Cosmetic after-feel modulates brain activity in sensory and reward networks: an fMRI study

The affective dimensions of cosmetic textures were investigated using functional magnetic resonance imaging (fMRI) to examine how after-feel, defined as residual tactile sensations persisting on the skin after product application, modulates sensory and emotional processing. Twenty healthy women took part in three conditions: no cream (control), cream A, or cream B, differing only in emulsifier composition. A fixed amount of cream was applied to predefined areas of the left hand. After absorption, participants stroked these areas at a controlled speed. fMRI data were acquired during this self-touch task, preprocessed using a standardized pipeline, and analyzed using a general linear model. Results showed that the no-cream and cream B conditions primarily engaged primary somatosensory regions, consistent with basic tactile encoding. In contrast, cream A additionally recruited brain areas involved in affective and reward processing, including the orbitofrontal cortex, amygdala, and putamen, with key reward-related responses, notably within striatal and insular regions, showing a right-hemispheric dominance contralateral to the hand receiving the tactile input. This broader activation pattern suggests that specific cosmetic ingredients can enhance the emotional salience of after-feel, potentially through C-tactile afferent pathways mediating affective tactile signals. These findings reflect a hierarchical integration of tactile input, from sensory encoding to higher-order affective appraisal. They highlight the potential of cosmetic formulations to influence central touch representation beyond surface-level sensation. This proof-of-concept study offers novel insights into how the sensory and emotional qualities of cosmetic products take shape in the brain, providing a neuroscientific foundation for the development of emotionally engaging textures.