How Trauma Changes the Brain

My name is Nicole Priesmeyer, I am a Licensed Clinical Social Worker.  I have both my Bachelor’s and Master’s Degrees in Social Work from Texas State University and my work experience has exposed me a great deal to traumatized children, adolescents, and adults.  While I have a background in trauma work I am not an expert and certainly am not a physician.  This is intended to be a very basic look at the brain, how it works and how it is affected by traumatic events.

Anatomy of the Brain

I wanted to start with a very basic look at the brain’s anatomy.  The brain develops from the bottom up and from the inside out.  It is put together like building blocks. The top part depends on the lower part for development.  The top part is the most changeable and the easiest part of the brain to modify.  The lower parts are the most impacted in childhood and adolescence and are harder to change particularly the older you get.

At the base of our brain is our survival mechanism, the brain stem.  It regulates breathing, heart rate, and blood pressure.  It speaks only the language of survival.  When we are born we are operating purely from our brain stem; distress or contentment; however, our feeling brain is beginning to develop by three months of age.

Above the brain stem is our Cerebellum.  It is also called the “little brain” and it is responsible for our movement, posture, and balance.

The next part of the brain, the top part, the Cerebrum, makes up about 85% of the brain and involves 2 hemispheres divided into 4 lobes, each controlling different functions.  This is the part of the brain that makes us fully human, but the other parts of the brain must develop healthy first.

  • The Frontal Lobe, behind the forehead, is responsible for reasoning, planning, speech, movement, emotion, and problem-solving –
  • The Parietal Lobe, behind the frontal lobe, handles movement, orientation, recognition,  and perception of stimuli
  • The Occipital lobe is located at the back of our head and controls our visual processing
  • The Temporal Lobe is near our temples and regulates our perception and recognition of auditory stimuli, memory, and speech.

Our right hemisphere is generally associated with creativity and our left with logic.

The area of the brain we are most concerned with for this presentation is buried deep within the Cerebrum and is known as the “limbic system or emotional brain”.  It contains The hypothalamus, the hippocampus, and the amygdela.

So why are we most concerned with the “Limbic System”?  Studies, imaging, research, and experience have taught us and continue to show us that traumatic events in childhood change the normal structure of the brain, particularly the hormone and chemical regulation centers of the brain, you guessed it the limbic system.  The limbic systems’ maturation is Experience-dependent.  The brain’s structural organization reflects the history of the organism, the host, the human.

The good news is that until the day you die you have the ability to add new neurons to your brain.  The brain is more like the skin in that it can rewire and heal its self in the most important areas.

How Trauma Effects the Brain

First lets take a look at how we define trauma.  According to an article by Kathleen Moroz:

Trauma – is a physical or psychological threat or assault to a child’s physical integrity, sense of self, safety or survival OR the physical safety of another person significant to the child.

What are traumatic events?  Some are obvious, while others may surprise you;

  • Abuse; sexual, physical or emotional
  • Exposure to violence
  • Severe natural disaster ( flood, fire, earthquake, tornado)
  • War/ Military Action
  • Abandonment
  • Witness to violence ( neighborhood, school settings, fights, law enforcement actions)
  • Personal attacks by person or animal
  • Kidnapping
  • Severe bullying
  • Medical Procedures ( surgeries, accidents, serious illness)
  • Anything life threatening can have the same effect as a soldier out of battle, particularly if there is restraint involved.

According to Dr. Bruce Perry, a human is exposed to 200,000 acts of violence by the time they are 19 years old.  Our brains create a blueprint for every experience we have and it stores the sight, sound and smell in different places in the brain.  You may have no conscious memory of the event but the imprint is there.

This is a particular challenge for pre-language children.  As adults when we have an experience of any kind, we store it with our language.  We assign a label or multiple labels to the experience and as Dr. Perry states, we then store it in multiple parts of the brain.  So we may hear a song that reminds us of a romantic encounter or smell a particular food that draws up memories from holidays and celebrations or we may see a field in the distance and be reminded of a place we have been before.  In fact, when damage is done to one part of the brain we may still have a memory stimulated of an event from another part of the brain because we store according to our language and our sensations.  We have multiple places and triggers from which to pull these memories.

These all sound like perfectly pleasant functions of our brain, however the same is true for negative experiences. For the pre-language child, these memories do not get assigned in the same way that they might for the child with language and can be very confused and sort of malingering in the brain without an assignment.  But again the blueprint is there.

The sponginess of the brain in childhood makes children more susceptible to trauma by way of the same mechanism that allows us to learn a language and walk by three years of age. Development is the transformation of external into internal regulation; that is how the brain systems regulate the interaction between the person and the social environment.

Effects of Trauma on Children

There are 2 response patterns to a trauma;

First, the startle or alarm reaction begins, and the nervous system is suddenly and significantly activated. This is the fight or flight response. Our heart rate increases, our blood pressure goes up, our respirations increase and our muscle tone increases. We are in a state of hypervigilance.  Our body releases high levels of major stress hormones including noradrenaline essentially setting the limbic part of the brain on fire.

When kids are chronically stressed they are so focused on survival that is difficult for them to connect with others.  When a child experiences fear, the thinking systems in the brain shut down.

The second thing that happens is that after so much of this overstimulation of the limbic system the brain will begin to dissociate;  The brain will disengage in the midst of a traumatic event, numbing, avoiding, and having a restricted affect.  In this passive state, the pain numbing and blunting occurs because the brain has released its natural opiates and cortisol which decreases blood pressure, heart rate, and respiration.

Trauma is cumulative, so in a repeated traumatic state, both the hyperarousal and the energy conserving components of the brain are hyperactivated.

In the developing brain, these responses become a part of the blueprint we talked about earlier and can result in an enduring state of arousal or disengagement.   Imaging of the brains of trauma victims shows more activity in the more primitive brain than the healthy brain which will show more frontal lobe activity.  Survival overrides thinking.

They also create a toxic chemical environment that causes cell death and structural alteration of the brain.   On MRI, we see functional, structural, chemical, and biological changes in the traumatized brain.  This will reduce the future adaptive coping functions of the brain.