The concept of sensation and its physiological basis. The physiological basis of sensations is the work of analyzers with a physiological apparatus. Sensation concept physiological basis types of properties of sensations

The physiological basis of sensations is the work of analyzers. The physiological apparatus through which sensation arises is the analyzer. An analyzer (sensory organ) is an anatomical and physiological apparatus located on the periphery of the body or in internal organs; it receives irritation from the external and internal environment. Each such device connects the brain with the outside world and provides a variety of information. In order for a person to have normal sensations, a healthy state of all three parts of the analyzer is necessary: ​​the conductive receptor; neural pathway; cortical part.

1. 3. 2. 4. 1. Neuroconducting pathways 2. Cerebral cortex 3. Sections of analyzers in the brain 4. Taste buds

Exteroceptive Interoreceptive Proprioceptive 1. Visual 2. Olfactory 3. Gustatory 4. Auditory 5. Temperature 6. Tactile 1. Sensation of pain 2. Sensation of balance 3. Sensation of acceleration Musculoskeletal

The process of irritation consists in the appearance of an action potential in the nerve tissues and its penetration into the sensitive nerve fiber. Stimuli cause excitation in nervous tissue. The specialized part of the analyzer, through which a certain type of energy is transformed into the process of nervous excitation, is called a receptor.

Physical process stimulus Sensory organ Physiological process excitation Conducting pathways Psychological process Center in the cerebral cortex

The quality of a sensation is a property that characterizes the basic information displayed by a given sensation, distinguishing it from other sensations. We can say this: the quality of sensation is a property that cannot be measured using numbers or compared with some kind of numerical scale. For visual sensation, quality can be the color of the perceived object. For taste or smell - the chemical characteristic of an object: sweet or sour, bitter or salty, floral smell, almond smell, hydrogen sulfide smell, etc.

It is important to understand that the intensity of the sensation depends on two factors, which can be designated as objective and subjective: - the strength of the current stimulus (its physical characteristics), - the functional state of the receptor on which a given stimulus acts. The more significant the physical parameters of the stimulus, the more intense the sensation. For example, the higher the amplitude of a sound wave, the louder the sound appears to us. And the higher the sensitivity of the receptor, the more intense the sensation.

A person exists in space, and the stimuli that act on the senses are also located at certain points in space. Therefore, it is important not only to perceive the sensation, but also to spatially localize it. 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.

Duration of sensation - it indicates the duration of existence of the sensation that has arisen. The duration of the sensation is also influenced by objective and subjective factors. The main factor, of course, is objective - the longer the effect of the stimulus, the longer the sensation. However, the duration of the sensation is influenced by both the functional state of the sensory organ and some of its inertia. After the stimulus begins to influence the sense organ, the sensation does not arise immediately, but after some time. Latent period various types sensations are not the same. For tactile sensations - 130 ms, for pain - 370 ms, 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.

General patterns of sensations: absolute threshold The absolute threshold of sensation (lower threshold of sensations) is those minimal physical characteristics of the stimulus, starting from which sensation arises. Stimuli whose strength is below the absolute threshold of sensation do not produce sensation. By the way, this does not mean at all that they do not have any effect on the body.

General patterns of sensations: The upper threshold of sensations is a high stimulus, at which it ceases to be perceived adequately. Another name for the upper absolute threshold is the pain threshold, because when we overcome it we experience pain: pain in the eyes when the light is too bright, pain in the ears when the sound is too loud, etc.

General patterns of sensations: relative threshold The relative threshold (discrimination threshold) is the minimum change in the intensity of the stimulus that causes changes in sensations.

Adaptation, or adaptation, is a change in sensitivity under the influence of a constantly acting stimulus, which is manifested in a decrease or increase in thresholds. Strong stimulus - weak sensitivity Weak stimulus - high sensitivity ADAPTATION RULE: When moving from strong to weak stimuli, sensitivity increases, from weak to strong it decreases (stimulus and sensitivity are in inverse proportion)

The interaction of sensations is a change in the sensitivity of one analytical system under the influence of the activity of another system. The general pattern of interaction between sensations is as follows: weak stimuli of one analyzer system increase the sensitivity of the other system, strong ones reduce it. For example, weak taste sensations (sour) increase visual sensitivity. Weak sound stimuli increase the color sensitivity of the visual analyzer. At the same time, there is a sharp deterioration in the various sensitivity of the eye due to the strong noise of an aircraft engine. All our analyzing systems are capable of influencing each other to a greater or lesser extent.

Increasing sensitivity as a result of the interaction of analyzers, as well as systematic exercises, is called sensitization. The possibilities for training the senses and improving them are very great.

