The concept of perception. properties of perception.
Classification of the main types of perception
1. The concept of sensation. Physiological basis Feel. Analyzer. Types of sensations.
THE CONCEPT OF SENSATION
Definition of feelings.
Knowledge about the individual properties of objects arises during the activity of any sense organ. For example, when an object is exposed (shown) for 1/100 sec, a person can say that he saw a light or a spot of a certain color, but he will not be able to say exactly what kind of object it is. Listening to speech in an unfamiliar language, a person captures individual properties of sound (pitch, loudness, timbre), although he does not perceive the content of speech.
Feeling- reflection of individual properties of objects with their direct impact on the senses.
Sensation is the primary form of orientation of the organism in the surrounding world.
Sensation is the initial form of development of cognitive activity.
Organic sensations are correlated with the objects of the external world, give rise to desires, serve as a source of volitional impulse. Movements and actions aimed at achieving the goal are regulated by the sensations that are necessary to build the action. Thus, sensations provide the vital activity of a person.
Feelings are not the only form of reflection of the world. More high forms sensory reflection (perception, representation) cannot be reduced to the sum or combination of sensations. Each of the forms of reflection has a qualitative originality, but without sensations as the original form of reflection, the existence of any kind of cognitive activity is impossible.
Without sensations, mental activity of a person is impossible.
Physiological basis of sensations.
Sensation can arise only when an object acts on the sense organ.
The sense organ is an anatomical and physiological apparatus located on the periphery of the body or in the internal organs. It is adapted to receive the effects of certain stimuli from the external and internal environment. The main part of each sense organ is the endings of the sensory nerve, which are called receptors. Such sense organs as the eye, ear, unite dozens of receptor endings. The impact of the stimulus on the receptor leads to the emergence of a nerve impulse, which is transmitted along the sensory nerve to certain areas of the cerebral cortex of the cerebral hemispheres. The response is transmitted along the efferent (motor) nerve.
Receptor, conductive nerves and areas in the cortex of g.m. called an analyzer.
Sensation is always associated with a response: either with movement or with the restructuring of vegetative processes.
Thus, the physiological mechanism of sensations can be characterized as a mechanism of conditioned reflex activity of analyzers, arising on the basis of a limited number of unconditioned reflexes. The primary signal mechanisms of human sensations include the activity of the second signal system.
TYPES OF SENSATIONS Classification of sensations.
Already the ancient Greeks distinguished five sense organs and their corresponding sensations: visual, auditory, tactile, olfactory and gustatory. modern science significantly expanded the understanding of the types of human sensations. Currently, there are about two dozen different analyzer systems that reflect the impact of the external and internal environment on receptors.
The classification of sensations is made on several grounds.
By the presence or absence of direct contact of the receptor with the stimulus that causes sensation, they are isolated distant (from vision, hearing, smell ) And contact ( taste, pain, tactile ) reception.
By location on the surface of the body, in muscles and tendons or inside the body, they are distinguished, respectively exteroception(visual, auditory, tactile, etc.), proprioception(sensations from muscles, tendons) and interoception(feeling of hunger, thirst).
According to the time of occurrence during the evolution of the animal world, they distinguish ancient And new sensitivity. So, distant reception can be considered new in comparison with contact, but in the structure of the contact analyzers themselves, more ancient and newer functions are distinguished. Pain sensitivity is more ancient than tactile.
Patterns of sensations. Sensory organization of personality.
Consider the basic patterns of sensations. These include thresholds, adaptation, sensitization, interaction, contrast, and synesthesia.
Thresholds of sensitivity.
The concept of the threshold of sensations, or sensitivity threshold expresses the psychological characteristics of the "dependence" between the intensity of sensation and the strength of stimuli.
In psychophysiology there are two types of thresholds: threshold of absolute sensitivity and threshold of sensitivity to discrimination.
The smallest force of the stimulus at which a barely perceptible sensation first arises is called lower absolute sensitivity threshold.
The greatest strength of the stimulus at which a sensation of a given type still exists is called upper absolute sensitivity threshold.
Thresholds limit the zone of sensitivity to stimuli. For example, of all electromagnetic vibrations, the eye is capable of reflecting wavelengths from 390 (violet) to 780 (red) millimicrons;
There is an inverse relationship between sensitivity (threshold) and the strength of the stimulus: the greater the force needed to create a sensation, the lower the sensitivity of a person. Sensitivity thresholds are individual for each person.
Threshold of sensitivity to discrimination- that smallest increase in the strength of the acting stimulus, at which there is a barely noticeable difference in the strength or quality of sensations.
So, in the sensation of pressure (tactile sensitivity), this increase is equal to 1/30 of the weight of the original stimulus. This means that 3.4 g must be added to 100 g in order to feel a change in pressure, and 34 g to 1 kg. For auditory sensations, this constant is 1/10, for visual sensations, 1/100. (check out Weber's research).
Adaptation- adaptation of sensitivity to a constantly acting stimulus, manifested in a decrease or increase in thresholds.
In life, the phenomenon of adaptation is well known to everyone. The first minute a person enters the river, the water seems cold to him. Then the feeling of cold disappears, the water seems warm enough. This is observed in all types of sensitivity, except for pain.
Staying in absolute darkness increases the sensitivity to light in 40 minutes by about 200,000 times.
Interaction of sensations- this is a change in the sensitivity of one analyzer system under the influence of the activity of another analyzer system.
