Research on Polyvagal Theory: Nervous System Regulation

BY NICOLE LAU

The Psychology of Internal Locus: Why Most Suffering is Optional

Polyvagal Theory, developed by Stephen Porges, reveals the neurobiological foundation of internal locus: the feeling of inherent worth is tied to ventral vagal state - when your nervous system feels safe, you can feel your value. Trauma and chronic stress push the nervous system into defensive states (fight/flight or shutdown) where worth feels absent or threatened. Polyvagal-informed therapy restores safety and regulation, enabling the felt sense of inherent worth.

The Three States: Autonomic Ladder

1. Ventral Vagal: Social Engagement

State: Safe, calm, connected, present. The "rest and digest" state plus social engagement.

Felt Experience: You can feel inherent worth. You're grounded, open, curious. This is somatic internal locus.

Physiology: Calm heart rate, relaxed muscles, easy breathing, facial expressiveness, prosody in voice.

2. Sympathetic: Mobilization

State: Fight or flight. Activated, anxious, hypervigilant.

Felt Experience: Worth feels threatened. You're scanning for danger. This is somatic external locus - worth depends on controlling threats.

Physiology: Elevated heart rate, tense muscles, rapid breathing, narrowed focus.

3. Dorsal Vagal: Immobilization

State: Shutdown, collapse, freeze. The oldest survival response.

Felt Experience: Worth feels absent. Numbness, emptiness, disconnection. This is the somatic value vacuum.

Physiology: Slowed heart rate, low energy, shallow breathing, dissociation.

Neuroception: Unconscious Safety Detection

Definition: The nervous system's unconscious evaluation of safety vs danger. Happens before conscious awareness.

Three Neuroceptions:

- Safety: Triggers ventral vagal (can feel worth)

- Danger: Triggers sympathetic (worth feels threatened)

- Life threat: Triggers dorsal vagal (worth feels absent)

Implication: You can't think your way into feeling safe. The nervous system needs actual safety cues to shift into ventral vagal where worth can be felt.

Co-Regulation: Safety Through Connection

Concept: Nervous systems regulate each other. A regulated person helps dysregulated person return to regulation.

Connection to Development: Secure attachment is co-regulation. Caregiver's regulated nervous system helps infant's nervous system learn to regulate. This builds capacity to feel safe and worthy.

In Therapy: Therapist's ventral vagal state helps client's nervous system feel safe enough to process trauma and access inherent worth.

Why This Matters for Internal Locus

Worth is State-Dependent: You can't feel inherent worth when nervous system is in defensive states. Ventral vagal state is required.

Trauma Creates Chronic Defensiveness: Trauma keeps nervous system stuck in sympathetic or dorsal vagal. Worth feels constantly threatened or absent.

Healing Requires Safety: To build internal locus, nervous system needs to feel safe enough to access ventral vagal state where worth can be felt.

Polyvagal-Informed Interventions

Building Safety:

- Slow, regulated breathing (activates ventral vagal)

- Gentle movement, yoga

- Singing, humming, chanting (vagal nerve stimulation)

- Safe social connection

- Nature, beauty, play

Tracking State: Notice which autonomic state you're in. This builds awareness and choice.

Glimmers vs Triggers: Notice "glimmers" - moments that cue safety and ventral vagal. Build capacity to notice and savor these.

Research Applications

Trauma Treatment: Polyvagal-informed therapy focuses on building safety and regulation before processing trauma content.

Attachment Healing: Understanding co-regulation helps heal attachment wounds through new regulating relationships.

Chronic Illness: Many chronic conditions involve dysregulated nervous system. Polyvagal interventions support healing.

Why This Matters

Polyvagal Theory matters because:

1. It's neurobiological. The feeling of worth is tied to nervous system state. This is body-based, not just cognitive.

2. It explains trauma's impact. Trauma keeps nervous system in defensive states where worth can't be felt. This is why trauma creates external locus.

3. It guides healing. To build internal locus, create safety so nervous system can access ventral vagal state where worth is felt.

4. It's evidence-based. Decades of research validate Polyvagal Theory and its clinical applications.

The Bottom Line

Polyvagal Theory shows that the feeling of inherent worth is neurobiologically tied to ventral vagal state - when your nervous system feels safe, you can feel your value. Trauma and stress push the nervous system into defensive states where worth feels threatened or absent. Polyvagal-informed interventions restore safety and regulation, enabling the felt sense of inherent worth. This is the neurobiology of internal locus.

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This concludes the somatic and neurobiological research of Part III.

The Psychology of Internal Locus series explores why most psychological suffering is optional and how internal locus of value prevents it at the root cause.

— Nicole Lau, 2026