Interpersonal tactile stroking stimulation activates different peripheral nerve fibers, especially C-tactile afferents, which encode pleasant and erotic sensations. Hence, humans typically stroke close interaction partners with velocities that are suited to stimulate C-tactile afferents in the touch receivers’ skin. We aim to replicate this finding and we furthermore hypothesized that humans adjust their stroking velocity depending on the relationship with the interaction partner. We tested 60 participants in total (29 men, 31 women, mean age 23.3 years ± 3.6 years SD). They were asked to stroke their partner, their friend, a female stranger, a male stranger, an artificial arm and a table. Stroking was recorded by a video camera and each participant rated the emotional closeness to and attractiveness of each human interaction partner. In addition, we determined the velocity that each participant preferred to be stroked with in a forced choice paradigm. The participants stroked other humans slower and more in the optimal range for C-tactile fiber activation than non-humans. The stroking velocity was related to ratings of sympathy. The participants did not adjust their stroking velocities towards the stimulation they preferred for themselves. In conclusion, our study reaffirms that interindividual stroking touch is targeted to activate C-tactile fibers in the touch receiver. Furthermore, humans adjust their stroking velocity according to sympathy and interindividual attraction.

中文翻译：

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情感亲密感对个体间接触的影响

人际触觉刺激会激活不同的周围神经纤维，特别是C触觉传入神经，这些传入神经会产生愉悦的色情感觉。因此，人类通常以适合于刺激触摸接收器的皮肤中的C触觉传入的速度来敲打紧密的交互伙伴。我们旨在复制这一发现，并进一步假设人类会根据与互动伙伴之间的关系来调整其抚摸速度。我们总共测试了60名参与者（29名男性，31名女性，平均年龄23.3岁±3.6岁SD）。他们被要求抚摸他们的伴侣，朋友，一个女性陌生人，一个男性陌生人，一只人造手臂和一张桌子。通过摄像机记录抚摸，每个参与者对每个人类互动伙伴的情感亲密程度和吸引力进行评估。此外，我们确定了在强制选择范式中每个参与者喜欢被抚摸的速度。与非人类相比，参与者在C触觉纤维激活的最佳范围内抚摸其他人类的速度更慢，幅度更大。抚摸速度与同情程度有关。参与者并没有根据自己喜欢的刺激调整他们的抚摸速度。总而言之，我们的研究重申了个体的笔触触摸旨在激活触摸接收器中的C触觉纤维。此外，