The dorsal vagal state

The dorsal vagal state is a state of the nervous system that shows itself through shutdown and withdrawal. When danger seems too great or escape is not possible, the nervous system can resort to this most primitive protection; the result is a feeling of numbness, heaviness, or turning inward. This state is not a choice but the body's last-resort protective response. The dorsal vagal state is associated with low arousal and withdrawal. This shutting down is one of the ways the system protects itself.