The property of sensation is determined by the strength of the acting stimulus and. The main properties of sensations in psychology. Systematic classification of sensations
Each sensation can be characterized in its properties. The properties of sensations can be not only specific to a given modality, but also common to all types of sensations. Basic sensory properties most commonly used:
Quality,
Intensity,
Duration,
Spatial localization,
Absolute threshold,
Relative threshold.
Feeling quality
Characteristics of not only sensations, but in general all characteristics can be divided into qualitative and quantitative. For example, the title of a book or its author - qualitative characteristics; the weight of the book or its length are quantitative. The quality of sensation is a property that characterizes the basic information displayed by this sensation, which distinguishes it from other sensations. We can also say this: the quality of sensation is a property that cannot be measured with help in numbers, compared with some kind of numerical scale.For the visual sensation, the 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.
Sometimes the quality of sensation is referred to as its modality (auditory sensation, visual or otherwise). This also makes sense, because often, in a practical or theoretical sense, one has to talk about sensations in general. For example, during the experiment, a psychologist can ask the subject general question: "Tell us about your feelings during ..." And then the modality will be one of the main properties of the described sensations.
Intensity of sensation
Perhaps the main quantitative characteristic of a sensation is its intensity. Indeed, for us it is of great importance whether we listen to quiet music or loud, it is light in the room, or we can barely see our hands.It is important to understand that the intensity of the sensation depends on two factors, which can be described as objective and subjective:
The strength of the acting stimulus (its physical characteristics),
The functional state of the receptor that this stimulus acts on.
The more significant the physical parameters of the stimulus, the more intense the sensation. For example, the higher the amplitude of the sound wave, the louder the sound appears to us. And the higher the sensitivity of the receptor, the more intense the sensation. For example, after being in a dark room for a long time and going out into a moderately lit room, you can be "blinded" by the bright light.
Duration of sensation
The duration of sensation is another important characteristic of sensation. It, as the name suggests, denotes the lifetime of the sensation that has arisen. Paradoxically, objective and subjective factors also affect the duration of the sensation. The main factor, of course, is objective - the longer the action of the stimulus, the longer the sensation. However, the duration of the sensation is influenced by the functional state of the sense organ and its certain inertia.Suppose the intensity of some stimulus at first gradually increases, then gradually decreases. For example, it can be a sound signal - from zero strength it rises to clearly audible, and then decreases again to zero strength. We do not hear a very weak signal - it is below the threshold of our perception. Therefore, in this example, the duration of the sensation will be less than the objective duration of the signal. Moreover, if our hearing previously perceived strong sounds for a long period and has not yet had time to "move away", then the duration of the sensation of a weak signal will be even shorter, because the perception threshold is high.
After the stimulus begins to affect the sensory organ, the sensation does not arise immediately, but after a while. The latency period for different types of sensations is not the same. For tactile sensations - 130 ms, for pain sensations - 370 ms, for gustatory sensations - only 50 ms. The sensation does not arise simultaneously with the onset of the stimulus action and does not disappear simultaneously with the termination of its action. This inertia of sensations manifests itself in the so-called aftereffect. The visual sensation, as you know, has some inertia and does not disappear immediately after the cessation of the action of the stimulus that caused it. The trail from the stimulus remains in the form of a consistent image.
Spatial localization of sensation
A person exists in space, and 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 which part of the body is affected by the stimulus.Absolute threshold of sensation
The absolute threshold of sensation is those minimal physical characteristics of the stimulus, starting from which sensation arises. Stimuli, the strength of which lies below the absolute threshold of sensation, do not give sensations. By the way, this does not mean at all that they have no effect on the body. Research by G.V. Gershuni showed that sound stimuli that lie below the threshold of sensation can cause changes in the electrical activity of the brain and even dilation of the pupil. The zone of influence of stimuli that do not cause sensations was named by GV Gershuni "sub-sensory area".There is not only a lower absolute threshold, but also the so-called upper one - the value of a stimulus at which it ceases to be perceived adequately. Another name for the upper absolute threshold is 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. However, there are some physical characteristics of stimuli that are not related to the intensity of exposure. This is, for example, the frequency of sound. We do not perceive very much low frequencies, nor very high: an approximate range of 20 to 20,000 Hz. However, ultrasound does not make us painful.
Relative threshold of sensation
The relative threshold of sensation is also an important characteristic. Can we distinguish between the weight of a pound kettlebell and a balloon? Can we tell the difference in the store the weight of two sticks of sausage that look the same? It is often more important to evaluate not an absolute characteristic of a sensation, but just a relative one. This kind of sensitivity is called relative, or differential.It is used both to compare two different sensations and to determine changes in one sensation. Suppose we heard a musician play two notes on his instrument. Was the pitch of these notes the same? or different? Was one sound louder than the other? or was not?
The relative threshold of sensation is the minimum difference in the physical characteristic of the sensation that will be noticeable. Interestingly, for all types of sensation, there is a general pattern: the relative threshold of sensation is proportional to the intensity of sensation. For example, if you need to add three grams (at least) to a weight of 100 grams (at least) to feel the difference, then to a weight of 200 grams for the same purpose you need to add six grams.
All sensations can be characterized in terms of their properties. Moreover, the properties can be not only specific, but also general for all types of sensations.
The main properties of sensations include:
1. Quality of sensationsis a property that characterizes the basic information displayed by this sensation, distinguishing it from other types of sensations and varying within the limits of a given type of sensation.
It should be borne in mind that very often, when talking 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.
2. The intensity of sensations - the quantitative characteristic 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.
3. Duration of sensation is a time characteristic of the sensation that has arisen. It is also determined by the functional state of the sense organ, but mainly by the time of action of the stimulus and its intensity. It should be noted that sensations have a so-called latent (latent) period. When an irritant is exposed to the sensory organ, the sensation does not arise immediately, but after a while. The latency period for different types of sensations is not the same. For tactile sensations, it is 130 ms, for pain sensations - 370 ms, and for gustatory sensations - 50 ms.
The sensation does not arise simultaneously with the onset of the stimulus action and does not disappear simultaneously with the termination of its action. This inertia of sensations is manifested in the so-called aftereffects.
The trail from the stimulus remains in the form of a consistent image. Distinguish positive and negative sequential images.
Positive consistent image corresponds to the initial irritation, consists in maintaining a trace of irritation of the same quality as the active irritant.
Negative sequential imageconsists in the emergence of a quality of sensation opposite to the quality of the influencing stimulus. The appearance of negative sequential images is explained by a decrease in the sensitivity of a given receptor to a certain effect.
4. Spatial localization of the stimulus... The analysis carried out by receptors gives us information about the localization of the stimulus in space.
All properties to one degree or another reflect the qualitative characteristics of sensations. The quantitative parameters of the main characteristics of sensations are important, in other words, degree of sensitivity. There are two types of sensitivity:
1. Absolute sensitivity- the ability to feel weak stimuli.
2. Sensitivity to difference- the ability to feel weak differences between stimuli.
In order for a sensation to arise, the strength of the stimulus must have a certain value.
Absolute threshold of sensation- the minimum value of the stimulus at which the sensation first occurs.
Stimuli, the strength of which lies below the absolute threshold of sensation, do not give sensations, but this does not mean that they have no effect on the body.
Subsensory area (according to G.IN.Gershuni) - the zone of influence of irritants on the body that do not cause sensations.
The beginning of the study of the thresholds of sensations was laid german physicist, psychologist and philosopher G.T.Fechner, who believed that the material and the ideal are two sides of a single whole.
