The study of the effects of fear on the mind’s memory is still mired in obscurity and controversy. Some studies claim that when people recall a time when they experienced traumatic fear; their memories are enhanced and their recall is detailed and vivid. Other studies claim that when people recall traumatic experiences; their memories – though detailed – are fragmented.
What happens in the brain when emotional trauma is experienced?
One study sought to delve into the memories of people who had experienced the severe trauma of an emergency aeroplane landing. Researchers analysed the memories of fifteen passengers; asking for their recollection of that particular flight, an event from that same year which they considered emotionally neutral, and the passenger’s experience of the September 11 U.S. terrorist attacks. Six of the fifteen interviewees displayed symptoms concurrent with post-traumatic stress disorder (PTSD.)
What they found was that, whether or not the subject showed signs of PTSD, they all possessed extremely vivid accounts of the plane-landing incident, supporting the hypothesis that the emotion of fear can change how memories are created and stored. The subjects who had developed PTSD were able to recall not just intricate details of the traumatic event itself, but also extraneous details of the September 11th event, suggesting that their brains had difficulty in editing their recollections or even fading out the memory contents entirely.
So what happens in our brains when these memories are being created?
The brain has multiple ways of creating memories. We have physical memory, for learning to ride a bike or throw a baseball. We have auditory memories, which aid us in singing songs. We also have declarative memories for things like maths equations and where we left our car keys. These particular memories are stored in the hippocampus.
Fear, however, activates a different memory-forming system entirely. Our amygdala is involved in emotional memories involving sex, fear, and drug use. When we make a memory that was completely “loud” and unexpected, it activates our amygdala.
Does fear keep us alive?
This may be a survival mechanism. When we see a tiger attack someone, we don’t need to see it more than once to know that we must fear and avoid the tiger. This memory formation is much different than studying for a Spanish test. The tiger memory arouses our emotions and activates our adrenaline. Researchers believe that these types of memories evolved to keep up alive.
Scientists have a grasp on the “how” of fear-based memories, but the “why” still eludes them. The closer they get to the “why,” they closer they get to a better understanding of how trauma affects the brain, and how to go about treating it.