The phenomenon of sensitization of the sense organs is observed in people long time engaged in certain types professional activity. The olfactory and gustatory sensations of tea, cheese, and wine tasters reach a high level of perfection. Tasters can accurately indicate not only what type of grape the wine is made from, but also the place where the grapes were grown. Painting places special demands on the perception of shape, proportions and color relationships when depicting objects. Experiments show that the artist's eye is extremely sensitive to assessing proportions. Our sensations develop under the influence of living conditions and the requirements of practical activity.

– compensatory sensitization due to the need to compensate for sensory defects (blindness, deafness); Loss of vision or hearing is compensated by the development of other types of sensitivity. There are cases where people who have lost their vision have developed skin sensitivity, they have well-developed tactile sensations and vibration sensitivity. A person suffering from deafness, by holding his hand on the throat of his interlocutor, can understand who is talking about what, and also, by picking up a newspaper, he knows whether it has been read or not. ANDREA BACHELLI RAY CHARLES DIANA GURTSKAYA

Desensitization is a decrease in the sensitivity of analyzers in the process of interaction of sensations. The interaction of sensations in some cases leads to sensitization, to an increase in sensitivity, and in other cases to its decrease, i.e. to desensitization. Strong excitation of some analyzers always reduces the sensitivity of other analyzers. Thus, increased noise levels in “loud workshops” reduce visual sensitivity.

The contrast of sensations is a change in the intensity and quality of sensations under the influence of a preliminary or accompanying stimulus. In the case of the simultaneous action of two stimuli, a simultaneous contrast occurs. This contrast can be traced in visual sensations. The same figure appears lighter on a black background, and darker on a white background. A green object against a red background appears more saturated. The phenomenon of sequential contrast is also well known. After a cold one, a weak warm stimulus seems hot. The feeling of sour increases sensitivity to sweets. If you fix your eye on a light spot for 20–40 seconds, and then close your eyes or move your gaze to a poorly lighted surface, then within a few seconds you can feel a fairly clear dark spot. This will be a consistent visual image.

Synesthesia (joint sensation) is the ability of a stimulus addressed to a specific sense organ to simultaneously evoke a sensation in another sense organ (the sight of a yellow lemon causes a sour sensation). Engineer K. L. Leontiev, using the phenomenon of synesthesia, developed a device that transforms sound signals into color ones. Color music was created based on this invention.

Complete deprivation of a person's sensory impressions, carried out for experimental purposes (for example, by immersion in water in special equipment). In response to the lack of sensations, imagination processes are activated, which in a certain way affect figurative memory. Vivid eidetic ideas arise, projected externally, which are assessed as protective (compensatory) reactions. As the time spent in S. d. conditions increases, at the stage of unstable mental activity people develop emotional lability with a shift towards low mood (lethargy, depression, apathy), which are briefly replaced by euphoria and irritability. There are memory impairments that are directly dependent on the cyclical nature of emotional states. The rhythm of sleep and wakefulness is disturbed, hypnotic states develop with the appearance of hypnotic ideas, which, unlike drowsy states that occur under normal conditions, last for a relatively long time, are projected outward and are accompanied by the illusion of involuntariness. The more stringent the conditions of self-control, the faster the thinking processes are disrupted, which manifests itself in the inability to concentrate on anything, consistently think through problems, and appear

Nature has endowed every person with the ability to understand the world in which he was born, including the ability to feel and perceive the world– people, nature, culture, various objects and phenomena. Path to knowledge environment and one’s own states begins with sensations.

Meaning of sensations:

1. sensations allow a person to navigate the world of sounds, smells, perceive colors, estimate the weight and size of objects, determine the taste of a product, etc.
2. sensations provide material for other more complex mental processes (for example, deaf people will never be able to comprehend the sounds of the human voice, blind people - colors);
3. especially developed sensations are a condition for a person’s success in a particular profession (for example, taster, artist, musician, etc.);
4. depriving a person of sensations leads to sensory deprivation (sensory hunger - lack of impressions), which can occur both in natural and laboratory conditions. (according to Lee, sensory deprivation is 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 a person’s condition through sensations (the sound of the surf, birdsong, aromatherapy, music).

Feeling (lat. sensus- perception) is mental cognitive process reflections individual properties of real outside world and the internal state of a person, which directly affect the senses V this moment .

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

Sensations are a sensory reflection of objective reality, as they arise due to the influence of various factors (stimulants) on the sense organs (vision, hearing, etc.). They are characteristic of all living beings with a nervous system. Moreover, some animals (for example, eagles) have significantly sharper vision than humans, a more subtle sense of smell and hearing (dogs). The eyes of ants detect ultraviolet rays that are inaccessible to the human eye. Bats and dolphins distinguish ultrasounds that humans cannot hear. The rattlesnake can detect minute temperature fluctuations of 0.001 degrees.

Feelings are both objective and subjective. Objectivity lies in the fact that they reflect a really existing external stimulus. Subjectivity is due to the dependence of sensations on individual characteristics and the current mental state of a person. This is exactly what the famous proverb says: “There are no comrades according to taste.”

