Touch or tactile sensations. Skin and tactile sensations

(touch)

After I have described the structure and structure of the nervous system, it is time to think about how this system works. It is very easy to see that in order for the nervous system to be able to direct the actions of the organism to the benefit of the latter, it must constantly evaluate the details of the environment. It is useless to lower the head quickly unless it is in danger of colliding with some object. On the other hand, it is very dangerous not to do so if such a threat exists.

In order to have an idea of the state of the environment, it is necessary to feel or perceive it. The body senses the environment through the interaction of specialized nerve endings with various environmental factors. The interaction is interpreted by the central nervous system in ways that differ from each other depending on the nature of the perceiving nerve endings. Each form of interaction and interpretation stands out as a special kind of sensory (sensory) perception.

In everyday speech, we usually distinguish between five senses - sight, hearing, taste, smell, and tactile sensitivity, or the sensation of touch. We have separate organs, each of which is responsible for one of the types of perception. We perceive images through the eyes, auditory stimuli through the ears, smells reach our consciousness through the nose, tastes through the tongue. We can group these sensations into one class and call them specialized sensations, since each of them requires the participation of a special (that is, special) organ.

No special organ is required to perceive tactile sensations. The nerve endings that perceive touch are scattered over the entire surface of the body. Touch is an example of a general sensation.

We are quite bad at differentiating sensations, the perception of which does not require the participation of special organs, and therefore we speak of touch as the only sensation that we perceive with the skin. For example, we often say that an object is "hot to the touch" when, in reality, touch and temperature are perceived by different nerve endings. The ability to perceive touch, pressure, heat, cold and pain is united by the general term - skin sensitivity, since the nerve endings with which we perceive these irritations are located in the skin. These nerve endings are also called exteroceptors (from the Latin word "extra", which means "outside"). Exteroception also exists within the body, since the endings located in the wall of the gastrointestinal tract are, in fact, exteroceptors, since this tract communicates with the environment through the mouth and anus. One could consider the sensations resulting from irritation of these endings as a kind of external sensitivity, but it is distinguished into a special type called interoception (from the Latin word "intra" - "inside"), or visceral sensitivity.

Finally, there are nerve endings that transmit signals from the organs of the body itself - from the muscles, tendons, ligaments of the joints, and the like. Such sensitivity is called proprioceptive (“proprio” in Latin means “own”). It is proprioceptive sensitivity that we are least aware of, taking the results of its work for granted. Proprioceptive sensitivity is realized by specific nerve endings located in various organs. For clarity, we can mention the nerve endings located in the muscles, in the so-called specialized muscle fibers. When these fibers are stretched or contracted, impulses arise in the nerve endings, which are transmitted along the nerves to the spinal cord, and then, along the ascending tracts, to the brain stem. The greater the degree of stretching or contraction of the fiber, the more impulses are generated per unit time. Other nerve endings respond to pressure in the feet when standing or in the gluteal muscles when sitting. There are other types of nerve endings that respond to the degree of tension in the ligaments, to the angle of the relative position of the bones connected at the joints, and so on.

The lower parts of the brain process incoming signals from all parts of the body and use this information to coordinate and organize muscle movements designed to maintain balance, change uncomfortable body positions and adapt to external conditions. Although the body's normal work of coordinating movements while standing, sitting, walking, or running eludes our consciousness, certain sensations sometimes reach the cerebral cortex, and thanks to them we are aware at any time of the relative position of our body parts. Without looking, we know exactly where and how our elbow or big toe is located, and with closed eyes we can touch any part of the body named to us. If someone bends our arm at the elbow, we know exactly what position our limb is in, and for this we do not need to look at it. In order to do this, we must constantly interpret the myriad combinations of nerve impulses that enter the brain from stretched or twisted muscles, ligaments, and tendons.

The various proprioceptive perceptions are sometimes lumped together under the heading of the position sense, or position sense. Often this sense is called kinesthetic (from the Greek words for "sense of movement"). It is not known to what extent this feeling depends on the interaction of the forces developed by the muscles with the force of gravity. This issue has become especially relevant for biologists in recent times, in connection with the development of astronautics. During long space flights, astronauts spend a long time in a state of weightlessness, when proprioceptive sensitivity is deprived of signals about the usual effects of gravity.

As for the exteroceptive sensitivity that perceives such modalities,

Tactile sensations Etymology.

Comes from lat. tactilis - tactile.

