What Is Polyvagal Theory and How Can It Help You Manage Stress and Trauma?
Episode 35: Behind the Therapy Door
This article draws on a conversation between therapists Sarah Thome and Matt Gallagher. Listen to the full episode for the stories behind the takeaways.
Your stomach drops before a difficult conversation. Your throat tightens when you try to speak up in a meeting. Your knees go weak when the phone rings at 2 a.m. These are not character flaws or anxiety disorders. They are your autonomic nervous system doing exactly what it was designed to do, and polyvagal theory explains why.
Related: About Sarah and Matt.
What Is Polyvagal Theory and Who Developed It?
Polyvagal theory was developed by neuroscientist Stephen Porges and describes how the vagus nerve (the largest nerve highway in your body, running from your brainstem to your major organs) governs three distinct nervous system states. It is not a cure. It is a framework for understanding why your body does what it does under stress, and that understanding alone can reduce shame and open the door to healing.
On Episode 35 of Behind the Therapy Door, Sarah Thome and Matt Gallagher break polyvagal theory into practical language and explain how they use it in their clinical practice with trauma clients, first responders, and everyday people navigating chronic stress.
Related: What is the Process Communication Model®?.
What Are the Three Branches of the Autonomic Nervous System?
Polyvagal theory identifies three branches, each with a distinct function and a recognizable set of physical sensations.
Your stomach drops before a difficult conversation.
Behind the Therapy Door
Ventral vagal (above the diaphragm): This is your social engagement system. When you are in ventral vagal, you feel safe, connected, curious, and creative. Your facial muscles are relaxed, your voice has natural prosody, and you can make eye contact without effort. This is where healing happens.
Sympathetic (fight or flight): This is your mobilization system. Heart rate increases, muscles tense, breathing becomes shallow. You are scanning for threats and preparing to act. This state is not inherently bad; it is what gets you out of danger. It becomes a problem when your body stays here long after the threat has passed.
Dorsal vagal (below the diaphragm): This is your shutdown system. When the threat is overwhelming and you cannot fight or flee, your system collapses into freeze, numbness, or dissociation. Energy drops. You feel flat, disconnected, or “gone.” In healthy doses, this branch also governs rest and digestion.
Related: Why does my anxiety get worse when I relax?.
How Does Trauma Get “Stuck” in the Nervous System?
Matt Gallagher makes a distinction that reframes everything for many clients: “The difference between grief and trauma is this: grief is about something that has happened. Trauma feels like it is still happening in the body.”
When a traumatic event overwhelms the nervous system’s capacity to process it, the body can get locked in a sympathetic or dorsal vagal state. The event ended, but the body does not know that. You may find yourself hypervigilant, easily startled, or chronically numb, not because something is wrong with you, but because your nervous system is still protecting you from something that is no longer there.
This is why talk therapy alone sometimes feels insufficient for trauma. You can understand your trauma intellectually and still feel it in your body. Polyvagal theory explains the gap.
Related: Why can’t I stop reliving the past?.
What Is Neuroception and Why Does It Matter for Therapy?
Neuroception is the autonomic nervous system’s unconscious scanning for cues of safety or danger. It happens below awareness: before you think, before you choose, your body has already decided whether the environment is safe. This is why you can walk into a room and feel uneasy without being able to explain why.
In therapy, neuroception means that genuine felt safety in the therapeutic relationship is a prerequisite for deep trauma work. If the client’s system does not register safety, regardless of what the therapist says, the body will not allow access to stored trauma. Sarah emphasizes that this is why the therapeutic relationship matters more than the technique.
Related: Why the therapeutic relationship matters more than the method.
“Grief is about something that has happened. Trauma feels like it is still happening in the body.”
— Matt Gallagher, LCPC
What Practical Techniques Help Regulate the Nervous System?
Sarah and Matt share several techniques they use in clinical practice to help clients shift between nervous system states.
Breathwork
Match your inhale to your exhale. Hold briefly. Exhale longer than you inhale. Direct your breath into the tightest areas of your body. This is not meditation; it is a physiological intervention that activates the ventral vagal branch.
