Understanding the Neurobiology of Trauma

This project is supported by Grant No. 2013-TA-AX-K045 awarded by the Office on Violence Against Women, US Department of Justice. The opinions, findings, conclusions, and recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the Department of Justice, Office on Violence Against Women.

 

 

 

 

 

 

 

 

 

 

 

End Violence Against Women International (EVAWI)

 

Understanding the Neurobiology of Trauma and Implications for Interviewing Victims Christopher Wilson, Psy.D. Kimberly A. Lonsway, Ph.D. Sergeant Joanne Archambault (Ret.) November 2016

 

 

Understanding the Neurobiology of Trauma and Implications for Interviewing Victims

November 2016

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Authors

Dr. Christopher Wilson is a licensed psychologist and nationally recognized speaker and trainer from Portland, Oregon. For the past 16 years he’s worked with victims and perpetrators of crime. He currently has a small private practice of individual clients, conducts psychological evaluations for the Oregon Department of Human Services, and trains nationwide on a variety of issues including sexual assault, domestic violence, and the neurobiology of trauma. His audiences have included judges, attorneys, civilian, campus, and military law enforcement officers, college and university Title IX administrators and investigators, victim advocates, and mental health professionals. He has provided training for organizations across the country including the US Department of Justice, the US Department of the Interior, the US Navy, the US Marine Corps, the US Army, the US Office for Victims of Crime, and the National Crime Victim Law Institute. Dr. Wilson is also a trainer for the US Army’s Special Victims Unit Investigation Course, and two nationally recognized programs: Legal Momentum, providing training for the judiciary, and the You Have Options Program. Dr. Kimberly A. Lonsway has served as the Director of Research for EVAWI since 2004. Her research focuses on sexual violence and the criminal justice and community response system. She has written over 60 published articles, book chapters, technical reports, government reports, and commissioned documents – in addition to numerous training modules, bulletins, and other resources. She has volunteered for over fifteen years as a victim advocate and in 2012, she was awarded the first-ever Volunteer of the Decade Award from the Sexual Assault Recovery and Prevention (SARP) Center in San Luis Obispo, CA. She earned her PhD in the Department of Psychology at the University of Illinois, Urbana-Champaign. Sgt. Joanne Archambault (Retired, San Diego Police Department) is the Chief Executive Officer for EVAWI. Prior to founding EVAWI, Sgt. Archambault worked for the San Diego Police Department for almost 23 years, in a wide variety of assignments. During the last 10 years of her service, she supervised the Sex Crimes Unit, which had 13 detectives and was responsible for investigating approximately 1,000 felony sexual assaults within the City of San Diego each year. Sgt. Archambault has provided training for tens of thousands of practitioners, policymakers and others – both across the country and around the world. She has been instrumental in creating system-level change through individual contacts, as well as policy initiatives and recommendations for best practice.

 

 

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Acknowledgements

We are extremely grateful to the following individuals, for their valuable contributions to this Training Bulletin:

• Rebecca Campbell, PhD, Professor, Department of Psychology, Michigan State University, East Lansing, MI

• Roger Canaff, JD, Expert, Child Protection and Special Victims Advocate, Author, Public Speaker, New York, NY

• Elizabeth Donegan, Sergeant Supervisor, Sex Offender Apprehension and Registration (SOAR) Unit Austin Police Department, Austin, TX

• Catherine Garcia, District Attorney Investigator, San Diego District Attorney’s Office, San Diego, CA

• James W. Hopper, Ph.D., Clinical Psychologist and Independent Consultant Teaching Associate in Psychology, Harvard Medical School, Boston, MA

• David Lisak, Ph.D., Forensic Consultant, Trainer, Lecturer, Founder of The Bristlecone Project, Placitas, NM

• Richard Mankewich, Sergeant, Major Case / Sex Crimes, Orange County Sheriff’s Office, Clermont, FL

