This post discusses new research that has altered the perspective on Polyvagal Theory.
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Who is Betsy Leighton?
I’m a writer, blogger, and healer dedicated to helping individuals reconnect with their innate peace and wholeness by healing nervous system dysregulation. My personal experience with chronic illness called Mast Cell Activation Syndrome (MCAS) shapes my work, and my content offers tools to empower those with chronic illness to improve their well-being and take charge of their health.
I created the Sacred Self-Healing Method and am a trained and certified Safe and Sound Protocol provider, an author, blogger, and A Course in Miracles Teacher. I hold a Master of Divinity in Spiritual Counseling and am a trained spiritual mentor, with certificates in sound healing, aromatherapy, nutrition, and Sacred Deathcare. I offer a self-study certificate program in the Sacred Self-Healing Method, provide spiritual counseling and coaching, courses, and supported subscriptions for the Safe and Sound Protocol.
What is MCAS?
Mast Cell Activation Syndrome (MCAS) is a chronic condition that affects all organ systems. It can cause severe, disabling symptoms every day, including potentially fatal anaphylaxis.
The common triggers for MCAS are infections, toxic exposures including mold exposure and EMFs, trauma, concussions, and stress.
MCAS often occurs with other chronic conditions like Ehlers-Danlos Syndrome (EDS) and Postural Orthostatic Tachycardia Syndrome (POTS). Managing MCAS is challenging because many healthcare providers are unaware of it, and diagnostic tests can be unreliable. Treatments include antihistamines and mast cell stabilizers in the form of medications and supplements, along with avoiding triggers. Check out this post on managing MCAS.
What is new research saying about Polyvagal Theory?
A 2026 critique by 39 experts led by physiologist Paul Grossman claims that Polyvagal Theory (PVT) is scientifically untenable and inconsistent with established neurophysiology, evolution, and anatomy. Critics argue that PVT’s core claims regarding the autonomic nervous system are not strongly supported by evidence, creating a debate over its legitimacy.
Core Controversies and Criticisms:
- Scientific Untenability: Experts argue that PVT’s claims regarding autonomic organization and the vagus nerve are not consistent with established, peer-reviewed neurophysiology.
- Anatomical Misrepresentation: The critique challenges the distinction between the “dorsal” and “ventral” vagal systems, arguing that mammalian nerve distinctions are not as biologically distinct as PVT proposes.
- Evolutionary Inaccuracy:Â Critics dispute the claim that the dorsal vagal nucleus is exclusively an older, shutdown mechanism, while the ventral vagus is solely for social engagement, arguing that this represents a misconception in evolutionary biology.
- Misleading Evidence: The 39 experts, along with other researchers, argue that PVT misrepresents the scientific literature and lacks empirical backing for its central pillars.
- Clinical vs. Scientific Value: While many therapists find PVT useful for understanding trauma, critics suggest it functions more as a “clinically useful metaphor” than a valid scientific model.
How is Unyte responding to the new research?
Unyte Health, the creator of the Safe and Sound Protocol, in partnership with its Chief Scientific Advisor, Dr. Stephen Porges, is addressing the 2026 scientific controversy surrounding polyvagal theory by reaffirming its scientific validity, refuting critics’ misrepresentations of the theory, and introducing new practical applications.
Following the publication of a 2026 paper by 39 researchers declaring polyvagal theory “untenable” and unsupported by current neurophysiological evidence, Unyte and Porges have responded through formal academic rebuttals, framing the critique as a “straw man” argument rather than a valid scientific refutation.
Key Aspects of Unyte’s Response to the Controversy
- Formal Scientific Rebuttal: Porges, on behalf of Unyte, published “A Scholarly Response To Grossman Et Al.’S Evaluation Of Polyvagal Theory” in Clinical Neuropsychiatry. The response argues that critics (Grossman et al.) failed to engage with the actual, peer-reviewed formulation of the theory, instead attacking an outdated or reconstructed version.
- Clarifying Misrepresentations: Unyte is educating practitioners that the critique relies on “persistent category errors,” such as conflating neuroanatomy with neurophysiology, and erroneously claiming that PVT requires the vagal system to be exclusive to mammals.