This is explained by cortical connections between analyzers.
General pattern The interaction of sensations is as follows: weak stimuli in one analyzer system increase sensitivity in another.
An increase in sensitivity as a result of the interaction of analyzers, as well as systematic exercises, is called sensitization.
The contrast of sensations- a change in the intensity and quality of sensations under the influence of a previous or accompanying stimulus.
With the simultaneous action of two stimuli, a simultaneous contrast occurs. Such a contrast is well traced in visual sensations. The same figure appears lighter on a black background, darker on a white one.
The phenomenon of successive contrast is widely known. After a cold, a weak thermal stimulus seems hot.
Consistent image- the physiological mechanism of its occurrence is as follows: the cessation of the action of the stimulus does not cause an instant cessation of the process of irritation in the receptor and excitation in the cortical parts of the analyzer.
Synesthesia- excitation by the arising sensations of one modality of sensations of another modality.
Synesthesia can be thought of as special case interaction of sensations, which is expressed not in a change in the level of sensitivity, but in the fact that the influence of sensations of a given modality is enhanced through the excitation of sensations of other modalities. Synesthesia enhances the sensory tone of sensations.
(So, the sound becomes colored, etc.)
SENSORY ORGANIZATION OF A PERSON - a characteristic level of development for an individual individual systems sensitivity and the way they are combined into complexes.
In the animal kingdom, the predominant level of development of sensitivity of any one modality is a generic feature. All representatives of one species (for example, eagles) have good eyesight, and the other (for example, dogs) have a good sense of smell. A feature of the sensory organization of a person is that it develops in vivo, it is influenced by activity.
3. The concept of perception. Perceptual Properties.
THE CONCEPT OF PERCEPTION
general characteristics perception.
Perception - this is a reflection of objects and phenomena in the totality of their properties and parts with their direct impact on the senses.
Perception depends on certain relationships between sensations, in addition to which it includes the past experience of a person in the form of ideas and knowledge.
The process of perception proceeds in connection with other mental processes of the individual: thinking (we are aware of what is in front of us), speech (we call the object of perception), feelings (we relate in a certain way to what we perceive), will (to some extent arbitrarily organize the process of perception).
The main x-kami of perception are constancy, objectivity, integrity and generalization.
constancy- this is the relative independence of the image from the conditions of perception, manifested in its immutability: the shape, color and size of objects are perceived by us as constant, despite the fact that the signals coming from these objects to the senses are constantly changing.
An important characteristic of perception is its objectivity. The objectivity of perception is manifested in the fact that the object is perceived by us as a separate physical body isolated in space and time.
This ratio is the basis of the orienting function of our behavior and activity.
Any image whole. This refers to the internal organic relationship of parts and the whole in the image.
The perception of the whole affects the perception of its parts. Several rules for grouping parts into a whole were formulated by Wertheimer.
1. The rule of similarity: the more parts of the picture are similar to each other, the more likely they will be perceived as located together. Similarity in size, shape, and arrangement of parts can act as grouping properties.
2. The rule of common fate. A set of elements moving at the same speed and along the same trajectory are perceived as a whole, as a single moving object (or when these objects are stationary but the observer is moving).
3. The rule of proximity. In any field containing several objects, those that are closest to each other are perceived as a single object.
The whole dominates the parts. There are three forms of such dominance: 1. The same element, being included in different structures, is perceived differently. 2. When replacing individual elements but while maintaining the m / y ratios, the structure of the image remains unchanged. 3. The structure is perceived as a whole even if some of its parts are missing.
Generalization means referring to a certain class of objects that has a name.
All considered properties of perception are not innate and develop during a person's life.
The physiological basis of sensations is the activity of complex complexes of anatomical structures, called by I. P. Pavlov analyzers. Analyzer- 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 department, called a 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) conducting nerve pathways(afferent department - transmits excitation to the central department; efferent department - a response is transmitted through it from the center to the periphery);
3) analyzer core- 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 takes place. The cortical part of each analyzer includes an area that is a projection of the periphery (i.e., a projection of the sense organ) in the cerebral cortex, since certain areas of the cortex correspond to certain receptors.
Thus, the organ of sensation is the central section of the analyzer.
Conditions for the sensation
For the sensation to arise, it is necessary to use all the components of the analyzer. If any part of the analyzer is destroyed, the occurrence of the corresponding sensations becomes impossible. So, visual sensations stop when the eyes are damaged, and when the integrity of the optic nerves is violated, 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)
· Environment or energy, which is distributed in the environment from the source to the subject.
For example, there are no auditory sensations in a vacuum. The energy emitted by the source may be so small that we do not feel it, but this energy can be registered by instruments. That. energy, in order to become tangible, must reach a certain value of the thresholds of the analyzer system.
Also, the subject may be awake or may be asleep. This should also be taken into account. In sleep, the thresholds of the analyzers are significantly increased.
Thus, sensation is a mental phenomenon, which is the result of the interaction of an energy source with the corresponding analyzer of a person. At the same time, we mean an elementary single source of energy that creates a homogeneous sensation (of light, sound, etc.).
Thus, existence is necessary 5 Conditions for Feelings:
Receptors
Analyzer core (in the cerebral cortex)
Conductive 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 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 for him an incomparably wider range of needs than for animals, and in activities aimed at satisfying these needs, human abilities, including the ability to feel, constantly developed. Therefore, a person can feel much large quantity properties of the objects around him than an animal.
