Animal Models-Fear Conditioning v.s. Trauma

Though animal models use nonverbal behavioral observations like increased freezing and startle behaviors and reduced time spent in open arms and exploratory behaviors to infer trauma-related emotion, other measures like monitoring autonomic arousal, neurohormonal changes, etc. can be useful indices for enhancing understanding of trauma’s neurobiological impact. Animal models for inhibitory avoidance, fear conditioning, and predator exposure simulate human trauma experiences in their characteristic uncontrollability and unpredictability. Uncontrollable shock, often the unconditioned stimulus in fear conditioning paradigms, leads to greater generalized fear than controllable shock. In fact loss of control is perceived as more stressful than lack of it due to its comparative contextual awareness. The same findings with regard to the extent of controllability or predictability have been found in the human as well (Foa, Zinbarg, & Rothbaum, 1992). Therefore perception of an event’s uncontrollability and unpredictability underlies its traumatic nature.

As noted earlier unpairing CS facilitates extinction. Due to species-specific differences animals need a real-time reexperience of the CS to facilitate extinction (Foa et al., 1992). On the other hand, humans don’t need the actual US-CS and UR-CR. They seem to be able to unpair CS during cognitive therapy through self-generating traumatic imagery in the present tense. Temporarily reliving the traumatic experience imputed with personal meaning helps to complete consolidation processes. This facilitates traumatic unpairing and ultimately results in extinction and arousal inhibition with full ability for traumatic memory retrieval.

References

Foa, E.B., Zinbarg, R., & Rothbaum, B.O. (1992). Uncontrollability and unpredictability in post-traumatic stress disorder: an animal model. Psychological Bulletin, 112(2), 218-38.

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