“Belly breathing” is just what its name implies—breathing with the belly. Most of us breathe this way as children; you have probably witnessed a baby blissfully rest as her belly moves slowly up and down. However, as we get older and accumulate stress, we become locked into the habit of shallow, chest breathing. The distinction may seem trivial, but it plays a significant role in our psychological and physical health.
Belly Breathing and the Autonomic Nervous System
The autonomic nervous system (ANS) has two main branches: sympathetic (“fight or flight”) and parasympathetic (“rest, digest, and heal”). Ideally, we spend most of our time in the parasympathetic; we activate sympathetic to deal with brief stressors (e.g., exercising) and then return to a parasympathetic baseline. However, if we experience chronic stress, we may have trouble maintaining the proper balance between sympathetic/parasympathetic.
Diaphragmatic breathing is a quick and effective way to stimulate the parasympathetic nervous system. It does so by recruiting the vagus nerve—a cranial nerve (emanating from the braintem) that plays a crucial role in regulating heart rate, digestion, and immune activity, among other bodily functions. It also plays a key role in social and emotional behavior, a we will learn below.
The Polyvagal Theory
To understand how belly breathing can help children with autism, it is helpful to have a grasp of Stephen Porges’ Polyvagal Theory. Porges proposes that the vagus nerve plays a crucial role in many of the social and emotional deficits in autism.
According to the Polyvagal Theory, the vagus (and its many pathways) evolved in three main stages, serving three distinct purposes. The first (and most evolutionarily ancient) is called the dorsal vagal or “unmyelinated” pathway. This pathway promotes the most basic survival mechanism—“freezing” or “shutting down." We share this defense mechanism with our reptilian ancestors. The second vagal pathway, crucial for mammals, regulates the “fight or flight” (sympathetic) system. The third vagal pathway—called the ventral or “myelinated” vagus—regulates social behavior. This “social” vagus is bound up with the parasympathetic (“rest, digest, and heal”) branch of the nervous system. Thus, we might also say that the parasympathetic nervous system is social—if it's not working properly, we experience difficulty regulating social-emotional behavior.
Autism and ANS Deficits
So, might autism be a disorder of the entire nervous system—not just the brain?
There is indeed evidence pointing to impaired parasympathetic activity in children with autism. Here are a couple examples from the literature:
Children with autism show lower heart rate variability (a marker of ANS regulation) compared to control subjects.
In children with autism, those with higher HRV demonstrate superior emotion recognition, social behavior, and language and cognitive abilities
Belly Breathing and the Brain
Belly breathing can have a "bottom-up" effect on the brain via parasympathetic (ventral vagal) activation. The vagus not only connects to heart, gut, and visceral organs, but has "bottom-up" projections to the brain--particularly in regions involved in social-emotional behavior (e.g., insula, amygdala, anterior cingulate). The same brain regions that regulate ANS activity (referred to as the "central autonomic network") also carry the responsibility of regulating social-emotional behavior.
Therefore, if the ANS (and "central autonomic network") is dysregulated, it can disrupt our social and emotional functioning!
Belly breathing calms the ANS, thereby helping quell limbic (i.e., emotional) activity, stimulating prefrontal activity (i.e., paying attention), and allowing these broader social-emotional networks to switch back on (because we are no longer under threat, i.e., "fight or flight" or "shut down").
How to Practice Belly Breathing
To get the most out of this technique, set aside 10-20 minutes per day to practice. You will notice that over time it becomes easier to breathe this way in your everyday life.
1. Get comfortable in a sitting or lying position. If you are sitting, it might be helpful to slouch so that the diaphragm region is more open.
2. Place one hand on your belly, and the other hand on your chest. Notice your natural breathing.
3. See if you can breathe so that the hand on your belly goes up and down, instead of the hand on your chest. You will be using your diaphragm to make this happen.
4. Slow the breath down. Count 4-5 seconds on the inhale, and 5-6 seconds on the exhale. Continue breathing like this for 10-20 minutes.
Link to Dr. Goodman and colleague's study using biofeedback/neurofeedback with children with autism.
Matthew S. Goodman, Ph.D., BCB is a Registered Psychological Assistant (PSB94024933) and Board Certified Biofeedback Therapist working under the supervision of Dr. Chris Marrero (PSY23017) in private practice. He specializes in teaching self-regulation techniques using practices such as mindfulness/meditation and biofeedback, and working with patient with co-occurring mental and physical health symptoms.