Features
Understanding the body’s response to psychological trauma – final part
For instance, while waiting for your friend to arrive, you might already be smiling as your amygdala (Panic alarm system in the brain) identifies her familiar posture and gait from a distance. In nervous system time, your smiling response appears long before you have consciously recognised her face as she approaches.
On the other end of the spectrum, it is also the amygdala that evaluates sensory information (what is seen, heard, etc.) as comprising danger. In such an instance it will raise an alarm and instruct the body to respond quite differently, to run away or dive for cover, fend off, go numb or faint (freeze).
Another structure in the limbic system, the hippocampus, is very important for managing, remembering, and recovering from trauma.
Among other things, it is the hippocampus that registers and then informs the cortex about the time context of an event. It marks the memory of each event with a beginning, middle and end.
It will usually do that for any event, recording and then telling the cortex when it started, how long it proceeded and ended. Take special note of that last step of hippocampal sequencing, recording that an event has ended.
With regard to recollecting traumatic event this is very important.
Typically, Post Traumatic Stress Disorder (PTSD) is the result of a hippocampus that was not able to mark the end of traumatic event. It was never able to tell the cortex that the trauma ended. Such a failure of the hippocampus is really the result of PTSD.
When the hippocampus is able to recognise and inform the cortex that a traumatic event has ended, the cortex can then instruct the amygdala that the trauma is over. Once informed, the amygdala can then halt its alarm response, telling the body there is no further need for hyper vigilance or flight, fight, or freeze. That is what happens when trauma is resolved—whether at the time or in the near or distant future.
The hippocampus recognises the end of it and informs the cortex, which in turn alerts the amygdala to stop all the defensive action. It is this feature of hippocampal function that makes trauma recovery possible. Without it, the amygdala will go on responding as if the trauma continues again and again.
This is what happens when the system fails and PTSD develops. In that case, the hippocampus fails to mark the end of the event, it is not able to inform the cortex, and the amygdala’s alarm persists.
By Robert Ekow Grimmond-Thompson