Significance of the Polyvagal Theory in Psychosomatic Correlation

Abstract

Because psychosomatic correlation is redefined as a bidirectional interrelationship between the center of the brain and the periphery of the body, the significance of the function of the autonomic nervous system (ANS) as a mediating variable for this relationship is gaining renewed attention. From this perspective, the “polyvagal theory” presents a novel view of the ANS through psychophysiological studies of the heart. Based on the anatomical fact that the efferent pathway of the vagus nerve is divided into two sections in mammals, the ANS is considered to exist as three components: the dorsal vagus complex, sympathetic nervous system, and ventral vagus complex. This theory shows that (1) there are two types of defense reactions: the mobilization system of the “fight or flight” system through the sympathetic nervous system (SNS), and the immobilization system of “freezing” to “collapse” through the dorsal vagal complex; and (2) the social engagement system of a “feeling of safety” through the ventral vagal complex presents a unique social function at the autonomic level and contributes to the elucidation of the mechanisms of (1) “onset” and (2) “recovery” of stress and trauma. This article examines the significance and challenges of this approach to psychosomatic correlations.