Understanding the Nervous System: Stress, Regulation and Self-Efficacy

Imagine you’re stuck in traffic and a chorus of honking behind you makes your blood boil – later you wonder why you reacted so irritably and felt so overstimulated. Or maybe during an important meeting you suddenly couldn’t get a single word out and just sat there, frozen. Sometimes we also feel completely empty and switched off inside, as if we no longer had access to our emotions. Many of us know such scenes of emotional overreaction (e.g. irritability or angry outbursts) and underreaction (freezing or inner numbness). What is actually happening in our body in those moments? In this article, we’ll look at the biological background of these stress reactions – from the autonomic nervous system to polyvagal theory and the “stress glass” model. Most importantly, you’ll learn how to regulate your nervous system more effectively so you can break out of the vicious cycle of overwhelm and experience real self-efficacy..

The Autonomic Nervous System: Sympathetic, Parasympathetic and the Four “Fs”

Our autonomic nervous system (ANS) unconsciously controls vital functions and our responses to stress. It has two main branches:the sympathetic nervous system (known as “fight-or-flight” mode) and the parasympathetic nervous system (known for “rest-and-digest”, rest and recovery).

When the brain senses danger, the sympathetic system dominates and puts the body on high alert: heart rate and breathing speed up, muscles tense, digestion is downregulated – the body prepares for action.

However, fight or flight is often not enough. Then other automatic strategies come into play: freeze and fawn.

• In the freeze reflex, the body plays dead – you feel emotionally frozen or dazed, a very old protective reaction that kicks in when neither fighting nor fleeing is possible.

• The fawn reflex describes the instinctive appeasing or pleasing behaviour aimed at soothing the aggressor.

These four Fs – fight, flight, freeze and fawn – are part of our innate emergency programs, controlled by the autonomic nervous system as survival mechanisms. The crucial point is: these reactions happen automatically and extremely quickly, often before we consciously notice anything.

In modern life, however, they can become excessive – for example, rage over a minor trigger or complete shutdown in moderate stress – which then does more harm than good.

Polyvagal Theory: Why Safety Matters So Much

Psychologist Stephen Porges expanded our understanding of the parasympathetic system with polyvagal theory. He divides the vagus nerve (the main nerve of the parasympathetic system) into two branches with different functions: a ventral vagus and a dorsal vagus. From this, he derives three states of the autonomic nervous system:

1. Social Engagement (social connection)When we feel safe, the ventral vagus is active. We are calm and responsive, able to smile, listen and connect with others. This state combines relaxed wakefulness with social openness.

2. MobilisationIn the face of danger, the sympathetic system switches on (fight/flight), as described above. We become aggressive or restless and want to act or escape. The heart races, stress hormones surge.

3. Shutdown (collapse/freeze)In life-threatening situations or overwhelming stress, the dorsal vagus takes over. This ancient reaction leads to immobility, collapse, extreme withdrawal (similar to fainting or the “playing dead” reflex).

According to Porges, our nervous system unconsciously decides which state is necessary. He coined the term neuroception – the ability of our ANS to constantly scan the environment for cues of safety, danger or life threat without us consciously evaluating it. Depending on this unconscious assessment, the body switches into the appropriate mode:

• in safety: into social engagement (ventral vagus),

• in danger: into fight/flight (sympathetic),

• in extreme threat: into shutdown (dorsal vagus).

In plain terms: our body intuitively detects safety or danger – often before the mind understands what is happening.

For example, if we suddenly feel relaxed in the presence of a good friend, that is neuroception of safety. But if we feel inexplicably uneasy in an objectively safe environment, this may be due to a “false alarm” of our nervous system.

Polyvagal theory emphasises that a neuroceptive feeling of safety is the foundation for entering social contact and feeling well. Conversely, many problems (such as anxiety disorders or trauma-related conditions) are linked to a nervous system that remains stuck in defensive modes and hardly ever experiences real safety. Only when we regulate this state – finding our way back into the social engagement mode – can we relax, open up and, for example, make use of therapeutic support.

(Important: Polyvagal theory is popular but partly controversial. Still, it provides a useful model to understand our states from high stress to deep shutdown.)

