Sensitization

The sensitization is strengthening of sensitivity of nerve centers under the influence of an irritant. Increase in sensitivity can happen in the course of expectation of a significant signal, acquisition of experience or as a result of exercises. It can be caused by specific requirements of activity or arise owing to compensation of touch defects. The high susceptibility of an eye of the artist to proportionality of forms and coherence of flowers and shades can be an example of a sensitization in the first case. In the second is a sharpening of hearing and remote sensitivity to obstacles at blind people.

The sensitization, adaptation and synesthesia are directly connected with changes of sensitivity of analyzers and belong to qualitative characteristics of feelings.

Sensitization of feelings

The sensitization of feelings represents sensitivity increase which happens under the influence of the following internal factors:

• System operation of analyzers and their interaction. At low intensity of feelings of one modality feelings of other modality amplify. For example, at insignificant cooling of skin the light sensitization appears;
• Pharmacological impact on an organism. Administration of various substances, such as adrenaline or Phenaminum, causes an essential sharpening of sensitivity of receptors;
• Mental set. Expectation of any event, especially significant, is capable to adjust of more accurate perception of irritants. So the forthcoming visit of the stomatologist can provoke strengthening of a dentagra;
• The gained experience. In the course of performance of this or that activity certain touch systems gradually develop. It is possible to give experienced tasters who carry out the touch analysis on almost inaudible nuances, or the musicians distinguishing aurally the relative duration of notes as an example of a sensitization.

Decrease in sensitivity of others can result from strong excitement of one analyzers. Desensitization is characteristic, for example, of workers of industrial workshops as high noise level worsens sight a little.

The compensatory sensitization arises at oppression or lack of different types of feelings when this shortcoming is compensated due to strengthening of a susceptibility of other analyzers. For example, hearing in the dark improves.

Sensitization and adaptation

If the sensitization is connected only with increase in sensitivity depending on psychological or physiological factors, then adaptation is caused by the environment and is characterized both by strengthening, and weakening of feelings. Adaptive abilities are shown, for example, at sharp change of level of lighting – some time that eyes adapted to darkness or bright light is required.

On degree of manifestation of feelings distinguish 2 types of adaptation:

• Anesthesia. Arises at long action of an irritant which leads to total disappearance of feelings. For example, during the day people do not feel touches of clothes or do not pay attention to a wedding ring;
• Obtusion of intensity of feelings. It is expressed as reaction to strong irritants. It can be accustoming to a pungent smell in medical institutions or in perfumery shop.

Synthesis of adaptation and sensitization is carried out when structuring the disorder elements. Painting close can look as chaotic color spots in which the picture becomes visible over time. In constant background noise it is also gradually possible to distinguish separate sounds. That is, in the course of accustoming to an intensive external irritant there is a possibility of its analysis, and the orientation of attention to separate elements promotes increase in a susceptibility to them.

Sensitization and synesthesia

Sensitization and synesthesia – closely connected properties of feelings. At sinestetichesky perception the irritation of one sense body is followed by the feelings corresponding to other body. The most widespread example of a sensitization with change of a modality is emergence of acid taste at the sight of a lemon. Also quite often there are visual objects during listening to music or reading. From the neurologic point of view this phenomenon is explained by what excitement of nervous structures irradiates from one modality in another therefore the set of sinestetichesky feelings – "color" hearing, "taste" of words, "smell" of color and other options is formed. The synesthesia is also considered a basis of metaphorical estimates and transfers.

The sensitization of feelings is capable to be shown by comparison of various irritants. For example, the light figure on a black background will seem white. The site of gray color on a green background will seem reddish, and on red – on the contrary, will get a green shade. Vertical lines seem more extended, than horizontal, with objectively identical length. Contrast of feelings is often beaten in advertizing, painting, in designs of clothes and an interior.

Researches show that the sensitization depends also on the following factors:

• Age. Increase of a susceptibility of receptors continues up to 30 years and afterwards slowly decreases;
• Type of a nervous system. The people with a weak nervous system who do not have endurance and stability are more predisposed to a sensitization.
• Endocrine balance of an organism. At pregnancy the sensitization of olfactory feelings is observed.

The temporary sensitization is caused by the brake condition of a cerebral cortex arising at overfatigue.

Perception participates in formation of behavior. Change of sensitivity of analyzers and interrelation of feelings provide receiving and information processing about the world around.