• Ronald Reid, Detective Sergeant (Retired, Washington DC Metropolitan Police) RKR Consulting, Clinton MD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Introduction Within the last century, the development of fingerprint technology, and then the discovery of DNA, both revolutionized the way law enforcement investigates crime. Both dictated widespread changes and adaptations in the practice of investigations, specifically with regard to suspect identification. Now new scientific advances have the potential to transform the way law enforcement conducts victim interviews, indeed, how victims are perceived. Specifically, neuroscience suggests that many common victim responses are actually the results of fear and trauma – not deception, as they have frequently been interpreted. Also, the way victims recount their experience often raises suspicion in the minds of investigators, prosecutors, judges, and the general public, including jurors, as well as their own friends and family members. This can be illustrated with case examples, such as Julie M., a local university student whose sexual assault was included in a report published by Human Rights Watch (2013). She was “forced to perform oral sex by a stranger,” and then “went to the hospital the next day and reported to the police” (p. 132). However, when police asked her to describe the assailant, she was unable to describe him in any detail. Julie M. felt like the police did not believe her, in part because she could not provide a specific description. Her case was subsequently closed (Human Rights Watch, 2013). Or the case of Jane Doe, also described in the Human Rights Watch report, who was sexually assaulted by a stranger after going out with friends. When she could not remember the name of the bar, the police reportedly questioned whether the report was legitimate (2013, p. 132). Then there is the victim who described to Sgt. Joanne Archambault how her report was handled by the detective assigned to her case. When she remembered a detail the day after her sexual assault, she called the detective to share the information. However, this

this raised such suspicion with the detective, she hesitated to offer any more information that came to mind. The examples go on and on. In too many cases, across the country and around the world, victims of sexual assault and other crimes have been subjected

to interview techniques that are at best ineffective – and at worst inappropriate or even abusive. Yet neuroscience research is now fostering a better understanding of the impact that trauma has on crime victims, and this has the potential to yield a number of critical improvements in the way interviews are conducted. At the same time, attention of policymakers and the public has increasingly focused on the low rates of reporting, investigation, prosecution, and conviction for sexual assault. One critical step in changing this reality is to improve the way victims are interviewed.

 

 

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Better interviews will result in more thorough investigations that can effectively exclude suspects, and support referrals for prosecution with a better chance to hold more offenders accountable. This training bulletin is designed to assist in this effort. The material included in this bulletin is drawn from a considerable body of research, including the publications and other resources in the Reference and Resource List at the end of the document. However, it is important to recognize that this list is simply a representative sample of publications in the field, not a comprehensive list.

Defining Trauma Before we can make sense of the neuroscience of trauma, and the implications for victim interviewing, we need to define the concept of trauma, understand a little bit more about the brain, and explore how we as humans have evolved to respond to threat and attack. For the purpose of this training bulletin, trauma is defined as an event that combines fear, horror, or terror with actual or perceived lack of control. Trauma is often a life-changing event with negative, sometimes lifelong consequences. In the past, all we had was an experiential definition of trauma. Due to scientific limitations, we were never able to talk about it beyond an individual’s subjective experience. With recent advances, however, we are now able to understand changes in the brain that occur both at the time of a traumatic incident, and in many cases in the days, weeks, months, and even years afterward. In other words, we used to be limited to “soft science” (i.e., social science) when describing the nature and impact of trauma. However, we can now have that discussion using “hard science” (i.e., changes in the brain during and following trauma). At the same time, trauma remains a fundamentally subjective event – what is traumatic to one person may not be for another, because what’s fearful or terrifying to me, may not be for you. What I experience as a lack of control, you may not. The distinction lies both in the “hard wiring” or conditioning of our brains, as well as the cumulative impact of learning and life experiences.

Brain Basics As we begin talking about “hard science” and the brain, there are a few disclaimers worth mentioning. First, when describing particular structures in the brain, we will be simplifying their function considerably. Each structure in the brain is involved in any number of functions, but we’re only going to be discussing a limited number of these functions here. To illustrate, you’re going to learn about the amygdala’s involvement in our response to threat, but the amygdala is involved in a lot more than threat responses. Second, while we can talk about the brain with more certainty than at any other point in history, we still have to consider that not every brain reacts the same way. Individual differences (including the results of nature as well as nurture) exert a significant

 

 

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influence on how the brain responds. This is why you’ll often see the phrases “for the most part” or “most of the time,” rather than more definitive language. What we will be describing are common victim reactions and behaviors, rather than absolutes. Finally, keep in mind that the discussion becomes even more complicated when you add drugs or alcohol into the mix. As complicated as brains are when they respond to trauma and threat, there are additional factors when substances are involved. So, with these disclaimers out of the way, let’s talk about the brain.

