THE PREFRONTAL CORTEX :
First, I will describe the main functions of the brain’s prefrontal cortex ; they are as follows :
- modulates feelings of fear associated with threat (eg calms us down if a raised alarm turns out to be a false alarm)
- controls the intensity of our emotions (so we are neither inappropriately under-emotionally aroused nor inappropriately over-emotionally aroused)
- helps us to plan and control impulsive, ‘knee-jerk’ reactions
- helps us to become mentally attuned to others and to empathize with them
- provides us with a moral awareness and ethical framework
- provides us with insight into the workings of our own minds
- helps us behave rationally
- helps us to think logically
- helps us maintain a healthy balance between hyperarousal (too much arousal) and hypoarousal (too little arousal).
How Early Trauma Adversely Affects The Development Of The Prefrontal Cortex :
Even in emotionally and mentally ‘healthy’ individuals, the prefrontal cortex does not become fully developed until the age of about 25 years; this is a major reason why the behaviour of someone aged, say, eighteen, is often more erratic and ill-considered than that of a person aged, for example, twenty-six years. (It follows from this that a strong argument can be put forward that courts of law should take into account the underdevelopment of the prefrontal cortex in younger adults when considering sentences for this age group.)
Also, crucially, the development of the prefrontal cortex is particularly sensitive to the emotional and psychological environment in which we grow up.
Indeed, if one has suffered severe trauma when growing up, the prefrontal cortex (specifically, the ventromedial prefrontal cortex) may not physically develop to its usual size and, therefore, in adulthood, be of a smaller volume than average.
This can inhibit the functions listed above to varying degrees (depending upon the degree to which the development of the brain region has been damaged). In particular, the individual affected in this way may develop hypersensitivity to stressful stimuli, an inability to calm him/herself down when experiencing stress (sometimes described by psychologists as an inability to self-regulate emotions) and abnormally high levels of fear and anxiety.
Extreme fear responses and high levels of anxiety are particularly likely to occur when an individual who has incurred damage to the prefrontal cortex due to childhood trauma experiences a stressful event or situation which triggers memories (on either a conscious or unconscious level) of the childhood trauma.
HOPE OFFERED BY NEUROPLASTICITY :
However, there is hope for people who have been affected in this way due to a quality of the brain known as ‘neuroplasticity‘ which allows the brain to repair itself. You can read about this in my article Mending The Mind With Self-Directed Neuroplasticity.
David Hosier BSc Hons; MSc; PGDE(FAHE).