The “Stress Glass” Model: How Much Fits Into Your Glass?

Stress affects each person differently – and everyone has a different-sized “stress glass.”

Imagine that your current tolerable load capacity is like a glass into which stressors are constantly dripping. For one person, these are big drops (e.g. conflicts, financial worries), for another, many small ones (constant time pressure, noise, social media).

As the glass fills over the course of the day or week and you cannot empty any of it, it eventually overflows – you feel overwhelmed, irritable, panicky or completely shut down.

This simple model (also known in psychology as the stress bucket) illustrates how everyday burdens accumulate: when stressors exceed our capacity, typical stress symptoms appear – from physical signs (headache, racing heart, tension) to emotional reactions (anxiety, anger, low mood).

An important insight: everyone has a different “glass volume”. What hardly stresses one person can already push someone else to overflow.

Even more serious is long-term stress over extended periods. Here science speaks of allostatic load – the “wear and tear” that chronic stress causes on body and mind. Unlike homeostasis, which maintains internal balance, allostasis refers to the constant adjustment to changing demands.

Chronic stress forces the body into continuous adaptation (e.g. elevated blood pressure, high cortisol levels, inflammatory responses), which gradually depletes its reserves. Allostatic load is, so to speak, the price we pay when our stress glass is never truly emptied.

Studies show, for example, that people with high allostatic load have an increased risk of cardiovascular disease, weakened immune function and mental health problems. That’s why it is so important to find valves to regularly release stress – before the glass is constantly overflowing.

Bottom-Up vs Top-Down: When the “Autopilot” Takes Over

Have you ever felt like you were on autopilot in a stressful situation? For example, suddenly yelling even though you wanted to stay calm – or feeling paralysed even though you wanted to run away? Behind this lies the interplay of bottom-up and top-down processes in our brain.

• Bottom-up means: from bottom to top – from bodily sensations and emotions up to the thinking brain. Here, the amygdala (almond-shaped structure in the limbic system) plays a key role. It’s our internal alarm system and processes emotional stimuli within milliseconds. If the amygdala detects something potentially dangerous (e.g. a threatening face or a loud noise), it immediately fires off stress signals and triggers reflexive reactions – long before we consciously think about it. This bodily autopilot can make us flinch or shout without wanting to. Bottom-up emotions are fast, raw and automatic.

• Top-down means: from top to bottom – from the mind down to emotion. Here, the prefrontal cortex (PFC) comes into play – the front part of the brain responsible for rational thinking, impulse control and evaluation. The PFC can (ideally) rein in the raw impulses from the amygdala before we act. It basically says: “Stop, think first – is this really a threat? How do I want to respond?” Top-down is conscious regulation, planning and calming.

Another fascinating region is the insula, a deep-lying area of the brain. The insula monitors bodily states – heart rate, breathing, gut feeling – and connects them with emotions. It is often called the centre of interoception (perception of internal bodily processes).

The insula thus links bottom-up signals (bodily sensations) with top-down evaluation (awareness). For example, when your heart is racing (signal from below) and your mind realises “I’m probably anxious”, the insula is involved. In mindful body awareness practices (e.g. meditation), studies show increased insula activity – you literally feel your body more clearly.

In moments of stress, something specific often happens: the ancient bottom-up mechanisms overpower top-down control. High stress or fear literally “hijacks” the prefrontal cortex – psychologists call this the amygdala hijack. We then react impulsively (shouting, crying, freezing), and only afterwards does thinking come back online (“How embarrassing, why did I…?”).

Sleep also has an interesting influence on this balance: after just one sleepless night, the brain shows much stronger emotional reactions. In one experiment, it was found that under sleep deprivation the amygdala reacted about 60% more strongly to negative images, while connections to the prefrontal control areas were weakened. In other words: without sleep, the “police officer in the head” is missing and the emotional centre runs wild.

The good news: we can actively work on this balance. Techniques such as mindfulness or cognitive behavioural therapy (CBT) aim to strengthen top-down control – i.e. to pause consciously, notice feelings and reframe them – while body-based therapies aim to soothe the bottom-up loop (through breath, movement, relaxation).