Category.

Form of skin sensitivity.

Specificity.

The sensations caused by touch, pressure, vibration, the action of texture and extension have a different character. They are caused by the work of two types of skin receptors: the nerve plexuses surrounding the hair follicles, and capsules consisting of connective tissue cells.

Psychological Dictionary. THEM. Kondakov. 2000 .

See what "tactile sensations" are in other dictionaries:

Tactile Feelings- a form of skin sensitivity, due to the work of two types of skin receptors: nerve plexuses surrounding the hair follicles, and capsules consisting of connective tissue cells. The sensations caused by touch have a different character, ... ... Psychological Dictionary

TACTILE SENSATIONS- the same as tactile. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910 ... Dictionary of foreign words of the Russian language

tactile sensations- ▲ feeling touch tactile feeling feeling touch. touch. touch. tactile. tangibility. feel (fabric is soft #). groping. soft (# seat). solid. hard. itching. itch. itch. overthrow. itching. scabies (#… … Ideographic Dictionary of the Russian Language

Tactile sensations- (or tactile) see Touch, Skin ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

Tactile sensations- ... Wikipedia

Tactile mouth sensations- (mouthfeel): tactile sensations perceived in the oral cavity, including the tongue, gums, teeth ... Source: ORGANOLEPTIC ANALYSIS. DICTIONARY. GOST R ISO 5492 2005 (approved by Order of Rostekhregulirovanie dated December 29, 2005 N 491 st) ... Official terminology

Feel- Sensation (English sensation) is a mental reflection of the properties and conditions of the external environment, arising from direct impact on the sense organs, differentiated perception by the subject of internal or external stimuli and stimuli during ... ... Wikipedia

- (English tactile sensations) one of the types of skin sensitivity. O. t. include sensations of touch, pressure, vibration, texture and length (reflection of the area of the mechanical stimulus). Their occurrence is associated with the activity of 2 ... ...

Kinesthetic body sensations- Tactile sensations and internal senses, such as recalled impressions and emotions, as well as a sense of balance. In NLP, this term is used as a collective name for all sensations, including tactile, visceral (in internal organs) ... ... Dictionary of Neuro-Linguistic Programming

Tactile sensations and internal senses, such as recalled impressions and emotions, as well as a sense of balance. In NLP, this term is used as a collective name for all sensations, including tactile, visceral (in the internal organs) ... ... Great Psychological Encyclopedia

Books

Tactile sensations, Sergey Slyusarenko. If one day you feel that the pen is slipping out of your hands, that familiar things have become alien, that everything around you is annoying - this is not necessarily crazy. Maybe you are on...

Tactile sensations

Good day, dear friends. I would like to talk today about what is tactile sensations and why they are so important to us.

Tactile sensations- ordinary mental states, which are a reflection of certainproperties and conditions of the environment arising from direct influence on the senses,differentiated perception internal or external stimuli and stimuli involving the nervous system

Are you sorely lacking in positive emotions? Experts assure that the state of mind depends on ourselves and is literally at our fingertips: depriving ourselves of touch, not giving the skin sensations, we deny ourselves the pleasure of rejoicing once again, feeling more confident, getting rid of anxiety and pressing problems

— How do you know?
- I feel.
- Not proof.
Close your eyes and give me your hand. What am I doing?
“You… are touching me…”
— How do you know?
- Feel...

In the pleasure of touch and new tactile sensations(not only and not so much erotic) both kids and very adult aunts and uncles need it. Which is quite understandable: outside of touch, a person does not exist. The world is known through touch. People are known through touch. Man himself is known through touch. The organs of touch, or tactile analyzers, are among the most ancient. And the sense of touch is so mysterious that its nature is still not fully understood. Imagine: the thickness of the thinnest material that a person can feel is only 13 nanometers. For comparison: this is 10 times less than !
By touching something with our fingertips, we launch a complex mechanism in which the cerebral cortex is directly involved. At the same time, touch is closely - more closely than sight and hearing - connected with the areas of the brain that control emotions.
The sense of touch occurs in a child already at the 3-4th month of intrauterine development. At the 32nd week, he can no longer move freely, since the uterus surrounding him, hugging, constantly comes into contact with many parts of the baby's body. Periodic contractions of the walls of the uterus (Brexton-Hicks contractions) give the child the experience of even stronger bodily sensations: tight hugs. The main tactile information comes to the child from the entire surface of the skin, which is hugged and stimulated by the uterus. These hugs become the subconscious background of the entire subsequent life of a person. Having been born, we find ourselves in a vast space, billions of times greater than that to which we are accustomed...

