The polyvagal theory 

Reviewed by Susan Radzilowski

What is the polyvagal theory? 

The polyvagal theory (poly meaning “many,” and vagal meaning “wandering”) explores the different parts of the nervous system and the body’s responses to stress. This theory considers how the vagus nerve—the longest nerve in the autonomic nervous system running from the brain stem to the colon—gives the mind and body their strong connection.  

The polyvagal theory was developed to examine the difference in human behavior and social skills when we feel safe versus when we are in danger. It may help provide insight into the symptoms associated with trauma and posttraumatic stress disorder (PTSD) triggers. 

Stephen Porges, PhD, currently a professor of psychiatry at the University of North Carolina, first presented the polyvagal theory in 1994. Porges’s theory makes psychological claims about the role of the vagus nerve in emotion regulation, fear responses, and social connection.  

Polyvagal theory diagram 

There are a number of versions of this popular diagram, which uses a color-coded mapping system (green, yellow, and red) to illustrate how the nervous system may respond to stress.  

According to the polyvagal theory, when arousal is low and the environment feels safe, the nervous system remains in the “green” zone, where optimal social engagement can take place. However, the nervous system may enter a fight-or-flight state once arousal rises.  

If arousal increases even more, the body may enter a frozen state. When a threat is no longer present, the nervous system returns to a safe, calm state. 

Neuroception explained 

Porges uses the term “neuroception” to explain the different ways in which the nervous system responds to cues of safety and danger. He stresses that neuroception occurs without our conscious awareness.  

However, bringing more awareness to the changes involved in neuroception, such as increased heart rate, collapsed posture, and changes in breathing, may help someone notice a shift in their nervous system. Once they observe these signs, they can begin to respond in a way that increases their sense of safety.  

The vagus nerve 

The vagus nerve, which transmits parasympathetic signals to and from the heart, lungs, and digestive tract, is composed of two branches: 

  • Dorsal vagus complex (DVC): According to the polyvagal theory, this branch is associated with primal survival strategies, causing some animals to “freeze” and become still when threatened. The DVC is also responsible for regulating our digestive processes.  
  • Ventral vagus complex (VVC): The polyvagal theory associates this branch with the regulation of sympathetic fight-or-flight behaviors, such as self-soothing and social communication.  

States of the nervous system 

The vagus nerve acts as the internal control center, regulating heart rate, blood pressure, sweating, and digestion. The polyvagal theory states that as the body takes in new information, the vagus nerve processes signals that dictate how a person reacts in three different states.  

1. Ventral vagal state 
According to the polyvagal theory, the ventral vagal state is considered the connection mode, or our “true self” state. During this state, nonstressful situations allow us to socialize and connect with others without fear.  

This state can look and feel like: 

  • A healthy immune system 
  • Adequate sleep 
  • Feelings of happiness and openness 
  • Emotionally relating to others 
  • A sense of calm 

2. Sympathetic state 
The sympathetic nervous system creates our reactions to stress. It is responsible for our fight-or-flight state, which causes us to confront or avoid a situation to find safety. 

The sympathetic state can look and feel like: 

  • A sense of threat 
  • Freezing to scan the surroundings 
  • A spike in heart rate  
  • Increased sweating 
  • Feeling anxious, scared, or angry 
  • Slowed digestion 
  • Increased blood flow to the muscles 
  • The need to run away or fight 
  • Focused senses  

3. Dorsal vagal state 
In this state, part of the parasympathetic nervous system causes us to shut down when an immediate threat is detected. Its purpose is to keep the body frozen or immobilized in order to survive and eventually fight or flee. 

The dorsal vagal state can look and feel like: 

  • Symptoms of dissociation  
  • Numbness, dizziness, and a sense of feeling trapped 
  • Decreased heart rate and blood pressure 
  • Nausea and vomiting 
  • Slowed breathing 
  • Tightness of the throat 
  • Difficulty speaking 
  • Loss of body awareness 
  • Collapsed posture 

The polyvagal theory in therapy 

Many different types of therapy employ elements of the polyvagal theory, including: 

  • Cognitive behavioral therapy (CBT): CBT focuses on reshaping negative thoughts to positively change behaviors and feelings, so people can improve their state of mind to find relief from anxiety, depression, and other mental health concerns.  
  • Dialectical behavior therapy (DBT): DBT teaches us how to focus on the present moment and cope with stress, regulate emotions, and improve relationships with others. The polyvagal theory gives more insight into the role of the body’s nervous system in achieving the goals of DBT. 
  • Psychodynamic therapy: Psychodynamic therapy involves talking freely with a therapist to explore past experiences and emotions and how they affect current behavior and thought patterns. The polyvagal theory can be applied in this practice to help someone understand their body’s response to certain triggers and which past experiences may be causing them. 
  • Eye movement desensitization and reprocessing (EMDR): EMDR is commonly used to help people recall past trauma and process the negative feelings it has caused. The polyvagal theory can be an important tool in EMDR by helping us understand how memories and experiences affect the body’s response and why.  

The Safe and Sound Protocol 
The Safe and Sound Protocol (SSP) is an evidence-based tool that uses music to stimulate the vagus nerve and calm the nervous system. The intention is for an individual to listen in 30- to 60-minute sessions over the course of 5 to 10 days. The SSP is based on the polyvagal theory and claims to support the listener’s emotion regulation and sense of safety, allowing them to improve their social engagement behaviors.  

Polyvagal theory exercises
These exercises are intended to help you track changes in your nervous system and practice techniques that help regulate the nervous system. Examples include diaphragmatic breathing, cold exposure, meditation, physical exercise, and singing. 

Criticism of the polyvagal theory 

Some experts point out a lack of scientific research to back the claims of the polyvagal theory. While the vagus nerve plays a role in transmitting emotion-related signals between the brain and the body, more evidence is needed to prove that it has any control over the body’s fight, flight, and freeze responses. Even so, the polyvagal theory can still help highlight the strong connection between the brain and body, despite potential overestimation of the vagus nerve’s superiority.  

Working with a professional therapist can help you better understand the mind-body connection and your stress responses. Look for a therapist near you today.