Memory deficits are implicated in the development of posttraumatic stress disorder (PTSD). Intentional recall of trauma memories is frequently disorganised or incomplete, whilst involuntary memory fragments are easily triggered by perceptual cues. Ehlers and Clark (Behaviour Research and Therapy 38 (2000) 319-345) propose that a predominance of data-driven processing (i.e., processing sensory impressions) during the trauma contributes to the development of this memory pattern, and therefore, predicts PTSD symptoms after trauma. Two experimental studies examined these hypotheses. Student volunteers viewed a distressing videotape as an analogue for a traumatic event. In Study 1, cognitive processing was manipulated; in Study 2, extreme scorers on a processing screening questionnaire were pre-selected. The results indicated that data-driven processing is associated with the development of PTSD-like memories and analogue symptoms.