THERE IS NOTHING MORE eloquent than a SILENT TOUCH

The need for touch persists throughout a person's life. Spouses who do not refuse hugs and kisses throughout their lives, as a rule, get sick less often and age much more slowly. In addition, the life expectancy of those adults who do not skimp on hugs and touches is longer than that of people who prefer to restrain their emotions. A light and pleasant touch on the human body at any age stimulates the activity of the central nervous system and immunity, reduces stress and mental tension by increasing the synthesis of oxytocin. Previously, it was believed that this hormone is exclusively “maternal”: it is responsible for uterine contractions during childbirth and the production of breast milk. However, it turned out that this is not its only function. Oxytocin is produced by both women and men and increases the amount of pleasure hormones serotonin and dopamine and also reduces the level cortisol(stress hormone). These reactions are triggered by touching human skin, so for any ailments, depression, children and adults need more affection. After all, such a cocktail of hormones, released with a gentle touch, heals in itself. Many scientific journals report how touch can improve well-being even in Alzheimer's patients and autistic children.

However, not all touches are healthy and cause positive emotions. For example, the brain perceives the touch of an unpleasant person as a threat. And then the level of stress hormones in the blood rises. This hormonal upheaval is followed by a natural reaction of the body: trembling, mood swings and blood pressure, increase in blood sugar levels, which adversely affects health. Adults, as a rule, do not allow strangers to display familiarity, but it would be good for parents to take care of children: do not allow anyone to squeeze your children if it is unpleasant for them

According to a study conducted by American psychologists, touch can influence our perception of another person, assessment of the situation and our judgments..

Guys, by the way, I recently acquired a very. Now I constantly do the most incredible hairstyles for my girls. So far, far from everything is working out, it’s painfully ingenious weaving, but there are a lot of pleasures!

Now you know the importance tactile sensations.

Indulge in the luxury of touch. And... live happily ever after!

Video of the day

(touch)

In everyday speech, we usually distinguish between five senses - sight, hearing, taste, smell, and tactile sensitivity, or the sensation of touch. We have separate organs, each of which is responsible for one of the types of perception. We perceive images through the eyes, auditory stimuli through the ears, smells reach our consciousness through the nose, tastes through the tongue. We can group these sensations into one class and call specialized sensations, since each of them requires the participation of a special (that is, special) organ.

No special organ is required to perceive tactile sensations. The nerve endings that perceive touch are scattered over the entire surface of the body. Touch is an example of a general sensation.

As for exteroceptive sensitivity, which perceives such modalities as touch, pressure, heat, cold and pain, it is mediated by nerve impulses that are generated in the nerve endings of a certain type for each type of sensitivity. For the perception of all types of stimuli, except for pain, nerve endings have certain structures, which are named after the scientists who first described these structures.

Thus, tactile receptors (that is, structures that perceive touch) often end in Meissner bodies, which were described by the German anatomist Georg Meissner in 1853. The receptors that perceive cold are called Krause's cones, named after the German anatomist Wilhelm Krause, who first described these structures in 1860. Thermal receptors are called Ruffini's end organs, after the Italian anatomist Angelo Ruffini, who described them in 1898. The pressure receptors are called Pacini corpuscles, after the Italian anatomist Filippo Pacini, who described them in 1830. Each of these receptors can be easily distinguished from other receptors by its morphological structure. (However, pain receptors are simply bare ends of nerve fibers, devoid of any structural features.)

Specialized nerve endings of each type are adapted to perceive only one type of irritation. A light touch on the skin in close proximity to the tactile receptor will cause an impulse in it, but will not cause any reaction in other receptors. If you touch the skin with a warm object, then the thermal receptor will react to this, and the others will not respond with any reaction. In each case, the nerve impulses themselves are identical in any of these nerves (indeed, the impulses are identical in all nerves), but their interpretation in the central nervous system depends on which nerve transmitted this or that impulse. For example, an impulse from a heat receptor will cause a sensation of warmth regardless of the nature of the stimulus. When other receptors are stimulated, specific sensations also arise, which are characteristic only for this type of receptor and do not depend on the nature of the stimulus.

