Three critical brain regions that may be adversely affected by significant and chronic childhood trauma are :
1) The thalamus
2) The amygdala
3) The hippocampus
Below, I will briefly describe the main functions of each of these three crucial regions of the brain, together with providing a summary of the damage they may sustain to their development due early adverse experiences.
1) Possible Adverse Effects Of Childhood Trauma On The Development Of The Thalamus :
The thalamus is the part of the brain that assesses all incoming sensory data (ie. information from sound, vision, touch, smell and taste) and then sends this information on to the appropriate, higher region of the brain for further analysis.
If a child constantly experiences trauma (for example, by frequently witnessing domestic violence perpetrated by a drunken father) the child’s thalamus can become so overwhelmed by the intensity and quantity of sense data it needs to process that it is no longer able to process it properly.
This can lead to the child’s memories of trauma becoming very fragmented.
Another effect of the thalamus being overloaded with traumatic sensory data is to shut down the cortex, resulting in impairment of rational thinking processes. Also, due to the shutting down of the cortex, many of the traumatic experiences are stored without awareness (so that they become unconscious memories).
Above : diagram showing the position of the thalamus, amygdala and hippocampus (together with other brain regions).
2) Possible Adverse Effects Of Childhood Trauma On The Development Of The Amygdala :
The amygdala is the brain region that responds to fear, threat and danger.
If a child experiences frequent fear due to childhood abuse the amygdala becomes overwhelmed by the need to process too much information. This can damage it in two main ways :
a) the amygdala becomes overactive and remains constantly ‘stuck on red alert’, leading the individual feeling constantly anxious and fearful, even at times when there is no need to feel this way, objectively speaking. An oversensitive amygdala is also thought to be a major feature of borderline personality disorder (BPD) is a serious psychiatric condition.
b) the amygdala shuts down as a way of protecting the individual from intolerable feelings of being in danger, which can have the effect of leaving the him/her feeling numb, empty, emotionally dead and dissociated.
3) Possible Adverse Effects Of Childhood Trauma On The Development Of The Hippocampus:
The hippocampus is the part of the brain responsible for long-term storage of memories. If trauma is severe, the consequential production by the body of stress hormones can have a toxic effect upon this brain area, reducing its capacity by as much as 25℅.
David Hosier BSc Hons; MSc; PGDE(FAHE).