In addition, sensations are not only the source of our knowledge of the world, but also of our feelings and emotions. The simplest form of emotional experience is the so-called sensual, or emotional, tone of sensation, that is, a feeling directly connected with sensation. For example, it is well known that certain colors, sounds, smells can by 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, have a positive emotional tone. The creak of a knife on glass, the smell of hydrogen sulfide, the taste of cinchona are unpleasant, have a negative emotional tone. Such simple emotional experiences play a comparatively 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 five (according to the number of sensory organs) basic types of sensations: smell, taste, touch, sight and hearing. This classification of sensations according to the main modalities is correct, although not exhaustive. B. G. Ananiev 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).
Consider systematic classification sensations (Fig. 3). This classification was proposed by the English physiologist Ch. Sherrington. Considering the largest and most significant groups of sensations, he divided them into three main types: interoceptive, proprioceptive and exteroceptive Feel. The former combine signals that reach 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, provide regulation of our movements; finally, others provide signals from the outside world and provide the basis for our conscious behavior. Consider the main types of sensations separately.
Interoceptive sensations that signal 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 oldest and most elementary group of sensations. Receptors that receive 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 sensation and always retain their proximity to emotional states. It should also be noted that interoceptive sensations are often referred to as 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 a static sensation, as well as a motor, or kinesthetic, sensation.
Peripheral receptors for proprioceptive sensitivity are located in muscles and joints (tendons, ligaments) and are called Pacchini corpuscles.
Peripheral balance receptors 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 connects a person with the external environment. The whole group of exteroceptive sensations is conventionally divided into two subgroups: to contact And distant Feel.
Contact Feel caused by the direct impact of the object on the senses. Taste and touch are examples of contact sensation.
distant sensations reflect the qualities of objects that are at some distance from the senses. These senses include hearing and sight. 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 that characterize the smell of the object, with which the olfactory receptor contacts, undoubtedly belong to to this subject. This is the duality of the position occupied by the sense of smell in the classification of sensations.
Since a sensation arises as a result of the action of a certain physical stimulus on the corresponding receptor, the primary classification of sensations that we have considered naturally proceeds 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 particular modality. Such sensations are called intermodal. These include, for example, vibration sensitivity, which connects the tactile-motor sphere with the auditory one.
Feeling the vibration is the sensitivity to vibrations caused by a moving body. According to most researchers, the vibrational sense is an intermediate, transitional form between tactile and auditory sensitivity.
In particular, some authors believe that tactile-vibrational sensitivity is one of the forms of sound perception. With normal hearing, it does not particularly protrude, but with damage to the auditory organ, this function of it is clearly manifested. Vibration sensitivity is of particular practical importance in visual and hearing impairments. It plays an important role in the lives of deaf and deaf-blind people. The deaf-blind, due to the high development of vibration sensitivity, learned about the approach of a truck and other modes of transport at a great distance. In the same way, deaf-blind-mute people know by vibrational sense when someone enters their room.
Consequently, sensations, being the simplest kind of mental processes, are in fact very complex and not fully understood.
It should be noted that there are other approaches to the classification of sensations.
Basic properties of sensations
All sensations can be characterized in terms of their properties. Moreover, properties can be not only specific, but also common to all types of sensations. The main properties of sensations include:
· quality,
· intensity,
· duration,
· spatial localization,
· absolute and relative thresholds of sensations
Quality - this is a property that characterizes the basic information displayed by a given sensation, distinguishing it from other types of sensations and varying within this type of sensation. For example, taste sensations provide information about certain chemical characteristics of an object: sweet or sour, bitter or salty. The sense of smell also provides information about the chemical characteristics of the object, but of a different kind: the smell of flowers, the smell of almonds, the smell of hydrogen sulfide, etc.
It should be noted that often, when speaking about the quality of sensations, they mean the modality of sensations, since it is the modality that reflects the main quality of the corresponding sensation.
Intensity sensation is its quantitative characteristic and depends on the strength of the acting stimulus and the functional state of the receptor, which determines the degree of readiness of the receptor to perform its functions. For example, with a runny nose, the intensity of perceived odors can be distorted.
Duration Feelings are a temporal characteristic of the sensation that has arisen. It is also defined functional state sense organ, but mainly - the duration of the stimulus and its intensity. It should be noted that sensations have a so-called latent (hidden) period. When a stimulus is applied to the sense organ, the sensation does not occur immediately, but after some time. latent period various kinds feelings are not the same. For example, for tactile sensations, it is 130 ms, for pain - 370 ms, and for taste - only 50 ms.
And finally for sensations characteristic spatial localization irritant. The analysis carried out by the receptors gives us information about the localization of the stimulus in space, that is, we can tell where the light comes from, it's warm or which part of the body is affected by the stimulus.
All of the above properties to some extent reflect the qualitative characteristics of sensations. However, the quantitative parameters of the main characteristics of sensations are no less important, in other words, degree of sensitivity. The human sense organs are surprisingly fine working apparatuses. For example, the human eye is a very sensitive instrument. He can distinguish about half a million shades and colors. If the air were perfectly clean, we could see the flame of a candle at a distance of 27 km. Water vapor and dust drastically impair visibility, so an ordinary fire is practically visible only 6-8 km away, and a lit match - about 1.5 km away. Each sense organ has its own limits of sensitivity.