(This is also true for specialized sense organs. It is a well-known fact that when a person receives a blow to the eye, sparks “fall” from it, that is, the brain interprets any irritation of the optic nerve as light. Sharp pressure on the eye will also cause a sensation of light. Then the same thing happens when the tongue is stimulated with a weak electric current.A person with such stimulation develops a certain taste sensation.)

Skin receptors are not located in every area of the skin, and where one type of receptor is present, other types may be absent. The skin can be mapped according to various types of sensitivity. If we use a fine hair to touch various parts of the skin, we will find that in some places a person perceives the touch, and in others he does not. With a little more work, we can similarly map the skin for heat and cold sensitivity. The gaps between receptors are small, and therefore, in everyday life, we almost always respond to stimuli that irritate our skin. In total, the skin contains 200,000 nerve endings that respond to temperature, half a million receptors that respond to touch and pressure, and about three million pain receptors.

As expected, tactile receptors are most densely located in the tongue and fingertips, that is, in those places that nature itself is intended to explore the properties of the surrounding world. The tongue and fingertips are hairless, but in other parts of the skin, touch receptors are associated with hair. Hair is a dead structure, completely devoid of sensitivity, but we all know very well that a person feels any, even the slightest touch to the hair. The obvious paradox can be explained very simply if we understand that when a hair is touched, it bends and, like a lever, puts pressure on the area of skin located next to it. Thus, there is a stimulation of tactile receptors located in the immediate vicinity of the hair root.

This is a very useful property, as it allows us to feel touch without direct skin contact with a foreign object. At night, we can locate an inanimate object (which we cannot see, hear, or smell) by touching it with our hair. (There is also the ability to echolocate, which we will discuss shortly.)

Some nocturnal animals perfect their "hair sensitivity". The most familiar example is the cat family, which includes the well-known domestic cats. These animals have whiskers, which zoologists call vibrissae. These are long hairs, they touch objects at a fairly large distance from the surface of the body. The hair is quite hard, so the physical impact is transmitted to the skin without attenuation, that is, with minimal loss. Vibrissae are located near the mouth, where the concentration of tactile receptors is very high. Thus dead structures, insensitive in themselves, became extremely subtle organs of perception of tactile stimuli.

If the touch becomes more intense, then it begins to stimulate the Pacinian corpuscles in the nerve endings that perceive pressure. Unlike tactile receptors located on the surface of the skin, the organs of pressure perception are localized in the subcutaneous tissues. There is a rather thick layer of tissue between these nerve endings and the environment, and the impact must be stronger to overcome the softening effect of this protective cushion.

On the other hand, if the touch lasts long enough, then the nerve endings of the touch receptors become less and less sensitive and eventually stop responding to the touch. That is, you are aware of the touch at its very beginning, but if its intensity remains unchanged, then the sensation of touch disappears. This is a reasonable decision, because otherwise we would constantly feel the touch of clothes and many other objects on the skin, and these sensations would load our brain with a mass of unnecessary and useless information. In this regard, temperature receptors behave in a similar way. For example, the water in the bath feels very hot to us when we lie down in it, but then, as we "get used" to it, it becomes pleasantly warm. Similarly, cold lake water becomes pleasantly cool some time after we dive into it. The activating reticular formation blocks the flow of impulses that carry useless or insignificant information, freeing the brain for more important and pressing matters.

In order for the sensation of touch to be perceived for a long time, it is necessary that its characteristics constantly change over time and that new receptors are constantly involved in it. Thus, the touch turns into a tickle or caress. The thalamus is able to localize such sensations to some extent, but the cerebral cortex must come into play to pinpoint the precise location of the touch. Such subtle discrimination is performed in the sensory area of the cortex. So, when a mosquito lands on our skin, a precise blow follows immediately, even without looking at the unfortunate insect. The accuracy of spatial discrimination varies depending on the location on the skin. We perceive as separate touches to two points on the tongue, separated from each other by a distance of 1.1 mm. In order for two touches to be perceived as separate, the distance between the stimulated points on the fingers must be at least 2.3 mm. In the nose, this distance reaches 6.6 mm. However, it is worth comparing these data with those obtained for the skin of the back. There, two touches are perceived as separate if the distance between them exceeds 67 mm.

