In this way, human beings, like all other mammals, are able to automatically adjust to various levels of safety or danger, whether that is internally or externally or even just perceiving threats or dangers. But this is more than just an automatic response: the vagal nerve also acts as a helper in overriding even the automatic response for emergencies when your body needs to respond even more quickly because of danger. So for example, if the vagal nerve withdraws from the heart, that can stimulate the heart rate to increase much more quickly than a message from the SNS can tell the heart rate to increase (Berntson, Cacioppo, & Quigley, 1993a) - that way by the time your muscles get the message to run, your heart is already beating fast and ready to go.
Simplified, your body uses the nervous system to initiate the fight-or-flight response, but the vagal nerve can beat it to the punch, so that all your organs are ready to go at the starting line by the time the race begins.
The vagal nerve can also do the opposite of flight-or-fight, which is known as rest-and-digest, to alert the body when the race is over and you are safe, so it’s okay to calm down. This is sometimes referred to as the “vagal brake” in reference to the myelinated vagal nerve, because it “stops” the flight-or-fight response. In our previous example with the heart, activation of the vagal nerve back to the heart again is what tells it to slow down.
Literally and metaphorically, it is the touching of the heart that brings healing and peace.
Some research seems to support Porges and his theory regarding the vagal brake. Examples confirmed are the process of self-soothing in infants (Huffman et al., 1998), and higher self-regulation in adults (Fabes & Eisenberg, 1997). However, research has not yet confirmed any link between the vagal brake and actual emotional expressivity (Demaree, Pu, Robinson, Schmeichel, & Everhart, 2006; Demaree, Robinson, Everhart, & Schmeichel, 2004; Pu, Schmeichel, & Demaree, 2010). Further, it cannot be assumed that greater vagal activity relates to greater health, because there are clear examples where too much really is too much: infant death syndrome, stress-induced asthma, stress-induced gastric ulcerations, and vasovagal syncope (see Ritz, 2009). The question remains, then, regarding the actual influence of the vagal nerve.
The changes in heart rate variability, or HRV, are one way to measure this influence. When a person has developmental trauma, chronic shame and/or chronic stress, or other experiences that induce repeated patterns of the flight-or-fight response, the power in the low-frequency domain of HRV tends to increase whilst the high-frequency power decreases (Berntson & Cacioppo, 2004). This effect is noted to be associated with anxiety, depression, chronic illness, and autoimmune disorders (Berntson & Cacioppo, 2004; Thayer & Friedman, 1997). However, it’s also true that the same effect happens when either the SNS or the PNS are out of balance, one being used more than the other. This complicates understanding the true impact of the vagal nerve itself, but also explains why safe touch and sensorimotor therapies such as EMDR, equine therapy, progressive muscle relaxation, grounding skills, etc. work so effectively with survivors. We will discuss this further in a bit, but it implies that what needs to be integrated is not actually so much the personality as the mind-body experience itself.
So researchers focus on exactly that: what integrates these systems to work together, in balance, to keep the entire system online.
Thayer and Lane (2000, 2009) proposed a general model of neurovisceral integration for the brain, visceromotor, neuroendocrine, and behavioral responses to explain how the body rapidly responds to environmental stimulation. This model focuses on the function of the entire autonomic network as being implicated in goal-directed behavior and adaptability (Benarroch, 1993; Thayer & Brosschot, 2005). This emphasizes the brain’s link to emotional responding (Benarroch, 1993), and gives the prefrontal cortex the stage in a top-down effect in integrating the mind-body experience.
This is what you experience in traditional talk therapy. You are able to share your experience, think about it, reflect on it, and make meaning from those experiences. It works because engaging the cortex activates the vagal nerve to the heart, sending safety signals back to your brain ((Wong, Massé, Kimmerly, Menon, & Shoemaker, 2007; Milad, Quirk, et al., 2007; Milad, Wright, et al., 2007).
However, it’s also what can make talk therapy difficult. When you have a new therapist that you are still unfamiliar with, or while still establishing safety, or when confronting difficult material, or if you have a therapist who is not attentive or maintaining attachment-connection or who is otherwise unresponsive in some way, it disrupts the process. Literally. Much like the attunement/misattunement research from shame theory, which we will discuss in a moment, there is a same kind of disconnect that actually happens in the brain during attachment rupture or when the frontal cortex gets kicked offline.
A withdrawal of parasympathetic activation and an increase in sympathetic activation, which is consistent with defensive responding, is what causes dysregulation. Dysregulation of these cortical pathways may result in prolonged increases in sympathetic activation, which in the long term could result in potential autonomic imbalance. Prolonged action readiness and SNS over-activity have been linked to deficits in self-regulation and psychopathology (Thayer & Brosschot, 2005). For specific and extensive literature review application to each specific diagnoses, please CLICK HERE for Megan Christina Bensley’s doctoral thesis on the social consequences of physiologic states.
Aside from specific application to DSM-5 diagnoses, Porges explains how these neurophysiological adjustments in our bodies have consequences for daily living. These physiologic states, or “modes”, can be categorized primarily into three groups of purpose or functioning:
Safe and Social (engagement) – located in our face and our heart;
Flight and Fight (mobilization) – located in our lungs and limbs; and
Shutdown (immobilization) – located in our stomach.
We don’t choose to do these. It’s a sequence. It happens in a certain order.
We start out in the safe zone, and then when exposed to trauma or a threat of any kind (even perceived), we drop down the “ladder” into flight to try and get away. When we cannot get away, we drop down to fight. When fighting doesn’t keep us safe, we drop down to shutdown. This is the sequence in response to any kind of danger perceived by the body as a threat.