8. The concept of sensation. Physiological basis of sensations. Types and basic properties, mechanisms for changing sensitivity, the problem of measuring sensation.
Feeling called mental reflection in the cerebral cortex of individual properties of objects and phenomena that directly affect the sense organs. For the emergence of sensations, it is necessary first of all to have objects and phenomena of the real world that affect the sense organs, which are called stimuli. The effect of stimuli on the sense organs is called irritation. Information about the external world can enter the brain, that is, the center that processes it, only through the sensory system, which can therefore be considered the gates of consciousness. sensory cell - receptor- converts the stimulus (impact) into short rhythmic electrochemical impulses. Then their flow is transmitted along the nerve pathways to various switching stations of the central nervous system, where these impulses, passing from one neuron to another, are synthesized and "decoded" into a system of data on the nature of the external influence.
All living beings with a nervous system have the ability to sense, but only those who have a brain with a highly developed cortex can be aware of their sensations. If the cerebral cortex is temporarily turned off (with the help of anesthesia or drugs), then a person cannot consciously respond even to severe pain.
The physiological basis of sensations is the complex activity of the sense organs. I.P. Pavlov called this activity analyzer, and cell systems, the most
complexly organized and being perceiving apparatuses that directly carry out the analysis of stimuli - analyzers.
The analyzer is characterized by the presence of three specific sections: peripheral (receptor), transmitting (conductive) and central (brain).
The peripheral (receptor) section of the analyzers consists of all the sense organs - the eye, ear, nose, skin, as well as special receptor apparatus located in the internal environment of the body (in the digestive, respiratory, cardiovascular system, genitourinary organs). This section of the analyzer reacts to a specific type of stimulus and processes it into a specific excitation. Receptors can be located on the surface of the body (exteroceptors) and in internal organs and tissues (interoceptors). Receptors located on the surface of the body respond to external stimuli. Visual, auditory, skin, taste, and olfactory analyzers have such receptors. Receptors located on the surface of the internal organs of the body respond to changes occurring inside the body (feeling of hunger, thirst). Organic sensations are associated with the activity of interoceptors. An intermediate position is occupied by proprioceptors located in the muscles and ligaments, which serve to sense the movement and position of the body's organs, and are involved in determining the properties and qualities of objects, i.e. the peripheral section of the analyzer plays the role of a specialized, perceiving apparatus.
Depending on the location of the receptor, external analyzers are distinguished (in which the receptors are located on the surface of the body) and internal (in which the receptors are located in the internal organs and tissues). An intermediate position is occupied by a motor analyzer, the receptors of which are located in the muscles and ligaments. For all analyzers, pain sensations are common, thanks to which the body receives information about the destructive properties of the stimulus for it.
types of sensations
Classifications of sensations: 1) by the presence or absence of direct contact with the stimulus that causes sensation: 2) by the location of the receptors, 3) by the time of occurrence in the course of evolution; 4) according to the modality (kind) of the stimulus.
By the presence or absence of direct contact of the receptor with the stimulus that causes sensation, distant (vision, hearing, smell - orientation in the nearest environment) and contact (taste, pain, tactile sensations) reception are distinguished.
The most ancient is organic (first of all, pain) sensitivity, then contact (tactile) forms appeared. And the most evolutionarily young are auditory and visual receptor systems.
According to the modality of the stimulus, sensations are divided into visual (85% of information), auditory, olfactory, gustatory, tactile, static and kinesthetic, temperature, pain, thirst, and hunger.
Visual sensations arise as a result of exposure to light rays (electromagnetic waves) on the sensitive part of the eye - the retina, which is the receptor of the visual analyzer. Light affects two types of light-sensitive cells in the retina - rods and cones. Due to auditory sensations (distant), a person hears speech, communicates with other people. Irritants for these sensations are sound waves - longitudinal vibrations of air particles, propagating in all directions from the sound source. The human hearing organ responds to sounds in the range from 16 to 20,000 vibrations per second. Auditory sensations reflect the pitch of the sound, which depends on the frequency of the sound waves; loudness, which depends on the amplitude of their oscillations; timbre of sound - forms of vibrations of sound waves. All auditory sensations can be reduced to three types - speech, musical, noise. Vibration sensitivity is adjacent to auditory sensations. Vibration sensations reflect vibrations of an elastic medium. This type of sensitivity is called "contact hearing". No specific vibration receptors have been found in humans. All body tissues can reflect the vibrations of the external and internal environment. In humans, vibrational sensitivity is subordinated to auditory and visual. Olfactory sensations (distant) reflect the smells of objects around us. Olfactory organs are olfactory cells located in the upper part of the nasal cavity. Taste sensations are caused by the action on taste buds of substances dissolved in saliva or water. Taste buds - taste buds located on the surface of the tongue, pharynx, palate distinguish sensations, sweet, sour, salty, bitter. Skin sensations. In the skin there are several analyzer systems; tactile (sensations of touch), temperature (sensations of cold and heat), pain. The system of tactile sensitivity is unevenly distributed throughout the body. But most of all, the accumulation of tactile cells is observed on the palm, on the fingertips and on the lips. The tactile sensations of the hand, combined with the musculo-articular sensitivity, form the sense of touch. If you touch the surface of the body, then press on the Negro, the pressure can cause pain. Tactile sensitivity gives knowledge about the qualities of an object, and pain sensations signal the body about the need to move away from the stimulus and have a bright emotional tone. The third type of skin sensitivity - temperature sensations - regulation of heat exchange between the body and environment. The distribution of heat and cold receptors on the skin is uneven. The back is most sensitive to cold, the least - the chest. Static sensations signal the position of the body in space. Static sensitivity receptors are located in the vestibular apparatus of the inner ear. Sudden changes in body position relative to the ground can lead to dizziness. A special place is occupied by interoceptive (organic) sensations that arise from receptors located in the internal organs and signal their functioning. These sensations form the organic feeling (well-being) of a person. These include the feeling of hunger, thirst, satiety, complexes of pain and sexual sensations.