In interpreting sensations, the central nervous system does not simply differentiate one type of sensation from another, or one site of stimulation from another. It also determines the intensity of stimulation. For example, we easily determine which of two objects is heavier if we take one in each hand, even if these objects are similar in volume and shape. A heavier object presses harder on the skin, more excites the pressure receptors, which in response are discharged with more frequent volleys of impulses. We can also weigh these items by moving them up and down alternately. A heavier object requires more muscular effort to overcome the force of gravity with movements of the same amplitude, and our proprioceptive sense will tell us which hand develops more force when lifting its object. (The same applies to other senses. We distinguish between the degree of heat or cold, the intensity of pain, the brightness of light, the volume of sound, and the strength of smell or taste.)

Obviously, there is a certain threshold of distinction. If one object weighs 9 ounces and the other 18, then we can easily determine this difference even with our eyes closed, simply by weighing these objects on the palms of our hands. If one object weighs 9 ounces and the other 10, then we will have to "shake" the objects on our hands, but in the end the correct answer will still be found. However, if one item weighs 9 ounces and the other weighs 9.5 ounces, then you probably won't be able to tell the difference. A person will hesitate, and his answer can be equally likely to be right or wrong. The ability to distinguish the strength of stimuli lies not in their absolute difference, but in their relative difference. A difference of 10%, rather than an absolute difference of one ounce, plays a role in distinguishing between objects weighing 9 and 10 ounces, respectively. For example, we won't be able to tell the difference between a 90 ounce and a 91 ounce item, even though the difference in weight is the same one ounce. But we can easily catch the difference between items weighing 90 and 100 ounces. However, it will be quite easy for us to determine the difference between the weights of objects if one of them weighs one ounce and the other one and a quarter ounce, although the difference between these values is much less than one ounce.

In another way, the same thing can be said like this: the body evaluates the difference in the intensity of any sensory stimuli on a logarithmic scale. This law is called the Weber-Fechner law, after the names of two German scientists - Ernst Heinrich Weber and Gustav Theodor Fechner, who discovered it. By functioning in this way, the sense organs are able to process a greater range of stimulus intensities than would be possible with their linear perception. Suppose, for example, that some nerve ending can discharge twenty times more often under maximum exposure than under minimum. (Above the maximum level of stimulus causes nerve damage, and below the minimum level, there is simply no response.) If the nerve ending responded to stimulation on a linear scale, then the maximum stimulus could be only twenty times stronger than the minimum. When using a logarithmic scale - even if you take 2 as the base of the logarithm - the maximum frequency of discharges from the nerve ending will be reached if the maximum stimulus is two to the twentieth power of the minimum. This number is approximately one million.

It is due to the fact that the nervous system works according to the Weber-Fechner law that we are able to hear the thunder and rustle of leaves, see the sun and barely noticeable stars.

Tactile Sensations Tactile sensations are a form of skin sensitivity due to the work of two types of skin receptors: nerve plexuses surrounding hair follicles and capsules consisting of connective tissue cells. The sensations caused by touch, pressure, vibration, the action of texture and extension have a different character.

Psychological Dictionary. 2000 .

See what "Tactile Sensations" is in other dictionaries:

tactile sensations- Etymology. Comes from lat. tactilis tactile. Category. Form of skin sensitivity. Specificity. The sensations caused by touch, pressure, vibration, the action of texture and extension have a different character. Due to work...

The same as tactile. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910 ... Dictionary of foreign words of the Russian language

- (or tactile) see Touch, Skin ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

- ... Wikipedia

Sensation (English sensation) is a mental reflection of the properties and conditions of the external environment, arising from direct impact on the sense organs, a differentiated perception by the subject of internal or external stimuli and stimuli during ... ... Wikipedia

SENSATIONS TACTILE- (English tactile sensations) one of the types of skin sensitivity. O. t. include sensations of touch, pressure, vibration, texture and length (reflection of the area of the mechanical stimulus). Their occurrence is associated with the activity of 2 ... ... Great Psychological Encyclopedia

Kinesthetic body sensations- Tactile sensations and internal senses, such as recalled impressions and emotions, as well as a sense of balance. In NLP, this term is used as a collective name for all sensations, including tactile, visceral (in the internal organs) ... ... Great Psychological Encyclopedia

Books

Tactile sensations, Sergey Slyusarenko. If one day you feel that the pen is slipping out of your hands, that familiar things have become alien, that everything around you is annoying - this is not necessarily crazy. Maybe you are on...
Tactile sensations, Slyusarenko S.S. If one day you feel that a fountain pen is slipping out of your hands, that familiar things have become alien, that everything around is annoying - this is not necessarily crazy. Maybe you are on...