It’s Not All in Your Head (Literally, It’s in Your Heart Too)

Why Your Heart Might Know Things Before Your Brain Does

Your heart has its own nervous system, sometimes called the “heart brain” or intrinsic cardiac nervous system (ICNS). We’re talking about over 40,000 specialized neurons (sensory neurites or intracardiac neurons) clustered in ganglia around your heart’s surface. That’s a lot of brain power sitting in your chest.

These neurons let your heart work semi-autonomously. They process sensory information, regulate rhythm, and even “remember” patterns without needing constant direction from your brain. The vagus nerve acts as the main highway between heart and brain, carrying messages both ways.

Here’s where it gets interesting. Research from the HeartMath Institute and neurocardiology studies (like Armour’s 1991 work) flipped traditional thinking on its head. Turns out, about 80-90% of vagal fibers are afferent, which means signals travel upward from heart to brain, not the other way around. Your heart is basically sending constant updates to your brain about what’s happening in your body and environment.

What This Means for Your Brain and Emotions

This bottom-up communication shapes activity in your amygdala (where emotions live), thalamus (your perception center), and prefrontal cortex (where you make decisions). Your heart rhythm patterns directly affect these regions before you’re even consciously aware of what you’re feeling.

When your heart rhythm is coherent and smooth, you tend to feel calmer and think more clearly. When the pattern gets erratic or chaotic, stress and anxiety can spike. This is why “gut feelings” or intuition actually make scientific sense. Your cardiac input is literally shaping your thoughts before they reach conscious awareness.

For Autistic & Neurodivergent Folks: This Explains A LOT

If you’re autistic or neurodivergent, you might already know that your body gives you information differently than it does for neurotypical people. The heart-brain connection helps explain some experiences that might feel confusing or overwhelming.

Interoception and the Autistic Experience

Interoception is your ability to sense what’s happening inside your body (hunger, thirst, heart rate, need to use the bathroom, emotions). Research shows that many autistic people experience interoception differently. Some folks have hyper-awareness of internal sensations, while others might not notice body signals until they’re really intense.

Here’s the thing: if your interoceptive processing is atypical, the constant stream of heart-to-brain signals might feel different too. You might:

• Feel your heartbeat more intensely than others do, especially during stress or excitement
• Have trouble identifying whether physical sensations are anxiety, excitement, hunger, or something else (because they all create similar heart patterns)
• Experience alexithymia (difficulty identifying and describing emotions) partly because the cardiac signals aren’t being interpreted the same way
• Feel overwhelmed by the sheer volume of body signals your brain is trying to process

This isn’t a deficit. Your nervous system isn’t broken. It’s wired differently, and that difference affects how heart-brain communication flows.

The Autistic Nervous System and Vagal Tone

Polyvagal theory (developed by Stephen Porges) adds another layer to this. The vagus nerve doesn’t just carry signals; it’s a key part of how we regulate our nervous system states. When you feel safe and connected, your ventral vagal system activates, supporting social engagement and calm. When you perceive threat, your sympathetic system kicks in, or in extreme cases, the dorsal vagal system can trigger shutdown responses.

Research suggests that autistic people may have different vagal tone patterns compared to non-autistic people. This doesn’t mean something’s wrong; it means your autonomic nervous system might move between states differently, or need different things to feel regulated.

For example:

• Social situations that feel “safe” to neurotypical people might trigger threat responses in your nervous system, causing your heart rate to spike even when you cognitively know you’re not in danger
• What others consider “calming” (like eye contact or light touch) might actually dysregulate your system
• You might need more recovery time after social interactions because your heart and nervous system worked harder to maintain regulation

Heart Rate Variability (HRV) and Neurodivergence

Studies using heart rate variability (HRV) as a biomarker show that people with higher HRV (more flexible, adaptive heart rhythms) tend to have better emotional regulation, stronger executive function, and more resilience to stress. Your heart’s rhythm flexibility is actually a window into your nervous system’s overall adaptability.

Some research indicates that autistic individuals may show different HRV patterns, particularly lower HRV during social interactions or novel situations. But here’s what matters: HRV can improve with practice and the right supports. It’s not fixed.

