Originally posted January 26, 2021.
In PTSD: 1 No, it’s not all in your head, we talked about the causes and the symptoms of PTSD.
In PTSD: 2 No, it’s not all in your head: The Neuroplatform of Emotion, we talked about the underlying neurobiological emotional platform, that forms the unconscious basis for our emotional responses in everyday life.
In PTSD 3: No, it’s not all in your head: the Vagus Nerve, we talked about the cranial nerves, and, more specifically, the vagus nerve and polyvagal theory.
In this article, PTSD 4: No, it’s not all in our head: Memory Encoding, we’ll talk about how traumatic memories are physically encoded differently in the brain than regular, non-traumatic memories.
In PTSD 5: No it’s not all in your head: How Emotions are Processed, we’ll talk about how emotions are processed in the brain, from the bottom up: from the emotional brain to the rational brain. This is relevant for those who suffer from PTSD, as emotional and subsequent physical symptoms are driven from the underlying neuroplatform of emotion, which has been physically impacted by trauma.
In the final article of this series, PTSD 6: No it’s not all in your head: Harness Neuroplasticity for Healing, we discuss how current trauma models, informed by neurobiology, integrate somatic therapies, attachment theory and mindfulness for healing on mind and body levels.
Neurodevelopment: Brain changes from trauma
I just wanted to mention that current brain scanning technology has allowed researchers to map the physical changes that profound and sustained trauma creates in the brain. We didn’t know just how “plastic” the brain was until we could physically map it.
Traumatic Memories Are Stored Differently Than Everyday Memories
Let’s take look at the biological differences between how everyday memories are stored and how traumatic memories are stored in the brain.
“Learning is a strengthening connection between neurons.” from Carla Hannaford (1995)
Everyday memories about everyday stuff are stored in a fashion that links the different composite parts together. When you learn something new, or when you experience an event, in an emotional atmosphere of relative safety, the memory is encoded in a cohesive manner.
The situation or the skill makes sense to you on multiple levels because the components of the memory, the narrative, sensations, and emotions, are all linked together. There is a cohesiveness about your experience because the timeline, context, emotional understanding, and the sensory experience of the event ..what it feels, looks and smells like… are all grouped together.
Below is some information about how a memory, or skill, is learned and stored by the brain when you’re not super stressed.
Memories are stored via a complex system of interlocking neurons in the brain. When we learn, or create a memory, millions of brain neurons connect to each other, to form the neurobiological underpinnings of the skill or memory.
The more this skill or memory is accessed, the stronger the neurobiological underpinnings of the skill (or memory) becomes, because the pathways become more tightly connected via myelination.
For example, driving is a complex skill that many people use every day. Driving requires multiple motion and attentional systems to be engaged all at once. Perception of obstacles, steering, braking – all of these are smaller tasks, that with repetition, become linked together in a bundle of neurons in your brain. The pathways linked together in your brain become covered in a fatty sheath, called myelin. Myelination enables a grouping together and a faster use of the bundled necessary skills.
Learning and memory are encoded in the brain in an orderly fashion during REM sleep. In REM, a process called memory consolidation occurs, when the brain sorts though the day’s events and stores them with similar, previously learned skills and memories.
However, the components of traumatic memories are stored in a disparate manner. In situations where is a high threat, the brain is impacted by hormones which disrupts orderly memory storage.
Traumatic memories are physically stored differently in the brain than everyday memories.
Integrated memory consolidation does not occur with traumatic memories. Intense emotions of fear and rage cause a surge of hormones that disrupts how the brain functions in the moment of trauma. The brain doesn’t have time to physically process the events as it normally would, so the memory of the event is actually stored in a disparate manner.
This rush of hormones and neurotransmitters from the fear and horror response, impacts the hippocampus, the amygdala and Broca’s area, which processes language.
The hippocampus stores the narrative or historical part of memory. There isn’t time for the brain to process what is happening, so there isn’t a cohesive narrative binding together the sights, sounds and content of the event.
The rush of adrenaline and other hormones activate and prime the emotional brain to react strongly to any sensory memory of the traumatic event. Everyday events may inadvertently remind the amygdala of the traumatic event, and touch off an emotional reaction, such as anxiety or dissociation, common trauma symptoms, which interfere with activities of daily life. Remember, the amygdala’s operates below conscious thought. Its job is check things out and to assign an emotional designation to situations. A traumatized brain is scanning and on hyper alert.
Broca’s area, the language part of our brain is affected by trauma, and so it can be difficult to form coherent verbalizations about the event, both at the present time and when describing the event. There are confusing periods of lost time. Part of the therapeutic healing is to create a timeline of the event, at your own pace, slowly filling in the gaps and verbalizing as tolerated.
When these disparate pieces of memory are re-processed later, in an atmosphere of safety, physical consolidation of the memory pieces can occur. For complex trauma, also referred to as C-PTSD, this reconsolidation requires a decision to heal, takes time, can be emotionally painful and usually imperfect.
How emotions are processed in the brain
The way traumatic memories are stored in the brain impacts our emotional response. Perceptions are processed bottom up…first, via our emotional brain, then, up through our rational brain. So, sights, sounds and smells trigger an emotional response, reflected in our bodies, before we are consciously aware of the response. We have a feeling of what is happening before we have a conscious interpretation about what is happening.
We access our intuitive, emotional response via our perceptions. Our perceptions can come from within or without. We can be dreaming or musing and happen upon a frightening emotional path, which stirs up our PTSD symptoms. Or we can perceive something in our environment, which can cause uneasiness and stirs up our PTSD symptoms.
The next article talks more about how we process perceptions and emotions in the body and mind.
Bibliography
Dana, D. (2018). The polyvagal theory in therapy. New York: W.W. Norton & Conpany.
Kain, K. and Terrell (2018). Nurturing resilience. Berkeley, California: North Atlantic Books
Hannaford, C. (1995), Smart Moves: Why learning is not all in your head. Salt Lake City, Utah: Great River Books
Van Der Kolk, B. (2014). The body keeps the score. Penguin Books: New York