Neural Networks or Brain Circuitry The brain is made up of billions of cells called neurons. These neurons pass information between each other, and then to the rest of our body, chemically and electrically. They often “fire” in groups that can be described as neural networks or brain circuitry,1 and as you can imagine, this can be extremely complex at the micro-level. However, there are two main things we want you to understand about brain circuitry for the purpose of this training material. They’re Automatic First, it’s important to understand that many responses to trauma (both during a sexual assault and afterward) are often automatic – the result of neurons firing in patterns that you can’t just “wish away” or logically “think away.” In fact, many of the circuits that condition our responses to trauma have been ingrained or “baked” into the brain. They Protect Us from Attack Second, if you believe in evolution, these circuits can be seen as the result of an evolutionary process developed to protect human beings from attacks by predators, long before we had access to advanced weaponry. If you believe in intelligent design, they can be seen as part of the incredibly intelligent design that is the human brain. They’re Here to Stay Moreover, the patterns in which brain circuits fire don’t just go away. Whether they are patterns developed through evolution, or established through repetitive behaviors (like habits), we often fall back on them even after years of inactivity. Take the story of an 86- year old former paratrooper who stumbled down some stairs on his way to the kitchen. Instead of falling and breaking his hip, he “dropped and rolled” just like he was taught to do 66 years earlier. He didn’t think about it, he just did it. In this case, his brain circuitry

1 People use different terms to describe a number of related concepts, including neural networks, brain circuitry, neural circuits, etc. While there may be subtle differences in how these terms are used by scientists, they are used interchangeably for the purpose of this training material. In other words, the terms can be understood as essentially meaning the same things for the purposes discussed here.

 

 

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served as a blessing. But for those who are sexually assaulted, these circuits and habitual responses can increase their vulnerability and undermine their credibility. We will talk more about this later, but at this point, suffice it to say that brain circuitry established during a sexual assault will not just “go away,” simply because the assault ended. This is true regardless of whether the assault ended minutes ago – or if it was weeks, months, or years before. This is the same reason why veterans are often startled by the sound of a car backfiring, and they react with terror as if shots were fired. This can be seen moments after leaving the battlefield, or years after their combat service – even if they have received treatment for PTSD. Their brain circuitry didn’t simply dissolve and go away, just because the battle, or even the war ended. The same is true for all of us: Brain circuitry that is activated during a traumatic event will often continue to guide our responses for years to come, perhaps all of our lives.

Prefrontal Cortex Now let’s look at some other brain structures that will help you to understand the impact of trauma on human behavior and memory. We’ll begin with the prefrontal cortex. Physical Location To get a sense of where this region is in the brain, make a fist with your thumb on the inside of your fingers and hold your arm up. While it’s a rough three-dimensional diagram, it’s a pretty good one. Your forearm is your spinal cord. Your elbow is the base of your spine. Your palm just below your thumb is the base of the brain. Your thumb represents something called your limbic system (which we’ll discuss in a bit), and the two fingernails of your middle and ring finger are your prefrontal cortex. Logical Thinking and Planning Most folks who have heard of the prefrontal cortex are aware that it plays a role in our ability to think logically and plan. When you thought about what you had to do at work today, you were largely using your prefrontal cortex. When you decided to read this training bulletin, or made plans to get married, prepared to buy a car, etc. … all those decisions involved a logical decision and some planning, which heavily involve your prefrontal cortex. These are critical functions that are important to understand. Integrating Memories into “Stories” The second function has to do with memory. When it comes to memories of events – like the time you took your son to his first fireworks display or hosted a party for your daughter’s third birthday – you will tell others about these memories as if they were stories. Granted, the older you get, the less of the story you may remember, but for the most part, our telling of events will typically have a beginning, middle, and end. So,

 

 