Olfactory Grounding
Inhaling essential oils or smelling salts activates the olfactory nerve, which is the closest sensory pathway to the limbic system and bypasses the thalamus entirely. Sarah uses this technique to manage abreactions, the unexpected intense activation that can surface during trauma processing.
Visualization Modulation
Mute the sound. Strip the audio from your mental replay of the event. Sarah explains that removing the auditory component often reduces the emotional charge significantly, letting you process the visual memory without the full sensory overwhelm.
Physical Grounding
Feet flat on the floor. Change your posture. Stand up and move. These simple physical shifts can disrupt the “stuckness” of a dorsal vagal freeze response and restore a sense of agency in the body.
Brainspotting
Resource spots and activated spots provide two anchors the client can toggle between, building the capacity to shift states deliberately rather than being hijacked by them.
Related: What is the Process Communication Model®?.
How Does PCM® Personality Type Affect Nervous System Responses?
Different personality types experience nervous system activation differently. Sarah and Matt reference several patterns from their clinical practice.
- Persister energy: tends to plow through activation with intensity and self-criticism, doubling down rather than pausing
- Harmonizer base: often recognizes overwhelm only after too many people have crossed boundaries, leading to dorsal vagal collapse
- Rebel energy: may resist using calming tools and just want to stop feeling what they are feeling: “I hate this.”
- Persister-Thinker combination: struggles with stillness because productivity-driven wiring reads rest as failure
Understanding your personality type does not change your nervous system, but it helps you recognize which state you tend to get stuck in and why your default coping strategies may not be working.
Related: PCM® personality types overview.
Why Is Tolerating Stillness a Trainable Skill?
Both hosts challenge listeners to practice five to ten minutes daily of deliberate stillness: no phone, no podcast, no multitasking. Modern life’s constant stimulation erodes the capacity to sit in ventral vagal safety, which is exactly the state the nervous system needs for recovery.
Sarah puts it bluntly: if you cannot tolerate five minutes of silence, that is diagnostic information. It does not mean something is wrong with you. It means your nervous system has learned that stimulation equals safety, and it needs to relearn that stillness is not the same as vulnerability.
Can Talk Therapy Alone Resolve Stored Trauma?
Sarah and Matt are direct about this: talk therapy is incredibly valuable, but if you have been in supportive talk therapy for years and still feel stuck, you may need specialized trauma processing. EMDR, brainspotting, and somatic approaches target the stored physiological pain that talking about the event cannot reach.
Their recommendation: even if you love your current therapist, consider doing some sessions with a trauma specialist to clear stored pain, then return to your regular therapist. The two approaches complement each other.
The episode closes with a message of hope: trauma can be healed. The body that stored the pain is the same body that can release it, when given the right framework and the right relational safety.
Related: How do you know when therapy is done?.
Frequently Asked Questions
What is polyvagal theory in simple terms?
Polyvagal theory explains that your nervous system has three modes: safe and social (ventral vagal), fight or flight (sympathetic), and freeze or shutdown (dorsal vagal). Your body shifts between these states automatically based on cues of safety or danger, often below conscious awareness.
What is the vagus nerve and why does it matter?
The vagus nerve is the largest nerve highway in your body, running from your brainstem to your heart, lungs, and digestive organs. It regulates your stress response, heart rate, digestion, and social engagement system. Understanding it helps explain why stress shows up as physical symptoms.
Can polyvagal theory help with anxiety?
Yes. Polyvagal theory explains why anxiety feels the way it does in your body and provides practical techniques, including breathwork, grounding, and olfactory stimulation, for shifting out of sympathetic activation and into ventral vagal safety. It normalizes the experience rather than pathologizing it.
What is neuroception?
Neuroception is your autonomic nervous system’s unconscious scanning for cues of safety or danger. It operates below awareness and determines your nervous system state before your conscious mind gets involved. It explains why you can feel unsafe in a room without knowing why.
Is EMDR or brainspotting better than talk therapy for trauma?
They serve different purposes. Talk therapy builds understanding and coping skills. EMDR and brainspotting target the physiological storage of trauma that talk therapy may not reach. Many clinicians recommend combining both approaches for the most comprehensive healing.
Add PCM® to Your Clinical Toolkit.
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