A comparison of flashbacks and ordinary autobiographical memories of trauma: cognitive resources and behavioural observations.

We investigated predictions derived from the dual representation theory of posttraumatic stress disorder, which proposes that flashbacks and ordinary memories of traumas are supported by different types of representation. Sixty-two participants, meeting DSM-IV diagnostic criteria for posttraumatic stress disorder, completed a detailed written trauma narrative, and afterwards identified those sections in the narrative that had been written in flashback and ordinary memory periods. Performance on cognitive tasks confirmed predictions that flashback periods would be associated with a specific decrement in visuospatial processing. Contrary to prediction, periods of both flashback and ordinary memory were associated with decrements on a verbal processing task. Independent observer ratings also confirmed that flashback periods were associated with increases in a wide range of autonomic and motor behaviours.