General properties of sensations
Different types of sensations are characterized not only by specificity, but also by properties common to them. These properties include: quality, intensity, duration and spatial localization.
Quality is the main feature of a given sensation, distinguishing it from other types of sensations and varying within a given type of sensation. The qualitative variety of sensations reflects the infinite variety of forms of motion of matter.
The intensity of sensation is its quantitative characteristic and is determined by the strength of the acting stimulus and the functional state of the receptor.
The duration of sensation is its temporal characteristic. It is also determined by the functional state of the sense organ, but mainly by the duration of the stimulus and its intensity. When a stimulus is exposed to a sensory organ, sensation does not occur immediately, but after some time, the so-called latent (hidden) period of sensation. The sensation does not arise simultaneously with the beginning of the action of the stimulus, it does not disappear simultaneously with the termination of its action. This inertia of sensations is manifested in the so-called aftereffect. A visual sensation, for example, has a certain inertia and does not disappear immediately after the cessation of the action of the stimulus that caused it. The trace from the stimulus remains in the form of a consistent image. Distinguish between positive and negative sequential images. A positive consistent image in terms of lightness and color corresponds to the initial stimulus, consists in the preservation of a trace of light stimulus of the same quality as the acting stimulus. If in complete darkness we light a bright lamp for a while and then turn it off, then after that we see the bright light of the lamp against a dark background for some time. The presence of positive successive images explains why we do not notice the breaks between successive frames of the film: they are filled with traces of previous frames - successive images from them. The sequential image changes in time, the positive image is replaced by a negative one. With colored light sources, the sequential image turns into a complementary color.
I. Goethe wrote in his “Essay on the Doctrine of Color”: “When one evening I went into a hotel and a tall girl with a dazzlingly white face, black hair and a bright red bodice came into my room, I looked intently at her standing in the semi-darkness at some distance from me. After she left there, I saw on the light wall opposite me a black face, surrounded by a bright glow, while the clothes of a completely clear figure seemed to me the beautiful color of a sea wave.
The occurrence of negative consecutive images is explained by a decrease in the sensitivity of a given area of the retina to a certain color. Under normal conditions, we do not notice successive images, since the eye makes continuous movements and therefore no significant fatigue is observed in any one part of the retina.
And, finally, sensations are characterized by the spatial localization of the stimulus. The analysis carried out by spatial receptors gives us information about the localization of the stimulus in space. Contact sensations are related to the part of the body that is affected by the stimulus.
The physiological basis of sensations
Introduction
2. The concept of sensation
3. Physiology of sensations
3.1 Analyzers
3.2 Properties of sensations
3.3 Classification of sensations
4. Types of sensations
4.1 Vision
4.3 Vibratory sensations
4.4 Smell
Bibliography
Introduction
It is known that a person is realized in activities that are possible due to the knowledge of the environment. In ensuring the interaction of a person with the outside world, the leading role is played by the properties of the personality, its motives, attitudes. However, any mental phenomenon is both a reflection of reality and a link in the regulation of activity. The regulation of activity begins already at the level of sensations and perceptions - from mental cognitive processes. Sensations, perceptions, representations, memory belong to sensory forms of knowledge. Sensual reflection in a person is always associated with logical knowledge, thinking. The individual in human sensory cognition is reflected as a manifestation of the general. In sensory cognition, an essential role is played by language, the word, which always performs the function of generalization. In turn, logical cognition (thinking) is based on the data of sensory experience, on sensations, perception and memory representations. In a single process of cognition, a continuous interaction of all cognitive processes is carried out. More complex cognitive processes are based on sensations: perceptions, ideas, memory, thinking, imagination. Otherwise, except through sensations, we cannot learn anything about any forms of movement. Sensation is called the simplest, further no longer decomposable mental process. The sensations reflect the objective qualities of the object (smell, color, taste, temperature, etc.) and the intensity of the stimuli affecting us (for example, a higher or lower temperature).
1. Sensory organization of personality
The sensory organization of the personality is the level of development of individual systems of sensitivity and the possibility of their association. The sensory systems of a person are his sense organs, as if receivers of his sensations, in which sensation is transformed into perception. Every receiver has a certain sensitivity. If we turn to the animal world, we will see that the predominant level of sensitivity of any species is a generic trait. For example, bats have developed sensitivity to the perception of short ultrasonic pulses, dogs have olfactory sensitivity. main feature sensory organization of a person is that it develops as a result of all his life path. The sensitivity of a person is given to him at birth, but its development depends on the circumstances, desire and efforts of the person himself.
2. The concept of sensation
Sensation is a manifestation of the general biological property of living matter - sensitivity. Through sensation there is a psychic connection with the external and inner world. Thanks to sensations, information about all the phenomena of the external world is delivered to the brain. In the same way, a loop is closed through sensations to receive feedback about the current physical and partly mental state of the organism. Through sensations, we learn about taste, smell, color, sound, movement, the state of our internal organs, etc. From these sensations, holistic perceptions of objects and the whole world are formed. It is obvious that the primary cognitive process takes place in human sensory systems, and already on its basis, cognitive processes that are more complex in their structure arise: perceptions, representations, memory, thinking. No matter how simple the primary cognitive process may be, but it is precisely this that is the basis of mental activity, it penetrates into our consciousness only through the “entrances” of sensory systems. the world.
2.1 Processing sensations
After receiving information by the brain, the result of its processing is the development of a response action or strategy aimed, for example, at improving physical tone, focusing more on current activities, or setting up for accelerated inclusion in mental activity. Generally speaking, the response or strategy worked out at any given time is the best choice of the options available to the person at the time of the decision. However, it is clear that the number of options available and the quality of choice are different for different people and depend, for example, on: - mental properties of the personality; - Strategies for relationships with others; - partly physical condition; - experience, the availability of the necessary information in memory and the possibility of retrieving it; - degree of development and organization of higher nervous processes, etc.
3. Physiology of sensations
3.1 Analyzers
Physiological mechanism sensations is the activity of the 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); - the central section of the analyzer - afferent or sensory nerves; - cortical sections of the analyzer, in which the processing of nerve impulses takes place. Certain receptors correspond to their sections of cortical cells. The specialization of each sense organ is based not only on the structural features of the receptor analyzers, but also on the specialization of the neurons that make up the central nervous apparatus, which receive signals perceived by the peripheral senses. The analyzer is not a passive receiver of energy; it is reflexively rebuilt under the influence of stimuli.
3.2 Properties of sensations
Any sensation can be described in terms of several properties inherent in it. The main properties of sensations are: quality, intensity, duration and spatial localization.
Quality- this is a specific feature of this sensation, which distinguishes it from all other types of sensations and varies within a specific modality.
For example, the qualities of visual modality include
Brightness,
Saturation,
Color tone.
Hearing qualities:
Volume,
Quality of tactile sensations:
Hardness,
Roughness, etc.
3.3 Classification of sensations
The most common, earliest and simplest classification of sensations according to the modality (kind) of the stimulus. Modality is a qualitative characteristic in which the specificity of sensation is manifested as the simplest mental signal, in contrast to the 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, gustatory 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 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 - arise under the influence of light rays on the retina of the eye; - auditory - are caused by sound waves of speech, music or noise; - vibrational - the ability to capture vibrations of an elastic medium (water, air, earth, objects); this is a kind 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 (sensation of touch), temperature and pain. The palms, fingertips and lips are very sensitive to touch - we touch them. Pain sensations have a strong emotional connotation - they are well heard or seen by other people. Temperature sensitivity is different in different parts of the body: the back is most sensitive to cold, and the chest is the least sensitive. In special states of the human psyche and body, pseudo-sensations can occur - hallucinations, when the stimulus is absent, but the sensation is present (mirage, visions, "voices", delirium, etc.).
4.1 Vision
The apparatus of vision is the eye - a sensory organ with a complex anatomical structure. Light waves reflected by an object are refracted, passing through the lens of the eye, and focused on the retina in the form of an image. The eye belongs to distant receptors, 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, the change in the size of the image on the retina when moving away or approaching the object, as well as the 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 come into a state of excitation under the influence of a light wave. The endings of the optic nerve differ in shape and function. Cone-shaped receptors are adapted to reflect color. They are located in the center of the retina and are daytime vision devices. Rod-shaped nerve endings reflect light. They are located around the cones, closer to the edge of the retina. This is a night vision device. Cone vision is not impaired when the rods are affected, and vice versa, i.e., the sensations of color and light have their own analyzer systems.
From what has been said, it is clear that two large groups of visual sensations can be distinguished: achromatic sensations, reflecting the transition from white to black, through a mass of shades of gray, and chromatic sensations, which reflect a color gamut with numerous shades and color transitions.
Auditory sensations are also distant sensations. The sensory endings of the auditory nerve are located in the inner ear, the cochlea with the auditory membrane and sensory hairs. The auricle, the so-called outer ear, collects sound vibrations, and the mechanism of the middle ear transmits them to the cochlea. The sensory endings of the cochlea are excited as a result of resonance, i.e. the endings of the auditory nerve, different in length and thickness, set in motion at a certain number of oscillations per second, and the received signals are transmitted to the brain. These oscillations occur in elastic bodies and are transmitted by the air medium. We know from physics that sound has a wave nature and is characterized by frequency and amplitude.
There are three types of auditory sensations: speech, music and noise. In these types of sensations, the sound analyzer distinguishes four qualities of sound:
Strength (loud - weak),
Height (high - low),
Sound duration and tempo-rhythmic pattern of perceived sounds.
Phonemic hearing is called hearing, using which you can distinguish the sounds of speech. It is formed during life and depends on the speech environment. Good knowledge of a foreign language involves the development new system phonemic hearing. The ability to learn foreign languages is determined phonemic awareness which also affects literacy writing. The musical ear of a person is brought up and formed, as well as speech. The ability to enjoy music is a centuries-old result of the development of the musical culture of mankind. Noises and rustles are less significant for a person, unless they interfere with his life. Noises can evoke a pleasant emotional mood, for example, the sound of rain, the roar of the surf, and, one of my acquaintances, a computer network administrator, said that he cannot fall asleep when he does not hear the noise of working fans from three or four computers. Noises can also serve as a danger signal - the hiss of gas, the clatter of feet behind your back, the howl of a siren.