By G.T. For Fechner, the process of creating a mental image can be represented by the following diagram:
Irritation -\u003e Arousal -> Sensation -> Judgment (physics) (physiology) (psychology) (logic).
The most important thing in Fechner's idea was that he first included elementary sensations in the range of interests of psychology.
According to Fechner, the sought border passes where sensation begins, that is, the first mental process arises.
Lower absolute threshold (according to Fechner) - the magnitude of the stimulus at which the sensation begins.
To determine this threshold, Fechner developed methods that are actively used in our time. Fechner based the methodology of his research on two statements called the first and second paradigm of classical psychophysics:
1. Human sensory system is a measuring device that responds appropriately to physical stimuli.
2. The psychophysical characteristics of people are distributed according to the normal law, that is, they randomly differ from some average value, similar to anthropometric characteristics.
The magnitude of the stimulus at which the subject's responses change corresponds to the threshold of disappearance of sensation (P 1)At the second stage of measurement, in the first presentation, the subject is offered a stimulus that he cannot hear in any way. Then, at each step, the magnitude of the stimulus increases until the subject's answers go from “no” to “yes” or “maybe yes”. This stimulus value corresponds sensation threshold (P 2). Two cases are possible:
P 1\u003e P 2 or P 1< Р 2 .
Absolute threshold ( Stp) is equal to the arithmetic mean of the thresholds of appearance and disappearance:
Stp \u003d (P 1 + P 2) / 2
Upper absolute threshold - the value of the stimulus at which it ceases to be perceived adequately. The upper absolute threshold is sometimes called pain threshold, because with the corresponding values \u200b\u200bof stimuli, a person experiences pain.
Absolute thresholds - upper and lower - define the boundaries of the surrounding world available to our perception. By analogy with a measuring device, absolute thresholds determine the range in which the sensory system can measure stimuli, but in addition to this range, the operation of the device is characterized by its accuracy, or sensitivity. The absolute threshold value characterizes the absolute sensitivity.
The weaker the stimulus causing the sensation, the higher the sensitivity.
The absolute sensitivity is numerically equal to,inversely proportional to the absolute threshold of sensations. If the absolute sensitivity is denoted by the letter E, and the magnitude of the absolute threshold R, then the connection between absolute sensitivity and absolute threshold can be expressed by the formula:
Different analyzers have different sensitivity.
The absolute sensitivity of the analyzer is equally dependent on both the lower and the upper threshold of sensation. The magnitude of the absolute thresholds, both lower and upper, varies depending on different conditions: the nature of the person's activity and age, functional state of the receptor, strength and duration of irritation etc.
Another characteristic of sensitivity is sensitivity to difference... It is also called relative,or difference, since it is a sensitivity to a change in stimulus. In order to feel the weight gain, you need to add three to five grams. Thus, in order to feel the minimum difference in the characteristics of the influencing stimulus, it is necessary to change the strength of its impact by a certain amount.
Discrimination threshold- the minimum difference between stimuli, which gives a barely noticeable difference in sensations.
More in 1760 the French physicist P. Bouguer on the material of light sensations, he established a very important fact concerning the magnitude of the discrimination thresholds: in order to feel the change in illumination, it is necessary to change the light flux by a certain amount.
In the first half of the XIX century. German scientist M. WeberInvestigating the sensation of heaviness, I came to the conclusion that comparing objects and observing the differences between them, a person perceives not the differences between objects, but the ratio of the difference to the size of the compared objects. To notice the increase in weight, you need to add approximately 3% of its mass to the original weight. Further research showed that a similar pattern exists for other types of sensations.
The threshold for differences in sensations is determined by the ratio:
DI- the amount by which the initial stimulus, which has already generated a sensation, must be changed in order for a person to notice that he has really changed.
I - the size of the acting stimulus.
Thus, the threshold of discrimination has a constant relative value, that is, it is always expressed in the form of a ratio showing which part of the initial value of the stimulus must be added to this stimulus in order to obtain a barely noticeable difference in sensations . This provision was called bouguer's law-Weber. In mathematical form, this law can be written in the following form:
DI / I \u003d const
Const (constant) is a constant value characterizing the threshold of difference in sensation, called weber's constant. The parameters of the Weber constant are given in the table.
Table. The value of Weber's constant for various senses.
Based on Weber's experimental data, another german scientist - G. Fechner - formulated the following law, usually called Fechner's law: if the intensity of stimuli increases exponentially, then sensations will grow in arithmetic progression. In another formulation, this law sounds like this: the intensity of sensations increases in proportion to the logarithm of the stimulus intensity.
The main meaning of this pattern is that the intensity of sensations increases not proportionally to the change in stimuli, but much more slowly. In a mathematical form, the dependence of the intensity of sensations on the strength of the stimulus is expressed by the formula:
S \u003d K * LgI + C
S - the intensity of the sensation.
I - the strength of the stimulus.
K and C- constants.
This formula reflects the position that is called the basic psychophysical law, or Weber-Fechner law.
American scientist C. Stevens proceeded from the assumption that for sensations, or sensory space, the same attitude is characteristic as for the space of stimuli. This pattern can be represented by the following mathematical expression:
DE / E \u003d K
E - primary sensation.
DE - the minimum change in sensation that occurs when the acting stimulus changes to the minimum amount that is noticeable to a person.
Thus, from this mathematical expression it follows that the ratio between the minimum possible change in our sensations and the primary sensation is a constant value - TO... If so, then the relationship between the space of stimuli and the sensory space (our sensations) can be represented by the following equation:
DE / E \u003d K x DI / I
This equation is called stevens law... The solution to this equation is expressed by the following formula:
S \u003d K x R n
S- the power of sensations.
TO- constant determined by the chosen unit of measure.
n- an indicator that depends on the modality of sensations and varies from 0, 3 for the sensation of loudness to 3, 5 for the sensation obtained from an electric shock.
R- the value of the influencing stimulus.
The world of stimuli again represents the Bouguer-Weber law, and Zabrodin proposed the structure of the sensory space in the following form:
DE / E z \u003d K x DI / I
Obviously, for z \u003d 0 the formula of the generalized law goes over into the logarithmic Fechner law, and for z = 1 - into the power law of Stevens.
Thus, the law proposed Yu.M. Zabrodin, removes the contradiction between Stevens and Fechner's laws. Therefore, it is no coincidence that he received the name generalized psychophysical law.
No matter how the contradiction between the laws of Fechner and Stevens is resolved, both variants quite accurately reflect the essence of the change in sensations when the magnitude of irritation changes. First, sensations change in proportion to the strength of the physical stimuli acting on the senses. Secondly, the power of sensation grows much more slowly than the magnitude of physical stimuli. This is precisely the meaning of psychophysical laws.
Topic 11
SENSATIONS
General concept of sensation
Types of sensations
Sensory adaptation and interaction of sensations
Sensory disturbances
General concept of sensation
Feeling is the most elementary mental process from which a person begins to understand the world around him. Being the initial source of all our perceptions of sensation, they provide material for other, more complex mental processes: perception, memory, thinking.
Sensation - this is a reflection in a person's consciousness of individual properties and qualities of objects and phenomena that directly affect his sense organs.
Sense organs - these are the mechanisms by which information about our environment enters the cerebral cortex. With the help of sensations, the main external signs of objects and phenomena and the state of internal organs are reflected (Fig. 1).