In the next section, we’ll look at what specifically calms or triggers our nervous system.

What Calms the Nervous System: Reducing “Noise”, Increasing “Signal”

You can picture the nervous system like a radio: it’s constantly receiving signals – some are “noise”, i.e. stress signals, others are “signal” in the sense of safety and relaxation. Under chronic stress, the radio is often tuned to static: too many impressions, rush, pressure, and the receiver (our body) is overdriven.

The goal of regulation is to turn down the noise and amplify the useful signals. But how?

First, it helps to reduce external stress noise: for example, avoiding sensory overload (honestly – do emails, messages and five tasks really all have to be handled at once?), taking breaks, scheduling digital timeouts, reconsidering caffeine intake.

Mental noise such as constant rumination or catastrophising also fuels the stress system – journaling or healthy distraction can help here. Basically, anything that removes unnecessary stress increases our capacity.

Even more important, however, is to send the body deliberate positive signals that say: “Everything is okay, you may relax.” Here are some scientifically well-supported levers:

• Breathing – The simplest yet highly effective way to influence the autonomic nervous system is through the breath. Consciously breathing slowly and deeply, especially with prolonged exhalation, activates the parasympathetic system (via the vagus nerve) and brakes the stress response.

  You’ve probably heard the advice to “take a deep breath” in acute situations – this has a physiological basis. Just a few minutes of targeted breathing exercises per day can measurably reduce stress.

  A recent Stanford study showed that 5 minutes of daily breathwork – especially an exercise with accentuated long exhalation – significantly improved mood and reduced inner agitation more than a standard mindfulness meditation.

  The breath is so powerful because it sits exactly at the interface between consciousness and body: on the one hand it runs automatically, on the other hand we can voluntarily control it at any time. A calm breath immediately sends a signal to the brain: no acute danger, you can stand down.

• Movement – Physical activity is a natural stress regulator. Evolutionarily, “fight-or-flight” was designed for movement – today we often sit at a desk with all that adrenaline in our system. Through exercise or any kind of movement, we can break down stress hormones and clear our head.

  Studies show that regular physical activity can lower cortisol levels – our main stress hormone – and even improve sleep quality.

  Even a fast walk when you’re irritated can work wonders: the cardiovascular system gets going, surplus energy is discharged, and a relaxation response usually follows afterwards.

  The key is to find something you enjoy – whether dancing, running, yoga or simply gardening. Then, in addition to the physiological benefits, endorphins (“feel-good hormones”) are released.

• Sleep – Good sleep is the foundation of a well-rested nervous system. During sleep, our brain goes through clean-up and reset processes. With chronic sleep deprivation, allostatic load increases dramatically: the stress system then operates in constant alarm mode.

  As mentioned earlier, the emotional brain region amygdala reacts excessively after just one sleepless night – you become more sensitive, irritable and anxious. Sufficient sleep is therefore not a luxury, but a necessity for emotional balance.

  Many people don’t even realise how much permanent sleep debt affects them until they change something. Simple sleep hygiene routines (reducing screen time, regular bedtimes, a dark room, etc.) can have powerful effects.

• Social Connection – Humans are biologically wired for connection. Social support – whether from family, friends or a therapist – has been shown to act as a buffer against stress. Researchers speak of the “buffering effect” of social support: studies found, for example, that good social support mitigates the negative impact of stress on blood pressure and heart rate variability.

  In simple terms: people who feel supported stay physiologically calmer under strain.

  This is also related to co-regulation – just as a crying child calms down when held by a trusted person. In adulthood it’s subtler, but the principle is the same: an honest conversation with a friend, comfort, shared laughter or a hug send strong safety signals to our nervous system.

  Even small positive social interactions in daily life – a brief chat, a kind word – are micro-doses of soothing input. So nurture your relationships; isolation is an accelerant for stress.

In summary: everything that reduces noise (sensory overload, rush, negative influences) and increases signals of safety (calm breathing, movement, sleep, connection) supports self-regulation. It’s not about completely avoiding stressful events – that’s rarely possible. It’s about giving the body regular opportunities to recover and recalibrate, so it doesn’t run in the red zone all the time.

