The Neurobiology of Sexual Assault

If you’ve ever spoken to me about sexual assault, then you know that I find the way our justice system handles these cases to be deeply flawed and in need of fixing. While working on a project for one of my classes, I had the chance to speak with Katie Eichele, the director of The Aurora Center. She shared with me a webinar, put on by the National Institute of Justice that could help the system work in favor of victim survivors. Dr. Rebecca Campbell of Michigan State University gives excellent insight to what’s been found in research surrounding what the body goes through during traumatic events. She then ties it to sexual assault reporting, which explains many problems, as well as provides potential solutions. The presentation was fascinating and it has me feeling as though there is truly a way to do better.

All too often, victims are blamed for what happened to them, they are discouraged from reporting, and the police can sometimes make the victim feel as though they are going through a second trauma. They may not believe the victim’s account of the events due to inconsistent memories or evidence that suggests the victim did not fight their attacker.

This is something called “sexual assault attrition”, part of the reason why so many reported sexual assault cases never result in convictions, as well as why so many victims never report what happened to them in the first place. In addition, many victims go through secondary victimization, which Campbell describes as “attitudes, beliefs, or behaviors of social system personnel that victims experience as victim blaming and insensitive.” This worsens the trauma that the person has already been through. According to one of Campbell’s studies, 69% of victims are discouraged from reporting, 51% are told that their situation is not serious enough, 70% are asked what they did to provoke the attacker, and a staggering 90% experience at least one secondary victimization.

What if there was an explanation as to why victims of sexual assault often have trouble remembering the exact details of the attack, or a way to explain why victims sometimes don’t fight back? Dr. Campbell’s presentation shows that there is in fact a neurobiological response to trauma, one that can help in improving the treatment of survivors. Below are some quotes that Dr. Campbell heard during her initial research on sexual assault attrition. She spoke to law enforcement and they shared some of their thoughts about interviewing those who report assault. They demonstrate just how desperately a change is needed.


I highly recommend watching the presentation for a fuller, more in-depth description of what a person’s body goes through during sexual assault, but the basic explanation is that a number of hormones in the brain are all firing at once and causing all kinds of reactions that are out of our control. This messes with the way our logical thinking processes work, how our minds encode memory, and how we react to bad situations.

During an assault, the amygdala, or the part of the brain that processes emotional memories, detects a threat. This then activates the part of the brain that communicates to all structures in the body what needs to happen for survival, releasing a “hormone flood” into the body. In some cases, this triggers a complete shut down of the body. While many of us are familiar with the idea of the “fight or flight” reaction, many people do not realize that sometimes the body will respond by freezing. This leads to Tonic Immobility, sometimes called rape-induced paralysis. This is an autonomic response to fearful situations and can lead to increased breathing, eye closure and paralysis. Research suggests that between 12 and 50% of victims experience this; continuing research leans towards the 50% mark.

When this happens, there is almost no way the victim is able to fight back. Dr. Campbell talks about a particular case in which the victim was assaulted multiple times. The woman froze during the attack and when her friend found her and tried to get her out of the situation, the friends says that trying to move the victim was like moving a dead body. When the police were called, they said that too many attackers were involved and it would be too difficult to figure out who those people were. In addition, the cops said that because the victim lay there and did not fight back, she must have wanted it.

In addition to affecting our flight, fight, or freeze response, trauma affects that way that we store memories. During a sexual assault, stress hormones in the body increase. In turn, the hippocampus, which processes information into memories, is impaired. This causes memories to be fragmented and makes memory recall slow and difficult. The events can be correctly recalled, even though it may take some time.

To explain this using Dr. Campbell’s example, imagine you’re taking notes about the presentation on Post-It notes. You couldn’t fit much information and you’d likely have to use many of them to get all the details. Now, take the notes and scatter them all over the world’s messiest desk – in folders, in pencil cases, everywhere. Imagine that you’re asked to recount what you learned, in order, during the presentation. Because the notes are scattered, it will take some time to find everything and string them together. It would be hard, right? The same thing happens with our memories after trauma; the information is there, but it takes sometime to piece together. Dr. Campbell has spoken to detectives who say that, when a victim is changing facts or hesitating, they will take some time to get the victim coffee and slow down the pace of the interview. Generally, this will give the victim a chance to collect their thoughts and this is when they are able to more confidently share their story.

So how does all of this help future victims? It’s actually pretty simple; now that we have research to explain the neurobiological responses to traumatic events, we need to spread awareness. Many law enforcement officers are never told that these phenomena exist. This leads to case attrition and secondary victimization. Therefore, educating first responders could make a real difference. Dr. Campbell explains that, from what she’s seen, it’s not that these people do not want to learn about tonic immobility, the flood of hormones, or the memory problems. They just have no idea.

It’s also important to consider other kinds of trauma and how they are handled. In the lecture, Dr. Campbell looks at shootings. When an officer is involved in a shooting, there should be two sleep cycles before any questioning goes on in order to give the person as much time as possible to process it. Shouldn’t sexual assaults be handled the same way? She does address the problem of the crime scene, that it may need to be processed sooner, but it is still possible to wait to give the victims a significant amount of time to collect their thoughts and avoid another traumatic incident.

While I’ve tried to summarize the lecture, I highly recommend investing 90 minutes to watch the entire things. My perspective on the reporting of sexual assault has changed so much from this presentation; I’d love to hear anyone’s thoughts on this talk in the comments! Campbell has already made some impressive steps in spreading awareness. She’s worked with a number of first responders in Detroit to share her knowledge of neurobiology of trauma. Overall, the response has been very positive. Additionally, Campbell has worked with the writers of Law and Order: SVU, as well as the Joyful Heart Foundation, to spread more awareness. She said the writers could include tonic immobility in an episode of the popular TV show as long as they checked in for accuracy. Campbell was also asked to write a blog post explain tonic immobility in everyday language. The response to the episode was great; Campbell presents one quote that, to me, shows that the work she is doing to others is truly making a difference: