The threshold of distinction is characterized by the relative size, a constant for this analyzer. For the visual analyzer this relation makes about 1/100, for acoustical - 1/10, for tactile - 1/3 Experimental verification of this provision showed that it is fair only for irritants of average force.
For feelings spatial localization of an irritant is also characteristic. The spatial analysis which is carried out by distantny receptors supplies to us with the information on localization of an irritant in space. Contact feelings (tactile, painful, vkusova correspond that part of a tel which the irritant influences. Thus localization of pain happens poured and less exact, than tactile.
Just as the feeling does not arise along with the beginning of action of an irritant, it also does not disappear along with the termination of its action. This inertia of feelings is shown in a so-called after-effect.
The feeling is the elementary mental process consisting in reflection of separate properties of subjects and phenomena of a material world, and also internal states of an organism at direct impact of irritants on the corresponding receptors.
Various sense organs supplying to us the information on a condition of the outside world surrounding us can display these phenomena with a bigger or smaller accuracy. Sensitivity of a sense organ is defined by the minimum irritant which in these conditions is capable to cause feeling. The minimum force of an irritant causing hardly noticeable feeling is called as the lower absolute threshold of sensitivity.
The lower threshold of feelings determines the level of absolute sensitivity of this analyzer. Between absolute sensitivity and size of a threshold there is an inverse relationship: the less size of a threshold, the is higher sensitivity of this analyzer.
As feelings result from impact of a certain irritant on the corresponding receptor, classification of feelings proceeds from properties of irritants which cause them, and receptors which these irritants influence. On nature of reflection and the location of receptors it is accepted to divide feelings into three groups: