Suicidal adolescents may have had a low tactile sensitivity and responsiveness and a low emotional investment in the body because of mental pain influenced by internal and external sources such as loss [ 46], wounding in earlier family life and poor interaction with the parents [ 47].
Our results clearly show that a lower skin temperature leads to a decreased tactile sensitivity.
In an interesting study by Stiasny-Kolster et al. [ 57] a three- to fourfold increase in sensitivity for pinprick stimuli in untreated RLS-patients was found, along with a reduced tactile sensitivity and paradoxical heat sensation.
This is in line with a deterioration of tactile sensitivity as a result of decreased skin temperature found by Gescheider et al. (1997), Green et al. (1979) and Daanen (2009).
A host of tactile sensitivity information exists for other parts of the body, however the same information is lacking for the head.
A reduction in tactile sensitivity was not seen following capsaicin administration.
Since cave-adapted arthropods exhibit reduced eyes and elongated sensory antennae [ 1, 2, 8], the loss of eyes as a result of selection for increased tactile sensitivity is an attractive general hypothesis for the convergent evolution of eye regression in cave fauna.
In tyrannosaurids, a scaly facial integument in association with multiple rows of neurovascular foramina on the snout and jaws serves as a reliable proxy for tactile sensitivity in these giant predatory dinosaurs.
Structurally correlated with a high level of tactile sensitivity are certain anatomic features of the skin of the hands and feet, such as the absence of pads on the palms and soles and the presence of a finely ridged pattern of skin corrugations known as dermatoglyphics (the basis for fingerprints).
This effect was likely separate from any that may have occurred due to alkylamide's ability to evoke a numbing sensation, as tactile sensitivity was assessed within the first 5 min following lingual administration.
Fig. 1 a Schematic illustration of the tactile sensitivity tester, which consisted of a micrometer and sample stage.