Figure: 1. Functions of sensations
The physiological basis of sensations is the activity of complex complexes of anatomical structures - analyzers (Fig. 2). Each analyzer consists of three parts:
1) a peripheral section called a receptor;
2) conducting nerve pathways;
3) the cortical sections, in which the processing of nerve impulses coming from the peripheral sections takes place.
| Temperature |
| Distant |
| Contact |
| Proprioceptive |
| Interoreceptive |
| Exteroreceptive |
Figure: 3. Classification of sensations
Visual sensations. Visual sensations serve to reflect light, color, darkness. Color occurs when the eye receptor is exposed to waves of different wavelengths from this range. It is believed that through sight a person receives about 90% of all information. The eyes are the windows of the psyche. In human ontogenesis, they are the first to stop their growth (somewhere at the age of seven). Visual sensations are, first of all, the sensations of color, since everything that surrounds a person is reflected in his consciousness by various colors.
Perceived colors are divided into chromatic (color spectrum) and achromatic (white to black). With the help of visual sensations, a person is able to distinguish up to 180 tones of color and more than 10,000 shades between them.
Auditory sensationsoccur as a result of the impact of a sound wave on the auditory analyzer.
A person is able to feel sound vibrations with a frequency of 20 to 20,000 Hz. All sounds that the human ear perceives can be divided into two groups: musical (sounds of singing, sounds of musical instruments, etc.) and noises (creaks, rustles, knocks, etc.). Auditory sensations allow a person to perceive the speech of other people, control many types of work, enjoy music, etc.
Figure: 4. Systematic classification of the main types of sensations
Olfactory sensationsarise as a result of the action of odorous substances in the air on the olfactory receptors located in the upper part of the nasal cavity.
Olfactory senses help a person distinguish between common in the air volatiles and smells. They provide the individual with information about the presence in the air of various chemical substances and act on the subconscious.
Taste sensations (often together with the sense of smell) are caused by the action of the chemical properties of substances dissolved in saliva or water on the taste buds (taste buds) located on the surface of the tongue, the back of the pharynx, the palate and the epiglottis.
Different parts of the tongue are sensitive to different substances in different ways: to sweet, the tip of the tongue is most sensitive, to sour - its edges, to bitter - the area of \u200b\u200bthe root of the tongue, to salty - the edges of the tongue and the middle. Taste sensations allow us to determine the qualitative characteristics of food consumed by a person and are dependent on the feeling of hunger.
Temperature sensations - these are sensations of warmth and cold. On the surface of the skin there are more cold cells (8-23 per 1 sq. Cm) than heat cells (0-3 per 1 sq. Cm), and they are closer to the surface by 0.17 mm than heat cells (0.3 mm) ... Therefore, the body reacts faster to cold than to heat.
Tactile sensations together with musculo-motor make up the sense of touch, with the help of which a person reflects the qualitative features of objects - their smoothness, density, as well as the touch of an object to the body, the place and size of the irritated skin area.
Via musculoskeletal sensations a person receives information about the position of the body in space, the relative position of all its parts, movement of the body and its parts, contraction, stretching and relaxation of muscles, etc.
Pain sensations signal about damage, irritants to human organs, are a kind of manifestation of the body's protective functions.
It is important to note that pain sensations protect the body from the danger of physical destruction. Pain makes a person careful, warns him against rash actions associated with a threat to life. At the same time, studies show that the intensity of pain is determined not only by individual pain thresholds, but also by the psychological factor of fear of the very expectation of pain. The intensity of pain sensations is influenced by: temperature (pain intensifies with cold), light (excessively bright lighting intensifies the pain), time of day (the pain is most acute at about 1 am), a tendency to addiction (drug addicts who are not in a drug state are very painful experiencing pain), ethnicity (blue-eyed, fair-haired Europeans tolerate pain worse than, for example, gypsies, blacks, and Chinese). The intensity of pain is different, reaching in some cases a great strength, which can even lead to a state of shock.
Tactile sensations are a combination, a combination of skin and motor sensations when touching objects, i.e. when you touch them with a moving hand.
The sense of touch is of great importance in the work of a person, especially when performing work operations that require great precision. For people without sight, touch is one of the most important means of orientation and cognition.
Organic sensations- sensations associated with interoreceptors located in the internal organs. These include feelings of satiety, hunger, suffocation, nausea, pain, etc. Interoreceptors are connected with the cortex through subcortical formations - the hypothalamus. Organic sensations do not provide accurate localization, and sometimes are subconscious in nature. Strong negative organic sensations can disorganize a person's consciousness.
Feelings of balance provide a vertical position of the human body. They arise as a result of the functional activity of the vestibular apparatus.
The organs of balance are closely related to other internal organs. With strong overexcitation of the balance organs, nausea and vomiting (the so-called seasickness or air sickness) is observed. However, with regular training, the stability of the balance organs increases significantly.
The "consumer" of information about the state of balance of the body can be both consciousness and the sphere of the unconscious. So, for example, the sensations of habitual body positions during everyday walking, sitting on a chair at a work table, as a rule, are not realized by a person. At the same time, it is funny and sad to observe a tipsy person walking along a sinusoid, trying with all the power of his consciousness to stay on his feet so as not to fall.
Feelings of movement - These are sensations that reflect the centrifugal and centripetal forces developing during the movement of a person. The receptors of the motor analyzer are located in muscles, ligaments and tendons, articular surfaces. Motor sensations signal the degree of muscle contraction and the position of parts of our body.
A person all the time needs to receive information about the world around him. The adaptation of the organism to the environment presupposes a constantly existing information balance between the environment and the organism.
Vibratingsensations appear in a person when the environment with which he is in contact fluctuates in the frequency range from 15 to 1500 Hz. It is these vibrations that are felt by the body as a whole and by its individual organs. Until now, it has not been clarified what generates this sensation more - information on the auditory canal or on the tactile. Most scientists do not distinguish this type of sensation as a separate one, considering it to be a consequence of other skin sensations, in particular, a pressure factor rapidly moving along the surface of the skin.
The vibrational sensation often helps a person in his practical activities. So, upon the fact of vibration, malfunctions in the operation of a car engine are detected, an abnormal flight regime of the aircraft is recorded by the test pilot (the notorious phenomenon of flutter). Carefully dosed and individually calibrated vibration procedures are used in sports medicine to relieve mental tension and increase a person's current performance. The vibrational sensation helps people with hearing and vision impairments to navigate the environment.
Informational balance is opposed by informational underload - sensory isolation, which leads to serious functional disorders of the body. With sensory deprivation, a person's need for sensations and affective experiences is actualized, which is realized in the form of sensory and emotional hunger.
Basic properties and characteristics of sensations
All sensations can be characterized in terms of their properties (Fig. 5).
Figure: 5. General properties of sensations
All of the above properties 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 - the degree (thresholds) of sensitivity (Fig. 6).
Figure: 6. Sensitivity thresholds
For any sensation to arise, the stimulus must have a certain intensity value.
The minimum value (strength) of a stimulus that can cause a sensation is called the lower absolute threshold of sensation, which characterizes the level of the analyzer's absolute sensitivity to the stimulus. The ability to feel these mild stimuli is called absolute sensitivity. It is always expressed in absolute numbers.
Examples of lower absolute threshold values:
- visual sensations of light from a candle flame burning in the dark in clear weather occur in a person at a distance of about 48 m;
- auditory sensations of the sound from the ticking of a manual mechanical watch in complete silence arise at a distance of 6 m;
- the feeling of sugar in water appears when one teaspoon of sugar is dissolved in 8 liters of water.
