Does emotional or repeated misinformation increase memory distortion for a trauma analogue event?

In general, memory of highly negative and even traumatic events can distort. However, the effect of misinformation exposure on such memories requires further investigation given the inconsistent past findings. With two experiments, we investigated: (1) whether misinformation distorts memory for highly negative analogue events, (2) whether memory distortion is increased for more emotional and potentially traumatic details compared to unemotional details, and (3) whether repeated misinformation exposure further increases memory distortion for highly negative events compared to single exposure, a possibility that has not been investigated to our knowledge. In both experiments, participants viewed a trauma analogue film with some scenes removed. Twenty-four hours later, they were given three "eyewitness" reports describing the film's events. To manipulate misinformation repetition, either zero, one, or all three of the reports described removed scenes. To determine whether memory distortion is increased for emotional details, half of the removed scenes were more traumatic than the other half. Participants exposed to misinformation falsely remembered more removed scenes compared to participants who were not exposed to misinformation. Further, memory distortion was increased for emotional (vs. unemotional) aspects of the film. Repeated misinformation exposure, however, did not lead to significantly higher error rates compared to single exposure. The lack of perceptual overlap between our written misinformation and film test items may have limited false memories even with repeated misinformation. Alternatively, the repeated vs. single misinformation effect may exist but be very small, as suggested by our raw means and effect sizes.