Research

Polyvagal Theory

Polyvagal Theory, developed by Dr. Stephen Porges, offers a framework for understanding how our autonomic nervous system responds to safety, danger, and life threat. It describes three major states:

Ventral Vagal: a state of safety, connection, and social engagement
Sympathetic Activation: the mobilization of fight-or-flight energy
Dorsal Vagal Shutdown: a state of collapse, numbness, or disconnection

These states shape our emotions, behaviors, and capacity to relate to ourselves and others. Though some aspects of the theory's anatomical and evolutionary claims are debated, its experiential map remains a valuable tool for supporting nervous system regulation and healing, by helping people map their experience and tracking shifts toward safety, connection, or overwhelm.

Stephen W. Porges, PhD. - Developer of Polyvagal Theory

Stephen W. Porges, Ph.D. is Distinguished University Scientist at Indiana University where he is the founding director of the Traumatic Stress Research Consortium. He is Professor of Psychiatry at the University of North Carolina, and Professor Emeritus at both the University of Illinois at Chicago and the University of Maryland.

His work integrates psychology, neuroscience, and evolutionary biology to understand how physiological states influence mental health and relational bonding.

https://www.stephenporges.com/about

Research by Stephen Porges:

"The Polyvagal Perspective" (2007)

With over 4,700 citations, this article provides an in-depth explanation of the Polyvagal Theory, focusing on how the vagus nerve supports adaptive reactions of the autonomic nervous system. It emphasizes the role of the "ventral vagal complex" in enabling social engagement and co-regulation

https://pmc.ncbi.nlm.nih.gov/articles/PMC1868418/

"The Polyvagal Theory: Phylogenetic Substrates of a Social Nervous System" (2001)

This paper explores the evolutionary underpinnings of the social engagement system, discussing how mammalian adaptations in the vagus nerve support behaviors like attachment and communication.

https://www.sciencedirect.com/science/article/abs/pii/S0167876001001623

“Orienting in a Defensive World: Mammalian Modifications of Our Evolutionary Heritage" (1995)

This foundational article introduces key concepts of Polyvagal Theory, such as the hierarchical organization of autonomic states and their role in survival and social behavior.

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-8986.1995.tb01213.x

"The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation" (2011)

This book consolidates Porges' research into a comprehensive framework for understanding how the autonomic nervous system influences emotional and social behaviors.

https://www.google.com/books/edition/The_Polyvagal_Theory_Neurophysiological/0-nxBGHj36oC?hl=en&gbpv=0

Deb Dana - Polyvagal Theory in Therapy

Deb Dana is a licensed clinical social worker, trauma specialist, and leading translator of Polyvagal Theory into clinical practice, known for creating the Rhythm of Regulation® framework to help individuals navigate autonomic nervous system states and resolve trauma. She authored foundational works such as “The Polyvagal Theory in Therapy”

“The Polyvagal Theory in Therapy: Engaging the Rhythm of Regulation” (2018)

Deb Dana's work emphasizes the Polyvagal Ladder, a metaphor illustrating the autonomic nervous system's hierarchical states (ventral vagal safety, sympathetic mobilization, dorsal vagal shutdown) and the necessity of moving through sympathetic activation to exit shutdown. Her concept "Story Follows State" highlights how autonomic states shape thoughts and behaviors, prioritizing nervous system regulation over cognitive interventions for trauma recovery

https://www.google.com/books/edition/The_Polyvagal_Theory_in_Therapy_Engaging/vzFeDwAAQBAJ?hl=en

Kindness and Compassion Practices and Nervous System Regulation

Feeling compassion is linked to increased vagal nerve activation, indicating that our bodies are physiologically wired to care for others

https://prevention.psu.edu/news/vid-exploring-the-new-science-of-self-transcendent-emotions/

“Further, Keltner shared that in a study done at the University of California, Berkeley, compassion was found to be linked to vagal activity. ‘When we get Berkeley students to feel compassion, they show elevated vagus nerve activation,’ Keltner said. ‘Our bodies are wired to care.’”

Compassionate behavior is associated with higher vagal tone, which is related to better physical and emotional well-being

https://greatergood.berkeley.edu/article/item/measuring_compassion_in_the_body

“Is there a biological fingerprint for compassion? Two scientific teams, one led by Zoe Taylor at Purdue and the other by Jenny Stellar at UC Berkeley, have found that the answer may lie in the Vagus nerve.”

Kindness and compassion have been shown to reduce stress and inflammation, potentially through the action of the vagus nerve and its influence on the inflammatory reflex

https://drdavidhamilton.com/loving-kindness-slows-ageing-at-the-genetic-level/

“Just as feelings of stress produce stress hormones (like cortisol and adrenalin), so feelings associated with kindness produce kindness hormones (like oxytocin, aka, the love drug, the cuddle chemical).

But exciting new research has taken things further. In a 12-week randomised controlled trial led by scientists at the University of North Carolina at Chapel Hill, researchers measured the length of ‘telomeres’ before and after 6 weeks of daily meditation practice.

In other words, feelings of kindness and compassion seem to slow ageing at the genetic level. This offers further evidence that kindness brings about effects that are physiologically opposite to stress, because stress is one of the ways that telomere loss speeds up.”

Effect of Kindness-Based Meditation on Health and Well-Being: A Systematic Review and Meta-Analysis

https://www.researchgate.net/publication/263518728_Effect_of_Kindness-Based_Meditation_on_Health_and_Well-Being_A_Systematic_Review_and_Meta-Analysis

“Kindness-based meditation (such as loving-kindness meditation and compassion meditation) showed evidence of benefits for the health of individuals and communities through its effects on well-being and social interaction.”

Meditation and Nervous System Regulation

Central and autonomic nervous system interaction is altered by short-term meditation

https://www.pnas.org/doi/10.1073/pnas.0904031106

“Meditation practices such as Integrative Body-Mind Training (IBMT)* have been shown to increase parasympathetic activity, as evidenced by higher heart rate variability (HRV) and reduced stress markers. This is linked to activation in brain regions like the anterior cingulate cortex (ACC), which regulate autonomic control.”

“These results indicate that after 5 days of training, the IBMT group shows better regulation of the ANS by a ventral midfrontal brain system”

*“IBMT primarily involves 3 components—body relaxation, mental imagery and mindfulness training” https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2017.00866/full

Neurobiological Changes Induced by Mindfulness and Meditation: A Systematic Review

https://pmc.ncbi.nlm.nih.gov/articles/PMC11591838

“Another important discovery regards the changes in the amygdala, a region associated with the processing of emotions, in particular fear and stress. Specifically, it has been determined that mindfulness can lead to a reduction in size and reactivity in the amygdala, which is in line with reports of reduced levels of stress and anxiety [49,50]. This downregulation of the amygdala is also associated with an improved capacity for the regulation of affective responses, leading to a calmer and more resilient mind [51].”

“Mindfulness also appears to connect more robustly and functionally across different brain regions. Functional magnetic resonance imaging (fMRI) studies have shown increased connectivity between the prefrontal cortex and the default mode network (DMN), which is a network of brain areas in self-referential thoughts and mind-wandering [52,53]. In meditators, activity in the DMN is lowered during meditation, which has been connected to a lesser degree of ruminations and mind-wandering, typical contributors to anxiety and depression [54,55].”

Trauma-Sensitive Meditation & Mindfulness

Meditation and mindfulness improve resilience and well-being by regulating the nervous system, reducing stress, and decreasing self-referencing. However, loosening the grip on self-identity and protective mechanisms can trigger underlying trauma, which is why trauma-informed practices are essential to ensure psychological and physiological safety, and create a supportive ecosystem for gradual unraveling of these protections.

The Cheetah House

https://www.cheetahhouse.org/mindfulness-trauma

Research led by Dr. Willoughby Britton (Cheetah House founder) at Brown University found that more than half of participants in Mindfulness-Based Programs (MBPs) reported some form of adverse effect, with 6–14% experiencing lasting negative effects. These can include perceptual hypersensitivity, emotional numbness, dissociation, and changes in sleep patterns.

Cheetah House and its collaborators highlight the importance of trauma-informed modifications to meditation practice. They recommend:

Recognizing that mindfulness may be contraindicated for some trauma survivors, especially if it leads to flashbacks, emotional overwhelm, or dissociation.
Adapting practices to keep individuals within their "window of tolerance" and allowing flexibility in how mindfulness is practiced (e.g., shifting attention, changing posture, or opening eyes during practice).
Educating practitioners and teachers on the signs of trauma and how to respond to distress in a way that avoids re-traumatization

Additional resource: https://casatondemand.org/2023/02/02/the-need-for-trauma-sensitive-mindfulness/

Meditation, Trauma and Suffering in Silence: Raising Questions about How Meditation is Taught and Practiced in Western Contexts in the Light of a Contemporary Trauma Resiliency Model

https://www.tandfonline.com/doi/abs/10.1080/14639947.2014.935264 (PDF)

Jane Compson’s 2014 article in the journal “Contemporary Buddhism” examines the potential psychological risks of meditation, especially for individuals with trauma histories, and critiques how meditation is often taught in Western contexts. She argues that while meditation has well-documented benefits, it can also lead to psychological distress if not taught or practiced with awareness of trauma and the body’s nervous system responses. Compson advocates for integrating trauma-informed approaches, such as the Trauma Resiliency Model (TRM), into meditation teaching and practice.