Behaviorally, we see this expressed in many ways. When we are safe, and our body feels safe, then our affects are bright and there is a great deal of range in our tone of voices and in our facial expressions. As we drop down the ladder, the changes in the vagal nerve literally flatten our affect by withdrawing signals to the facial muscles, our voices become more monotone, and our facial expressions are more limited. In the same way, as we move back up the ladder, our affects brighten and our voices and facial expressions have more range in presentation.
Further, they are responses to our external world, our internal world, and the way we perceive the world around us, but they also are the filters through which we see our world - which makes them reinforcing and happen in patterns for some people. This is especially true when we get stuck in one of these “modes”, and begin to filter all experiences through them.
For example, someone stuck in “fight” mode will perceive the world as a more dangerous place than it may be, and/or may find themselves in actual dangerous situations (or reenacting traumas) because they are focused on and looking for those situations that verify their internal experience of the world.
Or, someone in “flight” mode may have difficulty making eye contact, establishing relationships, or connecting with others even in superficial ways.
Trauma survivors experience these modes through triggers. They may feel safe and connected with their partner, or with their therapist, or in their own home, but if they have a sensory trigger like a smell or a sound or something that looks like something from the past, it may trigger a literal change in mode. The survivor then shifts from “safe and social” to “flight and fight”, with increased heart rate and panicked breathing, and maybe even literal running away or fighting against something familiar, or even to complete shutdown and being nonresponsive in a “freeze” or dissociated response.
The insight comes in understanding that switching or a “meltdown” or “spacing out” or some other trauma response may really not be coming from nowhere, but an actual physiological response to a particular trigger.
This perception at a neurological level was described by Porges when he coined the new term “neuroception”. Neuroception refers to how neural circuits in the brain and body distinguish whether situations or people or environments or experiences are safe or whether they are dangerous - such as why we may appreciate a hug from a friend, but not from a stranger. So basically, when this neuroception is faulty, there is an incongruence between whether you feel that you are safe and whether you actually are safe. This faulty neuroception, then, explains the neurobiological process of everything from autism to schizophrenia to anxiety disorders to reactive attachment disorder to dissociative disorders.
Neuroception is our body’s ability to detect risk outside of our body, bring that information in, and accurately and appropriately respond to that risk.
Each “mode” has its own neuroception “key” that unlocks specific behaviors. The safety and socialization mode has the neuroception key that encourages eye contact, prosocial behaviors, smiling, conversation, full range of voice, closer proximity of bodies, and safe touch. The neuroception of danger unlocks fight and flight behaviors such as being mobilized for running away or getting aggressive. But when something is life-threatening, that neuroception unlocks the behaviors of immobilization, or “freeze”, like dissociation.
And, when you are in one mode, you lose access to the behaviors in the other mode. Neuroception unlocks some behaviors in response to what is happening or perceived to be happening. But it also inhibits alternate behaviors that you could choose if you were in a different mode.
That is why, when you are dissociating, it is hard to maintain eye contact. It is hard to follow conversation. It is hard to perceive others around you as safe. It is hard to remember now time.
This is part of why, they think, that trauma survivors are so often abused or violated in different ways again and again as they become adults and even into adulthood. Once they are already dissociated, they lose access to the behaviors that would get them away from danger now that they are an adult - even if they could not get away while they were a child.
It’s also why those younger parts or child alters can be so difficult to orient to the present place and time.
This is why, in your therapist office, during your appointment, you may feel connected and strong and present and confident, and then later while on your own feel such a rush of panic or fear or do the opposite of what you had agreed on during safety planning.
This is why it takes domestic violence survivors so many times to actually leave such abusive situations.
When in the mode where your life is being threatened, or you feel (perceive) that your life is being threatened (even if only a trigger of memory time intruding into now time), you literally do not have access to the behaviors that you are able to do just fine when feeling safe and secure.
That’s unhealthy neuroception, when there is incongruence in any of those areas. Someone may be in danger but not recognize it. Someone may be safe, but think they are in danger.
Healthy neuroception is when there is congruence between what is happening and how your body is responding. It means that you are able to accurately to detect whether you are safe or in danger (in the present moment), correctly shift into the appropriate mode for that level of safety or danger, and then respond in a way that matches that mode and that level of safety or danger.
Healthy neuroception looks like connecting with someone safe when you are falling in love. It looks like mutual friendship and connection. It looks like recognizing the right therapist when you finally find them.
It also looks like recognizing red flags and acting accordingly, instead of dismissing what your intuition is telling you to do about it. It looks like setting boundaries when someone is being too intrusive, or when your workload is too much, or in ways that protect your Self, your time, and your energy. It looks like appropriate self-disclosure, by not sharing too much to everyone but also making an effort to connect with your sacred few.
THE CONNECTION BETWEEN TRAUMA AND POLYVAGAL THEORY
When someone experiences trauma, they shift into either immobilization or mobilization, unlocking behaviors of flight, fight, or freeze. We know this. But what we are learning from polyvagal theory, is that these behaviors are neurobiological responses.
When someone grows up with chronic trauma, or ongoing trauma, or gets stuck in one of those modes like dissociation, then that in and of itself becomes traumatic. Now, not only is there incongruence between what is actually happening and what it feels like is happening, but it also feels like you have no choice in how to respond or may even be unable to respond even if you wanted to try.
Here is Stephen Porges explaining it himself, in this video from The National Institute for the Clinical Application of Behavioral Medicine:
