Dissociation is an important aspect of responses to traumatic events. According to a number of influential theories, it negatively impacts cognitive performance including encoding of the trauma memories, leading to an increased risk of later conditions such as posttraumatic stress disorder . We tested this hypothesis experimentally in two studies by inducing dissociation in the laboratory and investigating the effects on several aspects of cognition, including time estimation, digit and spatial span, and story recall. Dissociation was related to decrements in (...) time estimation, digit span, and story retention, but did not affect perceptual attention, spatial span, or immediate story recall. The results are discussed in the context of theoretical models of PTSD and their implications for official questioning of traumatized individuals such as sexual assault survivors. (shrink)