Misinformation resistance in memory reports of one instance of a repeated event: Post-warnings reduce misinformation endorsement in recognition.

Previous research shows that remembering repeated events differs from remembering single events, yet little research has examined suggestibility in adults' memory for repeated events. In the present experiment, we investigated the effects of eyewitness misinformation and the role of a warning against misinformation in a repeated-event scenario. We examined how different types of misinformation - entirely new items versus items present in non-target instances - influence reporting. Three hundred and nine participants watched four surveillance-mission videos that shared a general story structure but differed in key details. Participants were later exposed to pieces of misinformation in a video narrative of someone else reporting the first mission. Reporting was measured using free recall, cued recall, and recognition. We replicated the standard misinformation effect in the repeated-event context. We found that the warning reduced misinformation reporting, but the effect was present only in the recognition task. Based on the source-monitoring framework, we expected it would be easier to resist external (entirely new) misinformation than misinformation consistent with what was present in non-target instances, and this was also true. The warning's lack of efficacy may be accounted for in two ways. First, the inherent difficulty of attributing details to specific instances of repeated events may have overshadowed the potential effects of the warning. Second, ours was a general warning; it might not have been strong enough to restore an adequate understanding of a memory task distorted by misinformation.