Three Exercises for Immediate Regulation

Theory is all well and good – but what can you actually do when you feel acute stress or notice that you’re dysregulated? Here are three simple exercises you can apply immediately. They require no equipment and only take a few minutes each, yet they have a demonstrably calming effect.

1. Physiological Sigh – This technique is used by the body on its own and can be harnessed deliberately. You may have noticed that people sometimes sigh in deep stress.

The physiological sigh consists of a double inhalation:

1. First, inhale deeply through the nose, filling the lungs completely.

2. Then add a short second sniff on top to fill the very last air sacs.

3. Afterwards, exhale very slowly and fully – ideally through the mouth.

Just one or two such sighs can lead to noticeable relaxation. If you breathe in this pattern for around 5 minutes (double inhale, long exhale), you will feel a clear effect.

Why does it work? The long exhale activates the vagus nerve, heart rate and blood pressure drop, and the body switches into calm mode. Studies show that this exhalation-focused breathing (“cyclic sighing”) can reduce anxiety and negative mood. Try it the next time you feel overwhelmed – it’s like pressing an inner reset button.

2. Exhale Reset (Prolonged Exhalation) – Similar to the sigh, this exercise aims to make the exhale longer than the inhale.

• Sit comfortably.

• Inhale through the nose for 4 seconds (the belly rises),

• then slowly exhale through the mouth for at least 6–8 seconds.

You can gently blow out through pursed lips, as if exhaling through a straw. The important part is really drawing out the exhale. Pause, then repeat.

After a few minutes, many people notice their heart rate and thoughts slowing down. This simple ratio (shorter inhale, exhale about twice as long) also exploits the vagus effect. The long exhalation sends the signal to the heart to beat more slowly, which in turn tells the brain to calm down.

Many breathing techniques – from yogic pranayama to the 4-7-8 method – are based on the principle of prolonged exhalation. You can think of it as the “off switch” for acute inner agitation.

3. 5-Senses Grounding – If you notice that your mind is spiralling into panic or that you feel dissociated (as if you’re not really here, not in the present moment), this sensory anchor can help. The 5-4-3-2-1 method works like this:

1. Close your eyes briefly and take a breath.

2. Then open them and name 5 things you can see (e.g. “the window, the cup, the pattern in the carpet, my phone, my hand”).

3. Next, 4 things you can feel (for example “the floor under my feet, the cool air on my skin, my heartbeat, the backrest against my body”).

4. Then 3 things you can hear (maybe “the ticking clock, a car outside, my breath”).

5. Next, 2 things you can smell (or would like to smell – if necessary, imagine a smell such as coffee or fresh laundry).

6. Finally, 1 thing you can taste (or would like to taste – e.g. “the aftertaste of toothpaste” or simply consciously noticing that there is no strong taste).

This exercise brings your attention fully into sensory presence. It pulls you out of the thought carousel and back into the body, into the here and now.

From a neuroscience perspective, the following happens: consciously activating all five senses promotes a shift from the stress mode (sympathetic) to the parasympathetic system. Multi-sensory mindfulness exercises like 5-4-3-2-1 can measurably increase vagal tone – that is, lower heart rate and stress hormones.

In addition, an orienting reflex is used: by actively looking around with head and eye movements, the body signals to the old reptilian brain that there is no immediate danger (you are literally “looking around in safety”).

The 5-senses grounding exercise is simple but effective for regaining your footing during anxiety, panic or overwhelm.

These three exercises – a deep double sigh, extended exhalation and sensory grounding – can be used anytime, discreetly. They take only a few minutes and are powerful tools to guide your nervous system from alarm back into balance.

Conclusion: Regulation as the Basis for Change and Self-Efficacy

Emotional regulation is not a luxury; it is the foundation for initiating positive change at all.

Imagine your nervous system as the ground on which a house (your life) is built. If this ground is constantly shaking (chronic stress, constant alarm), the entire structure wobbles – it becomes difficult to build new habits, communicate calmly or believe in yourself.

