How Does the Nervous System React to Safety?

Dr. Stephen Porches has developed a theory about how our nervous system can react to safety or lack of safety. He says there are three different systems that get activated when we feel threatened, but they're all designed to protect us from threat and danger. And he talks about something called immobilization without fear which is a sign of real safety. We want to maximize our green zone where we don't know what's going on in the world around us - so let's go through those different systems.