The upper absolute threshold of sensations - this is the maximum amount of irritation, a further increase in which causes pain or the disappearance of sensation. So, an ultra-loud sound causes pain in the ears, and an ultra-high sound (with a frequency of oscillations over 20,000 Hz) causes the disappearance of sensation (the audible sound turns into ultrasound). Pressure over 300 g / sq. mm causes pain.
The value of the threshold of sensations changes with age. The magnitude of the absolute threshold can be influenced by the nature of a person's activity, his functional state, the strength and duration of irritation, etc.
Along with the absolute one, the relative sensitivity is different - the sensitivity to changes in the intensity of exposure. Relative sensitivity is measured by the discrimination threshold (difference threshold).
Difference threshold - the minimum difference in the strength of two stimuli of the same type, necessary to change the intensity of sensation. The discrimination threshold is measured by a relative value (fraction), which shows how much of the initial strength of the stimulus must be added (or subtracted) in order to get a barely noticeable sensation of a change in the strength of these stimuli.
Examples of relative thresholds of sensation:
- a change in the sensation of weight occurs at a relative threshold equal to 0.02 \u003d 1/50 (this means that for the appearance of a sensation of weight change, it is necessary to reduce or increase the original weight by 1/50);
- a change in the sensation of pitch occurs at a threshold of 0.003.
The lower and upper absolute thresholds of sensations (absolute sensitivity) and discrimination thresholds (relative sensitivity) characterize the limits of human sensitivity. It should be remembered that the same stimulus for one person may be lower, and for another - above the threshold of sensation. The weaker the stimuli that a person is able to feel, the higher his sensitivity. In other words, the lower the absolute threshold of sensations, the higher the absolute sensitivity, and vice versa.
In humans, the thresholds of sensitivity (lower, upper, differential) are individual and vary depending on age and on a number of circumstances. Deviation (temporary) of sensitivity from the usual norm can be caused by a number of factors: time of day, mental state, fatigue, illness, etc.
During investigative experiments conducted in order to check the quality of sensations of witnesses and suspects, it is necessary to find out whether the subject was exposed to side irritants (alcohol, narcotic or similar pharmacological substances) that increase or dramatically dull the analyzer's sensitivity.
Similar information.
The general properties of sensations are quality, intensity, duration, and localization.
Quality Is a property of sensation that distinguishes him from others. The sensations of one species differ qualitatively from another, as well as different sensations within the same species. Examples of qualities, sensations are different colors and shades, sounds of different heights, different smells, tastes, etc. The quality of each sensation is determined by the property of the object that causes it. Each analyzer reflects a wide range of qualities. The image of perception reflects the objective definition of the world. The qualities given in sensations are included as an integral part of the objective characteristics of perceptions.
The intensity of the sensations Is their quantitative characteristic. The feeling of the same quality is always stronger or weaker. The intensity is determined by the strength of the stimulus. The quantitative and qualitative characteristics of the stimulus are closely related.
Each sensation is also characterized by duration, which is its temporal characteristic. The duration of the sensation depends on the duration of the stimulus.
Feelings are characteristic localization... This means that any image of sensation has elements of the spatial location of the stimulus. Color, light, sound are related to the source. Tactile, pain, temperature sensations - with that part of the body that causes this sensation. At the same time, the localization of pain is more blurred and less accurate.
General patterns of sensations
Sensitivity thresholds
An irritant, acting on the analyzer, does not always evoke a feeling. The touch of a fluff to the body cannot be felt. If the stimulus is very strong, there may be a moment when the sensation ceases to arise. We do not hear sounds with a frequency of more than 20 thousand Hertz. An irritant that is too strong can cause pain. Consequently, sensations arise when a stimulus of a certain intensity acts.
The psychological characteristic of the relationship between the intensity of sensations and the strength of the stimulus is expressed by the concept of the threshold of sensitivity. There are such thresholds of sensitivity: lower absolute, upper absolute and discrimination sensitivity threshold.
The smallest stimulus force that, acting on the analyzer, causes a barely noticeable sensation, is called lower absolute threshold of sensitivity... The lower threshold characterizes the sensitivity of the analyzer.
There is a visual relationship between the absolute sensitivity and the threshold value: the lower the threshold, the higher the sensitivity, and vice versa. Our analyzers are very sensitive organs. They are excited by the very low energy of the corresponding stimuli. This applies primarily to hearing, sight and smell. The threshold of one human olfactory cell for the corresponding aromatic substances does not exceed 8 molecules. And in order to induce taste sensations, you need at least 25,000 times more molecules than to create olfactory sensations. The very strength of the stimulus, at which the sensation of this type still exists, is called upper absolute threshold of sensitivity... Sensitivity thresholds are individual for each person.
This psychological pattern should be foreseen by the teacher, especially the primary school. Some children have decreased visual and auditory sensitivity. For them to see and hear well, it is necessary to create conditions for the best display of the teacher's language and the notes on the board. With the help of our sense organs, we can not only state the presence or absence of a particular stimulus, but also distinguish stimuli by their strength, intensity and quality.
Minimally increase the strength of the acting stimulus, which causes subtle differences between sensations, is called discrimination threshold.
In life, we constantly notice a change in light, an increase or decrease in sound. These are the manifestations of the threshold of discrimination or differential threshold.
If you ask two or three people to halve a line about a meter long, we will see that each will have its own dividing point. You need to measure the results with a ruler. The one who divides more precisely has the best discrimination sensitivity. The ratio of a certain group of sensations to an increase in the magnitude of the initial stimulus is constant. This was established by the German physiologist E. Weber (1795-1878).
Based on the teachings of Weber, the German physicist G. Fechner (1801 - 1887) showed experimentally that the increase in the intensity of sensation is not directly proportional to the increase in the strength of the stimulus, but slower. If the strength of the stimulus increases exponentially, the intensity of the sensation increases in arithmetic progression. This position is also formulated as follows: the intensity of sensation is proportional to the logarithm of the strength of the stimulus. It is called the Weber-Fechner law.
Adaptation
The sensitivity of the analyzers, determined by the magnitude of the absolute thresholds, is unstable and changes under the influence of physiological and psychological conditions, among which the phenomenon of adaptation takes a special place.
Adaptation, or adaptation, - this is a change in sensitivity under the influence of a constantly acting stimulus, which manifests itself in a decrease or increase in thresholds.
In life, the phenomenon of adaptation is well known to everyone. When a person enters a river, the water at first seems cold to him. But then the feeling of coldness disappears. This can be observed in all types of sensitivity, except for pain.
The degree of adaptation of various analyzer systems is not the same: high adaptability is characteristic of sniffing sensations, tactile (we do not notice the pressure of clothing on the body), it is less in auditory and sensations of cold. The phenomenon of adaptation in smelling sensations is well known: a person quickly gets used to a smelly stimulus and completely ceases to feel it. Adaptation to different aromatic substances occurs at different rates.
Slight adaptation is inherent in pain. Pain signals the destruction of the body, so adaptation to pain can lead to the death of the body.
In the visual analyzer, a distinction is made between adaptation to light and darkness. Getting into a dark room, at first, a person does not see anything, after three or four minutes he begins to distinguish well the light that enters there. Being in absolute darkness increases the sensitivity to light by about 200 thousand times in 40 minutes. If adaptation to darkness is associated with increased sensitivity, then light adaptation is associated with a decrease in light sensitivity.
The phenomenon of adaptation cannot be explained only by changes that occur in the functioning of the receptor during prolonged exposure to a stimulus (for example, renewal and decomposition of the visual substance in the rods and cones of the retina, etc.). Here, changes in the ratio of the processes of excitation and inhibition in the central parts of the analyzers are also important: after their excitation, inhibition occurs and vice versa. It is about the phenomenon of successive mutual induction.
Adaptation can also occur in a conditioned reflex way. If, for example, the effect of light after being in the dark for half an hour is combined with the beats of the metronome, then after 5 such combinations, the beats of the metronome cause a decrease in the sensitivity of the eyes in the subjects without any influence of the light stimulus.
Interaction of sensations
Interaction of sensations - this is a change in the sensitivity of one analytical system under the influence of the activity of another system. The change in sensitivity is explained by cortical connections between analyzers, to a large extent by the law of simultaneous induction.
The general regularity of the interaction of sensations is as follows: weak stimuli of one analytic system increase the sensitivity of the other system, while strong stimuli reduce it. For example, a weak taste (sour) increases visual sensitivity. Weak sound stimuli increase the color sensitivity of the visual analyzer. At the same time, there is a sharp deterioration in the different sensitivity of the eye due to the strong noise of the aircraft engine.
Visual sensitivity is enhanced by certain sniffing stimuli. However, a pronounced negative emotional coloring of the smell is caused by a decrease in visual sensitivity. There are known cases of increased visual, auditory, tactile, olfactory sensitivity under the influence of weak pain stimuli. So, all our analyzing systems are capable of more or less influence on each other.
Sensitization
The increase in 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.
Two areas can be distinguished that determine the increase in the sensitivity of the sensory organs:
- sensitization due to the need to compensate for sensory defects (blindness, deafness);
- sensitization due to the specific requirements of the activity.
Loss of vision or hearing is compensated by the development of other types of sensitivity. There are cases when people who have lost their eyesight, have mastered sculpture, they have a well-developed sense of touch, vibrational sensitivity. A Ukrainian psychologist, holding his hand on the throat of the interlocutor, can understand who is talking about what, and also, picking up the newspaper, knows whether he has read it or not.
The phenomenon of sensitization of the sense organs is observed in people who have been engaged in certain types of professional activities for a long time. A high level of perfection is achieved by the olfactory and gustatory sensations of the tasters of tea, cheese and wine. Tasters can pinpoint not only which grape variety the wine is made from, but also the place where the grapes are grown.
Painting makes special demands on the perception of form, proportions and color ratios when depicting objects. Experiments show that the artist's eye is extremely sensitive to the estimation of proportions. He distinguishes between changes that are equal to 1 / 60-1 / 150 of the size of the object. The possibility of color sensations is evidenced by the mosaic workshop in Rome - it contains more than 20,000 shades of primary colors created by man.
All of this is evidence that our senses develop under the influence of living conditions and the requirements of practical activity.
The contrast of sensations
The contrast of sensations Is a change in the intensity and quality of sensations under the influence of a preliminary or concomitant stimulus.
In the case of the simultaneous action of two stimuli, a simultaneous contrast arises. This contrast can be seen in visual sensations. The same figure on a black background appears lighter, on a white background - darker. A green object against a red background appears to be more saturated.
The phenomenon of consistent contrast is also well known. After a cold, mild warm irritant seems hot. Feeling sour increases your sensitivity to sweets.
The phenomena of sequential contrast or sequential image in visual sensations have been studied in sufficient detail. If you fix a light spot with your eye for 20 - 40 seconds, and then close your eyes or turn your gaze to a low-light surface, then in a few seconds you can notice a fairly clear dark spot. This will be a consistent visual image.
The physiological mechanism for the emergence of a sequential image is associated with the phenomenon of the aftereffect of the stimulus on the nervous system. The termination of the action of the stimulus does not cause an instant cessation of the process of irritation in the receptors and excitation in the cortical parts of the analyzer. According to the law of sequential induction, the process of inhibition arises over time in excited neurons. To restore the initial state of sensitivity of nerve tissues, several phases of induction change of excitation and inhibition pass. With a sufficient culture of observation, one can notice a change in the positive and negative phases of the sequential image.
Synesthesia
The interaction of sensations is also manifested in such a phenomenon as synesthesia. Synesthesia - this is the appearance under the influence of irritation of one analyzer of sensations characteristic of another analyzer.
It is observed in a wide variety of sensations. Often, visual-auditory synesthesia occurs when, as a result of the action of sound stimuli, a person has visual images. It is known that such composers as N. A. Rimsky-Korsakov, A. N. Scriabin and others possessed the ability to hear color. We find a vivid manifestation of this kind of synesthesia in the work of the Lithuanian artist M.K. Čiurlionis in his symphony of colors.
Engineer K. L. Leontiev, using the phenomenon of synesthesia, has developed an apparatus that transforms sound signals into color. Colored music was created on the basis of this invention. Sometimes there are cases of the appearance of auditory sensations under the influence of visual stimuli, gustatory - in response to auditory stimuli, etc.
Not all people have synesthesia, but no one is surprised at the possibility of using such expressions: velvet voice, dark sound, cold color, sweet sound, pungent taste, etc. The phenomenon of synesthesia is another evidence of the constant interconnection of the analytic systems of the human body, the integrity of the sensory reflection of the surrounding reality.
The considered patterns reveal a high dynamism of sensations, their dependence on the strength of stimuli, on the functional state of the analytic system caused by the onset or termination of the action of stimuli, as well as the simultaneous action of several stimuli on one analyzer or adjacent analyzers. We can say that the patterns of sensation determine the conditions under which the stimulus reaches consciousness. Biologically important stimuli act on the brain at lower thresholds and increased sensitivity, stimuli that have lost their biological significance at higher thresholds.
The concept of sensations. Types and properties of sensations
A person receives a variety of information about the state of the external and internal environment with the help of the senses, in the form of sensations.
Sensations are a cognitive process, a reflection in the human mind of individual properties of objects that directly affect our senses.
Sensations are the source of our knowledge of the world and ourselves. All living beings with a nervous system have the ability to feel. The vital role of sensations is to promptly and quickly bring to the central nervous system information about the state of the external and internal environment.
For sensation to arise, it is necessary to influence the stimulus on the sense organs. Material agents of various nature (physical, chemical) act as an irritant. The emergence of sensations is ensured by the work of analyzers, of which a person has five: visual, auditory, tactile-kinesthetic (ensures the distinction of touch and movement), olfactory, gustatory.
Analyzer - the nervous apparatus that performs the function of analysis and synthesis of stimuli emanating from the external and internal environment of the body. Analyzers take the influence of certain stimuli from the external and internal environment and process them into sensations.
Analyzers consist of the following parts:
· Receptors, or sense organs, converting the energy of external influences into nerve signals;
· The conductive nerve pathways through which these signals are transmitted to the brain and back to the receptors;
· Cortical areas of the brain.
Each analyzer has a separate area in the cerebral cortex. Each receptor is adapted to receive only certain types of influence (light, sound, etc.), i.e. possesses specific excitability to certain physical and chemical agents.
Types of sensations reflect the originality of the incentives that generate them.
Feelings can be classified according to different reasons.
According to the leading modality (qualitative characteristic), there are:
· visualsensations are caused by the influence of light, i.e.
Basic properties and characteristics of sensations
electromagnetic waves that are emitted or reflected by various physical bodies. The receptor is the retina membrane of the eye. Light waves vary in length, vibration amplitude, and shape. Length is the number of vibrations of a light wave per second. The more the number of vibrations, the shorter the wavelength, and, conversely, the less the number of vibrations, the longer the wavelength. The wavelength of the light determines the color tone. Colors have different psychological meanings. The vibration amplitude of the light wave determines the brightness of the color. The shape of the light wave, resulting from the mixing of light waves of different lengths with each other, determines the color saturation.
