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Neurobiology of Trauma

When someone experiences a traumatic event or experiences extreme fear, brain chemistry is altered and the brain begins to function differently--this is called the "Fear Circuity" and it is a protective mechanism which we all have inside of us.  The neurobiology of trauma--essentially the effects of trauma on the brain--is important to understand because it helps break down common misconceptions and victim-blaming about gender-based violence and it helps survivors to understand their experience and the aftermath in a new way.  We encourage you to watch the video below by Dr. Jim Hopper and read through the information on this page to learn more!

Neurobiology of Trauma helps to explain many of the common behaviors and experiences of survivors of gender-based violence.  Having an understanding of how trauma affects the brain helps to dismantle common misconceptions and victim-blaming statements about sexual violence.  Please read the Myth vs Fact document below to learn more!

Myth vs Fact

Key Concepts

The prefrontal cortex is the decision-making/choice-making part of the brain; it's the part of the brain responsible for rational thinking, planning effective responses, remembering important information, etc.  When a person is experiencing a traumatic event or experiencing extreme fear, their "Fear Circuitry" may kick in and the prefrontal cortex begins to function less effectively.  This means that in the midst of trauma, a person may not be able to think through the situation and make decisions such as calling for help.  It is not a matter of choice--their brain is in survival mode and the fear circuitry is bypassing their prefrontal cortex entirely.  

Many people are familiar with the concept of "fight or flight," but research shows that there is a third response called "freeze."  A common example is a deer in the headlights, and humans have this same fear response--in fact, freezing is the most common reaction to trauma or fear, rather than fighting back or running away.  

In addition to freezing, some survivors may experience extreme survival reflexes such tonic immobility or collapsed immobility.  If you've ever seen a possum go limp when it is scared, you are familiar with this brain response.  Going limp, feeling "sleepy" or passing out, or being completely unable to move or speak are survival mechanisms hard-wired into our brains--even apex predators like sharks have these responses!  It is not a sign of weakness, nor is it a choice the person is making. 

Survivors may also experience dissociation, which is a survival reflex where someone may feel disconnected from their body or may go into "auto-pilot" mode.  In auto-pilot mode, a person is not using their prefrontal cortex to make decisions, but is instead relying upon habitual modes of being.  Habitual responses are rooted in socialization--for example, women are socialized to be polite and pleasing, to "save face" or placate.  This means that during an assault, a person might engage in sexual acts, say polite things, even smile, but they are not consenting; they are actually experiencing extreme fear and their brain is operating on auto-pilot as a survival mechanism. 

Memories are encoded differently during a traumatic event.   The brain does not encode memories in chronological order, there are gaps in memory, and whatever the "fear circuitry" in the brain focused attention on during the assault is more likely to be encoded into memory than periphery details.  For example, a survivor may have a very clear memory of the smell of the perpetrator's cologne, but not have any memory of what the room looked like. Contextual information (e.g., the layout of a room) and time‐sequence information (e.g., the order in which sexual acts occurred) are often poorly encoded. Again, this is not a conscious choice a survivor is making about what to focus on or remember during an assault; it is a common  impact on the brain when the "fear circuitry" survival response kicks in. 

These are all based in normal brain processes that occur during extremely
stressful and traumatic situations. They can happen to police officers, soldiers – anyone who is attacked or fears for their life.