

parameters corresponding to the functional systems of the mental

activities are built on an informational verbal basis.

Only humans have the informational equivalent of functional

systems of mental activity is associated with speech function. In animals these

processes are limited to physical and emotional levels.

The emotional basis of mental activity. Thinking process

continuously accompanied by subjective emotional

a person’s experiences of his needs and subjective attitude towards

influence of environmental factors in order to satisfy these

needs. With the help of emotions, traces of memory are also realized. Emotions

a person evaluates his needs, the effect of environmental factors,

attitude towards objects and other individuals and, finally, satisfaction

needs. Mental needs, as well as biological ones, like

usually accompanied by emotional feelings of negative

character, and satisfaction of needs - diverse

positive emotions. Based on repeated satisfaction of the same type

mental needs, a positive anticipation is formed

emotions of need satisfaction due to its inclusion in the acceptor apparatus

result of the action. In a certain situation, it is foreseen and

negative emotions, which ultimately creates probabilistic forecasting

emotional states. Systemic organization of thinking on

emotional basis is genetically determined. It already appears in

newborns, deaf-blind people, as well as people in a circle

persons speaking a language foreign to them. Emotional basis

thinking, as experiments with self-irritation show, is also characteristic

for animals.

Pathological ones are built on strong emotional sensations

craving for alcohol and drugs. Emotional states

under certain circumstances can build independently

functional systems.

The verbal basis of mental activity. Verbal quantization

thinking is inherent only to man. A person's assessment of needs and their

satisfaction, as well as various external influences on the body

along with emotional sensations is carried out with the help

linguistic symbols, phrases, verbal and written concepts

character. This level of thinking requires special training, firstly

turn to the language. With the help of linguistic symbols, thoughts are realized in

discrete phrases that can constitute inner speech, as well as

transform into external speech and actions.

Mental activity that is formed in a person on verbal

basis, in comparison with emotional activity acquires

qualitatively new information properties, although its general architectonics

retains all the typical features of a functional system.

A type of verbal quantization of mental activity

is the process of singing. An emotional person can

learn a certain melody and fill this melody with appropriate

words that add up to systemic quanta - measures and couplets.

Brain asymmetry in the processes of mental activity.

The emotional and verbal basis of thinking, as shown by modern

research, is built by the functions of different hemispheres of the brain. Right

hemisphere determines predominantly sensual, emotional

component of mental activity. Left hemisphere defines functions

language and speech. The idea of

activity of the cerebral hemispheres based on their mutual complementarity. This

point of view fits well with functional systems theory. WITH

positions of the theory of functional systems in the implementation of effective

mental activity of both hemispheres on emotional and speech

basis should dynamically contribute to the achievement of the subject

adaptive results.

Structural foundations of mental activity. Processes

mental activity and human speech are associated with the activities of various

brain structures. Identify the participation of brain structures in these processes

allow clinical observations of patients with lesions in various areas

Agnosia. When the occipital parts of the cerebral cortex are damaged, a person sees

objects, walks around them without bumping into them, but does not recognize them. This

the violation of recognition is called agnosia (from the Greek gnosis - knowledge). At

In violation of the temporal parts of the cerebral cortex, auditory agnosia is observed.

A person hears sounds, but does not associate them with a specific sound

subject. Such patients lose the ability to perceive the meaning of speech

interlocutor. When the superior parietal cortex is damaged, patients experience

tactile agnosia - subjects lose the ability to recognize objects when

their feeling, although they feel the touch.

From a systemic point of view in subjects with visual, temporal

and parietal areas of the cortex, the mechanism of previously developed assessment is disrupted

results of action.

Apraksin. In case of damage to the motor cortex in humans

there is a violation of purposeful action, although he understands that

need to do. This disorder is called “apraxia” (from the Greek.

praxis - action). The patient cannot, for example, light a match, cut

apple, fasten the buttons, although his hands are not paralyzed. In this case

one can think about disruption of systemic processes of efferent synthesis and

actions.

Aphasia - speech disorder; motor aphasia develops when

dysfunction of the inferior frontal gyrus of the left hemisphere (frontal aphasia

Broca). The patient understands the speech of the interlocutor, but his own speech

extremely difficult or completely disrupted. In this case, it is lost

be saved. Patients are able to scream, make individual sounds, but

can't pronounce a single one meaningful word. Patients have impaired

efferent processes of speech formation.

Sensory aphasia occurs when the posterior pole of the superior

temporal cortex (sensitive, or temporal, Wernicke's aphasia). Wherein

in patients, the processes of speech perception are disrupted: they stop

understand both audible and written language. The ability to pronounce

speech phrases in such patients are not lost, they are even excessively

They are talkative, but their speech is distorted and completely incomprehensible. Such people

music (amusia). It can be assumed that in such patients the mechanisms

acceptor of the result of action and the ability to evaluate what has been achieved

the result of mental activity.

Other disorders are observed with damage to the parietal cortex:

patients forget individual words, more often nouns, cannot

recall the right words and replace them with a long description. Wherein

There is also a counting disorder (acalculia). Patients are impaired

RAM mechanism.

With bilateral damage to the base of the temporal and occipital

unusual agnosia is observed in the lobes of the cortex: patients cease to recognize

people by their faces (prosoagnosia), but nevertheless recognize them by

The visual parameter for assessing familiar personalities is selectively affected.

In case of damage to the angular gyrus without damage nearby

located Wernicke's area and Broca's area in patients in the absence of violation

perception of auditory information and speech; difficulties appear in

understanding writing and pictures (anomic aphasia). In this case

the transmission of visual information to Wernicke's area is disrupted.

Morphofunctional bases of visual object recognition.

Dynamics of subject recognition of a visual image and its reproduction

can be represented as follows. Primary identification and

evaluation of a visual object occurs in the primary visual cortex.

From here the excitation spreads to the angular gyrus and from it to

Wernicke's temporal area, where an object is evaluated on the basis of previously acquired

verbal concepts and knowledge. Excitement from Wernicke's area

spreads to Broca's area and to the speech motor structures of the motor cortex,

which determine the pronunciation of the name of the object.

Functions of speech in right-handers and left-handers. Speech functions in right-handed people, like

usually associated with the activity of the left hemisphere, which determines

processes of sequential analytical activity. Right hemisphere at

right-handers determine spatiotemporal relationships, for example

recognition of faces, identification of objects by their shape, recognition

musical melodies. Such a strict division of functions is relative.

Physiological basis of sensations

Introduction

2. The concept of sensation

3. Physiology of sensations

3.1 Analyzers

3.2 Properties of sensations

3.3 Classification of sensations

4. Types of sensations

4.1 Vision

4.3 Vibratory sensations

4.4 Smell

Bibliography

Introduction

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

1. Sensory organization of personality

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

2. The concept of sensation

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

2.1 Processing sensations

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

3. Physiology of sensations

3.1 Analyzers

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

3.2 Properties of sensations

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

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

For example, the qualities of the visual modality include

Brightness,

Saturation,

Color tone.

Quality of hearing sensations:

Volume,

Quality of tactile sensations:

Hardness,

Roughness, etc.

3.3 Classification of sensations

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

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

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

- distant(visual, auditory),

- contact(tactile, gustatory) sensations.

4. Types of sensations

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

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

4.1 Vision

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

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

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

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

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

Strength (loud - weak),

Height (high - low),

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

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

4.3 Vibratory sensations

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

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

4.4 Smell

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

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

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

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

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

There are several independent analyzing systems in the skin:

Tactile (touch sensations),

Temperature,

Painful.

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

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

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

4.7 Proprioceptive sensitivity

Kinesthesia

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

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

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

Vestibular sense

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