Photo: TriStar Picutres

Between the questionable confession of Making a Murderer’s Brendan Dassey and the new testimony from Serial’s Asia McClain confirming Adnan Syed’s presence with her in the library at the time of Hae Min Lee’s murder, memories in criminal investigations are having something of a cultural moment. Testimonies and confessions like these are often the difference between a “guilty” and “not guilty” verdict, and yet a criminal psychologist confirms in a Reddit AMA this week what Brian Williams taught us last year — the line between imagination and reality is much blurrier than you might imagine.

Julia Shaw is a lecturer at London South Bank University whose research focuses mainly on memories and how they’re used (and misused) in criminal cases. In her Q&A session with Reddit, she describes the way she studies false memories:

The technique I use in my research is essentially a combination of what’s called “mis-information” (telling people convincingly that something happened that didn’t) and an imagination exercise which makes a participant picture the event happening. The goal is to get my participants to confuse their imagination with their memory. I find, as do many other scientists who study memory, that it is often surprisingly easy to implant memories. All of my participants are healthy young adults, and in my last study 70% of them were classified as having formed these full false memories of crime by the end of the study. I am currently working on further research and analysis to see whether I can replicate this, since this success rate was incredibly high.

Seventy percent. Yikes. The thread quickly became a philosophy-meets-neuroscience exploration of what a memory even is, and how we can maintain accurate ones. One worried-seeming Redditor asked if there are certain types of people who are more likely to be seduced into making a false memory — or if it’s something to which we’re all potentially vulnerable. Shaw answered:

This is a question I get asked a lot! … Certainly there are individuals who we consider more vulnerable, such as those with low IQ, children and teenagers, and mental illnesses like schizophrenia that already make it difficult for individuals to engage in “reality monitoring” – essentially anyone who may already be bad at telling fact from fiction is probably more likely to generate false memories. HOWEVER, in my own research on “normal” adults, I did not find ANY systematic personality differences between those who did and those who did not form false memories. I tested for Fantasy Proneness, Compliance, and the Big Five personality types … in addition to testing for gender, age and education. I found nothing.

Another person asked about ridding yourself of false memories — does the fake memory disappear once you are aware that it’s fake? “Disappear is a very strong word!” Shaw answered. “Like any other memory, false memories have the ability to be forgotten, to fade, or to be replaced by other memories.” In other words, false memories work a lot like real ones. Most of the time, the only way to actually know if a memory is false is to corroborate it with other data. For example, if you thought a person was wearing a red shirt and a photograph from that day and time indicates they weren’t, you can invalidate your false memory — but we rarely get such explicit chances at validation.

Shaw also tackled the Dassey question in a column for Scientific American last month, arguing that the confession was coerced and that it illustrates how false memories can potentially be planted. Shaw further argues that false-memory research has some potential real-world implications::

The implications of false memory research for the criminal justice system are tremendous. It calls into question our current reliance on memories by suspects, victims, witnesses, even police officers and lawyers … It leads to us asking whether we can ever be certain “beyond a reasonable doubt” that someone committed a crime for cases that rely exclusively on memory recall. It also shows us how easily bad interview/interrogation techniques can create false memories, making us rethink police practices.

Shaw will make an appearance on PBS’s NOVA documentary Memory Hackers; her book, The Memory Illusion: Why You Might Not Be Who You Think You Are, will be published in June. That is, if I recall correctly.