The Brain’s “Information Processing System”

One of the Two Key Systems in the Trauma Response

(From Shapiro & Maxfield, in Healing Trauma, Solomon & Siegel, 2003, p.198)

“The information processing system is an intrinsic physical system that is geared to (deal with) psychological disturbance (and) mental health. Let us use the example of an argument with someone at work. Our body reacts, our minds chatter, and we feel upset. Then we talk about the incident, think about it, and maybe dream about it. Time passes, and soon the argument does not bother us any longer. We understand what happened in the interaction, we have an idea of what to do, we go back and talk to the person, we do not have that physiological arousal. It can be said that the experience was ‘adaptively resolved’. The useful aspects of the interaction were learned and stored in memory, with appropriate emotion, available to provide future guidance. The useless aspects were discarded, the negative self talk, the negative arousal, the negative emotions – all of these are gone. This natural, normal information processing takes us adaptively through the world and has a direct effect not only on cognition, but on emotion and body sensations.”

The Effect of Stress Hormones on Neural Integration

There are three factors involved :

The evolutionary learning process in which release of stress hormones primes the short term memory to replay the most highly charged aspects of the experience over and over again, so that the individual will learn from the dangerous situation.

Theoretically this is a functional system, if the experience is not too overwhelming.

The same flooding of stress hormones impairs hippocampal functioning due to an over-aroused amygdala, so that some aspects of the event are not encoded into explicit memory, but instead into implicit memory. As implicit memory, the event continues to intrude as a ‘here and now’ experience (remember how implicit memory works) – rather then ‘remembered facts’. The event is implicitly remembered as the impulse to flee, illogical emotional reactions, bodily sensations unconnected to events, and free-floating images of the trauma.

The long term effect is that the entire experience is not consolidated (integrated) into the permanent memory system of the neocortex. It continues to be processed by the lower brain functions of the brain stem and limbic system, where experience is registered as primitive, emotional, automatic (‘knee jerk’) reactions. If the experience were integrated into the higher brain, the neocortex, it would be able to be thought about, logically interpreted, made sense of intellectually, classified and put into a reasonable narrative with a beginning, middle and end.

The lower brain functions tend to induce rule-guided behaviour, whereas higher (cortex) functions are context-guided, ie, the thinking brain looks at actual situations and modifies the automatic rules of the primitive systems, including implicit memory. So people in shock after overwhelming experiences are often driven by low-route functioning (auto-pilot) unmoderated by the context-sensitive higher brain regions.

The repeated nightmares after a traumatic experience are the brain’s continued attempts to integrate the traumatic memories and feelings through REM sleep. But the fact that these dreams are nightmares indicates the unresolvable confusion.

What is Trauma?

The Role of Memory in Trauma

The Neurobiology of Psychological Trauma

Dissociation

An Evolutionary Model of Response to Danger

Further Resources and Reading (Trauma)