- There are two amygdalae per person normally.
- The memory of fear is the brain's ability to cope and survive.
- This research can aid in the development of the therapeutic strategies for fear suppression for veterans and others suffering from post traumatic stress disorder.
US scientists from the University of California were able to substantiate how fear formulates in the brain. Both researchers discovered that in a stressful situation, the hippocampus reacts to a specific context and encodes it in memory, and the amygdala activates protective functions, including the reaction in the form of fear. Hippocampus is a complex brain structure embedded deep into temporal lobe. It plays a major role in learning and memory. It is a plastic and vulnerable structure that gets damaged by a variety of stimuli.
Jun-Hyeong Cho, who is a lead researcher on the project, predicted the results. However, the data was missing to substantiate the hypothesis. During the experiments, the subject’s associative memory of traumatic events is actually formed by the connection between the hippocampus and the amygdala, a roughly almond-shaped mass of gray matter inside each cerebral hemisphere, involved with the experiencing of emotion. There are two amygdalae per person normally, with one amygdala on each side of the brain. They are thought to be a part of the limbic system within the brain, which is responsible for emotions, survival instincts, and memory. Therefore, it would mean, if the connection is loosed though external sources, it can completely erase fear from memory.
The memory of fear is part of the brain’s ability to cope and survive. The human brain remembers the situation, where there was danger present, to avoid similar experiences in the future. When a person survives a traumatic experience, even though they achieve physical recovery, they may still be afraid of the catalyst that caused them trauma. It could be fear of abandonment that resulted in trauma or a motor vehicle accident. During an accident, the brain has time to read and process information from all the body’s sensors: eyes, ears, and nose. It remembers the place of the event, the sounds associated with an incident, even the smell. The compounded information by the brain is processed and combined into one single image. Hence the “context” associated with the traumatic experience.
In the cases of post-traumatic stress disorder (PTSD), the protective process of the memory of the same fear becomes uncontrollable. Most often it is when the traumatic event was particularly terrible: war, terrorist attack, major disaster and abuse. Minor details that vaguely resemble the experience, in patients with PTSD can provoke excessive reactions: nightmares or insomnia, increased anxiety, depression that could linger for years. In this case many try to self medicate with drugs or alcohol.
The full research paper is entitled, “Encoding of contextual fear memory in hippocampal–amygdala circuit.”
Overall, this research can aid in the development of therapeutic strategies for fear suppression for veterans and others suffering from post traumatic stress disorder. It is time that we were able to address proper treatment and to increase the quality of life for people suffering through such disorders.