Pediatric OT · Nervous System & Regulation · Brewer, Maine
Your child's nervous system is more than "fight or flight."
By Earl Mamaril, MS, OTR/L — for a long time, I understood the nervous system the traditional way: sympathetic as "fight or flight," parasympathetic as "rest and digest." Then I learned a deeper way to look at it — one that completely changed how I see children's behavior. Once you see it, you can't unsee it.
What you'll take away
- Why a meltdown, shutdown, or "not listening" is often the body protecting itself
- The three states of the nervous system — and how to recognize each in your child
- Why you can't simply tell a stressed nervous system to "calm down"
- Small, doable shifts at home that help your child's body feel safe enough to heal
This framework is often described as the triune autonomic nervous system, connected to Stephen Porges' Polyvagal Theory. Polyvagal Theory proposes that the autonomic nervous system supports different states of safety, mobilization, and shutdown through distinct neural pathways that influence social engagement, emotional regulation, and physiological responses (Porges, 2025). It helped me understand something parents, caregivers, teachers, and therapists see every day:
The nervous system is always listening
The autonomic nervous system manages many automatic body functions — heart rate, breathing, digestion, circulation, muscle tension, facial expression, voice tone, and emotional regulation. It's deeply connected to how a child eats, sleeps, plays, learns, transitions, communicates, and connects with others. We can even measure parts of this regulation through markers like heart rate variability (HRV), a noninvasive window into autonomic function and stress regulation (Kim et al., 2018).
When a child feels safe, their body has more access to learning, social engagement, curiosity, flexible thinking, and connection. When a child feels threatened, overwhelmed, or unsafe, the body may shift into protection — running away, aggression, crying, shutting down, refusing, or being "too silly," "too loud," or "not listening." But underneath, the body may be saying: "I do not feel safe yet."
The three subsystems of the autonomic nervous system
Polyvagal Theory describes three major autonomic pathways that help us understand regulation, stress, and connection — the ventral vagal system, the sympathetic nervous system, and the dorsal vagal system (Porges, 2025). Each has a different role in survival and function.
1. The ventral vagal system: safety & connection
Often described as the social engagement system — the state where the body feels safe enough to connect. In this state, a child may be more available for eye contact, listening, communication, problem-solving, play, and learning (Porges, 2025).
This doesn't mean the child is perfectly calm or still. A child can be active, playful, energetic and regulated. The key is that their body feels safe enough to stay connected. This is why relationship matters in pediatric OT. Before we ask a child to tolerate a new texture, climb an obstacle, or try a new food, we first ask: does this child's body feel safe enough to participate? Safety is not just an idea — it's a body state.
2. The sympathetic nervous system: mobilization & protection
The one most people associate with fight or flight. It helps the body mobilize — heart rate increases, breathing quickens, muscles tighten, and the body prepares to run, push away, argue, or protect itself.
This response isn't "bad." It's protective. The problem comes when the body stays sympathetic-driven for too long. In daily life, this may look like a child who is constantly on edge — easily startled, quick to react, impulsive, anxious, restless. They may struggle with transitions, loud environments, or crowded spaces. Their body isn't trying to be difficult; it may be living in a state of constant readiness.
3. The dorsal vagal system: shutdown & conservation
Associated with immobilization, shutdown, and energy conservation — one of the body's oldest protective pathways. When stress feels too big or impossible to escape, the body may move into protective shutdown: freezing, going quiet, fatigue, dissociation, low motivation. A child who appears disconnected, flat, or "not there."
Shutdown is often misread as laziness or defiance. But from a nervous system lens, it may be the body saying: "This is too much for me right now." This system also has a close relationship with digestion and the gut, which may help explain why distress and gastrointestinal symptoms often appear together (Kolacz et al., 2019).
The nervous system responds in a hierarchy
When the body feels safe, the ventral vagal system supports connection and learning. When it senses danger, the sympathetic system activates. When it feels trapped or overwhelmed, the dorsal vagal system creates shutdown (Porges, 2025).
This is why regulation can't be forced. You cannot simply tell a stressed nervous system to "calm down." You cannot always talk a child out of a survival state. The body needs cues of safety. It needs rhythm. It needs predictable support. It needs co-regulation. It needs time.
What this means for parents
When we understand the nervous system, we see behavior differently. A meltdown may not be manipulation. Avoidance may not be laziness. Shutdown may not be refusal. These responses may be signs the child's nervous system has shifted into protection.
This doesn't mean removing all boundaries — children still need structure, expectations, and loving limits. But we stop asking only "How do I stop this behavior?" and begin asking a better question:
Healing begins when the body feels safe enough
The parasympathetic system is often called "rest and digest" — but rest and digestion don't happen well when the body is in survival mode. Healing isn't only about doing more. Sometimes it begins with better conditions for the nervous system: more rhythm, more connection, more outdoor time, more predictable routines, more sleep support, more movement, more sensory regulation — and less chronic overstimulation, less pressure, less chaos. Read more about stress and the developing brain →
The modern environment and stress load
Today's nervous system processes more than emotional stress. Many families live with constant stimulation, screens, noise, artificial light, poor sleep rhythms, and highly processed foods. Higher exposure to ultra-processed foods has been associated with increased risk of several adverse health outcomes (Lane et al., 2024). This doesn't mean guilt — it's a reminder that the body often functions best with steady nourishment from more whole, minimally processed foods when possible.
This doesn't mean living in fear — it means awareness matters. Small changes support the body's healing environment: more whole foods, fewer heavily fragranced products, more outdoor play, prioritized sleep, calm spaces, and predictable routines. These simple shifts may help reduce the total stress load on the nervous system.
A holistic view of regulation
Regulation is not just a behavior strategy, deep breathing, or a sensory tool. It's a whole-body process — the brain, gut, heart, breath, muscles, environment, relationships, nutrition, sleep, movement, and safety. When we support the nervous system from the bottom up, we create better conditions for learning, connection, development, and healing.
Final thought
The nervous system is not the enemy. A sympathetic response is often the body's attempt to survive the demands of the environment. A shutdown response is often the body's attempt to conserve energy when stress feels too big. Healing begins when the body feels safe enough to shift — safe enough to breathe, digest, connect, move, learn, and heal. When we stop seeing behavior as the problem and start seeing the nervous system as the messenger, we begin to support children in a more compassionate, holistic, and effective way.
Want help reading your child's nervous system?
At Sensory Therapy Place, we help parents understand the "why" behind behavior and turn neuroscience into simple, doable support at home.
References
Kim HG, et al. (2018). Stress and heart rate variability: a meta-analysis and review of the literature. Psychiatry Investigation, 15(3), 235–245. · Kolacz J, Kovacic KK, & Porges SW. (2019). Traumatic stress and the autonomic brain-gut connection in development. Developmental Psychobiology, 61(5), 796–809. · Lane MM, et al. (2024). Ultra-processed food exposure and adverse health outcomes: umbrella review. BMJ, 384, e077310. · National Institute of Environmental Health Sciences. (n.d.). Endocrine disruptors. NIH. · Porges SW. (2025). Polyvagal Theory: current status, clinical applications, and future directions. Clinical Neuropsychiatry.
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