· auditory sensations are caused by sound waves, i.e. rhythmic vibration of the air. There is a special physical unit by which the frequency of air vibrations per second is estimated - hertz - numerically equal to one vibration per second. The higher the frequency of vibrations in the air, the higher the sound we perceive. On average, a person hears sounds in the frequency range from 16 Hz to 20 kHz. Sound below the human hearing range is called infrasound; from 20 kHz to 1 GHz - by ultrasound, from 1 GHz and above - by hypersound. The loudness of the perceived sound depends on its strength or intensity, i.e. amplitude and frequency of air vibrations. To assess the loudness of the perceived sound, the unit is adopted - decibel. The average loudness values \u200b\u200bof various sounds are presented in Table 2.
Table No. 2
Average loudness values \u200b\u200bof various sounds
· olfactorysensations are a reflection of smells.
They arise due to the penetration of particles of odoriferous substances, spreading in the air, into the upper part of the nasopharynx, where they act on the peripheral endings of the olfactory analyzer, embedded in the nasal mucosa.
· flavoring sensations play an important role in the nutrition process, in distinguishing between different types of food. Taste senses have four main modalities: sweet, salty, sour, and bitter. All other varieties of gustatory sensations are a varied combination of the four basic ones. The olfactory analyzer plays an important role in the occurrence of certain taste sensations.
· tactile sensation or skin sensitivity is the most common type of sensitivity. The familiar sensation that occurs when an object touches the skin surface is the result of a complex combination of 4 others: pressure, pain, heat and cold. For each of them, there is a specific range of receptors, unevenly located in different parts of the skin surface. The strength and quality of sensations are in themselves relative. For example, when the surface of one skin area is simultaneously exposed to warm water, its temperature is perceived differently, depending on what kind of water we are acting on the neighboring skin area. If it is cold, then on the first part of the skin there is a feeling of warmth, and if it is hot, then a feeling of coldness. As a rule, temperature receptors have two threshold values: they respond to high and low impacts, but do not respond to medium ones.
These sensations are called exteroceptive and constitute a single group of analyzers, the receptors of which are located on the surface of the body or near it. Exteroceptive sensations are divided into contact and distant. Contact sensations are caused by direct contact with the surface of the body (taste, touch), distant sensations are caused by stimuli that act on the sense organs at a certain distance (vision, hearing). Olfactory sensations occupy an intermediate position between them.
TO proprioceptivesensations include a sense of balance, provided by the work of the vestibular apparatus, and a kinesthetic sensation, which carries information about the state of the muscular system. Kinesthetic sensations (from the Greek. kinesis - "movement") come from muscles, ligaments and tendons; allow you to perform and coordinate movements. They are formed automatically, enter the brain and regulate movements at a subconscious level.
Signals coming from internal organs are called visceral sensations and are interoceptive.These include feelings of hunger, thirst, nausea, and internal pain.
In addition, a person has several specific types of sensations that carry information about time, acceleration, vibration. Vibratingsensations take an intermediate place between tactile and auditory sensitivity.
Properties of sensations.Sensations have the following properties.
1. Modality - a qualitative characteristic of sensations is a property that allows one to distinguish one type of sensation from another.
2. Intensity Is a quantitative characteristic of sensations, which is determined by the strength of the acting stimulus and the functional state of the receptor.
3. Duration Is a time characteristic of sensations. It is determined by the functional state of the sense organ, the time of exposure to the stimulus and its intensity.
4. SensitivityIs the ability of the nervous system to respond to stimuli. Sensitivity is characterized by two thresholds - lower and upper. The lower threshold is the minimum amount of a stimulus that can produce a subtle sensation. The upper one is the maximum value of the stimulus at which a painful sensation occurs. High sensitivity corresponds to low thresholds, and vice versa, low sensitivity - high. The threshold for sensation is not the same for different people. The threshold value changes with age and depends on the health and mental state of the person. The sensitivity can be increased or decreased using pharmacological agents. An important role in changing the sensitivity is played by the training of the analyzer. Thus, musicians develop auditory sensitivity ("ear for music"), tasters develop olfactory and gustatory sensitivity.
5. Adaptation Is the adaptation of the sense organ to external conditions. Through adaptation, the receptor gets used to the sensation. For example, in the transition from bright light to darkness, at first we do not see objects, but gradually we begin to distinguish their outlines (adaptation to darkness).
6. Synesthesia - this is the appearance under the influence of irritation of a certain analyzer of a sensation characteristic of another analyzer. For example, in some people, the sounds of music are capable of evoking a sense of color (the so-called "color hearing") or a combination of colors generates musical associations.
7. Compensation - this is the property of sensations to an increase in some sensitive system when another is disturbed (for example, hearing is exacerbated with loss of vision).
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Feeling, their properties and types.
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The world is given to man in sensations. Feeling traditionally called the process of transmitting information about the external world to the brain through the sensory system. The sensory system plays the role of an input device, and the brain plays the role of a processing center, here the information is decoded and correlated with the existing one. Thus, sensation is a mental reflection in the cerebral cortex of individual properties, objects and phenomena that directly affect the sense organs.
Sensation is called the simplest, further not decomposable mental process. For example, speaking about the sensation of color, we mean only color, abstracting from the size and shape of an object. Sensation is the sensitivity to the physical and chemical properties of the environment. More complex cognitive processes are based on sensations: perception, representation, memory, thinking, imagination. The sensations are like The "gateway" of our knowledge... They represent the transformation of the energy of external influence into an act of consciousness, providing a sensory basis for mental activity, providing sensory material for building mental images.
Human sensations are different from animal sensations. A person's feelings are mediated by his knowledge, that is, by the social and historical experience of mankind. Expressing this or that property of things and phenomena in the word ("red", "cold"), we thereby carry out elementary generalizations of these properties, understandable to every person.
The sensations reflect the objective qualities of phenomena (color, smell, temperature, taste, etc.), their intensity (for example, higher or lower temperature, more tasty or less tasty) and duration. Human sensations are as interconnected as the various properties of reality.
Depending on the location of the receptors all sensations are shared into three groups: 1) the first group includes sensations that are associated with receptors located on the surface of the body: visual, auditory, olfactory, gustatory and skin sensations. it exteroreceptive sensations; 2) the second group includes interoreceptive sensationsassociated with receptors located in internal organs; 3) the third group includes kinesthetic (motor) and static sensations, the receptors of which are located in muscles, ligaments and tendons - proprioceptive sensations(from Latin "proprio" - "own").
Depending on the modality of the analyzerthe following types of sensations are distinguished: 1) visual; 2) auditory; 3) skin; 4) olfactory; 5) gustatory; 6) kinesthetic; 7) static; 8) vibrating; 9) organic; 10) painful.
Contact and distant sensations also differ. Thus, sensations are an integral part of human life. With the help of sensations, a person learns the world around him and interacts with it.
Certain properties of objects and phenomena that affect our sense organs are called stimuli, and the process of this impact is irritation... The nervous process resulting from irritation is called excitement.
The sense organs, receiving exposure to stimuli, convert the energy of external stimulation into a nerve impulse. Each sense organ (eye, ear, sensitive skin cells, taste buds of the tongue) is specialized in receiving and processing various specific external influences.
The main part of any sense organ is the endings of the sensory nerves. They're called receptors... From the receptor, the nerve impulse that has arisen in it through the centripetal nerve pathways enters the corresponding parts of the brain.
