The trauma response – how does the brain respond?
What happens within the body when we experience a traumatic event? How does that link with the experiences we have later in life?
Well, first of all, we need to take a look at the definition of trauma.
Trauma can be defined as the response to a deeply distressing or disturbing event that overwhelms an individual’s ability to cope. Causing feelings of helplessness, diminishing sense of self and the ability to feel a full range of emotions and experiences. Trauma is often differentiated as being physical or psychological in nature.
In early childhood, we may encounter various different experiences that overwhelm our ability to cope. During our formative years, as our psychological and social capabilities are developing, if we are exposed to certain stimuli or certain environments, it’s possible for us to be overwhelmed by a range of different experiences. This may include, for example, physical violence in the family home, emotional neglect by our caregivers, all the way to an embarrassing event at school that brings on intense feelings of shame or guilt.
As we grow older and our psychological development matures, we can still encounter many different scenarios that overwhelm our ability to cope. As adults, this may be in the form of relationship trauma – where you are exposed to either psychological intimidation or physical violence. It could involve the death of a loved one such as a partner or family member. It could also include going through a very difficult dynamic at work such as being bullied by a demanding boss. The mechanisms of trauma are widespread. But what happens in our bodies as we have these different experiences?
There are three well-known and commonly widely used phrases that explain our initial response to trauma. These are referred to as the fight, flight or freeze responses.
The fight response is when the sympathetic nervous system increases its activation level; which increases heart rate, increases blood pressure and respiration rate amongst many other bodily processes. Crucially, there is a change in blood flow from the muscles involved in digestion, with a shift in circulation towards the muscles in the arms and the legs. This change in blood circulation primes and readies the body to physically fight to defend itself. The fight response as with all of the responses to trauma is initiated by a small almond-shaped part of the brain known as the amygdala – sometimes called the ‘fear centre’ of the brain.
The next response is the flight response. Similar to the fight response, when activated by the sympathetic nervous system there is a shift in circulation from the digestive organs and processes towards the limbs. The arms and the legs prepare the body to run away. In this case, the nervous system is preparing itself to leave the threatening environment as quickly as possible in the hope of fleeing danger.
The freeze response is an additional adaptive option that can be taken in response to a traumatic experience. This is essentially feigning death. In this scenario, the person actually cannot move – the muscles enter a frozen state. This is a different kind of response to the fight or flight response in the way that there is both sympathetic nervous system activation and parasympathetic nervous system activation simultaneously. In the freeze response, there is an equal activation of both these nervous systems (like the accelerator and the brake being applied at the same time), and so we reach a position of freeze.
In terms of brain anatomy, this response is mediated by the peri aqueductal grey in the midbrain region. This part of the brain connects to higher brain regions which control the function and activity of the muscles. When the freeze response is engaged, the brain essentially completely decreases activation in the prime mover muscle groups. This causes the person to shut down in the hope that the predator will move away. While in this free state, people’s muscles become limp and their metabolism shuts down. A key difference in this freeze response is what happens alongside it.
When an individual enters the freeze response, the brain also releases endorphins. These are the brain’s natural painkillers. This is crucial because when the individual enters the freeze state they are limp and the body is shut down. This endorphin release helps the person to temporarily enter a state with no awareness of pain. The advantage to this is that if someone is experiencing a very disturbing event, the brain is able to go into this adaptive freeze response so you do not feel pain. You lose awareness of your surroundings and you temporarily shut down.
Running simultaneously to these fight, flight or freeze responses, the brain is also preparing itself for future safety. During the distressing event, the mind will record and store information for future protection. The mind will record the visual, auditory (sound), kinesthetic (feelings), smells and tastes that are being experienced at the time. The mind will compile this collection of sensory data into a specific format known as a Polarised Memory Image (PMI).
The impact of certain hormones released during the stress response during traumatic events prevents the smooth integration of the memory in the brain – in particular a region called the hippocampus. The hippocampus is crucial for both learning and memory. When the fight, flight or freeze response is initiated, part of the sympathetic nervous system initiates the release of a hormone called cortisol.
Cortisol is commonly associated with being the ‘stress hormone’. In reality, cortisol is very important as it helps to increase our metabolism to give us the energy to get ourselves going in the morning and throughout the day. But when Cortisol is released in excessive amounts, as in the case of during a traumatic experience, cortisol impacts the functioning of the hippocampus in the brain.
The effect of cortisol on the hippocampus is two-fold. The immediate effect is that the memory cannot be effectively processed and integrated which leads the painful experience to remain in the mind as a series of fragmented moments. These can create extreme emotional distress as they get replayed over and over again. Over the longer term, cortisol causes the hippocampus to shrink in size, reducing the effectiveness of short-term memory and diminishing the brain’s ability to process future memories.
After the formation of the PMI – which essentially is a catalogue of sensory data associated with an extremely painful or distressing event, the brain will now scan the environment for any semblance of similar circumstances. This process is called Neuroception. Anything that your mind can relate back to that original event will trigger the stress response. For example, if the event was that your mother was verbally critical and physically aggressive towards you in a specific moment during your childhood, your mind will store all of the visual, auditory and kinesthetic data from that experience in the PMI. When you are later involved in a situation that includes verbal criticism, the previously painful PMI will flash up in your mind’s eye (at a below-conscious level) triggering the natural stress response of the body in the same way that it did all those years ago. This will continue until the memory is effectively integrated, meaning some people will continue to be triggered years or even decades after the original event.
The longer the duration the PMI has been present, the more likely it is that it will undergo a cognitive distortion called a generalisation. This is when specific elements of a painful experience evolve, expand and generalise over time. In our earlier example, even though the initial event involved your mother, as your mother is a female when the event generalises you may notice that you become triggered in the presence of any female who in some way reminds you of your mother. This again is the process of neuroception at work, scanning your environment for any potential threats or challenges to your survival.
Depending on your initial response (fight, flight or freeze), you may notice that you continue to have the same type of response as you did back then.
One powerful way to reduce and potentially resolve the emotional impact of those previously painful experiences is to access and directly work with the PMIs.
As the polarised memory image is stored in the subconscious mind, traditional talking therapy may not be effective in helping you to successfully reduce the impact of the event. However, various other approaches – such as hypnotherapy – that allow you to connect or even communicate with the subconscious mind can be incredibly effective at helping you to reduce or resolve the impact of those stored PMIs.
When the PMI has been neutralised and integrated, the memory can fade away like every other memory that no longer serves you can. The result is, therefore, you no longer get triggered and you’re free to be present in the moment.