Elucidating what significance
touching one’s skin has through brain science research

Shiseido researchers in collaboration with those of Tokyo Metropolitan University investigated the neural mechanism and clarified neural substrates of the psychological and physiological significance of touching one’s skin by either oneself or others, using fMRI. These studies showed that touching one's own skin by oneself, or “self-touch,” makes oneself feel a secure feeling and promotes the self-awareness^*1, whereas the somatosensory information is adequately adjusted, depending on its emotional value (pleasant vs. slightly unpleasant) while being touched by others, or “passive touch”^*2. These findings suggest that skin-touch during skin-care by oneself or beauty treatments by others has an important psychological and physiological significance, because it not only helps maintain the health and beauty of one’s own skin, but also protects oneself from stress and anxiety, leading to one’s stable and comfortable state. These findings have been published as the academic papers and books, and presented at many academic conferences.

In this experiment, fMRI was used to measure and analyze the brain activity while participants softly stroked the back of their own left hand with their own right hand, with simple movements. As a result, deactivation was observed in multiple brain regions. These brain regions included the anterior cingulate cortex (ACC) and the amygdala, both of which are involved in the sympathetic activity^*3 associated with attention, emotion, and vigilance, and the rostral ventromedial medulla (RVM) which is involved in the blood pressure increase. These results suggest that touching one’s own skin by oneself has an effect of decreasing the sympathetic activity and adequately adjusting attention and vigilance towards the outside world, leading to one’s secure state.
Moreover, it was also found that the RVM activity is more decreased in individuals who showed higher temporal synchronization of the left and right SII activities. In addition, this synchronization was found to modulate the temporoparietal junction (TPJ) which plays an important role in the physical self.
When you are nervous in stressful situations, you may notice yourself unintentionally touching your own hair or cheeks. These fMRI studies clarified the brain mechanism underlying such unconscious and automatic behaviors. They are considered to have an essential role for the self-protection. That is, self-touch makes one feel a secure feeling and, at the same time, promote the self-awareness, leading to the return to one’s true self.
These findings suggest that touching one's own skin in daily skin care not only keeps the skin healthy, but also has an important role for confirming one's true self.

Here, brain activity was investigated while participant’s back of left hand was stroked by an aesthetic practitioner in two ways with different emotional values (pleasant vs. slightly unpleasant).
It was suggested that the pleasant stroking increased activity of the orbitofrontal cortex (OFC) involved in reward evaluation, including that of love, and beauty, etc., and decreased activity of the anterior cingulate cortex (ACC) involved in the sympathetic activity such as vigilance, and pain, etc.
Furthermore, it was found that there might be a kind of gate function mechanism; the somatosensory inputs were facilitated under the "pleasant" condition, whereas they were suppressed under ever the slghtly "unpleasant" condition. This gate mechanism is considered to be included in the well-known “descending pain inhibitory system”*4; the incoming sensory information is adequately regulated, based on the evaluation of its emotional or reward value In both of the OFC and ACC which are involved in pleasant evaluation and unpleasant evaluation, respectively.
Softly stroking by others makes one feel pleasant and comfortable, ease one’s mind, increase one’s feeling of security, and, at the same time, enhance the sensitivity of one’s own skin.