Lower HRV doesn’t mean you’re doing something wrong. It might mean your nervous system is working extra hard to process sensory input, manage uncertainty, or navigate social expectations that weren’t designed with your neurology in mind.

Why “Just Calm Down” Doesn’t Work

When someone tells you to “just calm down” or “stop being anxious,” they’re asking your brain to override signals that are coming from your heart. Your heart is detecting something in your environment or internal state and sending that information upward. Your brain is responding to real data.

For neurodivergent folks, this is even more complicated because:

• Your sensory system might pick up on things others don’t notice (fluorescent lights, background noise, social tension), triggering cardiac stress responses
• Your heart might respond to uncertainty or unpredictability more intensely because your brain craves patterns and predictability
• Masking (hiding autistic traits to appear neurotypical) creates chronic nervous system activation, keeping your heart in a higher-alert state

You can’t think your way out of a heart rhythm that’s signaling danger. You have to work with your body.

What Actually Helps: Body-Based Regulation

Neurocardiology research has found that the heart produces hormones like ANF (atrial natriuretic factor) and oxytocin, traditionally thought of as “brain” chemicals. These cardiac-produced hormones affect memory consolidation, social bonding, and stress response.

The insular cortex, a brain region involved in integrating body signals with emotional and cognitive processes, receives significant input from cardiac afferents. Neuroimaging studies show that when people focus on their heartbeat or practice heart-focused breathing techniques, insular cortex activity changes, along with activity in the anterior cingulate cortex (involved in attention and emotional regulation).

For autistic and neurodivergent people, working with the heart-brain connection can look different than typical “relaxation” advice:

Sensory-Friendly Cardiac Regulation:

• Deep pressure (weighted blankets, tight hugs from trusted people, compression clothing) can help regulate heart rate through proprioceptive input
• Rhythmic movement (stimming, rocking, pacing) can create coherent heart rhythms naturally
• Humming, singing, or making repetitive sounds stimulates the vagus nerve directly
• Cold water on your face triggers the dive reflex, which slows heart rate quickly

Breathing That Works for Neurodivergent Bodies:

• Coherent breathing (around 5-6 breaths per minute) can help, but if counting feels stressful, try breathing to a rhythm you create (tapping, rocking, walking)
• Some people find exhaling longer than inhaling calming (like 4 counts in, 6 counts out)
• Others need to match their breath to movement or visual patterns
• Box breathing (4 counts each for inhale, hold, exhale, hold) appeals to people who like symmetry and structure

Interoceptive Practice (Learning Your Body’s Language):

• Start by noticing your heartbeat without judgment. Put your hand on your chest. Count beats. Just observe.
• Practice labeling sensations with neutral language: “My heart is beating fast” instead of “I’m anxious”
• Keep a body journal to track patterns. Maybe your heart races every time there’s a schedule change. Now you have data.
• Use tools like heart rate monitors or apps if that helps you feel more connected to what’s happening internally

Why This Matters for Wellbeing

Your heart isn’t just pumping blood. It’s an active participant in creating your emotional and perceptual reality. This validates what you might already know: when people say “it’s all in your head,” they’re missing half the picture. Your experiences are real, they’re physiological, and they’re happening in a body-brain system that works differently.

Understanding this heart-brain connection helps explain:

• Why social situations can feel physically exhausting (your heart was literally working harder)
• Why meltdowns or shutdowns happen (your nervous system reached capacity)
• Why certain environments feel “wrong” even when they “should” be fine (your heart is detecting something your conscious brain hasn’t processed yet)
• Why you might know something is off before you can explain it (cardiac signals reach your brain before cognitive processing)

For Therapists, Providers, and Support People

When working with autistic and neurodivergent clients, recognize that nervous system regulation isn’t one-size-fits-all. What soothes one person might activate another. Build regulation strategies around the individual’s sensory profile, not generic relaxation scripts.

Listen when someone says something feels wrong in their body. Their heart might be processing information their brain hasn’t made conscious yet. That’s not anxiety that needs to be eliminated; that’s wisdom that needs to be understood.