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when you are asked, “What happened at the birthday party?” you may not put everything in chronological order, but you probably could, if the person you were talking to asked you to do that. In fact, you may not even respond to the question with a narrative description at all, but instead offer a basic summary (“It was great!”). That summary will typically be based on your ability to think about the party, evaluate your overall impression of what happened, and then put together a story of the event. Yet these memories do not become stories until the prefrontal cortex gets involved. Initially they’re just points of “data” – a collection of sights, sounds, and emotions. While a different part of the brain encodes the data points with context (such as temporal sequence) and associates the various data points with each other, the prefrontal cortex plays a crucial role in integrating those various data points and weaving them into a coherent account or narrative. This narrative is then what we produce when talking about a “memory” of an event, and it is what we expect people to produce when we ask them about an event they may remember. For example, it is what investigators typically expect to hear when interviewing a victim of a sexual assault. This is why they often react with suspicion when a victim doesn’t produce this type of memory or “story,” with a logical flow and a clear beginning, middle, and end. Controlling Attention The third role the prefrontal cortex plays is in helping us to control attention. With the assistance of your prefrontal cortex, you are typically able to decide what you want to focus on… whether it is a sunset, a conversation, or a training bulletin on the brain and trauma. This is called top-down attention. Why is it important for you to understand this? Because memory itself is a function of attention: If you’re not focused on something, it probably won’t get encoded into memory, so you won’t remember it. For example, if you’re sitting in a training workshop and your phone rings, your prefrontal cortex is involved in the ability to shift your attention from the workshop to make the decision to get up, leave the workshop, and take the call. To be clear, it may be habitual for you to look down at your phone when it rings, but the decision to focus on the call and decide whether to attend to it largely involves your prefrontal cortex. Summary of the Prefrontal Cortex So, to summarize briefly, the prefrontal cortex plays a role in three functions for our purposes: (1) Controlling our attention, (2) Integrating memory data into narrative “stories,” and (3) Planning/making logical (or rational) decisions.

Limbic System Now, let’s turn our attention to the limbic system, which includes a number of brain structures but can roughly be represented by your thumb, if you are still holding your folded fist in the air. In fact, all of the parts of the brain that are located below your fingers are called “sub-cortical,” which means they are not part of the “thinking brain.”

 

 

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Defense Circuitry One primary function associated with the limbic system is our defense circuitry. Remember those terms, neural network and brain circuitry? Well, the limbic system is part of our brain circuitry for defending ourselves against attack, which includes detecting threats in the environment and responding to them. Whenever you respond to a perceived threat, it’s going to involve the limbic system; it may not be something you are able to consciously think about or make logical decisions about. In fact, while we’re reacting to a threat, our prefrontal cortex may not even get involved. But, we will talk more about that later. For now, it is enough to know that the limbic system is involved in our defense circuitry, and therefore our responses to threat will often not be logical, reasoned, or thought-out. Memory Encoding The second function involving the limbic system is memory encoding. Earlier, we described how memory begins as a collection of data points in the form of sights, sounds, smells, or tastes. The limbic system plays a role in encoding those data points with context and associations that make it possible for the prefrontal cortex to later recall the data points in the context of a coherent narrative. Mess with the limbic system and you mess with the part of the brain that encodes data with the context and associations that help us tell the story of our memories. Emotions The final function of the limbic system that we will discuss is its role in emotion. You may have heard the phrase, “Emotions have no logic.” This saying is not entirely accurate in terms of neuroscience, but it comes from the fact that emotions get traction not in the prefrontal cortex (or logic center of our brains) but in the limbic system. As Chris Wilson often jokes in trainings, all you have to do is look at any 45-year-old man to know that having emotions and being aware of those emotions are two very different things! The having of emotion has more to do with the limbic system, while the awareness of that emotion comes from other brain systems. This is why you can sometimes see another person looking very sad or angry, but when you ask them whether they are feeling this way, they may genuinely say “no.” Of course, it is also possible they are lying, but for now, we just want to recognize that people sometimes have emotional experiences without conscious awareness. Summary of the Limbic System So, to summarize the limbic system for our purposes, it plays a role in three primary functions: (1) Emotion, (2) Memory encoding, and (3) Defense circuitry.

 

 

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The Brain and Threat or Fear Now we will turn our attention to exploring how the brain responds to threat and fear. This is critical for understanding the impact on behavior, memory, and later recall.

Ready State: Vigilance One primary role of the brain is to protect us by predicting what may or may not happen in the environment and to detect any threat to our survival. The technical term for this is vigilance. While many of us associate vigilance with post-traumatic stress and hyper- vigilance, we are all vigilant to some degree, all the time. When you and your kids are walking through a crowded mall, for example, you are more vigilant than when you are sitting at home in your living room. To be clear, you are still vigilant when you are sitting on your couch at home. It’s just that you are less vigilant than you might be at the mall. Similarly, a patrol officer driving on duty will be more vigilant than a civilian driving to the store. Both are still vigilant, it’s just that the higher level of vigilance in the officer will likely lead to picking up subtler cues in the environment suggesting the presence of a potential threat. This will lead to a relatively quicker response to the threat, which is why officers are trained to be more vigilant than civilians! Interestingly, our vigilance isn’t conscious most of the time – vigilance is a function of our brain circuitry that gets used so often we don’t have to think about it. The brain is constantly scanning the environment to detect anything that does not fit with what is predicted to be there, so we can identify potential threats, take measures to protect ourselves, and remain safe whenever possible.

