Abstract
The primary goal of the presented research was to investigate how processing post-event information affects memory of details in an event viewed on video. We used two forms of post-event information: classic misinformation (changing or implanting new information into memory) and a new form that involves a correct explicit or implicit negation of the existence of an object in the video. We followed the three-step procedure used in studies on the misinformation effect, with a final memory test that was either immediate or delayed by a week and consisted in indicating which objects appeared in the video. We replicated the misinformation effect. More importantly, in the delayed test condition, both explicitly and implicitly negated objects were falsely recalled more often than unmentioned objects. These results indicate that it is possible to induce negation-related false memories; they also show that memory is impaired by negated post-event information or misleading post-event information.