Research shows that children and adults with histories of child abuse often respond excessively to minor triggers. Traumatised children (and adult survivors) become increasingly responsive to relatively minor stimuli as a result of decreased frontal lobe functioning (learning and problem solving) and increased limbic system (amygdala) sensitivity (impulsiveness) (Streeck-Fischer & van der Kolk, 2000).
Decreased cortex activity
The cortex or the more rational, outer-layer of the brain is the seat of our thinking capacity. The cool, rational cortex is in constant communication with the amygdala and the hippocampus (the limbic system). The frontal lobes are situated in the cortex and are responsible for learning and problem solving. The capacity to learn from experience requires events to be registered in the prefrontal cortex, compared with other experiences and evaluated for an appropriate response (Streeck-Fischer & van der Kolk, 2000).
When children are under threat, the fast tracts of the limbic system are likely be to activated before the slower prefrontal cortex has a chance to evaluate the stimulus (Streeck-Fischer & van der Kolk, 2000). Only a state of non hyper-arousal allows activation of the prefrontal cortex needed for learning and problem solving.