The Amygdala: Early Warning System The brain then has an early warning system that detects potential threats in the environment – even before it can determine what to do about them. One way to visualize this early warning system is to remember the old TV show, Lost in Space. If you’ve never seen the show, the plot line is pretty simple: A family flies around in a space ship (which actually appears to be two paper plates, glued together and suspended by a string, with 1960s special effects at their very best). Together, the family lands on various planets, and inevitably their 10-year old son, Will, wanders off and gets himself into trouble. As you may remember, Will had a robot who accompanied him and warned him of potential danger by flapping his vacuum cleaner tube arms and saying, “Danger, Danger, Will Robinson!” Young Will then had a chance to respond to the threat (or in some cases get rescued), thanks to the robot companion who recognized the danger ahead of time. As trivial as this example may sound, it’s a great illustration of what’s going on in your brain in the context of a potential threat. Your amygdala is your “Danger, Will Robinson” robot; It alerts the brain to danger in the environment, even before you are consciously

 

 

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aware of it. Some people also think of the amygdala like a smoke alarm, alerting you to the potential of a fire that could destroy your home and even endanger your life. In other words, the amygdala plays an important role in the defense circuitry, triggering chemicals to be released into your brain and body, preparing you to react to the threat. (Sometimes this preparation takes place in only a fraction of a second!) We aren’t going to focus on those chemicals and the various roles they play here – but there are a number of sources of additional information listed in the Resource Box below. For our purpose here, it is enough to know that the amygdala triggers a cascade of responses to an identified threat in the environment. Where is the amygdala located? In your thumb, which is part of the limbic system, not the “thinking part” of the brain.

Scanning and Response Once a potential threat has been identified, we scan the environment to allow another part of our brain (the hippocampus) to help us compare what’s in the environment with what we know are indicators of either safety or danger. Essentially, the hippocampus provides us with “maps” of safety and danger that we can use to assess the threat. Here’s an illustration. When a fire alarm goes off, what do you automatically do? First, you freeze briefly and pay attention. Do you smell smoke? Do you hear a fire truck approaching? Do you see others exiting the building? Or is it simply a false alarm? Of course, you should always exit the building following the safety plan, regardless of whether or not the alarm is real. But chances are, you’re going to participate in a routine safety drill with a much lower heart rate than you would if the environment suggested that the threat is real, and there really is a fire. As an aside, one of the fascinating dynamics of our defense circuitry has to do with this process of freezing and scanning the environment. Imagine you are sitting at home and you hear a noise outside, or a knock on the front door. For most of us, those sounds don’t evoke fear or indicate threat, so our reaction is typically to approach to find out more (assuming the knock on the door is not a salesperson). In other words, we head outside to see what the commotion is all about, or we walk to the front door to see who is there. But if the sound we hear is associated with fear or threat, instead of approaching the sound, most of us simply freeze and scan the environment. You can probably remember a time when you had this reaction. It’s as though we have a built-in mechanism for not rushing blindly into a potentially dangerous situation. If our scan of the environment indicates that the threat is legitimate, we respond accordingly – but we do so largely without thinking or planning. This is so we can respond efficiently. To illustrate this point, imagine yourself facing someone you believe to be armed. If you see that person reaching for his/her waistband, it will not be efficient for you to engage in a process of thinking, questioning, or wondering. Efficiency equals instantly reacting – and relying on training that has ingrained brain circuitry and habitual behaviors that allow you to act without thinking. That’s why the prefrontal cortex may not be involved when we respond to a threat. It would slow us down and potentially distract

 

 

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us, placing us in even more danger. This makes sense from an evolutionary standpoint: If a predator is coming at you, and you stop to think, you’ll end up as lunch.

