The polyvagal theory explains how the autonomic nervous system (ANS) regulates behavior and physiology in response to social and environmental stimuli through the different branches of the vagal system. The ANS, which is responsible for regulating unconscious processes like heart rate and digestion, has two main branches: the sympathetic and parasympathetic nervous systems.
According to the theory, the ventral vagal complex is associated with social engagement and safety and regulates physiological processes through the activation of the parasympathetic nervous system. This branch of the vagal system slows down the heart rate, increases digestive activity, and promotes relaxation, allowing us to engage in social activities like talking, listening, and touching.
On the other hand, the sympathetic and dorsal vagal complexes are associated with threat response and immobilization. When the body perceives a threat, the sympathetic nervous system is activated, resulting in an increase in heart rate, blood pressure, and respiration, as well as the release of stress hormones like cortisol and adrenaline. If the threat continues, the dorsal vagal complex may take over, leading to a freeze response characterized by decreased heart rate, decreased respiration, and decreased blood pressure, as well as decreased consciousness and mobility.
The polyvagal theory suggests that the functioning of the different branches of the vagal system influences our behavior, emotions, and physiological responses in a dynamic way, and that these responses can be modified through therapeutic interventions that target the ANS. By understanding the way the ANS regulates behavior and physiology, the theory provides a framework for understanding and treating conditions that are related to the regulation of the ANS, such as anxiety, depression, and trauma.
