The coherence of traumatic and non-traumatic memories: A tale of equivalence

There is contention in the scientific literature about the mechanisms by which our memories for traumatic events operate. In one view, the extremely negative nature of traumatic events results in incomplete encoding, leaving memories for these events incoherent. In this view, incoherence promotes distress and therefore must be targeted over the course of treatment to enable recovery. In another view, traumatic memories operate using the same basic set of mechanisms as memories for non-traumatic events; traumatic memories are not uniquely incoherent, and evidence does not support the idea that treatment boosts coherence in a way that supports recovery. But across the literature, several counter-explanations hinder our interpretation of the existing findings. Over five experiments, we addressed these counter-explanations. We found little evidence to suggest people’s memories for traumatic events were incoherent, both in absolute terms and in relation to memories for non-traumatic events. Across our experiments, coherence did not vary in a systematic way depending on whether a memory was traumatic or non- traumatic. Moreover, we found evidence to suggest the way people recalled a memory affected their sense of how coherent that memory was. We also found that repeatedly recalling a memory, as happens in some therapies for posttraumatic stress disorder (PTSD), did not boost coherence. Instead, the data suggest repeated recall prevented a sense of lost coherence seen in memories not repeatedly recalled. Furthermore, we consistently found that memory coherence was not related to the degree of posttraumatic stress a person reported about that event. Mini meta-analyses on the data gathered across these five experiments, and their associated pilot studies, converged on the conclusions that a) traumatic memories are just as coherent as their non-traumatic counterparts, and b) there is no relation between coherence and symptomatology. Considered together, these findings are consistent with a basic mechanisms account of traumatic memories, and have implications for our conceptualisation of PTSD and the therapies designed to treat it