Ageing 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.

衰老伴随着触摸灵敏度和敏锐度的持续下降。相反，例如在抚摸期间所经历的令人愉悦的触感在老年时甚至更加令人愉悦。有许多生理变化可以解释这些知觉变化，但是研究人员尚未发现任何特定的机制。在这里，我们回顾了与老化相关的触摸系统的感知性和结构性变化。结构变化包括老年人皮肤弹性降低，以及皮肤触觉受体数量减少和形态改变。衰老对周围和中枢神经系统的影响包括脱髓鞘，其影响神经信号的时间，以及减少周围神经纤维的数量。衰老的大脑还经历着血液流动，新陈代谢，可塑性，神经递质功能以及（对于触摸）主要体感皮层的人体图。尽管有几项研究试图寻找知觉和结构变化之间的直接联系，但事实证明，这令人惊讶地难以捉摸。我们还强调，需要更多的证据来证明与年龄相关的多毛皮肤周围神经功能的变化以及触摸的社会和情感方面。