The Effects of Ageing on Tactile Function in Humans

is accompanied by a steady decline in touch sensitivity and acuity. Conversely, pleasant touch, such as experienced during a caress, is even more pleasant in old age. There are many physiological changes that might explain these perceptual changes, but researchers have not yet identified any specific mechanisms. Here, we review both the perceptual and structural changes to the touch system that are associated with ageing. The structural changes include reduced elasticity of the skin in older people, as well as reduced numbers and altered morphology of skin tactile receptors. Effects of ageing on the peripheral and central nervous systems include demyelination, which affects the timing of neural signals, as well as reduced numbers of peripheral nerve fibres. The ageing brain also undergoes complex changes in blood flow, metabolism, plasticity, neurotransmitter function, and, for touch, the body map in primary somatosensory cortex. Although several studies have attempted to find a direct link between perceptual and structural changes, this has proved surprisingly elusive. We also highlight the need for more evidence regarding age-related changes in peripheral nerve function in the hairy skin, as well as the social and emotional aspects of touch. This article is part of a Special Issue entitled: The Neurobiology of Social and Affective Touch. (c) 2021 IBRO. Published by Elsevier Ltd. All rights reserved.

Automated summary

With age, there are changes in the perception and structure of the touch system, such as reduced skin elasticity, decreased numbers of skin tactile receptors, and demyelination of the nervous system. Despite attempts to find a direct link between perceptual and structural changes, it remains elusive.