Updated: Sep 25, 2019
Amygdala, hippocampus, limbic system...oh my!
Ever feel like you experienced a stressful event and you tell people, "I felt frozen"? Or maybe you start fighting with someone and you become so angry or upset that it's like you were a different person or you can't recall the event clearly once you're calm? Or maybe when you experience stress you want to run away from it as soon as you can. Maybe you physically run or maybe you binge watch Netflix or you get drunk, or even feel suicidal?
You're not alone. This is your brain reacting to stress or trauma just as it's been trained to do biologically since prehistoric times. We hear the word 'trauma' a lot more than we used to but what is it really?
Dr. Robert Scaer defines it as: "Any negative life event that occurs in a position of relative helplessness".
Often trauma is experienced as a surprise (not the fun kind); something unexpected that takes us off-guard. We feel a sense of powerlessness as an immediate result. Francine Shapiro, the founder of EMDR, says we can have "big T" trauma like the PTSD a veteran might experience or from other life-threatening events, or neglect (emotional and physical), but also "little t" trauma. Some may experience one life event and others experience an accumulation of negative life events over time, e.g., death of a pet or loved one, bullying, emotional abuse, witnessing others' trauma, etc.
Whether we call it trauma or stress, the response in the body and brain is the same.
So before you continue to blame yourself, say that you're broken, insist you need fixing; let's look at how our brain always strives toward resilience and survival.
Thalamus—this is the relay center part of the Limbic System. It takes in sensory information through our eyes and tells the brain what to do with the information. This was great in caveman days when the saber-toothed tiger showed up at the cave entrance and the brain and body knew to go into fight or flight mode. There wasn't anything else our ancestors needed to do back then. They didn't need to think about whether or not this tiger was a danger to them or not. It was. They didn't need their Cortex to help them decide if they were being irrational or not.
Our Limbic System hasn't changed much since the caveman days but our external worlds sure have. Danger comes in many more forms (Big T/Little t).
Amygdala —this is the key brain region for processing, interpreting, and integration of emotional functioning. The amygdala is where fear learned from past experience is permanently stored; like if you were bit by a dog when you were 5, you may still feel fearful around dogs.
The amygdala is the first recipient of information from our Thalamus. It processes it within seconds and sends messages to the rest of our body as to how to respond. We call this the stress response system or the "flight or fight" response. Over time, with many stressors, the amygdala can misinterpret information and get hijacked into thinking "oh, I recognize this...this is bad...I remember this stress from before" sounding the alert bells inaccurately. Like with the dog. The amygdala thinks all dogs are to be feared, but is that really true? No.
The Amygdala creates the following experience:
State of high alert • Action, not thought • Inability to think clearly • Extreme thoughts
• Hypervigilance • Attention to threat • Intense and prolonged anxiety • Drive to take action
The good news is with EMDR and practicing coping skills, we can retrain the amygdala.
Hippocampus — The hippocampus is critical to the process of learning. It takes short term memory and converts it into long-term memory. It plays a major role in memory. Stress hormones and stress-related neurotransmitter systems target the hippocampus. Hormones like cortisol appear to alter hippocampal synapse formation, which can shrink the size of the hippocampus and keep new synapses from developing. We find that people with PTSD and other traumas can have memory and learning problems.
Cortex—This is the thinking part of the brain. It takes 12 milliseconds for the amygdala to respond to sensory information while it takes the Cortex 24 milliseconds. If we can re-educate our amygdala, the thinking part of our brain has time to come online and provide us with a different response to our experience of anxiety, depression or stress. With our thinking brain we can see a dog and notice our fear start rising. We can say, "oh my amygdala is firing". We can take a breath or practice a strategy to calm the alert bells, and then switch into our Cortex and say, "But this dog appears friendly and isn't showing me any signals of danger". Now we have gotten through that situation with greater ease. The Cortex takes longer to come online but it also takes in more information from our Thalamus helping us respond more rationally and thoughtfully.
Resilience—this can be defined as the ability to adapt well to adversity, trauma, tragedy, threats, and significant sources of stress. An analogy of resilience is a rubber band. It can be stretched and endure strain placed upon it, and it can bounce back to its original shape and position.
Some of us have more innate resilience than others, but resilience can be built. This is why I like being a therapist; because if we have at least ONE strong, positive relationship (connection), we will become more resilient in the face of adverse events. This is also why I love EMDR. It helps retrain our brain and make room for more resilience.
Next time you notice yourself having a stress response reaction, remind yourself this is your brain doing what it knows to do to survive. Your amygdala got hijacked. It doesn't mean you are bad, broken or crazy. It just means you need to help your brain learn a different way to respond. It is possible.
Acknowledgements: The Neurobiology of Trauma, Dr. Casey Hanson, Sherman Counseling April 12, 2017