Department of Psychology, PhD Program in Behavioral Neuroscience, Sapienza University of Rome, Via dei Marsi 78, Rome, Italy.
Department of Dynamic and Clinical Psychology, and Health Studies, Sapienza University of Rome, Via degli Apuli 1, Rome, Italy.
Neurosci Biobehav Rev. 2021 Dec;131:88-95. doi: 10.1016/j.neubiorev.2021.09.026. Epub 2021 Sep 16.
The processing of hedonic aspects of touch, namely affective touch, is associated with the activation of C-Tactile (CT) fibers. CTs were thought to be present only in hairy skin, with glabrous skin being often used as control site in affective touch studies. Nevertheless, several articles comparing pleasantness perception across hairy and glabrous skin reported no significant differences. Surprisingly, CT fibers have also been recently detected on the glabrous palm, further questioning whether affective touch perception across both hairy and glabrous skin is comparable. The present meta-analysis thus aimed to quantify pleasantness perception of affective tactile stimulations on both hairy and glabrous sites. Pooled effect sizes (Hedges' g) from 18 studies were analyzed using random effect models. No systematic preference towards affective stimulations on hairy or glabrous skin was observed. Moreover, studies were highly heterogeneous, suggesting high variance in the results of the retrieved articles. Results were not affected by publication bias nor by other moderators. Variables affecting affective touch perception on hairy and glabrous skin and methodological considerations were discussed.
触觉愉悦方面的处理，即情感触觉，与 C 型触觉（CT）纤维的激活有关。CT 纤维被认为仅存在于有毛发的皮肤中，无毛皮肤通常被用作情感触觉研究的对照部位。然而，一些比较有毛和无毛皮肤愉悦感感知的文章报告称，两者之间没有显著差异。令人惊讶的是，最近也在无毛的手掌上检测到 CT 纤维，这进一步质疑有毛和无毛皮肤的情感触觉感知是否具有可比性。因此，本荟萃分析旨在量化情感触觉刺激在有毛和无毛部位的愉悦感知。使用随机效应模型对 18 项研究的汇总效应大小（Hedges'g）进行了分析。没有观察到对有毛或无毛皮肤的情感刺激有系统的偏好。此外，研究结果高度异质，表明检索文章的结果差异很大。研究结果不受发表偏倚或其他调节因素的影响。讨论了影响有毛和无毛皮肤情感触觉感知的变量以及方法学考虑因素。