4.3 Vibratory sensations
Vibration sensitivity is adjacent to auditory sensations. They share the nature of reflected physical phenomena. Vibration sensations reflect vibrations of an elastic medium. This type of sensitivity is figuratively called "contact hearing". No specific vibration receptors have been found in humans. At present, it is believed that the vibrational feeling is one of the most ancient types of sensitivity, and all tissues of the body can reflect the vibrations of the external and internal environment.
In human life, vibrational sensitivity is subordinated to auditory and visual. The cognitive value of vibration sensitivity increases in those activities where vibrations become a signal of malfunctions in the operation of the machine. In the life of the deaf and deaf-blind, vibrational sensitivity compensates for hearing loss. On the body of a healthy person, short vibrations have a tonic effect, long and intense vibrations are tiring and can cause painful phenomena.
4.4 Smell
Olfactory sensations are distant. 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 the smell, the animal finds food or avoids danger.
In humans, olfactory sensations have little to do 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 for their designation, 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, helps to recognize the quality of food. The sense of smell warns of a dangerous air environment for the body, allows you to distinguish in some cases chemical composition substances.
Taste sensations are contact, arising from the contact of the sense organ (tongue) with the object itself. The sense of taste detects molecules dissolved in saliva. There are four main qualities of taste stimuli: sour, sweet, bitter, salty. From the combinations of these four sensations, to which tongue movements are added, a complex of taste sensations arises. Initially, the sensory process occurs in the taste buds, and each of the papillae has from 50 to 150 receptor cells, which are quickly worn out from contact with food and then renewed. Sensory signals then travel along nerves to the hindbrain, thalamus, and gustatory cortex, which processes taste sensations.
Taste sensations, like olfactory ones, increase a person's appetite. By analyzing the quality of food, taste sensations also have a protective function and are important for survival. When fasting, taste sensitivity increases, when satiated or satiated, it decreases.
In the skin there are several independent analyzer systems:
Tactile (sensation of touch),
temperature,
Painful.
All types of skin sensitivity are referred to as contact sensitivity. The largest accumulation of tactile cells is in the palm, on the fingertips and on the lips. Skin receptors transmit information to spinal cord, making contact with motor neurons, which makes possible reflex actions such as, for example, pulling the hand away from the fire. The sense of touch is the tactile sensations of the hand along with the musculo-articular sensitivity.
Temperature sensitivity regulates heat transfer between the body and the environment. The distribution of heat and cold receptors over the skin is uneven. The back is most sensitive to cold, the least - the chest.
Strong pressure on the surface of the body causes pain. The receptor endings of pain sensitivity are located under the skin, deeper than the tactile receptors. Where there are more tactile receptors, there are fewer pain receptors. Tactile sensitivity gives knowledge about the qualities of the object, and pain sensitivity gives a signal about the harm caused by the stimulus.
4.7 Proprioceptive sensitivity
Kinesthesia
Kinesthetic sensations are sensations of movement and position of individual parts of the body. Kinesthetic sensation receptors are located in muscles and tendons. Irritation in these receptors occurs under the influence of muscle stretching and contraction.
A large number of motor receptors are located in the fingers, tongue and lips, since these organs need to carry out precise and subtle working and speech movements. The activity of the motor analyzer allows a person to coordinate and control his movements.
Speech kinesthesias are formed in the infantile and preschool periods of human development. Education foreign language requires the development of such speech kinesthesias that are not typical for mother tongue.
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 movement and gravity and transmit them to the cerebellum and the cortex of the temporal region. Sudden and frequent changes in the position of the body relative to the plane of the earth, such as swinging on a swing or sea rolling, lead to dizziness - "seasickness".
indicating the topic right now to find out about the possibility of obtaining a consultation.Feel - is a reflection of specific, individual properties, qualities, aspects of objects and phenomena of material reality that affect the senses at a given moment.
For the emergence of sensations, it is first of all necessary to have objects and phenomena of the real world affecting the sense organs, which are called in this case irritants.
The effect of stimuli on the sense organs is called irritation.
In the nervous tissue, the process of irritation causes excitation. Excitation of the systems of nerve cells, the most perfect in their organization, with the obligatory participation of the cells of the cerebral cortex, gives sensation.
I.P. Pavlov. The physiological basis of sensations is a complex analyzer activity of the sense organs.
Analyzer- This is a system of cells that are most complexly organized and are perceiving apparatuses that directly carry out the analysis of stimuli.
The analyzer is characterized by the presence of three departments:
1. peripheral (receptor),
2. transmitting (conductor),
3. central (brain).
The peripheral (receptor) section of the analyzers consists of all the sense organs - the eye, ear, nose, skin, as well as special receptor apparatus located in the internal environment of the body (in the digestive, respiratory, cardiovascular system, genitourinary organs). This section of the analyzer reacts to a specific type of stimulus and processes it into a specific excitation.
Function peripheral department - fulfills the role perceiving apparatus.
Receptors are divided into:
1. exteroceptors- to be on the surface of the body. They respond to external stimuli. Such receptors are possessed by visual, auditory, skin, taste, olfactory analyzers.