Receptors that conduct nerve pathways and corresponding sites in the cerebral cortex are called analyzers... For the emergence of a sensation, the work of the entire analyzer as a whole is necessary; therefore, it cannot be said that visual sensations arise in the eye. Only the analysis of the nerve impulse coming from the eye to the corresponding parts of the cerebral cortex leads to the appearance visual sensation.
The activity of analyzers is conditioned reflex. Formed in the cerebral cortex, a nerve impulse arriving along the centrifugal nerve pathways, to motor or secretory mechanisms, leads to one or another response, causes a corresponding adjustment of the sensitivity of the receptor. The brain, receiving a feedback signal about the activity of the receptor, continuously regulates its work.
The sense organs are inextricably linked with the organs of movement. For example, in the process of visual sensations, the eye makes continuous movements, as if feeling an object. The fixed eye is practically blind. Thus, the process of sensations is not a one-act passive reflection of this or that property, but an active process, the most complex activity of analyzers, which has a certain structure. The activities of various analyzers are interconnected. The collection of all analyzers is called the sensory sphere of the human psyche.
Sensations not only carry information about the individual properties of phenomena and objects, but also perform a function that activates the brain. There are cases when the patient had only one sensory organ, the eyes, and when the patient closed his eyes (the only channel connecting him with the outside world), he immediately fell asleep.
Lower and upper absolute thresholdssensations characterize the limits of human sensitivity... But each person's sensitivity varies with different conditions. So, entering a poorly lit room, at first we do not distinguish objects, but gradually under the influence of these conditions the sensitivity of the analyzer increases.
Being in a smoky room or in a room with any smells, after a while we stop noticing these smells. When we get from a poorly lit space into a brightly lit space, the sensitivity of the visual analyzer decreases.
Different types of sensations are characterized not only by specificity, but also by properties common to them. These properties include: 1) quality- this is the main feature of this sensation, which distinguishes it from other types of sensations and varies within this type of sensation; 2) intensity- is a quantitative characteristic and is determined by the strength of the acting stimulus and the functional state of the receptor; 3) duration- time characteristic of sensation; 4) spatial localization- analysis carried out by spatial receptors provides information about the localization of the stimulus in space.
The psychological relationship between the intensity of sensation and the strength of the stimulus causing it is determined threshold of sensations.
The work of each analyzer has its own specific patterns.
Along with this, all types of sensations are subordinated to a common psychophysiological laws... For any sensation to arise, the stimulus must have a certain intensity value. The minimum amount of irritation that causes a barely noticeable sensation is called the absolute lower threshold of sensation... The ability to feel these weakest irritations is called absolute sensitivity... It is always expressed in absolute numbers. For example, for the appearance of a feeling of pressure, an effect of 2 mg per 1 sq. mm of skin surface.
Upper absolute threshold of sensation- the maximum amount of irritation, a further increase in which causes the disappearance of sensation or pain. For example, an ultra-loud sound causes pain in the ears, and an ultra-high sound (with an oscillation frequency of more than 20,000 Hz) causes the sensation to disappear (the audible sound turns into ultrasound). Pressure 300 g / sq. mm causes pain.
Along with absolute sensitivity, one should distinguish relative sensitivity- sensitivity to distinguishing the intensity of one impact from another. Relative sensitivity is characterized by a discrimination threshold.
Discrimination threshold, or differential threshold- a barely perceptible minimal difference in the strength of two stimuli of the same type.
35. CLASSIFICATION OF SENSATIONS. PROPERTIES OF SENSATIONS
The threshold of discrimination is relative magnitude (fraction), which shows how much of the initial strength of the stimulus must be added (or reduced) in order to get a barely noticeable sensation of a change in the strength of these stimuli.
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All sensations can be characterized in terms of their properties. Moreover, the properties can be not only specific, but also general for all types of sensations. The main properties of sensations include:
quality,
intensity,
duration,
spatial localization,
absolute and relative thresholds of sensations
Quality -this property characterizing the basic information displayed by this sensation, distinguishing it from other types of sensations and varying within this type of sensation. For example, gustatory senses provide information about some of the chemical characteristics of an 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: floral smell, almond smell, hydrogen sulfide smell, etc.
It should be noted that, when speaking of the quality of sensations, they often mean the modality of sensations, since it is the modality that reflects the main quality of the corresponding sensation.
Intensitysensation 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 the perceived odors may be distorted.
Duration sensations are a time characteristic of a sensation that has arisen. It is also determined by the functional state of the sense organ, but mainly by the time of action of the stimulus and its intensity. It should be noted that sensations have a so-called latent (latent) period. When an irritant is exposed to the sense organ, the sensation does not arise immediately, but after a while. The latency period for different types of sensations is not the same. For example, for tactile sensations it is 130 ms, for pain sensations - 370 ms, and for gustatory sensations - only 50 ms.
And finally for the sensations characterized by spatial localizationirritant. 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 goes, or which part of the body is affected by the stimulus.
The sensation begins to develop immediately after the baby is born. A short time after birth, the baby begins to respond to stimuli of all kinds. However, there are differences in the degree of maturity of individual feelings and in the stages of their development. Immediately after birth, the baby's skin sensitivity is more developed. At birth, the baby trembles due to the difference in mother's body temperature and air temperature. A newborn child reacts to touch, and his lips and the entire mouth area are most sensitive. It is likely that a newborn may feel not only warmth and touch, but also pain. By the time of birth, the child has a rather highly developed gustatory sensitivity. Newborn babies react differently to the introduction of a solution of quinine or sugar into their mouth. A few days after birth, the baby distinguishes the mother's milk from the sweetened water and the latter from plain water. From the moment of birth, the child's olfactory sensitivity is already sufficiently developed. The newborn baby determines by the smell of breast milk whether the mother is in the room or not. If the baby ate mother's milk for the first week, then he will turn away from the cow's milk only when he smells it. However, olfactory sensations, not associated with nutrition, develop for a long time. They are underdeveloped in most children, even at the age of four or five. Vision and hearing go through a more complex path of development, which is explained by the complexity of the structure and organization of the functioning of these sense organs and their less maturity by the time of birth. In the first days after birth, the child does not respond to sounds, even very loud ones. This is due to the fact that the ear canal of the newborn is filled with amniotic fluid, which is absorbed only after a few days. Usually, the child begins to respond to sounds within the first week, sometimes this period is delayed up to two to three weeks. The child's first reactions to sound have the character of general motor excitation: the child throws up his arms, moves his legs, and makes a loud cry. Sound sensitivity is initially low, but increases in the first weeks of life. After two to three months, the child begins to perceive the direction of the sound, turns his head towards the source of the sound. In the third to fourth months, some babies begin to respond to singing and music. As for the development of speech hearing, the child first of all begins to respond to the intonation of speech. This is observed in the second month of life, when an affectionate tone has a calming effect on the child. Then the child begins to perceive the rhythmic side of speech and the general sound pattern of words. However, the distinction of speech sounds occurs by the end of the first year of life. From this moment, the development of the actual speech hearing begins. First, the child develops the ability to distinguish between vowels, and at a later stage he begins to distinguish consonants. Vision develops most slowly in a child. The absolute sensitivity to light in newborns is low, but increases markedly in the first days of life. From the moment the visual sensations appear, the child reacts to light with various motor reactions. Color discrimination grows slowly. It has been established that the child can distinguish color as early as the fifth month, after which he begins to show interest in all kinds of bright objects. A child, starting to feel light, at first cannot see objects. This is due to the fact that the child's eye movements are not coordinated: one eye can look in one direction, the other in the other, or it can be closed altogether. The child begins to control eye movement only by the end of the second month of life. He begins to distinguish objects and faces only in the third month. From this moment, a long-term development of the perception of space, the shape of an object, its size and distance begins. In relation to all types of sensitivity, it should be noted that absolute sensitivity reaches a high level of development already in the first year of life. The ability to distinguish sensations develops somewhat more slowly. In a preschool child, this ability is developed incomparably lower than in an adult. The rapid development of this ability is noted during the school years. It should also be noted that the level of development of sensations in different people is not the same. This is largely due to human genetic characteristics. - For more information, see Referatwork.ru: http://referatwork.ru/psyhology-2014/section-18.html
There are two types of sensitivity: absolute sensitivity and sensitivity to discrimination. Absolute sensitivity is understood as the ability of the sense organs to respond to the minimum, weakest stimuli. Differential sensitivity, or difference sensitivity, is the ability to perceive subtle differences between stimuli.