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

Analyzer structure:

The physiological basis of sensations is laid 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 (both about the external environment and about his own, internal state).

Analyzer – a nervous formation that carries out the perception, analysis and synthesis of external and internal stimuli acting on the body.

Each type of analyzer is adapted to highlight a certain property: the eye reacts to light stimuli, the ear to sound stimuli, the olfactory organ to odors, 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. A receptor is a specialized cell designed to perceive a certain stimulus from the external or internal environment and to convert its energy from a physical or chemical form into the form of nervous excitation (impulse).

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

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

Sensation is essentially a mental process that occurs when processing information received by the brain.

Depending on the type of sensitivity, visual, auditory, olfactory, gustatory, skin, motor and other analyzers are distinguished. Each analyzer selects stimuli of a certain type from the entire variety of influences. For example, a hearing analyzer identifies waves generated by vibrations of air particles. The taste analyzer generates an impulse as a result of " chemical analysis» molecules dissolved in saliva, and olfactory molecules in the air. The visual analyzer perceives electromagnetic vibrations, the characteristics of which give rise to this or that visual image.

The physiological basis of sensations is the activity of complex complexes of anatomical structures, called analyzers by I. P. Pavlov. Analyzer– 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) peripheral section, called a receptor (a 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) nerve pathways(afferent department - transmits excitation to the central department; efferent department - it transmits a response from the center to the periphery);

3) analyzer core– 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.

Conditions for the occurrence of sensations

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. For blind people, visual sensations do not exist.

In addition, for sensations to arise, 2 more conditions must be present:

Sources of irritation (irritants)

· Medium or energy that is distributed in the environment from the source to the subject.

For example, in a vacuum there are no auditory sensations. The energy emitted by a source may be so small that we do not feel it, but this energy can be recorded by instruments. That. Energy, in order to become perceptible, must reach a certain threshold value of the analyzer system.

Also, the subject may be awake or asleep. This should also be taken into account. During sleep, the thresholds of analyzers increase significantly.

Thus, sensation is a mental phenomenon that is the result of the interaction of an energy source with the corresponding human analyzer. In this case, we mean an elementary single source of energy that creates a homogeneous sensation (of light, sound, etc.).

Thus, existence is necessary 5 conditions for sensations to arise:

Receptors

Analyzer nucleus (in the cerebral cortex)

· Conducting paths (with directions of impulse flows)

Source of irritation

· Environment or energy (from source to subject)

It should be noted that human sensations are a product of historical development, and therefore they are qualitatively different from the sensations of animals. In animals, the development of sensations is entirely limited by their biological, instinctive needs. In humans, the ability to feel is not limited by biological needs. Labor created in him an incomparably wider range of needs than in animals, and in activities aimed at satisfying these needs, human abilities were constantly developing, including the ability to feel. Therefore, a person can sense a much larger number of properties of the objects around him than an animal.

In addition, sensations are not only the source of our knowledge about the world, but also our feelings and emotions. The simplest form of emotional experience is the so-called sensory, or emotional, tone of sensation, that is, a feeling directly related to sensation. For example, it is well known that some colors, sounds, smells can themselves, regardless of their meaning, memories and thoughts associated with them, cause us a pleasant or unpleasant feeling. The sound of a beautiful voice, the taste of an orange, the smell of a rose are pleasant and have a positive emotional tone. The creaking of a knife on glass, the smell of hydrogen sulfide, the taste of quinine are unpleasant and have a negative emotional tone. This kind of simplest emotional experiences play a relatively insignificant role in the life of an adult, but from the point of view of the origin and development of emotions, their significance is very great.

Classification of sensations

Exist different approaches to the classification of 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 believed 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, on the one hand, and according to the principle of complexity or level of their construction, on the other).

Let's consider systematic classification sensations (Fig. 3). 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, heart and circulatory system and others 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.

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: to contact And distant Feel.

Contact Feel are caused by the direct impact of an object on the senses. Examples of contact sensation are taste and touch.

Distant sensations reflect the qualities of objects located at some distance from the sense organs. These senses 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 arise 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 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.

Vibration sensation- This is 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, some authors believe 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. Vibration sensitivity acquires particular practical importance in cases of damage to vision and hearing. In the lives of the deaf and deaf-blind, she plays big role. Deaf-blind, thanks high development 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.

Basic properties of 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 sensations. The main properties of sensations include:

· quality,

· intensity,

· duration,

· spatial localization,

· absolute and relative sensation thresholds

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 item: sweet or sour, bitter or salty. The sense of smell also provides information about the chemical characteristics of an object, but of a different kind: flower smell, almond smell, hydrogen sulfide smell, etc.