2. interoceptors are found in internal organs and tissues. 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.
3. Intermediate position is occupied proprioceptors, located in the muscles and ligaments, which serve to sense the movement and position of the body's organs, and also participate in determining the properties, qualities of objects, in particular when they are touched by hand.
Analyzers depending on the location of the receptor, they are divided into:
1. external analyzers(which have receptors on the surface of the body)
2. internal analyzers(whose receptors are located in the internal organs and tissues).
3. Intermediate position occupies motor analyzer, whose receptors are found in muscles and ligaments.
Common to all analyzers are pain, thanks to which the body receives information about the destructive properties of the stimulus for it.
Properties of sensations:
1. Adaptation- increase or decrease in the sensitivity of analyzers as a result of continuous or prolonged exposure to stimuli.
2. Contrast- weak stimuli increase sensitivity to other simultaneously acting stimuli, and strong ones decrease this sensitivity.
3. The lower threshold of sensation- the minimum amount of stimulus that causes a barely noticeable sensation. Signals with less intensity lower threshold are not felt by humans. upper threshold- the maximum value of the stimulus that the analyzer is able to adequately perceive. The interval between J o and J max is called the "sensitivity range"..
4. Difference threshold of sensation- the smallest difference in intensity between homogeneous stimuli, when they are still felt as different.
5. Sensitization - an increase in the sensitivity of analyzers due to an increase in the excitability of the cerebral cortex under the influence of the simultaneous activity of other analyzers. The sensitivity of the analyzer can be increased by pharmacological means.
6. Sequential images are a continuation of the sensation when the action of the stimulus has already ceased. When the receptor of one or another sense organ is felt, it is in a state of excitation for some time .. after the cessation of exposure to the stimulus, the excitation in the receptor does not disappear immediately.
Types of sensations
There are the following bases for the classification of sensations:
1. by the presence or absence of direct contact with a stimulus that causes sensation. Allocate remote and contact reception. Sight, hearing, smell are related to remote reception. These types of sensations provide orientation in the nearest environment. Taste, pain, tactile sensations - contact.
2. by location receptors. Ek stereoreceptive sensations- reflect the properties of objects and phenomena of the external environment. Interoceptive(organic) Feel, which arise from receptors located in the internal organs and signal the functioning of the latter. These sensations form the organic feeling (well-being) of a person. proprioceptive sensations These are sensations that reflect the movement of the body. With the help of muscle-motor sensations, a person receives information: about the position of the body in space, about relative position all its parts, about contraction, stretching and relaxation of muscles, etc.
3. by time of occurrence in the course of evolution.
4. by modalities(kind of) stimulus. According to the modality of the stimulus sensations are divided into visual, auditory, olfactory, gustatory, tactile, static and kinesthetic, temperature, pain, thirst, hunger.
Let us briefly characterize each of the modalities of sensations.
visual sensations. They arise as a result of exposure to light rays (electromagnetic waves) on the sensitive part of our eye - the retina, which is the receptor of the visual analyzer. Light affects two types of light-sensitive cells in the retina - rods and cones, so named for their external shape.
auditory sensations. These sensations are also distant and also have great importance In human life. Thanks to them, a person hears speech, has the ability to communicate with other people. Irritants for auditory sensations are sound waves - longitudinal vibrations of air particles, propagating in all directions from the sound source. The human hearing organ responds to sounds in the range from 16 to 20,000 vibrations per second.
Auditory sensations reflect the pitch of the sound, which depends on the frequency of the sound waves; loudness, which depends on the amplitude of their oscillations; timbre of sound - forms of vibrations of sound waves.
All auditory sensations can be reduced to three types - speech, music, noise.
vibration 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 specific vibration receptors have been found in humans. At present, it is believed that all tissues of the body can reflect the vibrations of the external and internal environment. In humans, vibrational sensitivity is subordinated to auditory and visual.
Olfactory sensations. They refer to distant sensations that reflect the smells of objects around us. Olfactory organs are olfactory cells located in the upper part of the nasal cavity.
The group of contact sensations, as already noted, includes taste, skin (pain, tactile, temperature).
Taste sensations. Caused by the action on the taste buds of substances dissolved in saliva or water. Taste buds - taste buds located on the surface of the tongue, pharynx, palate - distinguish between sensations of sweet, sour, salty and bitter.
Skin sensations. There are several analyzer systems in the skin: tactile(sensation of touch) temperature(feelings of cold and heat) painful. The system of tactile sensitivity is unevenly distributed throughout the body. But most of all, the accumulation of tactile cells is observed on the palm, on the fingertips and on the lips. Tactile sensations of the hand, combined with musculo-articular sensitivity, form touch- a specifically human, labor-developed system of cognitive activity of the hand.
If you touch the surface of the body, then press on it, the pressure can cause painful feeling. Thus, tactile sensitivity provides knowledge about the qualities of an object, and pain sensations signal the body about the need to move away from the stimulus and have a pronounced emotional tone.
The third type of skin sensitivity is temperature sensations - is associated with the regulation of heat transfer between the body and the environment. The distribution of heat and cold receptors on the skin is uneven. The back is most sensitive to cold, the chest is the least sensitive.
The position of the body in space is signaled static feeling. Static sensitivity receptors are located in the vestibular apparatus of the inner ear. Sudden and frequent changes in body position relative to the ground plane can lead to dizziness.
