The Vagus Nerve and Occupational Therapy: A Foundation for Safety and Resilience

Occupational therapy has always understood something fundamental: people do their best learning, connecting, and participating in daily life when they feel safe in their bodies. Polyvagal Theory, developed by neuroscientist Dr. Stephen Porges, gives us a powerful, evidence-based framework to understand why safety matters so deeply—and how we can intentionally support it in our practice.

At its core, Polyvagal Theory explains the relationship between the autonomic nervous system, emotional regulation, social engagement, and our capacity to participate in meaningful occupations. Occupational therapists support how people feel, move, and engage in daily life, making this framework a natural fit for occupational therapy practice.

Understanding Polyvagal Theory & Its Impact on Regulation

Polyvagal Theory describes the autonomic nervous system as an organized, hierarchical system shaped by evolution to support survival. Rather than simply being “calm” or “stressed,” our nervous systems move through predictable physiological states, each associated with different patterns of feeling, behavior, and engagement. These physiological states have been represented by Deb Dana as a ladder:

1. Ventral Vagal Complex: Safety and Social Connection

The ventral vagal pathway supports the Social Engagement System. When this system is active, the body experiences safety. This state allows for eye contact, vocal prosody, curiosity, cooperation, play, digestion, and restorative processes. From an OT perspective, this is the state that supports learning, participation, and relationship-based therapy.

2. Sympathetic Nervous System: Mobilization

When the nervous system detects danger, sympathetic activation prepares the body for action - fight or flight. This may look like hyperarousal, impulsivity, anxiety, aggression, or constant movement. These responses are not behavioral “choices,” but adaptive survival strategies.

3. Dorsal Vagal Complex: Shutdown and Immobilization

When threat feels overwhelming or inescapable, the dorsal vagal system tends to take over. This can result in shutdown, dissociation, collapse, withdrawal, or reduced responsiveness. In therapy, this often presents as low engagement, fatigue, or appearing “unmotivated,” when in fact the nervous system is protecting itself.

Crucially, these shifts occur through neuroception—a subconscious process by which the nervous system continuously scans internal sensations, the environment, and relational cues to determine whether a situation is safe, dangerous, or life-threatening (Porges, 2004).

Why Polyvagal Theory Matters in Occupational Therapy

Polyvagal Theory reminds us that behaviour is often the nervous system responding to stress or feeling unsafe, rather than someone choosing to be difficult.

Occupational therapy already addresses sensory processing - how individuals receive, interpret, and respond to sensory information. Trauma, chronic stress, and neurodivergent sensory profiles can significantly alter autonomic regulation, contributing to patterns of hyper-arousal, hypo-arousal, or rapid state shifts. These patterns directly impact participation in daily activities, learning, relationships, and self-care.

A polyvagal-informed OT approach emphasizes:

• Bottom-up regulation, rather than relying solely on cognitive or behavioral strategies

• Creating environments and interactions that send consistent cues of safety

• Supporting flexible movement between nervous system states, rather than enforcing calm

  
  

When the nervous system feels safe and supported, stress responses calm down, making learning, connection, and participation easier (Porges, 1995; Porges et al., 2013).

The Safe and Sound Protocol (SSP): Polyvagal Theory in Action

One practical, evidence-informed application of Polyvagal Theory in occupational therapy is the Safe and Sound Protocol (SSP). SSP is a non-invasive listening intervention designed to support autonomic regulation through the auditory system.

SSP uses specially filtered music that emphasizes the frequency range of the human voice. This input supports the function of the middle ear muscles and acts as a neuroceptive cue of safety, directly stimulating the Social Engagement System and ventral vagal pathways (Porges et al., 2014).

In OT practice, SSP is typically integrated alongside sensory integration approaches, relational therapy, and functional goal-setting, rather than used in isolation.

What Does the Evidence Say?

Emerging research and clinical studies have documented meaningful outcomes associated with SSP, particularly in areas central to occupational performance:

Sensory Processing

Studies report reductions in auditory hypersensitivity, tactile defensiveness, and improvements in feeding, selective eating, and digestive function (Heilman et al., 2023; Porges et al., 2014).

Social and Emotional Regulation

Improved spontaneous speech, listening, social communication, and emotional regulation have been observed following SSP interventions (Porges et al., 2013).

Behavioural Organisation and Daily Living

Studies have reported that some children and adults experience improvements in flexibility, attention, and daily living skills, making everyday routines easier to manage (Rajabalee et al., 2022).

Mental Health and Trauma

Improvements in symptoms associated with anxiety, depression, and trauma - often measured using validated tools - have been noted in polyvagal-informed interventions (Kroenke et al., 2001; Spitzer et al., 2006; Weathers et al., 2013).

From Protection to Connection: Finding the "just right" fit

Polyvagal Theory fits closely with what occupational therapy is built on: people are more able to learn, participate, and feel well when they feel safe, connected, and supported.

By using polyvagal ideas and tools like the Safe and Sound Protocol, occupational therapists help the nervous system settle and feel safer. When this happens, people can become more flexible, regulated, and resilient in everyday life. Instead of expecting someone to “try harder” or “behave better,” therapy focuses on creating the conditions where the body feels safe enough for the person to engage and complete any "just right" challenges set in therapy and as a part of daily life.

If Polyvagal Theory or the Safe and Sound Protocol is something that you are interested in, please reach out and book an appointment via hello@enablemeoccupationaltherapy.com.

Alternatively, if you want to know more about Polyvagal Theory and Occupational Therapy practice, contact katie@enablemeoccupationaltherapy.com to purchase our on-demand evidence-based course.

References

• Dana, D. (2018). The Polyvagal theory in therapy: engaging the rhythm of regulation. WW Norton & Company.

• Heilman, K. J., Heinrichs-Graham, E., Ackermann, M., et al. (2023). Effects of the Safe and Sound Protocol™ on sensory processing, digestive function, and selective eating in autistic children and adults. Journal of Developmental Disabilities, 20(1).

• Kroenke, K., Spitzer, R. L., & Williams, J. B. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606–613.

• Porges, S. W. (1995). Orienting in a defensive world: Mammalian modifications of our evolutionary heritage. Psychophysiology, 32(4), 301–318.

• Porges, S. W. (2004). Neuroception: A subconscious system for detecting threat and safety. Zero to Three, 24(5), 19–24.

• Porges, S. W., Macellaio, M., Stanfill, S. D., et al. (2013). Respiratory sinus arrhythmia and auditory processing in autism: Modifiable deficits of an integrated social engagement system? International Journal of Psychophysiology, 88(3), 261–270.

• Porges, S. W., Bazhenova, O. V., Bal, E., et al. (2014). Reducing auditory hypersensitivities in autistic spectrum disorder: Preliminary findings evaluating the Listening Project Protocol. Frontiers in Pediatrics, 2, 80.

• Rajabalee, N., Kozlowska, K., Lee, S. Y., et al. (2022). Neuromodulation using computer-altered music in a child with functional neurological disorder. Harvard Review of Psychiatry, 30(5), 303–316.

• Spitzer, R. L., Kroenke, K., Williams, J. B., & Löwe, B. (2006). A brief measure for assessing generalized anxiety disorder: The GAD-7. Archives of Internal Medicine, 166(10), 1092–1097.

• Weathers, F. W., Litz, B. T., Keane, T. M., et al. (2013). The PTSD Checklist for DSM-5 (PCL-5). National Center for PTSD.