It should be noted that when speaking about the quality of sensations, they often mean the modality of the 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, when you have a runny nose, the intensity of perceived odors may be distorted.

Duration sensations are 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.

And finally, for the sensations 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, degree of sensitivity. Human senses are amazingly fine-working devices. For example, the human eye is a very sensitive device. He can distinguish about half a million shades and colors. If the air were completely clear, we would be able to see the flame of a candle at a distance of 27 km. Water vapor and dust sharply impair visibility, so an ordinary fire is practically visible only 6-8 km away, and a lit match is approximately 1.5 km away. Each sense organ has its own sensitivity limits.

State budget educational institution

Higher vocational education

"Yaroslavl State Medical Academy"

Ministry of Health Russian Federation

Department of Pedagogy and Psychology with EITI course

COGNITIVE MENTAL PROCESSES

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

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

Yaroslavl

UDC 15

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

Reviewer:

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

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

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

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

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

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

© Yaroslavl State Medical Academy, 2013.

INTRODUCTION	4 s.
§ 1. SENSATIONS	7 p.
1.1. Physiological basis of sensations	8 p.
1.2. Classification of sensations	8 p.
1.3. Properties of sensations	9 p.
1.4. Phenomena of sensations	11 p.
1.5. Development of sensations in ontogenesis	14 p.
§ 2. PERCEPTION	15 s.
2.1. Physiological basis of perception	16 p.
2.2. Classification of perception	16 p.
2.3. Properties of perception	20 s.
2.4. Phenomena of perception	22 p.
2.5. Development of perception in ontogenesis	22 p.
§ 3. ATTENTION	23 p.
3.1. Physiological basis of attention	24 s.
3.2. Classification of types of attention	25 s.
3.3. Properties of attention	25 s.
3.4. Distraction of attention	27 p.
3.5. Development of attention in ontogenesis	27 p.
§ 4. MEMORY	29 p.
4.1. Classification of types of memory	30 s.
4.2. Main memory characteristics	32 pp.
4.3. Factors influencing memorization	33 p.
4.4. Basic laws of memory	34 p.
4.5. Development of memory in ontogenesis	35 s.
§ 5. THINKING	36 pp.
5.1.Operations and forms of thinking	37 p.
5.2. Types of thinking	39 p.
5.3. Individual characteristics of thinking	40 s.
5.4. Diagnostic thinking of a doctor	42 pp.
5.5. Speech and language	43 p.
5.6. Modern representations about the structure of intelligence	45 pp.
§ 6. IMAGINATION	47 p.
6.1. Physiological basis of imagination	47 p.
6.2. Types of imagination	48 p.
6.3. Functions of the imagination	50 s.
6.4. Imagination and creativity	51 p.
6.5. Individual characteristics of imagination	53 p.
TEST CONTROL OF KNOWLEDGE	55 pp.
BIBLIOGRAPHY	60 s.

INTRODUCTION

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

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

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

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

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

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

Professional speech development helps a student acquire knowledge, improve his thinking, memory and other qualities. Specialist without enough high level professional speech will not be able to successfully perform his duties. It is very important that students expand their general and professional dictionary, developed the skills and abilities of fluent and correct proficiency in professional language, learned to briefly, clearly and logically express their thoughts in class, and developed speed reading skills.

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

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

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

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

FEEL

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

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

Physiological basis of sensations

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

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

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

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

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

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

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

Classification of sensations

There are different approaches to classifying sensations:

1. According to the main modalities there are:

- sense of smell;

- taste;

- touch

- vision;

- hearing.

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

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

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

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

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

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

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

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

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

Properties of sensations

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

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

2. Intensity – This quantitative characteristic, which depends on the strength of the current stimulus and the functional state of the receptor, which determines the degree of readiness of the receptor to perform its functions.

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

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

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

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

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

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

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

Phenomena of sensations

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

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

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

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

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

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

Based on sustainable changes occurring in the body;

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

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

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

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

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

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, chemical substances 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.

Specialization of the sense organs is a product of long evolution, and the sense organs themselves are products of adaptation to influences external environment, therefore, their structure and properties are adequate to these influences. In humans, subtle differentiation in the area of ​​sensations is associated with historical development human society and with social - 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 internal state person.
• 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 (receptor) section of the analyzers consists of all sense organs - the eye, ear, nose, skin, as well as special receptor devices located in the internal environment of the body (in the digestive and respiratory organs, in the cardiovascular system, in the genitourinary organs). This section of the analyzer reacts to a specific type of stimulus and processes it into a specific excitation. Receptors can be located on the surface of the body (exteroceptors) and in internal organs and tissues (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 are represented by, for example, different points The retina of the eye is represented by a spatially different arrangement of cells in the cortex and the organ of hearing. 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 single 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 along the centripetal nerve reaches 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 a stimulus 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 effect (reflex - automatic response of the body to the action of any 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 nerve 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.