How Trauma Hijacks the Brain

Have you ever wondered how trauma might be impacting your brain?

Today, I’m going to introduce the concept of the triune brain, and how each part of your brain may process your traumatic experiences. Triune means, literally, “three in one.” The triune brain model describes three areas within the brain that have a unique way of understanding and processing information; however, they are meant to function as a cohesive whole.

However, trauma and attachment issues can disrupt this cohesion and lead to things operating out of sync.

The triune brain model

The reptilian brain

In the triune brain model, the oldest part is the reptilian brain. It’s fully developed at birth and includes the brain stem and cerebellum. It operates on instinct and is responsible for the survival-related functions of the body.

The reptilian brain is most closely linked to sensorimotor or body processing. Examples of reptilian brain functions include: reflexes or instinctive trauma responses such as fight, flight, or freeze, startle responses, crying for help, aggression, and urges to hoard resources. It also controls autonomic responses that we experience as body sensations and basic life-sustaining processes like digestion, heart rate, body temperature, and respiration.

The reptilian brain is active whether we are asleep or awake to make sure that these vital functions are working properly. Because the reptilian brain governs basic instinctive actions, it acts very quickly, much more quickly than the neocortex, which we’ll get to later. If a baseball is flying at your head, you don’t typically have to think about your response: your reptilian brain will make you duck instinctively.

The mammalian brain

The mammalian brain, a.k.a. the emotional or limbic brain, is responsible for our emotional and relational experiences. The mammalian brain includes the thalamus, amygdala, and hippocampus. It is also available to us at birth and connects the reptilian and neocortex parts of our brains.

Emotions lend another dimension to our experience by letting us know of our likes and dislikes, helping to identify what is emotionally important or meaningful to us. It also colors how we perceive pain and pleasure, and adds emotional richness to our lives and relationships.

In regards to our relationships, it allows us to be aware of our impact on others and of their impact on us, and it allows us to socially engage with others and attach. It’s also responsible for us feeling drawn towards or away from things and to hold emotional memories of our experiences.

How do these parts of the mammalian brain work? The thalamus receives information from our five senses. When that information includes threat or danger cues, the amygdala signals us to protect and defend ourselves. The amygdala also alerts us to stimuli associated with good feelings. The hippocampus remembers important information and consolidates it into long-term memory. These experiences of shared pleasure or pain are also encoded as nonverbal memories of attachment experiences, laying down templates for expectations of future relationships.

The neocortex

The neocortex, a.k.a. cerebral cortex, frontal cortex, or the neomammalian brain, is the front structure of our brain and is split across the left and right hemispheres.

The right hemisphere is fully present at birth and is associated with creativity and intuition. It processes information in a more symbolic, implicit, and nonlinear fashion.

The more rational left hemisphere is undeveloped at birth. This part of the brain matures and develops beginning in childhood through early adulthood. It houses most of our language abilities. This hemisphere of the brain processes information in an explicit, logical, analytical, and linear fashion. The corpus callosum is a bridge between the left and right hemispheres of the brain. It aids in the communication, coordination, and consolidation of information between the hemispheres. It’s important for our functioning that everything is integrated and linked.

How trauma impacts brain development

The development and functioning of the three brains rely on our early experiences. This includes early attachment figures like caregivers, conditions in our environment, and traumas.

These experiences affect how our brain grows connections, as its goal is to help us to adapt as best we can to both positive and negative life experiences.

With the information I’ve given you, you may be able to start imagining what the landscape of our brains may look like if we have many traumatic experiences throughout our lives, especially early childhood as our brain is growing.

Our mammalian brain and reptilian brain, which are related to emotions and the body, are typically primed to deal with stress and threat as a precaution to ensure our survival.

Consequently, if you have ongoing or repeated threats in life, our brains become hypersensitive to cues that remind us of those traumatic experiences. We can then have intense emotional reactions to cues and our reptilian brain will activate our flight, fight, freeze, or fawn survival responses.

For example, if you grew up with a hypercritical mother who engaged in verbal abuse, you may have intense anxiety anytime someone is upset with you. You may have a fawning response such as people-pleasing to your own detriment. Another example might be if you ran into a man who had a similar build and face as a person who sexually assaulted you in college. You might feel emotionally numb, disassociate, or freeze.

When we are triggered and in a threat mode, our neocortex is temporarily less active. When we are in danger, we don’t have time to think, so our mammalian and reptilian brain take over and prompt us to act quickly in order to stay alive.

While this is good in the case of ducking a baseball, it can make it incredibly difficult to think clearly, analyze, plan, or learn new information.

Because of how each of our three brains processes trauma, these experiences can make it so they don’t work in unison. For instance, our neocortex might tell us that we are safe, but our emotions and our body will tell us that we are not. If one part of your brain is more dominant it can override the others.

For example, if your thinking brain is dominant, you might feel like you are “stuck in your head” all the time and feel disconnected from your emotions. If your mammalian and reptilian brain are dominant, you might feel like you are emotionally hijacked by triggers frequently. Most of us, at least to some degree, have had at least one experience where we were so overwhelmed that our thinking brain stopped functioning.

I sometimes think of it as the “blue screen of death” that computers used to get when there was a malfunction. There was only one way out: you had to reboot the system.

Rebooting the system

Working through trauma is highly personal and specialized, but I wanted to offer a few tips to get you started.

First up, if you want the computer to work well, you have to read the manual.

You can start by reflecting on how each of your three brains responds in various situations. Remember that your neocortex is cognitive processing, mammalian brain is emotional processing, and reptilian brain is body processing. Try to identify situations in which each is most active. These can be situations that are both positive and negative.

This information can be used later when you are identifying interventions that can help. Pay attention to what works at different levels.

I tell my patients all the time that a skill that works when we are at a 4 out of 10 might be different from a skill that works at a 9 out of 10. When you’re lower on the scale, you might notice that cognitive interventions like positive self-talk are more helpful; however, when you’re at a 9, you might need to do body-focused activities, like breathing exercises, to help calm you down.

The most important thing is you give yourself what you need without judgment. The great thing about our brains is that they are malleable. The more you intervene with the trauma responses, the more you can teach your brain to respond more effectively and significantly reduce or eliminate the impact of these traumas.