What happens neurologically after a traumatic event has occurred?
We human beings are tough, and we are programmed to survive. However, when we have survived trauma, the need to escape it again in the future can intensify to the extent that we live in a state of ongoing threat and arousal, and this can wreak utter havoc in our employment and relationships. Being traumatised means that life is organised as if the trauma is still happening and so the nervous system changes. In PTSD, the body continues to try to defend against an event that occurred historically, and the frontal parts of the brain are offline. The amygdala cannot distinguish between the past and present, so the powerful stress hormones and nervous system responses keep on happening. It is incredibly disruptive if your smoke detector shouts ‘fire’ when this is absolutely not the case. However, the body and brain would rather be safe than sorry, and so it becomes hypervigilant for cues from the original threat. This ongoing effort can take its toll on the body, leading to autoimmune diseases, chronic fatigue and many other physical symptoms. When a traumatic event is particularly overwhelming, dissociation is often the result. Dissociation occurs when the overwhelming experience splits itself off, and the sensations of the traumatic event take on a life of their own, intruding into the present. Defensive, emotionally reactive responses keep happening even though the original trauma is over. Minor problems become major issues. Organising life to prevent against triggers is exhausting and can lead to fatigue and depression. Therapy can support you to make connections between the past and the present, and to understand which emotions underlie this sort of reactivity in response to the original threat/trauma. There is an indescribably strong link between mental and physical processes and working with trauma means helping the individual identify, name and eventually control sensations and emotions (Van Der Kolk, 2015).
If you are a ‘details’ person, the following points highlight some key neurological processes to do with traumatic responses:
{Bessel Van Der Kolk's (2015) book 'The body keeps the score' supported me in writing this section and is a fascinating read}.
The thalamus, which processes all of the sensory inputs, can break down in the midst of trauma. So instead of sensory inputs being remembered as a narrative or a story with a beginning, middle and end, they are experienced instead as intrusive emotions, images and thoughts related to the trauma. The body then moves from a ‘green’ state to an ‘amber’ or ‘red’ state, meaning that it is flooded with stress hormones and over-aroused. This is the essence of the ‘re-experiencing’ element of PTSD - perhaps as intrusive thoughts, unwanted memories or nightmares.
The body has two main brain systems - the mammalian and the reptilian brain. The mammalian brain leads to the fight or flight response and the reptilian brain leads to collapse - freeze or faint/flop. Following trauma, the nervous system changes so that danger and safety are perceived differently. When the amygdala (smoke detector) malfunctions, this can lead people to approach situations that are actually dangerous because it helps them feel alive compared to the less-favourable sense of shut down/collapse, but it can also mean people stay in traumatic, abusive situations instead of defending themselves. The reptilian brain, or ‘emotional’ brain, is deeply connected to the nervous system and its primary function is to look out for your wellbeing through neuroception (sensing danger or safety). It is much simpler than the mammalian (rational) brain and leaps to conclusions, using pre-programmed escape plans (fight/flight/freeze). But the sensations triggered by the emotional brain impact our decisions deeply - where we hang out, who we like/dislike, our hobby preferences etc.
When an individual has experienced trauma, attention is more naturally diverted towards possible threat cues, even if they aren’t threatening at all. The front/mammalian brain (capable of language, rational thought, empathy, planning and predictions) goes ‘offline’ and therefore so does its capacity to accurately assess a situation for genuine danger. For example, if a person attacked you who was wearing a red hoodie at the time, every time you see a red hoodie, they amygdala shouts fire! But if they’re clearly going to do you no harm, this is problematic. The rational brain is usually able to help you understand the smoke detector is overreacting and this means that you don’t become angry every time you are made to wait for something. PTSD means that this capacity becomes impaired, so emotional impulses are far harder to control. Intense feelings such as sadness, fear or anger mean that areas of the frontal lobes/rational brain/mammalian brain shut down and you can find yourself overreacting to small frustrations, freezing quickly if someone touches you or startling to any loud noise.
Flashbacks make you feel as if you are actually back in the traumatic event. This is because the part of the brain responsible for timekeeping shuts down (the right and left dorso pre-lateral frontal cortex) and it feels as if time collapses with no sense of past, present or future.
When aspects of trauma are replayed repeatedly, they become engraved in the mind and ordinary day-to-day events become less enjoyable. It becomes harder to feel in tune with the usual ups and downs of everyday life, and there may be difficulties with concentration. This bodily focus on the trauma, which feels inescapable, keeps the individual feeling locked in their past rather than grounded in the present.
When trauma is particularly overwhelming, the natural response is dissociation. There may be a vivid mental picture of what happened without any feelings - hence feeling numb. It is characterised at the time of the trauma by the mind going blank, feeling nothing and all areas of the brain showing minimal activity (depersonalisation). Or there may be intense feelings like shame, horror or fear, but no story to map those feelings onto - hence re-experiencing. It is like a ‘join the dots’ picture, but with no means to join the dots. In this state, the body and mind are ‘dis-integrated’. This is particularly likely to occur when the trauma is repeated and particularly overwhelming. If a child mentally ‘checks out’ during episodes of sexual abuse for example, this can extend into adulthood with the individual describing that they feel disconnected and unsure whether events really happened to them or not.
Reference
Van Der Kolk, B. (2015) The body keeps the score: Mind, brain and body in the transformation of trauma. London: Penguin.