The more we learn about neurocardiology, the clearer it becomes: your heart and brain are partners in creating your lived experience. Neither one runs the show alone. For neurodivergent folks, both partners might be speaking a slightly different language than the neurotypical instruction manual assumes.

That’s not a problem to fix. That’s your unique neurology doing exactly what it’s designed to do. The goal isn’t to make your heart-brain communication look like everyone else’s. The goal is to understand your system well enough to support it.

Your heart knows things. Your brain knows things. Together, they’re telling your story. And it’s not all in your head.

Want to Keep Learning? Here’s Your Reading List (No Boring Textbooks, Promise)

If this stuff lit up your brain and you want to go deeper, here are some actually-readable resources that won’t make you feel like you’re back in school:

Books That Get It:

The Polyvagal Theory in Therapy by Deb Dana
This one makes polyvagal theory actually make sense, with practical exercises. Dana writes like she’s talking to you, not lecturing at you. Bonus: she includes neurodivergent-friendly adaptations.

Interoception: The Eighth Sensory System by Kelly Mahler
Written by an autistic OT, this book is specifically about interoception and autism. It’s got practical activities and actually understands that autistic bodies aren’t broken neurotypical bodies.

The Body Keeps the Score by Bessel van der Kolk
Yeah, everyone recommends this one, but for good reason. Van der Kolk explains how trauma lives in the body and why talk therapy alone doesn’t always work. Some content can be heavy, so pace yourself.

Unmasking Autism by Devon Price
While not specifically about the heart-brain connection, Price brilliantly explains how masking affects your nervous system. You’ll suddenly understand why you’re so exhausted after pretending to be neurotypical all day.

Accessing the Healing Power of the Vagus Nerve by Stanley Rosenberg
Super practical, full of exercises you can actually do. Rosenberg explains the vagus nerve without getting too technical, and the techniques are sensory-friendly.

Articles & Research (The Interesting Kind):

“The Heart-Brain Connection: How Your Heart Affects Your Mental Health” - HeartMath Institute
Free on their website, breaks down the science without assuming you have a PhD. They’ve got actual studies plus explanations normal humans can understand.

“Interoception and Autism: A Narrative Review of Behavioral and Neurobiological Data” - Frontiers in Psychology (2021)
Okay, this one’s a research paper, but it’s open-access and surprisingly readable. If you like understanding the actual science behind your experiences, this is solid.

“Rethinking Autism and the Autonomic Nervous System” - Spectrum News
Great article that connects polyvagal theory to autistic experience. Written by science journalists who actually get neurodiversity.

Online Resources Worth Your Time:

The HeartMath Institute website (heartmath.org)
They have free resources, research summaries, and tools. Some of their stuff veers into the woo-woo, but the science is solid and the practical techniques actually work.

Autonomy Worksheets by Megan Anna Neff (neurodivergentinsights.com)
Megan’s an autistic psychologist who creates amazing infographics and resources about nervous system stuff specifically for neurodivergent folks.

Kelly Mahler’s Interoception Resources (kelly-mahler.com)
Free activities, assessments, and explanations. Everything’s designed with neurodivergent folks in mind.

Podcasts for Your Special Interest Rabbit Hole:

Polyvagal Podcast with Justin Sunseri
Short episodes that explain polyvagal theory in everyday language. Justin connects it to real-life experiences and includes neurodivergent perspectives.

The Sensory Project
Covers interoception, sensory processing, and body-based regulation. Hosted by OTs who actually work with autistic people and listen to them.

A Few Friendly Reminders:

You don’t have to read everything. Pick what calls to you. If a book or article starts making you feel bad about yourself, put it down. Good resources should make you feel understood, not broken.

Some of these authors aren’t neurodivergent themselves, so take what resonates and leave what doesn’t. Your lived experience matters more than any expert’s theory.

And if reading isn’t your thing? Audiobooks, podcasts, YouTube videos, and infographics can teach you just as much. Learn however your brain learns best.

Happy exploring. Your heart (and brain) will thank you. 💙