The Body/Brain Connection in the Conditioned Fear Response (Part 2)
Individuals exposed to highly stressful environments, who have a history of abuse, rape, combat situations, and other experiences that can result in PTSD, will often have a reduction in hippocampal volume (Hamner et al., 1999).
Traumatic experience and fear conditioning
Conditioned responses to fear provoking stimuli have been linked to the re-experiencing (flashbacks, for example) symptoms of PTSD and other traumatic experiences (Hamner, Lorberbaum & George, 1999). Understanding the function of fear conditioning and the way it relates to how trauma survivors process and learn from fear provoking events is fundamental for those who would seek to assist in bringing relief to those battling with this very disabling condition.
According to those in the field of trauma treatment, the limbic system plays a major role in traumatic memory processes. Since it is also considered the part of the CNS (central nervous system) responsible for self-preservation and survival of the species, as well as for guiding the emotions and influencing behavior, it is imperative that we understand the brain mechanisms underlying the fear processes that drive it. This also assists those working with this population in understanding why this part of the brain tends to remain in an alarm state as it does in PTSD and some other anxiety disorders. When we have at least a basic concept of how these areas of the brain function, we can better understand how external influences affect the way trauma related memories can activate such powerful physiological arousal in conditioned fear processes as they do.
Another example of reactions to fear provoking stimuli, in addition to those already mentioned, are flashbacks, intrusive memories and nightmares that are seemingly unrelated to one's current experiences, and yet invade the individual's life in ways that are beyond one's control. What is often the case, though these things occur outside of conscious awareness, is that they are reactions to some external cue. In Pavlovian terms, we might refer to these as contextual cues. In the controlled laboratory environment this type of reaction has been seen in rats that have been conditioned in particular cages to certain fearful stimuli, and then have shown high levels of fear when returned to those same cages at a later time. This is a conditioning context or a contextual cue. When we observe such behaviors, we would say that we are seeing the brain mechanisms of fear being activated. It is important that
Latest Articles