Past research highlights the importance of gentle social touch for health and well-being, with C-tactile (CT) afferents—specialized mechanosensory fibers that respond to slow, gentle stroking—playing a key role. However, how CT-relevant touch is processed by the brain and the neural mechanisms through which it supports affect and homeostasis remain largely unknown.

A reason for this is that studying touch experimentally, particularly by contrasting different mechanosensory systems, poses significant technical challenges. Our group has addressed these by designing an EEG-compatible social touch robot. This innovation led to the discovery of an event-related potential component, the sN400, which appears uniquely tied to CT signaling. Its response properties differ from other somatosensory indexes like Rolandic rhythms, which are linked to mechanoreceptors other than CTs, are typically suppressed by touch, and show greater intra- and inter-individual variation.

In this talk, I will present our recent findings on the brain’s responses to gentle stroking, focusing on both CT and non-CT mechanosensory signals. I will explain how these signals interact and, surprisingly, how non-CT signals play a critical role in shaping cortical representations of CT-relevant touch. These findings suggest that non-CT processes are as important as CT processes in mediating the affective and health-regulatory benefits of social touch.