Lower absolute sensitivity threshold- the minimum strength of the stimulus, causing a barely noticeable sensation. This is the threshold for conscious recognition of the stimulus.
Upper absolute threshold of sensitivity the maximum strength of the stimulus is called, at which a sensation adequate to the acting stimulus still arises. A further increase in the strength of the stimuli acting on our receptors causes only a painful sensation in them (for example, an ultra-loud sound, blinding light).
The magnitude of the absolute thresholds, both lower and upper, varies depending on various conditions: the nature of the person's activity and age, the functional state of the receptor, the strength and duration of stimulation, etc.
The sensation does not arise immediately, as soon as the desired stimulus began to act. A certain time passes between the onset of the stimulus action and the appearance of the sensation. This is called the latency period. Latent (temporary) period of sensation - the time from the onset of the stimulus to the onset of sensation. During the latency period, the energy of the acting stimuli is transformed into nerve impulses, their passage through the specific and nonspecific structures of the nervous system, switching from one level of the nervous system to another.
the law of the constancy of the magnitude of the increment of the stimulus was established, independently of each other, by the French scientist P. Bouguer and the German scientist E. Weber and was called the Bouguer-Weber law. Bouguer-Weber law - a psychophysical law expressing the constancy of the ratio of the increment in the magnitude of the stimulus, which gave rise to a barely noticeable change in the strength of sensation to its original magnitude:
where: I - the initial value of the stimulus, D I - its increment, K - constant.
Another revealed pattern of sensations is associated with the name of the German physicist G. Fechner (1801-1887). Due to partial blindness caused by observing the sun, he took up the study of sensations. In the center of his attention is the long-known fact of differences between sensations, depending on what was the initial magnitude of the stimuli causing them. G. Fechner drew attention to the fact that similar experiments a quarter of a century earlier had been carried out by E. Weber, who introduced the concept of "a barely noticeable difference between sensations." It is not always the same for all types of sensations. This is how the idea of \u200b\u200bthe thresholds of sensations appeared, that is, the magnitude of the stimulus that causes or changes the sensation.
Exploring the relationship that exists between changes in the strength of the stimuli acting on the human senses and the corresponding changes in the magnitude of sensations and, taking into account Weber's experimental data, G. Fechner expressed the dependence of the intensity of sensations on the strength of the stimulus by the following formula:
where: S is the intensity of sensation, J is the strength of the stimulus, K and C are constants.
According to this provision, which is called the basic psychophysical law, the intensity of sensation is proportional to the logarithm of the strength of the stimulus. In other words, with an increase in the strength of the stimulus exponentially, the intensity of sensation increases in an arithmetic progression. This relationship was called the Weber-Fechner law, and G. Fechner's book "Fundamentals of Psychophysics" was of key importance for the development of psychology as an independent experimental science.
QUESTION 5 FEELING - direct sensory reflection of individual properties of the object. They make up: the sensory-perceptual level of mental reflection. At the sensory-perceptual level, we are talking about those images that arise with the direct impact of objects and phenomena on the sense organs.
The image is the result of perception, therefore the properties of the image \u003d the properties of the perceived object. He can be perceptual (actually, perception) and non-perceptual (imagination, memory, thinking)
1. An image, the object of which is in the field of perception, i.e. resulting from the stimulation of our sensory systems - a perceptual image or a perception image. A prerequisite here is the activity of the receptor systems, physiological processes of the peripheral order (the mental image (with closed eyes) is associated with the processes of the central nervous system). Perceptual images are divided:
By modality (visual, auditory, tactile);
Extraceptive / intraceptive, i.e. images of the external world / internal state (the latter are worse, since the receptor of feelings is poorer) - this division arose late. Small children and animals do not differentiate between these conditions!
On conscious / unconscious images (in perception and imagination, most images are unconscious)
The paradox of the perceptual image - different people see the same object differently (even one person at different periods of life). Why? Because the image is not passively perceived, but is actively built by the subject. Objects do not perceive us, but we find them in the environment. Perceptual images, in contrast to non-perceptual ones, have a sensory basis. Properties of the perceptual image:
Reality - a person believes in the objective existence of a perceived object, images of perception live in real time and space;
Objectivity - the images are projected outwardly, are carried out into the space of the external world;
Integrity / objectivity - the perception is not of the sum of different-modal sensations, but of a whole object;
Polymodality is an organic unity of data from various senses.
Constancy - constancy - the images of objects are constant and do not depend on the conditions of perception (illumination) and the properties of the subject itself (ex. From his appearance), i.e. it is the independence of the properties of a familiar object from the conditions of its perception (in children it is broken - one can be afraid of the father in the image of D. Moroz)
Significance - ex., Looking at the spoon, we already see its function, influencing social and individual experience.
An image, the object of which is outside the process of perception - a non-perceptual image - when, without seeing the object itself, we imagine it, i.e. we do not have a real image, but we have an image associated with the processes of imagination, memory, thinking (ex., the image of memory is a former percept). Non-perceptual images have a quasi-sensory character.
- mental image: an image of imagination or memory, arises without the participation of peripheral nervous processes and is created by the experience or creativity of a person; can be visual, auditory, or any other sensory modality, as well as purely verbal .;
- synesthesia: accompaniment of perceptual sensations of one modality with pseudo-sensations of another modality (“assorted” feelings, color hearing, etc.); this interaction of the senses ("color hearing", for example). This is a formal definition, and the idea of \u200b\u200bsynesthesia is that once the senses did not differ from each other, which has indirect confirmation: temperature sensitivity is directly used to assess the human appearance (a person is warm, cold, light, etc.)
- body diagram: a person's idea of \u200b\u200ba certain system of activity that he controls, it also includes physical components that go beyond the body. Kinesthetic and temperature-tactile representations are considered important components of this image. The scheme of the body is included in the "image of I", but the latter is broader;
- phantom images: a part of the image of one's own body that persists even despite the loss of the corresponding bodily organ (usually a limb);
- hallucinatory images: occur without external stimulus, the subject is convinced of the reality of an external object, this is a projection of the subject's internal image into the external world. Hallucinations differ from mental images in clarity and detail. Their special case is hypnological images (on the verge of sleep and wakefulness);
- phosphenes: usually appear as unsaturated spots or relatively stable patterned images. The term is also used to refer to dots or colored spots visible when the eye is inadequately stimulated, for example, by mechanical pressure or electric shock.
- eidetic images: common in 70% of children - this is the result of the inertia of the visual system. The eidetic sees, but does not remember! disappeared image within minutes and even hours (Rykiel's experiments with the painting). According to Vygotsky, eidetism is widely represented among primitive peoples (it is the basis of topographic memory). In modern man, eidetism is destroyed by higher mental functions and social influence.
