Understanding Your Brain & Nervous System: A Science-Based Guide on Biohacking Your Way to a Healthier, More Aligned Life
Many of us experience burnout, mental fatigue, and feel stuck in loops of overthinking or emotional overwhelm, especially in midlife or when navigating the world as a neurodivergent individual. But understanding how your brain and body work together can help you break the cycle and support your well-being in ways that are scientifically grounded and deeply empowering.
When I first started my education of becoming a coach, I was so amazed when we learned about neuroscience and the different parts of the brain that impact different actions, thoughts, and mental states. I have heard people say this is education for the coaches to know how our tools support our clients, but for me personally, it helped me tremendously to be able to self-assess and know how to biohack my way to a more calm, balanced, and positive state. I’m committed to sharing this with my clients so they can reap the benefits as well.
This guide offers a clear, neuroscience-informed explanation of the brain and nervous system, their roles in stress and resilience, and evidence-based practices for regulation and healing.
🧠 The Brain: An Integrated, Evolving System
While the outdated triune brain model (reptilian, limbic, and neocortex) offered a helpful metaphor, modern neuroscience recognizes the brain as a highly interconnected system, where no part works in isolation.
Instead of seeing the brain in layers of “primitive to advanced,” it’s more accurate to understand how different regions contribute to emotional processing, decision-making, survival, and self-awareness through integrated networks.
We can still explore the brain using the general framework of three main systems:
🔹 Brainstem (Also known as the Reptilian Brain)
Location: Base of the brain
Function: Regulates essential survival functions like breathing, heart rate, sleep cycles, and arousal
Connection to Stress: Triggers basic fight/flight/freeze responses via the autonomic nervous system
Evolutionary Note: Most ancient part of the brain, shared with reptiles and early animals
🔹 Limbic System (Sometimes called the Emotional Brain)
Includes: Amygdala, Hippocampus, Hypothalamus
Function: Emotional processing, memory, motivation, and fear response
Amygdala: Rapidly detects threats and initiates a stress response
Hippocampus: Forms and retrieves memories, regulates emotional charge of events
Hypothalamus: Regulates hormones and homeostasis, key to the stress response via the HPAaxis
Evolutionary Note: Evolved with early mammals to support emotional bonding and social learning
🔹 Neocortex (Also called the Rational Brain or Thinking Brain)
Includes: Prefrontal Cortex (PFC) and other cortical areas
Function: Higher-order thinking, decision-making, impulse control, language, imagination, and emotional regulation
Prefrontal Cortex: Governs executive function, empathy, and planning
Challenge: Under chronic stress, PFC activity decreases, impairing clear thinking and regulation
Evolutionary Note: Newest and most complex part, allowing abstract thinking and creativity
🌿 The Role of the Nervous System
The nervous system consists of the central nervous system (CNS) and the peripheral nervous system (PNS).
🔹 Autonomic Nervous System (ANS)
Controls involuntary functions like heart rate, digestion, and stress response. It has two main branches:
Sympathetic Nervous System (SNS) – “Fight or Flight”
Activates during perceived threats
Increases heart rate, blood pressure, and glucose release
Parasympathetic Nervous System (PNS) – “Rest and Digest”
Slows heart rate, aids digestion, promotes recovery
🔹 The Vagus Nerve
A key part of the parasympathetic system
Connects the brain to the heart, lungs, and gut
Stimulating the vagus nerve through breathwork, cold exposure, or humming helps regulate stress
The brain and nervous system are in constant communication:
· The amygdala triggers a threat response
· The HPA axis releases stress hormones
· The prefrontal cortex can calm the system once safety is recognized
· The vagus nerve carries signals between brain and body to restore balance
💥 How Stress Affects the Brain and Nervous System
When your brain perceives danger—whether it’s a car swerving into your lane or an overwhelming deadline, it activates the Hypothalamic-Pituitary-Adrenal (HPA) Axis. This triggers the release of cortisol and adrenaline, preparing the body to respond by engaging the sympathetic nervous system.
But here’s the catch, we’re often not being chased by a tiger. Sometimes, we’re just opening our email inbox, running late, or responding to a tense conversation. But to the brain, those modern stressors can feel just as threatening.
Chronic Stress Impacts:
· Amygdala becomes overactive, increasing anxiety and fear responses
· Hippocampus shrinks, impairing memory and emotional regulation
· Prefrontal Cortex activity decreases, making it hard to focus or make decisions
· Vagus nerve signals weaken, reducing recovery from stress
Over time, this loop can become dysregulated. But with consistent practices, we can retrain the system. A process known as neuroplasticity.
🛠️ Evidence-Based Tools to Shift Out of Stress Loops
These tools are backed by neuroscience and help you access a more regulated, calm state:
1. Bilateral Eye Movements (e.g., EMDR or Visual Tracking)
What it is: Move your eyes side-to-side while thinking of a stressful memory or emotion
Why it works: Activates both brain hemispheres, helps reprocess emotional memories, reduces amygdala activity
Try this: Slowly move your eyes left and right for 30 seconds while focusing on breath
2. Slow, Deep Breathing (Especially Extended Exhales)
What it is: Inhale for 4 counts, exhale for 6-8 counts
Why it works: Stimulates the vagus nerve, reduces heart rate and cortisol, improves heart rate variability
Try this: 4-7-8 breathing or box breathing
3. Cold Exposure (e.g., Splashing Face, Cold Showers)
What it is: Brief exposure to cold water
Why it works: Stimulates vagus nerve, triggers parasympathetic rebound, builds stress tolerance
Try this: End your shower with 30 seconds of cold or splash cold water on your face
4. Grounding and Interoception
What it is: Bring awareness to bodily sensations in the present moment
Why it works: Activates insular cortex, calms mental chatter, reconnects to safety in the body
Try this: Notice your feet on the ground or do a body scan meditation
5. Movement & Somatic Practices
What it is: Gentle or vigorous movement like walking, dancing, shaking, yoga
Why it works: Releases stress hormones, increases dopamine, improves emotional regulation
Try this: Shake your arms and legs for 1 minute or go for a brisk walk or put on headphones and dance to your favorite tunes
6. Visualization
What it is: Mentally imagine a calming, safe, or empowering scenario
Why it works: Reduces amygdala activity, reengages the prefrontal cortex, activates parasympathetic nervous system
Try this: Close your eyes and picture a place where you feel safe and at ease, breathe deeply while holding that image for a few minutes
🧩 Final Thoughts
When you learn how your brain and body respond to the world, you gain the power to shift your internal state, reclaim your energy, and live with more ease and clarity.