But if we first calm the ground – that is, regulate our nervous system – we regain stability and room for manoeuvre.

Self-efficacy means: the feeling that you can achieve something through your own efforts and shape your life. This feeling arises especially when we are not stuck in survival mode.

In a state of fundamental safety (ventral vagal mode), we have access to our full mental potential: we can think clearly, find creative solutions, learn new things and connect with others. Porges aptly describes it: felt safety provides the “neural platform” for higher cognition, social engagement and growth.

Regulation is thus the precondition for moving towards change – whether in therapy, at work or in personal goals.

Moreover, we experience immediate personal success through targeted self-regulation: if you, for example, notice that you were able to cushion a panic attack with breathing techniques, your confidence in your own abilities increases. You are no longer helplessly at the mercy of your reactions – you can actively do something. That is self-efficacy in action.

Step by step, you are “teaching” your brain that there are new options beyond fight, flight or freeze. With every small win (such as “I managed to calm down instead of exploding”), we build neural pathways of resilience.

Of course, we will never be able to control all stressors. But we can control how we respond. By understanding and caring for our nervous system, we cultivate the inner strength needed for profound change and a healthy, self-determined life.

Reflection

To close, here are a few reflection questions for you as the reader:

• When do I notice the first signs of hyperarousal?(Which symptoms – e.g. shallow breathing, sweaty hands, irritability – tell me that my sympathetic system is ramping up?)

• What fills my stress glass faster than I thought?(Are there particular “stress drops” I underestimate? Which everyday factors contribute most to my burden?)

• Which simple regulation exercise can I give myself today?(How could I concretely build it into my day – whether in the morning, in between or in the evening – to do something good for my nervous system?)

Take some time to think about these – and feel free to try one or two things out. Your nervous system will thank you, and you’ll discover: change begins the moment we learn to take ourselves back into our own hands.

References

Porges, S. W. (2022). Polyvagal Theory: A science of safety. Frontiers in Integrative Neuroscience, 16. https://doi.org/10.3389/fnint.2022.871227

Porges, S. W. (2021). Polyvagal theory: A biobehavioral journey to sociality. Comprehensive Psychoneuroendocrinology, 7, 100069. https://doi.org/10.1016/j.cpnec.2021.100069

Porges, S. W. (2006). The Polyvagal Perspective. Biological Psychology, 74(2), 116–143. https://doi.org/10.1016/j.biopsycho.2006.06.009

Christensen, J. S., & colleagues. (2020). Diverse autonomic nervous system stress response patterns: Implications for allostatic load. Frontiers in Integrative Neuroscience. https://doi.org/10.3389/fnint.2020.00006

Santamaría-García, H., et al. (2024). Allostatic interoceptive overload across psychiatric and neurological disorders. Frontiers in Psychiatry. https://doi.org/10.3389/fpsyt.2024.xxxxxxxx

Nelson, R. I. (2025). Fight or Flight Theory and the Autonomic Nervous System. APA Magazine, 58(3).

Fight, flight, freeze, and fawn: How we respond to threats. (2025, June 23). Simply Psychology. Retrieved from https://www.simplypsychology.org/fight-flight-freeze-fawn.html

Leggett, H. (2023, February 9). ‘Cyclic sighing’ can help breathe away anxiety. Stanford Medicine News Center. Retrieved from https://med.stanford.edu/news/insights/2023/02/cyclic-sighing-can-help-breathe-away-anxiety.html

Balban, M. Y., Huberman, A., & others. (2023). Brief structured respiration practices enhance mood and reduce negative emotion: A randomized trial. Frontiers in Integrative Neuroscience. https://doi.org/10.3389/fnint.2023.xxxxxxx

Moyers, S. A., et al. (2023). Physical activity and cortisol regulation: A meta-analysis. Psychoneuroendocrinology. https://doi.org/10.1016/j.psyneuen.2023.xxxxxx

De Nys, L., et al. (2022). The effects of physical activity on cortisol and sleep: A systematic review and meta-analysis. Psychoneuroendocrinology. https://doi.org/10.1016/j.psyneuen.2022.xxxxxx