A couple of years ago I was thinking about applying for a nursing job with a sexual assault support team, so I decided to learn more about the body’s fight/flight/freeze response to trauma such as sexual assault. What I found out was really interesting, and it’s been brought to mind lately reading about fellow bloggers’ experiences of sexual assault, so I thought I’d share.
The amygdala is a primitive part of the brain that processes emotional reactions and memories related to threats. The amygdala automatically reacts to rape as though it is potentially life-threatening, regardless of whether the perpetrator is known to the victim or not. It then triggers activation of the fight/flight/freeze response, stimulating what’s known as the hypothalamic-pituitary-adrenal axis to release a rush of hormones, including cortisol, norepinephrine, endogenous opioids, and oxytocin.
The prefrontal cortex, the most evolutionarily advanced part of the brain, takes a backseat when the amygdala starts going full-throttle. Norepinephrine starts flooding the prefrontal cortex, and logical reasoning, rational decision-making, and higher-level regulation of thoughts and emotions all go right out the window.
The body naturally makes its own opioids, including endorphins. In threatening situations, the amygdala triggers the release of these opioids, which makes sense if you’re a caveman running from a tiger and you don’t want pain slowing you down. This also tends to flatten people’s affect (facial expression of emotions) for several days, which might seem curious to those that think that a victim “should” have a visible emotional reaction to the trauma they’ve just experienced.
Oxytocin tends to be known for its role in pregnancy and mother-infant bonding, but it also functions to counteract pain. It is released as part of the hormone soup of trauma, and one of the odd effects is that it can cause victims to laugh while recounting the traumatic events.
The freeze part of the fight/flight/freeze response is impacted by cortisol and the simultaneous activation of both the sympathetic and parasympathetic nervous system. One source I looked at said up to 50% of rape victims (particularly if they’ve had a previous assault) experience what’s called “tonic immobility”, which involves muscle paralysis while maintaining awareness. Another source said that this happens in up to 85% of victims.
There is also an effect called “critical incident amnesia” This begins to improve after the first night of sleep post-incident, but it is only after the second night of sleep that all of those memories become fully accessible. Alcohol can impair the encoding of contextual details of memory, but sensory information still gets encoded (particularly smell due to the location of the olfactory bulb). Those sensory details can serve as a gateway to access memories of the event.
Society has so many expectations of how people “should” look/feel/act. People think that they can predict how someone “should” “rationally” react to trauma. But that caveman amygdala has been around a heck of a lot longer than all these “shoulds” and rationality, and when it’s in the driver’s seat slamming on the gas of the fight/flight/freeze response, it’s doing its own thing. What people “should” do, including police and judges, is educate themselves.
The Mental Health @ Home Store has a mini e-book on PTSD Treatment Options: An Overview that covers a number of evidence-based therapies for PTSD. It’s also available as part of the Therapy Mini-Ebook Collection.