Learning from Experience Once a threat has passed, we can engage our prefrontal cortex to take action and minimize our risk, as well as integrating the experience into our existing maps of safety and danger. This integration allows us to learn from the experience. Let’s explore an example that brings this point to life. Imagine you are at the top of a skyscraper in Chicago, Los Angeles, New York, or any major city in the United States. Just for fun, picture yourself leaning against the glass window to peer down to the street below. As you’re looking down and commenting that the people down there look like ants, imagine that you hear a loud BOOM and feel the floor shake. The first part of your defense network to respond to this event is your “Danger, Will Robinson” robot. Your amygdala fires in recognition of a potential threat in the environment, and your defense circuitry responds by triggering a release of chemicals that will help you deal with that threat. Next, you scan the environment to assess the threat, aided by your hippocampus, which compares what you are seeing, smelling, and hearing with your existing maps of safety and danger. You do all of this without thinking. For the purpose of this example, let’s say that you don’t hear any alarms or smell any smoke, and when you look at the people around you, they all appear to be calm. In fact, they are continuing to engage in conversations that have nothing to do with the noise you heard. At this point, your brain determines that this is an environment consistent with a map of safety, thanks in large part to your hippocampus. So, the chemicals that were released begin to re-absorb into your system, and your prefrontal cortex can take action based on your conscious processing of the event. Most of us are very well aware of the events of September 11, 2001, so we might respond to this situation by heading down the stairs to the street, in an effort to minimize our risk. It is a particularly poignant aspect of 9/11 to realize that most of the people who were in the floors above the first plane did not have a map of danger that alerted them to the risk. This is because they had no similar experience to learn from; nothing like that had ever happened before, so many of the people on the floors high above the impact of the first plane didn’t find out about the situation until they heard it on the news or were called by a loved one. On the other hand, we will never forget the events of that day, so we are likely to head for the stairs, just in case. That’s one role of the prefrontal cortex: To learn from experience and take action to minimize risk.

Summary: Response to Threat So, before we move on, let’s summarize what we have covered with respect to threat and fear. First, the brain is constantly vigilant, trying to detect potential danger and anything that doesn’t fit with our predictions of what will happen in our environment. The

 

 

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specific level of vigilance will depend on our previous experiences as well as the environment, but even in the safest environments, our defense circuitry remains vigilant to some degree. Then, when a threat is perceived by the brain, our amygdala signals “Danger Will Robinson!” In other words, our internal smoke alarm goes off. We respond by freezing and scanning the environment, and thanks to the hippocampus, we compare what’s in the environment with our existing maps of safety and danger. If the environment is consistent with a map of danger, we respond to the threat largely without thinking or planning. If the environment is consistent with a map of safety, however, we can engage our prefrontal cortex and either take action to minimize risk and/or integrate the experience into our maps of safety and danger to continue learning.

Ramifications for a Traumatized Brain Now let’s examine the impact of trauma on the brain. Inherent in the definition of trauma is the requirement that something about the event is threatening, so our defense circuitry takes control over how we react. This dynamic has a number of important ramifications.

Prefrontal Cortex Impaired First, think back to how the brain deals with threat in general – it senses danger, often freezing briefly while scanning the environment, assessing the threat, and then reacting or responding to that threat. In particular, remember that the prefrontal cortex often doesn’t come into play until the threat has passed (depending how severe the threat is, and how long it lasts). This fact is supported by research, but it also makes sense anecdotally. For example, most of us have experienced periods of extreme stress at some point in our lives, so we are familiar with the struggle we might have experienced when trying to think clearly. The research shows a significant difference between a situation that is highly stressful and a situation that is both stressful and involves threat, danger and/or fear. The difference is that you can sometimes use stress reduction techniques to regain your ability to think clearly in a high stress situation, if it is not dangerous. Introduce threat or fear into that situation, however, and the dynamic changes dramatically. Chris Wilson gives a concrete example:

In the fall of 2015, I was invited to give a talk on this very subject of the neurobiology of trauma, at a conference in Texas. When I give these talks, I bring my own computer, and I try to make sure I have enough time before my presentation to test whether the videos and audio clips will play on their system. Unfortunately, for this particular talk I didn’t have that opportunity. So, when I went to play my first video, it started without any audio.

