The Neurobiology of Trauma

Why we all should understand the brain

When you hear ‘neurobiology of trauma’, what is your first thought?
Perhaps you recall the four Fs: fight, flight, freeze, and fawn. Maybe the word neuro makes you think of the brain. Or maybe ‘neurobiology of trauma’ is a whole new concept to you.

No matter where you are in your understanding of the neurobiology of trauma, there always seems to be more we can learn about how the brain responds to the world around us. Because we have all experienced some form of trauma at some point in our lives, understanding what happens to our minds and bodies during a traumatic event could help us better understand everything we do, or don’t do, after that event. This understanding could also help us appreciate why no two people will respond to a traumatic event in the same way.

Does normal even exist?

My normal and your normal may be very different. So, who exactly determines what is normal?

Think back to your childhood. No one, not even your sibling (if you had any), had the same childhood experience that you had. What we experience in our childhood is our personal normal. Then, as we move into adolescence and adulthood, we may realize that some experiences aren’t what we’d consider normal anymore. But this does not change the fact that in our youth these particular things were “normal” to us.

The bee sting analogy

I want to offer a simple example of a traumatic event: your first bee sting. Think back to your reaction. How did you respond?
— Did you say “ouch!” and move on?
— Fall to the ground and scream and cry?
— Or maybe you had seen someone else have an allergic reaction to a bee sting and this caused you to feel panic and fear?
All of these reactions are normal, based on our experiences of the world around us and how our brain has processed and stored these experiences.

I don’t remember my first bee sting. I imagine it hurt, but I quickly moved on. However, I do remember my brother’s first bee sting. We were sitting on the back porch, eating frozen treats we just got from the ice cream truck. They were dripping down our hands and legs and we were enjoying the experience. I remember him saying ‘OUCH!’ and crying a little. Within a minute or two, his entire leg was swollen, and the swelling rapidly spread across his entire body. I remember his eyes swelling shut alongside my parents' growing fear and sense of urgency. He was taken to the hospital and given epinephrine. This is how we discovered his allergy to bees. And now that I have children, I feel fear and anxiety when I see a bee near them because I don’t know if they’re allergic. I don’t know if they’ll be okay or swell quickly, gasping for air.

If you felt panic and fear from the bee sting, there is a chance that you don’t entirely remember the sequence of events that followed the actual sting. But your brain did a great thing by having an acute response — it reminded you that this bee sting could be fatal, and it made sure you responded accordingly at the moment. This is typical for any major trauma, like sexual assault. After a sexual assault, victims often struggle to put the pieces of their story together. This is normal because of how the brain responds during the actual assault.

“I should be able to remember what happened to me…” “Maybe it wasn’t as bad as I thought…” “Maybe I said yes, but…” These are words that often come from the mouths of survivors. They may feel shame, guilt, frustration, or even a sense of betrayal by their brains. However, our brains are wired for survival. It’s instinctual. When our brain detects danger, it takes over to keep us alive.

Sexual violence and the brain

Rebecca Campbell, Ph.D., a Professor of Psychology at Michigan State University, did extensive research on the neurobiology of trauma. Dr. Campbell conducted MRIs on individuals who’d been sexually assaulted and found that the same parts of the brain lit up no matter what type of sexual assault occurred. She theorized, therefore, that the trauma induced by the assault is the same, no matter the type of assault (i.e., rape, harassment, trafficking, etc.).

Campbell notes, specifically though, that because the information that enters the victim’s brain and body during a sexual assault is “one of the most psychologically damaging forms of crime that anybody could experience” the amygdala is going to recognize this as a threat to the sustainability of the organism (this same response, Campell recognizes, occurs in a victim of attempted murder). The amygdala, processing at this level of severity, signals to the hypothalamus that there is an incoming “threat to the sustainability of the organism”. The hypothalamus, then, signals to the pituitary and the HPA axis, which results in a “flood” of hormones into the victim’s body. It is then the combination of hormones that will determine the variety of outcomes the victim will have available to them.

What is so telling about the severity of sexual violence, according to Campbell’s research, is that the brain is impacted similarly, no matter what type of assault. This is one of the reasons that conceptualizing sexual violence along a continuum is extremely important. Sexual violence is not merely rape, though it is likely that many believe that to be true. No matter the behavior or offense, the impacts can be the same for every survivor. It is important to note that there is one thing that every single behavior has in common no matter where it lies on the continuum — they’re nonconsensual. Sexual violence is the act of violating another’s sexual boundaries or denying their right to sexual boundaries through force, intimidation, coercion, manipulation or other abuses of power. Sexual violence is often experienced as life-threatening. Even ‘minor’ forms of sexual violence can be experienced as life-threatening due to the potential of escalation (STAR, 2020).

The (dis)order of things

What is a behavior that you’ve observed in someone discussing or recounting a sexual assault that seemed suspicious or “sketchy,” or different from how you thought a sexual assault victim should act? Maybe you’ve seen this firsthand, or perhaps on a television show or movie.

There are many reasons why a victim’s story may be out of order, or why pieces may return days after their traumatic event, or why their responses may be different from what we would deem normal. This is the neurobiology of trauma.

Brain anatomy and function

Take your palm and place it on your forehead (aka — facepalm); this is your prefrontal cortex. This is the part of our brains that makes us human — it’s our planning center, decision maker, where working memory and problem solving occur.

During traumatic experiences, for example, a sexual assault, our prefrontal cortex shuts down, which means our decision-making/problem-solving center isn’t functioning as it should. Instead, the amygdala wakes up and our survival instincts take over. Think of these instincts as automatic responses. Have you ever heard stories of individuals gaining superhuman strength in a stressful situation? Their logical thinking would tell them they could never perform such a feat, but their automatic response says otherwise. This is also where ‘fight, flight and freeze’ occur. The amygdala determines the best response to keep us alive. This part of the brain also processes emotions and signals the hippocampus to encode a memory of the trauma.

The amygdala isn’t the only thing firing during a traumatic experience. Once a threat is detected, it notifies the adrenal gland that there is danger. The adrenal gland responds by sending a flood of stress hormones through the body.

During a traumatic event, our brain is keeping us alive, hormones are causing physical and emotional responses beyond our control, and our automatic responses may not be what we think they will be. During a sexual assault, an individual may resist, or not, they may show emotion or no emotion (or maybe both), and there is the possibility of ‘positive’ emotion, such as laughter. It’s important to remember that this is an automatic response, not because an individual thinks anything is funny. This automatic response happens in less than a second. Automatic responses may be actions, words, behaviors, etcetera. Imagine you stub your toe very hard…what comes out? A scream, a curse word, tears? What comes out is an automatic response to a painful (or stressful) situation.

Both the amygdala and the hippocampus are very sensitive to hormones — and there are a lot of hormones coursing through the body. Due to the increase of stress hormones, and impaired functioning in the hippocampus, memories may be fragmented, and recall may be slow and difficult, often coming back in pieces that aren’t chronological or properly oriented. However, events of the trauma can be accurately recalled in most cases. An individual needs time after an assault, or any traumatic event, to put the pieces together. Drug or alcohol use, whether voluntary or involuntary, may prevent memory encoding and can mean a survivor will be unable to recall some or all of their trauma.

Labeling survivors before identifying the impacts of trauma on the brain

It’s not unusual for survivors of sexual assault to be deemed liars. Sexual trauma can greatly affect memory recall and, oftentimes, the assault and aftermath can be overwhelming and even re-traumatizing. If a survivor calls 911 for help after an assault, they will first have to speak with dispatch, then a patrol officer, then a detective, then the triage team at the hospital, which will likely be followed by the intake/administrative person, a nurse, possibly a doctor, a medical advocate, and maybe even more individuals. Given this information, consider the potential for inconsistent statements. Bits and pieces of their assault come back over time; therefore, the story will most likely change — this does not mean they’re lying. Some ways that a sexual assault can affect memory recall include:

• Inconsistent story
• A timeline that seems out of order
• Appears to make it up as they go along
• Lack of emotion during the recount
• Lack of resistance during the assault
• Pieces missing or “cloudy”
• The story becomes “sketchy”
• Interpreted as evasiveness or lying

Waiting 24–48 hours to request details allows the best chance for a comprehensive story from a survivor. This also allows them time to collect their thoughts, reduce the initial overwhelm, and find some of their bearings.

Key takeaway: Believe Survivors

The best thing you can do if you’re talking to someone who’s experienced a sexual assault is to believe them.
Listen: “I hear you.”
Empathize with compassion: “Thank you for trusting me with this, I cannot imagine how difficult that experience has been for you.”
Validate their experience: “Everything you’ve said/felt is okay.”
Provide support: “Know that I am on your side.”
All of these things will empower them to heal. Through a better understanding of what happens in the brain and body during a traumatic event, maybe we can all work to show more grace to those around us. We never know what trauma a person has been through.