Marked C‐tactile afferent suppression by a plastic film does not proportionately diminish pleasantness of gentle brushing

Abstract

C‐tactile (CT) afferents have been proposed to play a key role in signalling the pleasant aspects of gentle touch, and individuals with hereditary disorders affecting CT function exhibit abnormal affective touch perception. We previously demonstrated that applying a thin elastic film to the skin alters the perceived pleasantness of brush stroking. Here, we investigated how a thin elastic film modulates responses in unmyelinated CT and myelinated low‐threshold mechanoreceptors. Using microneurography in human subjects, we found that the film markedly suppressed firing in CT afferents during gentle brushing. Likewise, myelinated low‐threshold mechanoreceptors generally showed a robust reduction in brushing responses following film application. In contrast, psychophysical measures revealed only a modest reduction in perceived touch pleasantness. Despite pronounced suppression of peripheral afferent activity, the perceptual effect remained limited. These findings suggest that the relationship between CT activity and pleasant touch perception may be more limited than often assumed, highlighting an important contribution of central processing. image