The Two Pedals (Part 2 of 10)
Think of the sympathetic nervous system as the accelerator and the parasympathetic nervous system as the brakes. As we drive down the highway, we need both of these functions. If the drive is smooth, sometimes we will gently accelerate and sometimes we will gently brake. The same process applies to our physical, mental and emotional functioning. If the “drive” is smooth, our mind and body enjoys a gentle oscillation between accelerating and braking.
This is even reflected in our heart rhythm. A healthy rhythm is indicated by a consistent repetition of fast/slow, fast/slow, fast/slow. The reason for this gentle pendulation is so that the entire organism, at a moment’s notice, can either further accelerate or further break, as needed. A heartbeat that is either consistently fast or consistently slow or irregularly fast/slow is not a healthy rhythm because these circulation styles cannot allow for the gentle oscillation between accelerating and braking that is required for a smooth ride.
Let’s return to our driving analogy. If you are driving down the highway and a truck carelessly swerves right in front of you, you will probably have all of the reactions represented by the polyvagal theory: You may swear and flash various fingers (social engagement goes offline), you may suddenly accelerate, or you may slam on the breaks. But after the danger is averted, you will most likely return to your baseline of gently oscillating between accelerating/braking as needed — until the next threat again requires more extreme action.
Now let’s assume you have experienced so many roadside perils that you decide never to let down your guard. You are poised at every moment to yell and scream at other drivers, unpredictably accelerate and unpredictably brake. If you are really frazzled, you may even attempt to accelerate and brake simultaneously. Over time, this becomes your new default driving style, regardless of the driving conditions: cuss everyone out, suddenly accelerate, suddenly brake. (You may have noticed that in some major cities, this sort of driving is common.) Do you see how this will lead to a wild ride? Even if the driving conditions would otherwise have been relatively smooth, they won’t be anymore. And even if no danger would otherwise have been present, now there is. You are off to the races …
This blog post is an excerpt from Trauma stabilization through polyvagal theory and DBT, an article published by the American Counseling Association on September 14, 2021 by Kirby Reutter.
If you would like to learn more about how to use trauma-focused DBT with a variety of trauma-based disorders, I recommend the following resources to get started:
- The Dialectical Behavior Therapy Skills Workbook for PTSD: Practical Exercises for Overcoming Trauma and Post-Traumatic Stress Disorder by Kirby Reutter, 2019
- “DBT for Trauma and PTSD” (DBT Expert Interview series at psychotherapyacademy.org/dbt-interviews)
- Survival Packet: Treatment Guide for Individual, Group, and Family Counseling by Kirby Reutter, 2019
- “The Journey From Mars: Brain Development and Trauma” webinar (youtube.com/watch?v=WSFqHS_axOc)