- Advocating for “Science of Safety”: Unyte continues to emphasize that, despite the debate, the practical applications of PVT regarding “neuroception” (the nervous system’s detection of safety/danger) and the “science of safety” remain valuable for trauma treatment.
- Product Launch (Rest and Restore): Despite controversy, Unyte is expanding its polyvagal-informed product line by collaborating with Polyvagal Music LLC to launch the Rest and Restore Protocol, designed to target the dorsal vagal complex and complement the existing Safe and Sound Protocol (SSP).Â
How the Controversy Affects Unyte’s Products (SSP)
The controversy primarily focuses on the underlying biology of the vagus nerve’s branches, not necessarily the beneficial outcomes reported by users. Professionals still utilize Unyte’s Safe and Sound Protocol (SSP), and proponents argue that even if the theory is refined, the “bottom-up” auditory intervention remains a valuable clinical tool for nervous system regulation.
What does this mean for the Safe and Sound Protocol (SSP)?
The Safe and Sound Protocol (SSP) offers nervous system benefits by utilizing specifically filtered music to stimulate the vagus nerve, thereby calming the nervous system and enhancing auditory processing, despite ongoing scientific debates surrounding Polyvagal Theory. By “tuning” the nervous system toward safety, it reduces sensory oversensitivity, anxiety, and traumatic stress while improving emotional regulation and social engagement.Â
How the SSP Benefits Users Despite Theoretical Doubts
- Physiological Regulation:Â The protocol functions as a non-invasive acoustic vagal nerve stimulator, directly influencing the autonomic nervous system to reduce “fight-or-flight” responses, thereby improving calmness and decreasing anxiety.
- Auditory Processing Improvement:Â By filtering music to match human speech frequencies, the SSP helps “retune” the middle ear muscles, thereby reducing auditory sensitivity and enabling the brain to distinguish speech from background noise better.
- Improved Emotional Regulation: By increasing a sense of safety, users often experience improved regulation of emotions, less anxiety, and reduced trauma-related hypervigilance.
- Enhanced Social Communication: The stimulation helps individuals with Autism or trauma histories transition from a state of defensiveness to a state of engagement, improving social interaction and communication.
- Complementary Tool for Therapy: Many find that the SSP enhances other therapies by calming the system enough for the patient to better engage in verbal or behavioral work.
Even for skeptics of the underlying theory, the auditory stimulation and “safety cues” delivered by the music can act as a useful, calming intervention for stress, auditory sensitivity, and emotional regulation.
How the SSP has helped me
I never bought into Polyvagal Theory because it seemed too theoretically weak and confusing. So, for me, the newly aired doubts about Polyvagal Theory do not change my views on the Safe and Sound Protocol (SSP) in the least.
Before using the SSP, I was severely limited in my diet, my body was extremely inflamed, and I reacted to more environmental stimuli than anyone else I had ever encountered. After using the SSP for about 12 listening rounds over the past two years, I have cleared major trauma and made significant improvements in my health:
As I share in this post, my MCAS was triggered by a combination of gut dysbiosis (causing leaky gut), trauma from caregiving and repeated concussions, toxic mold exposure, and several chronic infections.
In 2024, I could only tolerate twelve foods. I worked hard to find different ways to prepare these ingredients, adding variety to my diet. After doing several listening rounds of the SSP, I can now eat everything except gluten, sugar, and garlic.
In 2024, I was taking over 40 supplements and medications. Today, I am taking only 12 supplements and medications. I consider my MCAS to be managed and in remission. I occasionally have SIBO symptoms if I get a bump on my head (because of my multiple concussions), but a quick refresher with the Safe and Sound Protocol (SSP) corrects that within a day.
In 2024, I also struggled to exercise regularly and often could only walk short distances due to pain and inflammation. Over the summer, I gradually built up my stamina so I could successfully solo backpack over 300 miles. My latest book tells the story of that journey, from being able to backpack only one mile at a time to completing a solo backpacking trip on the Superior Hiking Trail. You can read more about my solo backpacking exploits here.
The SSP has helped my clients!
In addition to my success with the SSP, I have many clients who have healed concussions, gut dysbiosis, and other chronic issues with the help of the SSP. Many of my clients report that the SSP has helped them become less reactive to everyday stressors and that they can now face changes that would have been too disruptive to their lives with greater ease. One of my clients said,
“Generally, I am noticing a more consistent awareness of my patterns to protect myself in everyday life. In real-time, I’m connecting the understanding that these patterns are no longer necessary. The patterns feel really old – possibly from early childhood or even before.”
Another client, JD, who moved across the country, said,
“The SSP helped support me through a transformative year of change. I could count on it working, despite the ambiguity. It has been helpful to have the SSP with me throughout this HUGE change. I was unaware of this move when I made the purchase. SSP has been a steady support.”
Another client said,
“Listening to this calming music each morning puts me in a good mood each day. The music is helping to keep me happy!”
Yet another client with sleep issues said,
“Last night I had a hard time sleeping, felt agitated, so I did the 30-second reset as you suggested to help stop my thoughts from looping. It seemed to work, and I was able to sleep.”
The bucket theory
The bucket theory simplifies understanding symptom reactions with MCAS. Imagine your body as an empty bucket you don’t want to overflow. Reactions to various stimuli fill the histamine bucket at different rates, forming the total histamine level (how full your bucket is). More histamine means more symptoms. By managing triggers, reducing exposures, and taking medications and supplements, you can control your bucket’s level.
Know your typical symptom progression
Understanding your symptom progression during a flare is key to developing your rescue plan. This post discusses how to recognize symptom progression so you can be prepared to address them.
Get my free ebook, symptom log, and meal plan!
Want a tool to easily track your symptoms?
Check out these circadian health tools!
I’m an affiliate with Bon Charge, a company that makes tools for circadian health, and you can receive 15% off your order with my coupon code BETSYL.
Bon Charge offers tools such as yellow– and red-tone blue-blocking glasses, red light therapy devices, PEMF mats, infrared saunas, and EMF-blocking products.
Sign up for the SSP!
I’ve found the Safe and Sound Protocol (SSP) to be the most helpful bottom-up healing strategy if your nervous system has been overloaded with toxic exposures, including mold or non-native EMFs, chronic infections, concussions, stress, or trauma. The SSP is a passive listening therapy that helps heal nervous system dysregulation. Many people with MCAS and other chronic conditions have nervous system dysregulation stemming from infections, toxic exposures, concussions, and trauma. The SSP is an easy-to-use app that lets you listen to specially filtered music for 30 minutes each day as part of a 5-hour cycle. Studies show the SSP has a profound effect on mental health and chronic conditions. Here’s a short podcast describing the Safe and Sound Protocol.
You can sign up for the SSP here!
Heal your mind!
While the SSP is a bottom-up, somatic therapy for healing the nervous system, the Sacred Self-Healing Method I offer is a top-down nervous system-healing modality that focuses on cognition, attention, perception, and emotion, using the mind’s higher functions. The SSP and the Sacred Self-Healing Method complement each other and together produce lasting results. Here’s a short podcast on my self-healing practice.
I provide one-on-one in-person and remote chronic illness and caregiver coaching, as well as Sacred Self-Healing Sessions based on the Sacred Self-Healing Method, a proven, novel co-creative healing modality detailed in my Books.
Order my books!
Here’s a short podcast highlighting my five books.
My latest book, Living In The Light: Healing with Forgiveness, Sound, and Light, is all about the tools that have been most helpful for me to heal: forgiveness, sound, through nervous system retraining using the Safe and Sound Protocol, and light, through entraining my circadian rhythm with the energy of the sun. Living In The Light is available here!
Rocks and Roots chronicles my solo backpacking journey on the Superior Hiking Trail and my efforts to overcome nervous system dysregulation, gut dysbiosis, and Mast Cell Activation Syndrome symptoms to complete the 328-mile hike successfully.
The Sacred Self-Healing Method ebook is available here and in most ebook retailers!
The Sacred Self-Healing Workbook is available for purchase here!
Betsy’s first book, Sacred Self-Healing: Finding Peace Through Forgiveness, is available here
Companion Recordings
The companion audio recordings of chants, guided meditations, and sound healing demonstrations that accompany the Sacred Self-Healing Method are available for free on my YouTube channel here
What do you think?
I’d love to have your reply below!
Disclaimer
The preceding material does not constitute medical advice. This information is for information purposes only and is not intended to be a substitute for professional medical advice, diagnosis, cure, or treatment.
