Sensations, their types. Concepts of sensitivity, absolute and relative thresholds of sensations

What are sensations

First, let's consider what sensation means for a person. This is, first of all, a psychophysical process of reflecting the direct action of objects and phenomena of the material world on the senses. It is with their help that a person learns about the world around him. This is how we can give the concept of sensations, the patterns of which reveal to us how, with the help of analyzers, a person cognizes and establishes a connection with the environment.

An analyzer is an anatomical and physiological apparatus that receives the influence of any stimuli from the outside world and converts them into sensations. It consists of the following parts:

• Peripheral section - receptors.
• Sensory nerve pathways.
• Central division of the nervous system.

Next, we will consider the types and properties of sensations.

Adaptation

Adaptation is the body’s getting used to the influence of certain stimuli. Kinds:

1. Complete loss of sensation due to prolonged, intense exposure to irritants.
2. Dulling of the senses due to strong exposure to external stimulants.
3. Increased sensitivity due to weak exposure to unpleasant factors.

In psychology, several thresholds are identified, at each of which a person experiences different sensations from the influence of external stimulants. When studying them, you need to take into account a number of factors that influence the manifestations of feelings in order to understand what will happen in similar situations in the future.

Types of sensations

Depending on where the receptors are located, there are the following types of sensations:

• Interoceptive. They are located inside the body in tissues and organs and respond to changes occurring in them.
• Exteroceptive. Receptors are located on the surface of the body and respond to external influences.
• Proprioceptive. Receptors are located in muscles and ligaments.

Organic sensations correlate with objects in the external world. They are a source of volitional impulses, give rise to desires and are divided into types:

• Olfactory. Olfactory receptors are stimulated by gaseous substances.
• Visual. Visual receptors are involved.
• Flavoring. Taste buds are stimulated by chemicals in food.
• Auditory. Receptors of the auditory analyzer are involved.
• Tactile. Tactile receptors are stimulated by tactile stimulation.

Concept and essence

Sensitization is a psychological concept that explains the increased sensitivity of nerve centers. Similar phenomena occur under the influence of various stimuli.

Organs that perceive information from the outside world:

• tongue - taste sensations;
• skin - exposure to temperature, chemicals;
• eyes - collect information about the size, shape, color of objects;
• nose - sense of smell;
• interoceptive receptors - sensations emanating from internal organs;
• vestibular apparatus - determining the position of the body in space;
• ligaments, tendons, muscles - movement.

With the help of functional analyzers, a person collects primary information. It is then transmitted to individual elements where it is analyzed. After the initial processing, the highest evaluation of the data occurs, which occurs in the cerebral cortex.

Properties of sensations

Properties that are inherent in sensations:

• Quality. Determined by the qualities of the object that causes sensations. This is one of the characteristics of perception.
• Intensity. Depends on the strength of the stimulus and the sensitivity of the receptors. The quality and intensity of sensations are closely related.

• Duration. Depends on the strength and intensity of the effect, the state of the receptors and the duration.
• Localization. Any sensations have particles of the spatial location of the stimulator.

Having examined the types and properties of sensations, let’s move on to patterns. What is the relationship between analyzers that determines the development of processes in cognition and perception of the world?

Sensitivity

The sensitivity threshold is the relationship between the intensity of sensations and the strength of the irritating factor. Not every stimulus can cause sensations, so they are divided into several types.

Thresholds of sensations:

• Lower absolute. Characterizes how sensitive the analyzer is. These are barely noticeable sensations that are caused by the least force of the stimulus.
• Upper absolute. The lower the sensitivity threshold, the higher the sensitivity. The upper absolute threshold is the strength of the stimulus at which sensations are still preserved.
• Discrimination sensitivity threshold. This is a minimal increase in the strength of the stimulus, at which subtle differences become visible. For example, increasing or decreasing the sound.

Depending on what task a person faces, he uses certain thresholds of sensations. The physical stimulus may be above or below the threshold of sensation.

Device

The device represents a change in sensitivity during exposure to one stimulus. In this case, sensitivity thresholds will change. Regularities of sensations cannot exist without this property.

So, for example, we adapt by gradually entering cold water. Or we float our feet, getting used to the rising water temperature.

A high degree of adaptation in the receptors of the olfactory and tactile organs. Lower for the receptors of the auditory analyzer.

Adaptation to different aromas occurs at different speeds for everyone. Adaptation to pain may be detrimental to the body, but to a small extent it is inherent to the body.

The receptors of the visual analyzer are responsible for adaptation to light and darkness. Light adaptation does not require high sensitivity, which cannot be said about adaptation.

