Scientists Implanted And Then Reversed False Memories In Trippy Study

For most of his childhood, famed Swiss psychologist Jean Piaget believed that he was kidnapped as a child, and the memory was so vivid that he recalled the subway station where it happened.  It was only at the age of 14 that Piaget learned this memory was completely false.

While the average person may not have false memories to this degree, the experience of remembering something that didn’t really happen is incredibly common—and potentially dangerous. In recent years, scientists have shown how implanting false recollections through suggestion has run rampant through the criminal justice system, leading to false confessions and allegations.

But there may be hope yet for disentangling real memories from imposters thanks to new research published this month in the journal PNAS by psychologists from the U.K. and Germany. For the first time in a realistic setting, this research team showed that it is possible to implant false memories and then reverse them. 

Part of what makes it so easy for our memories to be confused or fragmented in the first place, explained Aileen Oeberst, professor of psychology at the University of Hagen and first author on the paper, is that the content of a memory and the source of a memory are often stored separately in our minds.

In an email, Oeberst said that this “may lead to the retrieval of content without its correct source (e.g. the interviewer/parents/therapists) or even direct source confusions or source misattributions (e.g. taking images from dreams or family narratives as actual recollections of own experiences).”

To attempt to reverse these kinds of experiences in their study, Oeberst and colleagues recruited 52 young adult volunteers and (with the help of their parents) used suggestions to implant several false, yet plausible, memories. For example, that they had run away in the past or been in a car accident. 

During the course of three memory interviews over two weeks, the participants were asked to remember two real and two false events. By the third interview, up to 56 percent of the participants had developed false memories around the non-existent events that were suggested to them.

With the participants thoroughly inoculated to their false memories, the research team then employed two methods to attempt to reverse the process they’d just set into motion. The first reversal method was called “source sensitization” and second “false memory sensitization.”

Both methods relied on simply reminding patients about the unreliability of memory. For source sensitization, a researcher prompted participants to remember that memories may not always be based on our lived experience but could instead come from a family photo album or another person’s narrative. With false memory sensitization, the researchers explained to participants that false memories can sometimes be created by repeatedly recalling memories—as they had been doing over their three memory interviews. When participants revisited their memories after experiencing both reversal methods, the researchers reported that belief in their false memories dropped to as low as 15 percent. After following up with participants a year later, these belief levels had dropped even lower to just 5 percent.

Even with the success demonstrated in these trials, Hartmut Blank, co-author on the study and researcher of experimental and social psychology at the University of Portsmouth, said that the question still remains whether such methods could be used to reverse long-held false memories.

“There is not much research on the reversibility of distorted memories yet,” says Blank in an email. “It is well possible that (false) memories that have been held for longer (and that people are perhaps emotionally invested in) may be more difficult to reverse.”

For such long-held memories, Oeberst suggests that the reversal phase may need to be proportional in length. But ultimately, Oeberst hopes that these methods can help relieve the suffering often felt by those who believe in false memories and give them back control over their own story.