Sorry for the details, but while picking my teeth after a heavy dinner, I made an unexpected observation – tactile sensitivity and accuracy of touch at the tip of the tongue are higher than those of the fingers. Feeling my teeth with my tongue, I “see” them large, as if through a magnifying glass – much larger than with a similar palpation with my hands.
Maybe it seemed to me? I had to ask a couple of questions to Google…
In the psychological dictionary (article “Touch”), they mentioned the high sensitivity of the language:
A person is able to touch with the whole skin, however, the thresholds of touch in different areas vary widely. Thus, the thresholds for the sensation of touch are 2 for the tip of the tongue, 3 for the fingertips, 5 for the back of the hand, 48 for the lower back, and 250 g per mm2 for the soles.
And in the book “Psychology of the Blind and Visually Impaired” A. G. Litvak wrote about the high resolution of the language:
The spatial discrimination threshold of tactile sensitivity, or the acuteness of passive touch, is determined by the sensation of a separate touch of two stimuli. The spatial threshold is measured using Weber’s compasses and is calculated in millimeters according to the distance between the legs of the compass that simultaneously touch the skin. As well as absolute, discriminative thresholds are not unambiguous for different areas of the skin. The highest sensitivity (in millimeters) is possessed by the tip of the tongue – 1.1, the ends of the fingers -2.2, the lips – 4.5; and the smallest – neck – 54.1, hips and back – 67.4.
I was especially surprised by the high spatial threshold of the neck. I tried to test it, and began to poke myself in the neck, first with my fingers and then with toothpicks. But being both an observer and an observed introduces such a significant error into the results of the experiment that, as a result, I did not understand how rough and insensitive my surface is :)