Co-Regulation: The Physiology of Trust

Co-Regulation. This one word embodies a brilliantly complex interpersonal process that is oftentimes easily described, but not fully understood. Co-regulation is essential to interpersonal relating and connecting with others. In our everyday lives, each of us encounters this process as we navigate a multitude of interactions and situations. But what is co-regulation?

Some have described it as an emotional energy exchange where one person is able to help another return to a calmer state by remaining regulated themselves. While there is truth in this description, it only begins to scratch the surface. As social creatures we experience rich complex emotional lives. However, our fast-paced world does not always lend us the opportunities to fully appreciate the emotional interplay that so often occurs when one person provides another with a deep sense of trust and security. Understanding this interpersonal process requires us to examine not only what happens in the space between two people, but to look even further within ourselves.

Polyvagal Theory explores how our own autonomic nervous system is the key to human social connectedness and regulation.1 When it comes to social engagement, safety and trust is at its foundation. Now being able to figure out whether or not we are safe may seem obvious at first but doing so actually goes far beyond what we can consciously perceive. Deep within us and well outside of our consciousness, lies the autonomic nervous system. You may be familiar with this system’s role in controlling bodily processes such as breathing, heart rate, and digestion, but according to Polyvagal Theory it also serves an adaptive purpose: to keep us safe.

Our nervous system is constantly assessing the environments and situations we encounter through a process called neuroception.3 euroception would not be possible without it’s key figure, the vagus nerve. Also known as the “wandering nerve,” it connects the lower part of the brain to the neck, chest, and abdomen and is the longest and most complex of all the 12 pairs of cranial nerves.”4 As we move throughout our environment and interact with others, the vagus nerve becomes stimulated and responds to cues of either safety or danger.Like a sixth sense, our neuroception begins to sense for us, before we can even realize and process what’s going on around us. “In fact, our nervous system uses information from those around to make its evaluations. For example, an individual’s facial expression and tone of voice are all clues that our nervous system uses to evaluate risk.”6

 What does our nervous system do with this information? Most of us have heard of the term “fight or flight” or maybe used the analogy of feeling like a “deer caught in the headlights.” Those simple sayings actually describe very real neural defensive processes which automatically come online in an attempt to protect us. “To accomplish this adaptive flexibility, the human nervous system retained two more primitive neural circuits to regulate defensive strategies (i.e., fight/flight and freeze behaviors).”7 However, if no threat is detected, our social engagement system, which in evolutionary terms is a newer neural system, becomes available.8 Our autonomic nervous system is then able to switch between defense and social engagement systems based on the processing of sensory information that is receives from both the environment and “viscera” or internal organs, specifically in the abdomen (think about when you get a “gut feeling.”) 9 At the autonomic nervous system level, the human experience is the same:  We must be in a safe environment to allow our nervous system the opportunity to inhibit or shut down it’s automatic defense systems. Once these systems are offline, so to speak, our heart rate begins to decrease as we experience safety, which in turn allows us to socially connect with others in order to experience a calming. 10

Regardless of how we communicate, at any moment during an interaction our autonomic nervous system can initiate these systems which serve to protect us. When this happens, our whole body essentially goes on alert and we begin to experience an increase in blood pressure, heart rate, and breathing.11 When this happens, our social engagement system which allows us to connect with others in order to calm and co-regulate is “inhibited” and unable to come online. Through Polyvagal Theory, Stephen Porges describes how feeling secure begins deep within our autonomic nervous system and that when safety is detected, our nervous system works to calm us. Interacting with a person whom you trust deeply, creates a safe environment. Our nervous system is hard wired to recognize the cues that represent safety all of which come from another person’s facial expressions and tone of voice. When we are in the presence of someone we know cares about us, we not only feel safe, we begin to build trust, especially when these experiences are repeated over and over with that same person.

