A phenomenon whereby misleading post-event information distorts an eyewitness's recall of an event, as when a victim of a sexual assault who is subsequently told that an arrested suspect has a tattoo on his left arm comes to believe that she can recall seeing a tattoo on the perpetrator's arm. The effect may be caused by the post-event information overwriting the original memory, or by the eyewitness becoming confused about the sources of different items of information, without the original memory necessarily being impaired. These processes were first studied systematically by the US psychologists Elizabeth F. Loftus (born 1944) and John Palmer (born 1954), who reported their findings in the Journal of Verbal Learning and Verbal Behavior in 1974, and the effect was discussed at length by Loftus in her book Eyewitness Testimony (1979). In the original experiment, participants viewed a video recording of two cars colliding, and they were then asked how fast the cars were going when they hit or when they smashed into each other; when the word smashed was used in the question, the participants estimated the speed as 7 miles per hour faster, on average, than when the word hit was used, and a week later, 32 per cent of those exposed to the word smashed falsely recalled broken glass in the video, compared to only 14 per cent of those exposed to the word hit. Also called the misinformation effect. See also experimentally induced false memory, false memory, false memory syndrome, paramnesia (1), Piaget kidnapping memory, reality monitoring, recovered memory.