Believers in UFOs/ghosts/lake monsters/ Santa often tell us that we should believe the report because the witness was a reliable person, not someone who is normally easily confused. There’s a perception that anyone who misperceives things is foolish. But that’s not true, with a bit of suggestion it’s possible to implant a false memory in anyone. The day before QED I accidentally implanted a false memory in a neuroscientist who shares an office with me, lets call her ‘Susie’
I was going to leave my office to drive to Manchester for QED, when I realised I couldn’t find my wallet. I thought back to when I last saw it. I had brought some petrol on the way to work, and then a sandwich at lunchtime.
‘I can’t find my wallet ‘ I said, as a crawled round behind the filing cabinet ‘but I’m sure I had it at lunchtime’
‘Mmm, yes, oh dear’ said Susie, concentrating hard on her systematic review
I thought back to lunchtime, Susie had asked to borrow some money to buy some chips, I’d explained that I only had a few pounds in cash, but I could go to the cashpoint. She’d laughed, and told me that she had only wanted to borrow some money because she was too lazy to go to the cashpoint herself.
‘Susie, do you remember at lunchtime, when you asked to borrow that money, I had my wallet didn’t I?’
She looked up from her forest plot.
‘Yes, you were standing just there, holding it in your hand’
This was annoying. If I had been holding it at lunchtime, that meant it must have gone missing that afternoon. I’d spent the afternoon wandering around the hospital trying to recruit people into my study. I could have dropped it anywhere. It was a bad time to loose my wallet, I was about to go to QED, and I’d need a credit card to check into my hotel. How was I going to manage a trip to manchester without any cash at all.
Nevertheless, it was clear. I was going to have to cancel the card, borrow some cash off my wife, and QED would include considerably less alcohol. With a heavy heart I rang my bank and did the honours.
Contemplating an alcohol-free weekend I dragged myself back to my car, and found my wallet sitting on the passenger seat. Of course it had been there all along. How could this be? I had left the care at about 8.15 am, and Susie had told me that she had seen my wallet at around 1pm. Had Susie lied to me? Or I had convinced her she’d seen something that she hadn’t seen.
It’s possible to implant a false memory in anyone – if the circumstances are right, and it’s possible for any eye witness to be mistaken. One of the most famous studies was by Loftus and Pickerall in 1995. They recruited a 24 students, and spoke to their relatives to obtain three stories of events that had happened in their childhood, and to confirm that they had never been lost in a shopping mall. They then presented the participants with a short summary of the four events and asked them to write a detailed account of all four events. A week later they were interviewed and asked to recall their memories again, and rate them for clarity. They were all able to give detailed descriptions of the false memory, though it was less clear, at this point the investigators explained that one of the memories had been false, and were asked to select which memory was false and which was true : 5 students, (20%) said that they recalled the ‘false’ memory as being true.
Think about that it is possible to convince 1 in 5 people that a false memory of being lost in a shopping mall is true. This study has been replicated a number of times, so it’s not just a one off. People are more likely to recognise a memory as ‘false’ if it is implausible, in 1997, Pezdek, Finger and Hodge found that it easier to implant a memory of a culturally Jewish event in Jewish high school students than in Catholic ones, (and visa versa). The younger a child is the more susceptible they are to having false memories implanted. Recently scientists have taken things a step further and have been able to create entirely false memories in mice.
Further reading –