The Neuroscience of Trauma

The word trauma is thrown around quite a bit these days. We think we know it when we see it, but defining it is a harder. However, recent advances in neuroscience help us to understand what’s happening in the brain during trauma, and to distinguish trauma from anxiety and depression, which are often related. And while we’re only at the beginning of understanding how the brain works, neuroscientists now better understand the functions of different parts of the brain and how they relate to trauma.

With all the stigma and confusion around trauma and mental health these days, going back to science is a path forward in not only creating more understanding and empathy, but also in providing holistic treatment. For the purposes of this piece, we will focus on the five key parts of the brain that most significantly compose the neuroscience of trauma.

For background, the brain is considered part of the nervous system. Humans have two main nervous systems that communicate with one another to coordinate movement and sensory information by transmitting signals to different parts of the body. The brain and spinal cord together are the central nervous system (or known as the “command center”) and it communicates with the peripheral or autonomic nervous system, which is throughout the body. As a reminder, “autonomic” means involuntary, without conscious control. When we talk about the “mind-body connection,” it isn’t pop psychology—it’s hard science that must be understood to treat trauma effectively. Put simply, the brain is part of the body.


Amygdala (The Watch Tower)

Through the senses, the amygdala receives information from the person’s external environment and determines whether that information is safe or threatening. It is the first responder. This part of the brain receives information more quickly than the cortex (the part of the brain that plans and ponders) and mobilizes the body into action accordingly. Understandably, you’d want your body to automatically respond to a threat before being able to think about and make sense of what is happening. For example, when you hear someone break into your home, you want to run or reach for a weapon before you are able to organize the sequence of sound and movement into a coherent narrative.

During and following trauma, the amygdala is hyperactive. The amygdala triggers mobilization to perceived threats more easily. It remains in a constant state of vigilance because it interprets all external activity as a potential threat. The amygdala takes longer to trust environments and only begins to let the body rest after the thinking part of the brain has determined that there’s no danger.   

Hippocampus (The Memory)

When functioning properly, the hippocampus is able to house memories with context and accuracy. The hippocampus codes experiences as events in the past. It also tracks more emotional information, takes a panoramic with lots of contextual information, and has a time stamp (i.e. commits the experience to long-term memory). Naturally, for survival, the hippocampus emphasizes negative experiences more strongly than positive ones, so that it can collaborate with the amygdala, when needed.

During and after trauma, the hippocampus is underactive because the amygdala triggers a stress response and saturates the hippocampus with cortisol, resulting in memory errors. [Note: the memory center will atrophy over time with sustained high levels of cortisol. The good news is that neurogenesis is possible in this part of the brain.] Very often following trauma, memories are not encoded properly because there is:

  • Loss of Context—rather than a panoramic snapshot with lots of context, only certain details are recorded, and recorded as dangerous, making it difficult to assess a threat accurately.
  • Generalization of Fear—the memory is fuzzy and anything that resembles what is dangerous will trigger arousal. For example, if a gun is coded as fuzzy, any image that loosely resembles a gun (such as a blow dryer) will turn on the alarm bells. Unfortunately, as more time goes by without treatment, the generalizations get more generalized. Time doesn’t heal trauma.
  • No Time StampRather than remembering a traumatic experience, you relive it because the memory never ages. Moreover, understandable avoidance of the traumatic experience leads to worsened symptoms. There is no moving on from something that is still happening.

Insula (The Mind-Body Center)

The insula is the site of proprioception (felt sense of where your body is in space) and interoception (how your body feels). Known as the mind-body center, the insula combines physical sensations with cognitive elements to form emotions. Therefore, it is critical for emotional awareness.

When functioning properly, the insula is where emotions are generated. Briefly, emotions comprise three elements:

1. Physical Sensations 2. Core Affect (averse or pleasant) 3. Thoughts

That’s right: Thoughts are not separate from emotions, but a piece of it. Without thoughts, you don’t have complete emotions; you just have a physical sensation with core affect. Here’s an example to explain:

Physical Sensation: Your insula notices your body is lifting out of its seat and your heart is racing PLUS Core Affect: Negative/Averse PLUS Thought: Plane is going down and going to crash. EQUALS Emotion: Terror

During and after trauma, the insula is either hyperactive (reactivity, catastrophic interpretation, magnification of physical sensations, re-living the event) or underactive (dissociative/floating off somewhere else, numbing emotions/no emotions, disconnected from body).

Cingulate Cortex (The Judge/Emotional Regulator)

The cingulate cortex acts like judge, gathering information from different parts of the brain to determine what is being seen, what it thinks, what it feels, and what to do. This part of the cortex monitors conflict through investigating different and opposing emotions and regulates emotions accordingly (the cingulate cortex is also involved in pain expectancy).

To regulate your emotions means you feel them in an integrated and secure way that aligns with what you deem as valid. To regulate your emotions does not mean you do not feel.

During and after trauma, the cingulate cortex is underactive and not able to regulate emotions well, if at all. When the other parts of the brain involved in trauma aren’t working well, the judge can’t accurately retrieve and assess data. Rather, the body keeps reacting without the person being able to organize their experience and determine what is real and what needs to be done. As you can imagine, this is part of what is traumatizing.

Prefrontal Cortex (The Personality)

The prefrontal cortex (PFC) is the part of our brain that allows for an integrated and stable identity. The PFC engages you in rational thought, decision and goal making, personality expression, and moderating social behaviors/impulse inhibition.

Following trauma, the PFC is underactive and results in deficits in identity formation. It becomes very difficult to make decisions, set goals, focus, act, have stable and healthy connection in relationships.


While the neuroscience of trauma is far more complex than what has been laid out above, having a basic understanding helps to remove the terrible stigma associated with trauma. With a brain that is overall hyperactive, those suffering from trauma are working hard—too hard—to get through life. A common phrase I hear among my clients is, “I’m just trying to get through this hour.”

Treatment must address the concrete, physical realities that the neuroscience has verified.

Otherwise, treatment will leave the traumatized person even more disconnected from themselves and others.

It will be tempting to victimize the person suffering from trauma. The last thing someone working so hard to survive wants is to be perceived as helpless. Ignoring trauma worsens symptoms, but applying a victim lens keeps the person stuck. It’s also untrue. The “command center” is meant to keep you alive, and it worked by going into overdrive. They are survivors, not victims.

The first stage of treatment must be calming down the amygdala so that it can safely engage in a memory reconsolidating therapy (like EMDR, among others). Trauma modalities have discovered in recent decades that the brain can heal itself. The same brain—through traumatizing experiences, epigenetics, and developmental trauma—that is over-functioning to survive can also, with help, figure out a way to heal. Healing happens from and within the brain.

To hear an example of this, click here.

If you have any questions about Therapy With Heart’s EMDR Intensive, please contact us.


Nicole Rizkallah


(480) 203-2881
8737 E. Via De Commercio, Suite 200 Scottsdale, Arizona 85258