Social touch and allostasis

Interoception, the sense of the body’s physiological state, incorporates information from the skin. Both interoceptive input and social/affective touch are conveyed to the central nervous system through small diameter, unmyelinated afferent fibers that ultimately converge on the posterior insula. This relation is traceable developmentally to the heavy reliance of the fetus and infant on their mother/caregiver for autonomic regulation. Caregiving alleviates homeostatic/allostatic imbalances such as cold, hunger, and pain, and is delivered in the context of social touch. The predictive sensorimotor loops that characterize the interplay between interoceptive and visceromotor signals are initially a shared system between infant and caregiver. With development, autonomic regulation becomes more autonomous, but with residual dependence on social contact to continue to maintain allostasis.