For adaptation, the relationship between the processes of excitation and inhibition in the cerebral cortex, where the main centers of all analyzers are located, is important. A phenomenon called sequential mutual induction is observed. It is worth noting that adaptation occurs in a conditioned reflex way.

World of Psychology

SENSITIVITY

Sensitivity
(English sensitivity).

1. In comparative psychology and animal psychology, Sensitivity is understood as the ability for an elementary form of mental reflection - sensation. It was with Ch., according to the hypothesis of A.N. Leontyev and A.V. Zaporozhets, the development of the psyche in phylogenesis begins. In contrast to irritability, the concept of “Sensitivity” uses the criterion of signaling: Sensitivity is the body’s reflection of such influences that are not directly biologically significant (for example, due to their energetic weakness), but can signal the presence (change) of other environmental conditions, which are vital (necessary or dangerous). Sensitivity allows you to direct (lead) the body to vital components of the environment or away from unfavorable and dangerous components of the environment. To provide Ch., special organs (receptors) are required that respond to biologically insignificant influences; a creature deprived of such organs must lose all reactions (including metabolic) to signal stimuli. Thanks to Ch., such behavioral effects arise as an anticipatory reaction (a reaction to an event that has not yet occurred) and a disproportionality of the reaction energy compared to the weak power of signal, biologically neutral stimuli. (B.M.)
2. In classical psychophysics, Sensitivity is the reciprocal of threshold. Like the rapids, Ch.m.b. absolute, difference (differential), etc. Psychophysical theories that deny the threshold principle of operation of sensory systems (see Classical theory of sensory continuity) use not a threshold as a measure of frequency, but some other indicators (see Coefficient d', Sensory threshold, Psychophysical model of signal detection theory).
3. Sensitivity (in the biological sense) is the ability of a living organism to “perceive” adequate and inadequate stimuli, responding to them. image: movement, conscious sensation, vegetative reaction, etc.; in a narrow sense, the ability of sensory organs and analyzers to respond to the appearance of a stimulus or its change.

A distinction is made between absolute and differential. Part 1 is understood as the ability to “perceive” stimuli of minimal magnitude (detection); 2nd - as the ability to “perceive” changes in a stimulus or distinguish between close stimuli. (K.V. Bardin.)

Psychological Dictionary. A.V. Petrovsky M.G. Yaroshevsky

Sensitivity

1. general ability to sense; Ch. appears in phylogenesis, when living organisms begin to respond to environmental factors that perform a signaling function in relation to influences that have direct biological significance;
2. in differential psychology and characterology - increased readiness for affective reactions;
3. in psychophysics, a quantity inversely proportional to the threshold of sensation. Accordingly, a distinction is made between absolute and differential (difference) Ch.

The classification of types of sensations coincides with existing classifications of sensations. Thus, there are types of Ch., differing in the degree of detail of the sensory analysis performed. Considering the nature of the stimulus, we can talk about Ch. to the action of mechanical, optical, chemical, temperature and other stimuli. The health of the body can be assessed not only on the basis of sensations, but also by changes in the course of various psychophysical processes.

As a rule, the result is slightly different indicators. For example, visual frequency, determined by the reaction of changes in the integral rhythms of the brain, turns out to be higher than frequency, assessed on the basis of the subject’s verbal report. In recent years, thanks to the use of new theoretical concepts (signal detection theory), more generalized definitions of frequency have appeared in psychophysics, independent of the concept of “threshold of sensation.”

Dictionary of psychiatric terms. V.M. Bleikher, I.V. Crook

Sensitivity is the body’s ability to perceive irritations coming from the external environment or from internal organs and tissues. The physiological basis of Ch. is the activity of analyzers, that is, the process of transmitting impulses that arise in connection with the influence of stimuli to the central nervous system. The classification of types of perception is based on a taxonomy of types of reception and associated subjective experiences. In this regard, a distinction is made between exteroceptors, which perceive stimuli from the outside, and interoceptors, which perceive stimuli arising in the body itself.

With more differentiated discrimination, they distinguish pain (nociceptive), visceral, gustatory, deep (proprioceptive), directional (based on some properties of the environment, orientation in space is formed, a certain direction is highlighted), discriminatory (discriminatory), differential (the ability to perceive differences in intensity stimuli), interoceptive, cutaneous, olfactory, proprioceptive, light, auditory, temperature, exteroceptive, electrodermal, complex (integrative perception of stimuli by receptors of various modalities).