Gratitude Practices

Counting blessings versus burdens: an experimental investigation of gratitude and subjective well-being in daily life

https://pubmed.ncbi.nlm.nih.gov/12585811/

Focusing on gratitude (e.g., listing blessings) significantly boosts positive emotions and subjective well-being compared to fixating on hassles or neutral events.

The effects of gratitude interventions: a systematic review and meta-analysis

https://pmc.ncbi.nlm.nih.gov/articles/PMC10393216/

While effects on physical health were inconsistent, gratitude practices notably increased prosocial behaviors and life satisfaction across three experimental trials

Prayer and Chanting

Unpacking the Relationship Between Prayer and Anxiety: A Consideration of Prayer Types and Expectations in the United States

https://pmc.ncbi.nlm.nih.gov/articles/PMC9713100/

In examining the multidimensional nature of prayer and its effects on mental health, this study examines how the type of prayer matters. The results suggest that prayer efficacy (belief that prayer can solve problems) and prayers for support (requests for health, financial aid, etc.) correlate with higher anxiety, while devotional prayer (praise of God and prayer for others), and prayer expectancies (belief that God answers prayers) are associated with lower anxiety.

The neurophysiological correlates of religious chanting

https://www.nature.com/articles/s41598-019-40200-w

The study positions religious chanting as a practice that harmonizes evolutionarily ancient restorative mechanisms with modern cognitive processes, potentially offering mental health benefits through neural synchronization and stress recovery

Effect of Muslim Prayer (Salat) on α Electroencephalography and Its Relationship with Autonomic Nervous System Activity

https://pmc.ncbi.nlm.nih.gov/articles/PMC4086364/

This study investigates how Muslim prayer (salat) affects brain activity (EEG) and autonomic nervous system activity (HRV) in 30 healthy Muslim men. It found that during salat, there was increased alpha wave activity in the occipital and parietal regions of the brain, along with increased parasympathetic activity and decreased sympathetic activity based on HRV measurements. The study suggests regular salat practice may promote relaxation, reduce anxiety, and lower cardiovascular risk.

Yoga other Somatic Practices

Yoga and HRV (Vagal Tone)

Yoga’s HRV improvements support its use in cardiac rehabilitation and stress-related disorders, with specific asanas offering targeted autonomic modulation [1, 2]. However, responses vary by yoga style, with gentler practices generally showing more consistent parasympathetic benefits compared to physically intense forms [1, 3]

[1] Unlocking the mind-body connection: An HRV-based assessment of cardiac autonomic responses to yogic postures. https://www.ijcap.org/html-article/23879

[2] Yoga in school sports improves functioning of autonomic nervous system in young adults: A non-randomized controlled pilot study. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0231299

[3] Blood pressure and heart rate variability responses following an acute bout of vinyasa yoga and a prolonged seated control: A randomized crossover trial. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0294945

Effects of progressive muscle relaxation [PMR] on cerebral activity: An fMRI investigation

https://pubmed.ncbi.nlm.nih.gov/27261979/

“Results: […] PMR gradually decreased activity in the superior frontal gyrus (SFG), inferior frontal gyrus (IFG), and posterior cingulate cortex (PCC). In a region of interest (ROI) analysis, interactions between sessions were observed in the putamen, anterior cingulate cortex (ACC), postcentral gyrus (PCG), and insula.

Conclusions: That PMR led to few areas showing changed activity suggests that the technique may suppress brain activity. Even novices may be able to induce such a focused mental state.”

Quiet Mind and Inner Knowing

“How Enlightenment Changes Your Brain” (2016)

https://www.google.com/books/edition/How_Enlightenment_Changes_Your_Brain/Pye3CwAAQBAJ?hl=en&gbpv=0

Andrew Newberg's research identifies a neurological signature of enlightenment involving reduced activity in the parietal lobe (linked to self-perception) and frontal lobe (associated with analytical thought). His work suggests that practices inducing mental calmness (e.g., meditation, mindfulness) or even pharmacological agents like psychedelics may facilitate the neural "letting go" required for transcendent experiences, mirroring how relaxation fosters insight by quieting overactive cognitive processes.

“The Eureka Hunt: Why Do Good Ideas Come To Us When They Do?"

https://www.scribd.com/doc/4463595/ah-ha

Key findings include the role of the right hemisphere and prefrontal cortex in sudden problem-solving, the importance of relaxation (e.g., walks, distractions) over intense focus to trigger insights, and the counterintuitive need to avoid over-concentration for creative solutions.