Research reveals that trauma doesn't just affect your emotions and thoughts - it literally rewires how your brain interprets physical sensations. From the vestibular system that controls your sense of balance to the regions responsible for detecting internal bodily signals, trauma creates a cascade of changes that can leave you feeling unsafe in your own body.

In this deep dive, we'll explore how interoception, sensation and trauma or extreme stress are all interlinked, and the fascinating neuroscience behind these changes. 

This is not new work to me. It is my chosen area of specialism and yet, it still feels surreal, when we see that helping the brain update in this way, physically changes symptoms – even getting rid of them entirely.

So, today we'll consider how your sensory experiences are changed after trauma or extreme stress and why this also may make you feel disconnected from your body. As ever I'll include some resources that may help you, but I should remind you also that theBody Mind Connect membership helps with exactly these processes.

The vestibular system is the system that helps you have a sense of balance, recognise when you are in motion versus still and your spatial orientation. Brain imaging research shows that in PTSD, the vestibular nuclei (a specific brain region in the vestibular system) has reduced connectivity with another brain region, the posterior insula (4). The posterior insula is the main region of the brain that is responsible for you being able to detect your internal bodily state (interoception/interoceptive processing). For example, recognising an increased heart rate, hunger or gut feelings. When the vestibular nuclei and the posterior insula are having connectivity issues, the brain will have difficulties correctly appraising and contextualising physical symptoms you are experiencing. Essentially it can create a misinterpretation of bodily sensations that is therefore experienced more threateningly, creating a snowball effect of chronic hypervigilance to internal bodily sensations and potentially external situations that feel consequently more overwhelming.

These studies were conducted in the context of PTSD, where there has been extreme stress (trauma) resulting in a range of physical and emotional changes. Therefore, the findings are not necessarily applicable to those without PTSD – and yet – they still tell us something valuable. We can see how brain regions communicate with each other to impact physical experiences and also inform a sense of self existing in the world and how these processes change under particular conditions (extreme stress). So it follows that similar but less extreme conditions, can result in similar but perhaps less extreme changes to processing. Research supports the premise that high degree of stress outside of PTSD results in changes to processing that resemble changes seen in PTSD (1,5).

The changes in these brain regions can explain the 'shutting down' or 'numbing out' response of the nervous system (including the autonomic nervous system and somatic nervous system) that can lead to emotional disengagement, dissociative experiences and even not feeling pain.

At the bottom of your brain are what are thought of to be the most foundational and primitive brain structures, the brainstem and midbrain. The ones that could keep you alive even if the top parts of your brain (the parts that allow you to consciously think, feel, act and respond) were out of action. These areas integrate sensory input and coordinate survival responses before the information reaches your higher order conscious brain regions. High degrees of stress and trauma can disrupt these regions too, which can mean that your muscles automatically tense, your autonomic nervous system automatically primed for action and other regulatory systems primed for arousal in case of threat without a conscious thought (1,8). So if I haven't convinced you enough already – that means it is not you and your thoughts that are converting sensory experiences, but a baseline shift in how your brain is processing before you've even had a conscious thought. Now – the good thing about this is that it just because you aren't causing it with your thoughts, it doesn't mean how you think, what you do and how you work with your brain and body, can't make a big difference to the processing of these brain structures.

An area of the midbrain, called the periaqueductal gray (PAG), integrates sensory information with emotion. This determines if something is safe or threatening. The sensory experiences and threatening contexts of them, can mean that the PAG easily matches hints of the sensation with the same emotion, so that you are sufficiently alerted to the threat (9,10). The difficulty in this process is that what this quite often means in practice, is that this brain activity creates a loop, meaning you feel stuck in active symptoms or fear of symptoms.

This research (and much more) illustrates why to feel connected to yourself and help yourself feel safe again, it is so important to work directly with your body and brain. Thinking and updating how your brain is conceptualising things from top-down (conscious, thinking brain down to unconscious sensing brain and nervous system) is one part of the equation for sure, but physically and emotionally feeling is another huge component. This is where people are increasingly turning to somatic therapies, which can be hugely transformative.

It's important to recognise that in the brain (and therefore the nervous system) there is an integration problem. There's reduced or changed connectivity. What we need is to improve communication between these brain regions and systems. Therefore, in my clinical practice and in the Body Mind Connect community, I facilitate exploration, practices and strategies that are focussed on improving this integration. Some of that is experiential work and some of that is cognitive. As you work on both, your brain becomes better able to integrate again for you, in a safer and more regulated way.

Your brain's sensory processing gets disrupted - the vestibular system and posterior insula lose communication, making you misinterpret bodily sensations as threatening

Physical sensations become danger signals - your periaqueductal gray matches current sensations with past threatening experiences, creating automatic fear responses

You feel disconnected from yourself - reduced connectivity between brain regions responsible for sensing your body and feeling present leaves you feeling "not like me"

Your nervous system stays on high alert - primitive brain structures automatically tense muscles and prime your system for threat before conscious thought kicks in

The key insight: Heightened pain sensitivity and disconnection after trauma aren't "all in your head" or your fault - they're real physiological changes in how your brain processes sensations to keep you safe.

Bottom line: Feeling transported back to fear by physical sensations is your brain's protective mechanism gone into overdrive. Healing requires both top-down cognitive work and bottom-up body practices to help your brain integrate and feel safe again.