What Happens to the Brain During a Sexual Assault?

ACASA_logo 2015What Happens to the Brain During a Sexual Assault?

Imagine one of your friends invites you to come watch a movie. You accept thinking nothing would happen since you are simply friends. But as the movie goes on, your friend starts kissing you, and you feel uncomfortable. How do you react?

Society expects victims of sexual assault to fight back during the assault, or at least to scream to alert others. How many of us have heard “if it were me I would have…” or “if she/he didn’t want it to happen, she/he would have found a way to stop it.” Unfortunately, it is not that easy because the brain reacts in different ways depending on the situation we are in.

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The information that is coming into the victim’s brain and body during a sexual assault is traumatic, threatening, and horrifying. During a sexual assault, the amygdala, the part most responsible for feeling afraid, is going to recognize this as a threat and signal it to the hypothalamus. The hypothalamus is going to send signals to the pituitary and the hypothalamic-pituitary-adrenal (HPA) axis is going to kick in. There is going to be a hormonal flood in the victim’s body.

The catecholamines, hormones secreted by the adrenals during a traumatic event, are often going to be at a very high levels during the assault. These hormones are very helpful for the fight-or-flight response. However, they impair the circuits in our brain that control rational thought. So the parts of the prefrontal cortex that allow humans to do “IF this THEN that” do not work at their optimal levels when catecholamine levels are high. So someone under normal levels of catecholamine might be able to look at a situation and say, “Oh, well of course the rational, logical thing for me to do is this.” The victim can’t think like that during the assault. A victim can’t think “IF this THEN that”

The opiates, hormones that act like a natural morphine in the body, are released in very high levels during a sexual assault and block the physical and emotional pain. However, because the opiates act like morphine, the affect that a victim might be communicating during the assault and afterward may be very flat, incredibly monotone. Opiate morphine is not letting emotions come through. The victim’s emotions have been blunted.

Finally, for some victims, it’s the corticosteroids, a group of steroid hormones, that have dumped out at very high levels and reduce the energy available to the body. For these victims, they don’t fight back or flee the situation. Their body freezes on them because of this hormonal activation by the HPA axis. It can trigger essentially an entire shutdown in the body. This is called tonic immobility.

Tonic immobility is an automatic response: it is not something a victim decides to do. Behaviorally, it is marked by increased breathing, eye closure, but the most marked characteristic of tonic immobility is muscular paralysis. A victim in a state of tonic immobility cannot move. She is paralyzed in that state of incredible fear. Research suggests that between 12 and 50 percent of rape victims experience tonic immobility during a sexual assault, and most data suggests that the rate is actually closer to 50 percent than 12 percent.

Many victims feel guilty and ashamed because they “froze” or didn’t “fight back,” and many other people blame them for doing so. It is important to remember that these physical responses are instantaneous and natural responses to an outside threat.

Holding the victim responsible for what has happened to her/him, also known as victim-blaming is the result of the lack of knowledge from the general population about sexual assault. Because sexual assault is a sensitive and stigmatized topic, many people do not know about the many ways a victim can react during a sexual assault. Education and knowledge is the key to end victim-blaming.