Abstract:
Affective touch plays an important role in human social bonding, affiliative behavior, and in general emotional well-being. A system of unmyelinated low-threshold mechanosensitive C-type afferents innervating hairy skin (C-tactile or CT system) is postulated to provide the neurophysiological background of affective touch perception. C-tactile afferents respond optimally to soft and slow strokes, and this response correlates positively with pleasure ratings of tactile stimuli. As gentle touch is consistently associated with oxytocin release further promoting prosocial behavior, it has been suggested that this effect is mediated by the response of C-tactile afferents. This study assesses a possible link between CT-optimal touch, its subjective pleasantness, EEG indices of cortical arousal, and peripheral oxytocin response. EEG was recorded in 28 healthy volunteers during resting state and tactile stimulation[gentle slow brush strokes on forearm (CT-targeted touch) and palm (non-CT-targeted touch)]. Saliva samples were collected before and after the touch stimulation. Oxytocin concentration increase was significantly associated with greater subjective ratings of CT-targeted touch but not of non-CT-targeted touch, and with lower peak alpha frequency values indicating decreased cortical arousal. The findings suggest that CT-targeted stimulation triggers oxytocin release but only when the touch is perceived at an individual level as having clearly positive affective salience. This corresponds to previous studies reporting that oxytocin response to touch can be related to different personality factors, and bears important implications for planning touch-based interventions in social and medical care.
摘要:
情感触摸在人类社会纽带中起着重要作用,附属行为,和一般的情感幸福。假定无髓鞘低阈值机械敏感性C型传入神经支配毛状皮肤的系统(C触觉或CT系统)可提供情感触摸感知的神经生理学背景。C触觉传入神经对柔和和缓慢的中风反应最佳,这种反应与触觉刺激的愉悦等级呈正相关。由于温柔的触摸始终与催产素释放有关,进一步促进亲社会行为,有人认为,这种作用是由C触觉传入的反应介导的。这项研究评估了CT最佳触摸之间的可能联系,它的主观愉悦,皮层觉醒的脑电图指标,和外周催产素反应。在静息状态和触觉刺激[前臂(CT靶向触摸)和手掌(非CT靶向触摸)上轻柔的缓慢笔触]期间,在28名健康志愿者中记录了EEG。在触摸刺激之前和之后收集唾液样品。催产素浓度增加与CT靶向性触摸的主观评分显著相关,但与非CT靶向性触摸的主观评分无关。峰值α频率值较低,表明皮质觉醒降低。研究结果表明,CT靶向刺激会触发催产素释放,但仅当在个人水平上感觉到触摸具有明显的积极情感显着性时。这与以前的研究报告说催产素对触摸的反应可能与不同的人格因素有关。并对规划基于接触的社会和医疗干预具有重要意义。