 

 

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As my stress level began to rise, I figured I would do my best to describe what folks would be hearing, using a bit of humor. Then a voice came over the sound system, and said, “Dr. Wilson, will you please restart your computer?” I remember thinking in my head, “Well, see, I’m sort of in the middle of something,” but I also realized this might actually work. So, I restarted my computer, and within a few seconds, I was asked to enter my password. It’s a password I knew well. Very well. And for the life of me, I could not retrieve it from memory. That’s how stressed out I was. My prefrontal cortex, which is used to deliberately search for and retrieve information from memory, was gone. Fortunately, I was able to face away from the audience, close my eyes, go to my “happy place,” and remember my password. That’s the difference between a highly stressful situation and a traumatic situation. Had there been a threat present in the environment that was activating my defense network, I would not have been able to close my eyes and regain the functioning of my prefrontal cortex. If there had been a real threat in that environment (e.g., someone holding a gun to my head while I tried to retrieve my computer password), I would have likely continued to struggle to recall my password, and lost my ability to think logically, plan or problem solve the situation.

Keep in mind that an impaired prefrontal cortex also means that we lose the ability to control our attention and encode memory data into an integrated narrative. But for now, we will focus on the ramifications of not being able to plan and think logically.

Habitual Behavior So, what are we left with when our prefrontal cortex is impaired, and we’ve lost the ability to plan and think logically?” One answer is habit. The power of habit can be demonstrated by any number of examples, but one comes from law enforcement. At a recent training, Chris Wilson was speaking with two Minnesota State Troopers who informed him that their procedures for the use of tasers had changed over the years. They explained that initially they were taught to discharge their tasers upon starting their shift, with a short one-second burst, just to confirm that they were operational. However, at the time, a taser needed to be triggered for about five seconds in order to operate properly. When those officers went into the field, and their prefrontal cortex was impaired in the face of a serious threat, their habitual behaviors kicked in from their training, and they attempted to trigger their tasers using the same one-second burst they had been repeating at the start of every shift. Once the administration realized this was happening, they changed their officers’ training, so they had to discharge their tasers at the start of each shift for a full five seconds. That solved the problem because it instilled a new, more effective habitual behavior Since that time, taser technology has continued to evolve, so they now only need a one- second burst to fully function. However, the example illustrates the power of habit in determining our behavior. When we find ourselves in a traumatic situation, we often

 

 

Understanding the Neurobiology of Trauma and Implications for Interviewing Victims

November 2016

Wilson, Lonsway, Archambault

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End Violence Against Women International www.evawintl.org

 

 

 

respond to a threat without the benefit of our prefrontal cortex, so our brain reverts to behaviors that are habitual and ingrained, rather than those based on logical planning or thought. In addition, our brain may respond with a variety of survival reflexes, which are often characterized as “fight or flight,” but are better described as a “defense cascade.”

The Reaction Formally Known as Fight or Flight If you ask people how human beings respond to threats in the environment, many will use the phrase “fight or flight.” Unfortunately, as popular as the saying is, it doesn’t accurately represent the full range of possible responses. In fact, research now suggests that our response can be categorized as a defense cascade, which very often begins with a freeze response (Kozlowska, 2015). This freeze response can be confused with two survival reflexes (called tonic immobility and collapsed immobility), where the victim is literally unable to move part or all of their body (including the parts that are needed to speak). But, being unable to move is not part of the freeze response we are describing here. With this more typical freeze response, we have the ability to move, and in fact, part of this response is about preparing to move (e.g., take some sort of action, in order to protect our survival). Hiding from Detection The freeze response developed through evolution serves two primary purposes. The first is to prevent detection by a predator. Just think of the proverbial deer in the headlights. The reason the deer freezes is because the car is identified as a threat, and the deer’s response was developed to respond to their primary threat, which is a predator. If that deer was in the forest, and a mountain lion entered the vicinity, the frozen deer may not be seen by the mountain lion. The mountain lion’s attention might even be drawn to a deer that has not yet frozen, because predatory instincts evolved to detect movement. Unfortunately, this “freeze” response that evolved to protect the deer from the mountain lion leaves it completely unprotected against the threat of a car approaching at 60 mph. You can even see this freeze reflex reflected in conscious responses to threatening situations. If you think back to a time when you were afraid as a child that the “boogeyman” was in your closet, what did you do? Most of us instinctively held very still, so the boogeyman wouldn’t see us. This can be a conscious strategy, in which case it is not the freeze response we are talking about here – because the freeze response originates in your thumb and doesn’t involve the thinking part of the brain. However, it is interesting that the conscious strategy reflects this instinct. We see this very same freeze response across many different species, and it makes a lot of sense on the most fundamental level: If the predator can’t see the prey, the predator won’t attack.

 

 

Understanding the Neurobiology of Trauma and Implications for Interviewing Victims

November 2016

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