Decades of psychological research cast doubt on the accuracy of eyewitness testimony by showing that false details put forth during an interrogation can lead some people to develop vivid memories of events that never happened.
While this “false memory” phenomenon is alive and well, new research from Washington University in St. Louis and Carleton College suggests that a bit of misinformation also has potential to improve our memories of past events — at least under certain circumstances.
“Providing eyewitnesses with misleading information about a crime can alter their memories for key details of the crime scene, but our study suggests that this effect is not ubiquitous,” said study co-author Henry L. “Roddy” Roediger, an internationally recognized expert on human memory at Washington University.
“In situations where the original event was pretty well remembered, a later attempt to provide misinformation can actually boomerang and make details of the original scene even more memorable,” added Roediger, the James S. McDonnell Distinguished University Professor in Arts & Sciences.
Published in the journal Psychological Science, the study is co-authored by Roediger and two of his former graduate students in the Department of Psychological and Brain Sciences at Washington University: Adam L. Putnam, a 2015 doctoral graduate now a psychology professor at Carleton College, and Victor Sungkhasettee, who received a masters degree in 2014.
“Our experiments show that misinformation can sometimes enhance memory rather than harm it,” Putnam, the study’s lead author, said in an Association for Psychological Science news release on the study. “These findings are important because they help explain why misinformation effects occur sometimes but not at other times — if people notice that the misinformation isn’t accurate, then they won’t develop a false memory.”
Using a series of experiments that tested how well 72 undergraduates recalled details from images in six slide shows, researchers set out to identify circumstances under which misinformation has the greatest potential to induce false memories.
As it turns out, the devil is in the details, or more specifically, how well details of a past event are remembered in the first place, they argue.
“When people remember an event well enough to spot misinformation when it’s later presented, that recognition process may trigger the recall of specific details that support this assessment,” Roediger said. “As we’ve seen in other memory research, successful recall is key to reinforcing our ability to accurately remember important information.”
While the study generally replicates other findings that suggest false memories can be induced by misinformation, it offers a few important caveats to this general rule.
Most importantly, misinformation seems to be most effective at altering memories when details of the event are hard to recall in the first place.
The study also has practical applications to court cases and other real-life situations by showing the mere fact that a person (or witness) has been exposed to misinformation may not mean false memories have been implanted. In the case of memorable details, the misinformation may cue a covert retrieval of the initial event and enhance memory for it.
“If the initial event was memorable, the misinformation may remind them that ‘no, that’s not what it was, it was X,’ and they actually do a better job of recalling those details later,” Roediger said.
This study was supported by National Science Foundation Grant DGE-1143954 and by a Collaborative Activity Grant from the James S. McDonnell Foundation.