These are the foundations of what is needed for our nervous system to calm via co-regulation. When a minimal speaker, nonspeaker, or unreliable speaker is spelling to communicate, not only are they working incredibly hard to maintain the connection between mind and body in order to initiate intentional motor movements, they are doing all of this while trying to maintain a regulated state. A regulated state supports greater focus and attention which can only be sustained if one’s autonomic nervous system is certain that they are in a safe and secure environment. Now perhaps we can truly begin to understand and appreciate why a trusted communication regulation partner (CRP) is so necessary for our spellers.

Finally, Stephen Porges offers the following: How does our society at large define safety as? If we consider Polyvagal Theory, what one person’s neurology detects as a threat, may not be what another’s neurology would consider a threat…What are the priorities of our culture and society in respecting individual needs for safety? We need to understand what features in the world disrupt our sense of safety and realize the cost to human potential of living in an unsafe world.12

1. Porges, Stephen W. (2009, April). The polyvagal theory: New insights into adaptive reactions of the autonomic nervous system. Retrieved November 23, 2019, from
2. Clarke, J. (2019, August 5). Polyvagal Theory and How It Relates to Social Cues. Retrieved November 23, 2019, from
3. Porges, S. W. (2009, April). The polyvagal theory: new insights into adaptive reactions of the autonomic nervous system. Retrieved December 13, 2019, from
4. Seymour, T. (2017, June 28). Vagus nerve: Function, stimulation, and further research. Retrieved December 13, 2019, from
5. Clarke, J., Polyvagal Theory and How It Relates, (2019, August 5).
6. Levine, P., Porges, S., & Phillips, M. (2015). Healing Trauma And Pain Through Polyvagal Science: An E-Book . Retrieved from
7. Porges, S. W. (2007, February). The polyvagal perspective. Retrieved January 3, 2020, from
8. Levine, P., Porges, S., & Phillips, M. Healing Trauma and Pain, (2015).
9. Porges, S. (2017, October). The Neuropsychotherapist, 5(10), 13–23. Retrieved from
10. Porges, S., The polyvagal theory: New insights, (2009, April).
11. Seymour, T., Vagus nerve: Function, (2017, June 28).
12. Porges, S.,The Neuropsychotherapist, (2017, October).

1. Clarke, Jodi. “Polyvagal Theory and How It Relates to Social Cues.” Verywell Mind, Verywell Mind, 5 Aug. 2019,
2. Levine, Peter, et al. HEALING TRAUMA AND PAIN THROUGH POLYVAGAL SCIENCE: AN E-BOOK. Maggie Phillips, PhD, 2015, ,
3. Porges, Stephen W. “The Neurobiology of Feeling Safe.” The Neuropsychotherapist, 10 Oct. 2017,
4. Porges, Stephen W. “The Polyvagal Perspective.” Biological Psychology, U.S. National Library of Medicine, Feb. 2007,
5. Porges, Stephen W. “The Polyvagal Theory: New Insights into Adaptive Reactions of the Autonomic Nervous System.” Cleveland Clinic Journal of Medicine, U.S. National Library of Medicine, Apr. 2009,
6. Seymour, Tom. “Vagus Nerve: Function, Stimulation, and Further Research.” Medical News Today, MediLexicon International, 28 June 2017,

Additional Resources:
1. Gillespie, L. (n.d.). It Takes Two: The Role of Co-Regulation in Building Self-Regulation Skills. Retrieved January 3, 2020, from

2. Porges, S. W. (2015). Making the World Safe for our Children: Down-regulating Defence and Up-regulating Social Engagement to ‘Optimise’ the Human Experience. Children Australia, 40(2), 114–123. doi: 10.1017/cha.2015.12

Deborah Spengler
S2C Practitioner



The mission of I-ASC is to advance communication access for nonspeaking individuals globally through trainingeducationadvocacy and research I-ASC supports all forms of augmentative and alternative communication (AAC) with a focus on methods of spelling and typing. I-ASC currently offers Practitioner training in Spelling to Communicate (S2C) with the hope that other methods of AAC using spelling or typing will join our association.

Posted By on Wednesday, February 12th, 2020 in Advocacy,Families,Motor,Nonspeakers,S2C,Spelling to Communicate,Training

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