Recovered memory

Mechanisms of interference

Traumas can interfere with several memory functions. van der Kolk divided these disturbances into four sets

• traumatic amnesia; this involves the loss of memories of traumatic experiences. The younger the subject and the longer the traumatic event is, the greater the chance of significant amnesia.
• global memory impairment; this makes it difficult for subjects to construct an accurate account of their present and past history. In the sensorimotor organization of traumatic memories, sensations are fragmented into different sensory components.
• dissociative processes; this refers to memories being stored as fragments and not as unitary wholes.
• traumatic memories’ sensorimotor organization. Not being able to integrate traumatic memories seems to be the main element which leads to PTSD.

van der Kolk and Fisler’s hypothesis is that under extreme stress, the memory categorization system based in the hippocampus fails, allowing these memories to be kept as emotional and sensory states. Excessive arousal at the moment of trauma interferes with the clear memory processing of the event, leaving unaltered memory traces. When these traces are remembered and put into a personal narrative, they are subject to being condensed, contaminated and embellished upon. When traces are recalled, increased activity in the amygdala might cause the personal assignment of accuracy and individual significance.

van der Kolk states that trauma responses are bimodal. The response to trauma is hyperamnesia, over reaction to stimuli and reexperiencing the trauma, which exists with numbing, avoidance and amnesia. When compensating for chronic hyperarousal, subjects with PTSD may shut down and avoid stimuli similar to the trauma. PTSD subjects may go directly from stimuli to response without an adequate appraisal of the situation, due to their overgeneralization of incoming stimuli, creating flight or fight reactions.