FOLLOW @USATODAYHEALTH FOLLOW @USATODAYHEALTH Psychological research has shown various ways "false memories" are created, such as through the power of suggestion or through vivid imagination. Now scientists studying imagination have found that people who watched a video of someone else doing a simple action often didn't remember and thought they had done it themselves when asked about it two weeks later. "This is a completely new type of false memory," says Gerald Echterhoff, a psychology professor at the University of Muenster in Germany and co-author of the paper published in the September issue of the journal Psychological Science. "This is a false memory from just observing someone," he says. Psychologist Daniel Schacter of Harvard University in Cambridge, Mass., who has edited a book on false memories, says he hasn't read the new paper, but it "sounds like an extension of earlier work that has shown imagining you'd done something can result in false memories." "I think it's partly new and partly related to earlier work," Schacter says. "You saw something on TV that you think actually happened. It's another kind of example of what people have talked about as a source memory failure." Echterhoff says, on average, participants reported false memories of doing an action they really didn't do almost a quarter of the time. In this study, as well as in several follow-up experiments, the majority of participants misremembered, thinking they had done something they had merely observed. Since the first research on 170 participants, findings have been replicated with almost 500 participants, he says. The paper details three different experiments in which participants read about or actually performed a series of simple actions, such as shaking a bottle or shuffling a deck of cards. Then they watched videos of someone else doing simple actions — some of which they had done and some they had only seen being done. Two weeks later, they were asked which of as many as 30 actions they had done themselves. Researchers found the subjects were much more likely to falsely remember doing an action if they had watched someone else do it. Echterhoff says the research controlled for the common situation of thinking you had done something because you do it yourself every day. And, he says, participants had false memories even when cautioned about the possibility. "It's very hard to counteract this type of false memory, even when participants were warned it could happen," Echterhoff says. The paper suggests that observation of another person's action "may trigger a covert simulation of the action and thus activate motor representations similar to those produced during self-performance." Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more