According to H. Head [1920], a distinction is also made between the phylogenetically more ancient protopathic (Greek protos - first, primary, pathos - disease, suffering) and the phylogenetically new epicritic (Greek epikrisis - judgment, decision) part. The first is characterized by an increase in the threshold of perception, qualitative difference in perception from normal, diffuse nature of sensations caused by external stimuli; the quality of irritation is not differentiated clearly enough, but with a certain intensity of irritation they cause a sharp feeling of unpleasantness. Epicritic pain is characterized by a lower threshold of irritation, the ability to perceive light touch, precise localization of external irritation, and more perfect recognition of the quality of the external stimulus. The specified types of Ch., according to M.I. Astvatsaturov [1936], underlie the forms of emotions (see Emotions of form according to Astvatsaturov ).

Neurology. Complete explanatory dictionary. Nikiforov A.S.

Sensitivity is the ability to perceive irritations, to feel the impact on the receptor apparatus of endogenous and exogenous stimuli of various natures.

Vibration sensitivity - synonym: Seismosthenia. The ability to sense vibration.

Oxford Dictionary of Psychology

Sensitivity - The ability to have sensations, to be sensitive in any of the senses of the term, although senses 4 and 5 are usually implied.

subject area of ​​the term

COMPLEX SENSITIVITY - sensitivity based on the integration of the activity of receptors of different modalities; includes a sense of discrimination, two-dimensional, sense of localization and stereognosis; with undisturbed Ch. impulses arrive simultaneously along several receptor pathways

VIBRATION SENSITIVITY (eng. vibratory sense) - sensitivity to mechanical, primarily sound, vibrations acting on the skin. Vibration sensations differ from sensations of pressure and touch on the skin (see Tactile sensations). No specific receptors for V. h. were found.

There are several hypotheses about the nature of V. h. According to one of them, V. h. is a transitional form from tactile sensitivity to auditory sensitivity; The 2nd hypothesis interprets it as a submodality of proprioceptive sensitivity; 3rd - as sensitivity characteristic of all tissues of the body. The VHF range is very wide: from 1 to 10,000 Hz; The highest sensitivity is to frequencies of 200-250 Hz. A person distinguishes vibration frequency with an accuracy of 8-10%, and amplitude - up to 3-5 microns. V. h. is not the same in different parts of the body: the distal parts of the extremities, the skin of the neck, shoulder girdle and thigh are the least. With the help of V. h., a person, using special codes, can perform complex types of activities, for example, tracking. V. h. plays an important role in teaching speech pronunciation to the deaf.

Sensitivity of measurements is the ability of measurements to detect small changes in the dependent variable.

TEMPERATURE SENSITIVITY (English: temperature sense, thermal sense, thermal sense) - an afferent link of reflex reactions to maintain the thermal balance of the body and the environment, such as chills, changes in blood flow speed, sweating, etc.

Syn. thermal feeling. information about temperature is sent to the c. n. With. from specialized receptors. Receptors of pain, like pain receptors, are free endings of thin nerve fibers. They are located in the second sensitive layer of skin between the keratinized debris and subcutaneous tissue. Nerve endings are located in both hairy and hairless areas of the body. In the second case, they end in capsules consisting of connective tissue. However, as studies show, T. h. is equally high in both cases. Therefore, the question of the mechanism underlying temperature sensations is not completely clear. See Receptors, Reception, Somesthesia.

SENSITIVITY SIMPLE - includes extero-, intero- and proprioceptive sensitivity, i.e. in each case, impulses arrive through only one receptor pathway (see Interoception, Proprioception, Exteroception)

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Sensory contrast and synesthesia

If sensations, their intensity and quality change under the influence of a preliminary or accompanying stimulus, then this can be called a contrast of sensations.

After a cold drink, a warm one will seem hot to us. And after sour, barely sweet, very sweet. Likewise, on a black background, light appears lighter, and on a white background, darker.

This is explained by the fact that a sharp cessation of the influence of the irritating factor does not cause an immediate cessation of irritation processes in the receptors. If we recall the law of induction, then the process of inhibition in excited neurons occurs gradually over time. In order to restore the original sensitivity threshold, several phases of excitation and inhibition of the induction shift must pass.

Synesthesia is when, as a result of the influence of one stimulus, sensations characteristic of another arise. So, hearing one sound, we imagine a certain image. Artists create paintings by translating music into colors. But not all people have such abilities. Synesthesia shows us that all the analytical systems of the human body are interconnected.

The properties and patterns of sensations emphasize the dependence and significance of analytical systems on their functioning under the influence of stimuli.