As any detective, interrogator, or Christopher Nolan movie can tell you, your memory is far from a perfect copy of past events. It’s an ever-changing bundle of recollections, stories, and ideas that’s constantly undergoing editing and rehashing.
In a new study, researchers have shown how it’s possible to plant false childhood memories into a person’s imagination and then correct the false recollections without damaging true memories.
Psychologists from the University of Hagen in Germany and the University of Portsmouth in the UK gathered 52 people to join a study on childhood memories. Prior to the experiment, the researchers sent questionnaires to the participant's parents, asking for two events that occurred in their childhood and another two that never happened, but sounded plausible. The participants were then encouraged by their parents to believe that all of the memories were real. For instance, it might be a fake story about them getting lost on holiday, running away from home, or being involved in an accident.
Thereafter, the 52 participants were called in for multiple interview sessions where they were asked to recall the past events sent in by their parents. After being subjected to suggestion techniques by the interviews, up to 56 percent of the participants believed the false events had actually occurred — rich false memories had been subtly nudged into their minds.
The findings were recently reported in the journal Proceedings of the National Academy of Sciences.
Crucially, the researchers were also able to remove the false memories without explicitly telling them which story was a lie. In one technique, they would remind participants that memories are not always based on experiments, but can be picked up from stuff like photographs or a family member's story. In this instance, they were asked to recall the source of the memory, which often revealed that the story was, in fact, a fantasy.
Another technique simply highlights that repeatedly recalling an event can sometimes generate false memories. With this in mind, the participants were asked to recall their own event memories, and most realized which memories were false.
“Does our study support the idea that the case for false memories has been overstated and that there is not much to worry about them as they can be made to go away? The answer is an emphatic no. What our study shows is that false memories can both be induced under suitable conditions and reversed under other suitable conditions,” the study authors conclude.
The researchers say their work isn’t just a demonstration of how malleable memories can be, but they also argue it could change the way we see courtroom confessions and integrations. If it’s possible to easily implant a false memory using subtle methods of suggestion, then it further highlights the unreliability of witness testimonies.
“We designed our techniques so that they can principally be applied in real-world situations. By empowering people to stay closer to their own truth, rather than rely on other sources, we showed we could help them realize what might be false or misremembered – something that could be very beneficial in forensic settings," Dr Hartmut Blank, study co-author of the research from the University of Portsmouth’s Department of Psychology, said in a statement.