That Neuroscience Guy - The Neuroscience of False Memories

Episode Date: March 20, 2024

Remember when the sun was blue? Or what about that time bugs took over the world? Sometimes, our brain creates memories out of events that never happened which can cause drastic changes in behaviour. In today's episode of That Neuroscience Guy, we discuss the neuroscience behind how our brain creates false memories and how that process compares to making real memories. 

Hi, my name is Olaf Kregolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to the podcast. And sorry right away if I'm a bit sniffly right now. I've been battling some kind of bug and, well, you might hear some sniffles. I'll see what I can do about it. So today's topic is kind of an interesting one. We've sort of talked about it briefly before, but someone came back or a couple of people actually came back messaging us sort of saying,

can we learn more about false memories? Now, if you remember what I said, or even if you don't, modern memory theory from a neuroscience perspective would predict that roughly half of what we actually remember to be true isn't true. In other words, half of our memories are false. So let's talk about why that is. And what I'm going to do is walk you through a bit of some examples, basically, and some of the research, and then we'll come to some conclusions about why half your memories are actually false. Well, if you don't remember our podcast on memory, there's been a couple. Here's the 30-second Coles Notes. Basically, our brains receive sensory input

that comes in through our eyes or our ears or other senses, and that gets pushed into short-term memory or working memory. And if we want to remember something, well, that we go through a rehearsal process where we're rehearsing the information over and over again, and that should lead to encoding. And that's when memories move into long-term memory and consolidation is the process where that memory firms up. And we've talked about that in the past. And sometimes information from short-term memory is displaced. That's not what we're talking about.

That's the example where you're introduced to someone and 30 seconds later, you can't remember their name. So another view on memory is that there's short-term memories, there's long-term memories, but there's also long-lasting memories. And these are things that last months to a lifetime. And that's what we're really focused on is these really, truly long-lasting memories. The ones that are in there, the stuff you remember from childhood, basically. Now, here's an example of a false memory. In 1986, Nadine Kuhl, a nurse's aide in Wisconsin, sought therapy from a psychiatrist to help her cope with her reaction to a traumatic event experienced by her daughter. During therapy, the psychiatrist used hypnosis and other

suggestive techniques to dig out buried memories of abuse that Kuhl herself had allegedly experienced. In the process, Kuhl became convinced that she had repressed memories of having been in a satanic cult, of eating babies, of being raped, of being asked to do some horrible other things, and being forced to watch the murder of her eight-year-old friend. Kuhl was told she had experienced severe childhood sexual and physical abuse. Now here's the problem. Kuhl finally came to the realization that the false memories had been planted. Even though she believed they were true, they never happened. She sued the psychiatrist for malpractice in March in 1997 after five weeks of trial and the case was settled out of court. So basically,

Kuhl had these pretty extreme memories, but none of it was real even though she thought they were. Here is another example. In Missouri in 1992, a church counselor helped Beth Rutherford to remember jerping therapy that her father, a clergyman, had regularly assaulted her between the ages of 7 and 14 and that her mother sometimes was aware that it was happening. Under her therapist's guidance, Rutherford remembered her father twice impregnating her and forcing her to abort the fetus herself. The father had to resign from his post as a clergyman when the allegations were made public. Another horrible memory that was there.

Subsequent medical examination of the daughter revealed, however, that she had never had sex before and she had never been pregnant. The daughter sued the therapist and received an out-of-court settlement. So another example of a horrific false memory that just simply wasn't true, even though the person thought it was real and it had happened to them. Now on a definitely lighter note, this is some research by a couple of old friends of mine, Don Reed and Stephen Lindsay, and some other people who I've not actually met. And they ran a really cool experiment.

And here's the way it worked. Family members took part in the study. So they went out and found out family members, right? And you basically had to generate or get three photos. So three photos were of real things that have happened, and the one was a false photo. And the whole point of the false photo was to show you a picture of something that had never happened. Now we've all used photo adjustment software in our time, so basically what they did is they would cut out the picture of, say, a father and son, and then they transferred that picture so they were on a hot air balloon ride. Now, the key part is for the false photo is that it never happened. And then what happened is they interviewed these people about these childhood memories. And here's sort of an example script. Interviewer, and again, if you want to tell me as much as you can recall about this event without

leaving anything out. Subject. Hmm, no, never actually thought I'd been in a hot air balloon, so there we go. Interviewer. You can't remember anything about this event. Subject. Nah, though it is me, no memory whatsoever. Interviewer.

If you want to take the next few minutes, you can concentrate on getting a memory back. Something about the event? No, yeah, honestly, no, I can't. That's really annoying. So then what happened is they did repeat these interviews over a period of time. Same person, interviewer three, same again, tell me everything you can remember about event three. This is the false photo without leaving anything out. Subject, I'm just trying to work out how my sister was trying to get the exact when it happened, but I'm still pretty certain it occurred when I was in form one, sixth grade. This study was done in New Zealand at the local school there. Basically for $10 or something, you could go up on a hot air balloon and go up about 20 odd meters. It would

have been a Saturday and I think we went with, yeah parents. And no, it wasn't, not my grandmother, not certain who any other people are there. And I'm pretty certain that mom was down on the ground taking a photo. So this person over the course of this experiment, just three interviews, has created this memory where they believe that they were actually in the hot air balloon, even when they weren't. And this happened to multiple, multiple subjects. And this is where this idea of false memories comes from, is that people will generate fictitious memories of the past. And what's crazy about it are the statistics. 50% in that specific study of the recalled stuff never actually happened. People obviously did better with the true memories, all right, but there was

this massive ability to create false memories. And there's been lots of other studies where they've done this. Another study by a similar group of researchers basically showed people pictures of themselves in elementary school, but what they did was they, you know, substituted some people out or manipulated the actual photograph. And the same thing is true. These images that were false made people fabricate these incredible stories. And it also happens in children. It's not just adults. With children, they obviously try to be a bit more ethical and not do anything wrong. But basically, for 10 weeks, preschool children were interviewed by a trained adult. And the children were shown a set of cards, each with

different events on them. And the cards are read to the child to ask if that event had ever happened to them. Got finger caught in a mouse trap and had to go to a hospital to get the trap off. Think real hard and tell me if this ever happened to you. Can you remember going to the hospital with the mousetrap on your finger? Now, this was all happening when the kids, they were still kids. Now, after 10 weeks, a new adult came into the room. Tell me if this ever happened to you, a mousetrap. Can you tell me more? What did you see? Who is with you? Depending on each child's answers.

And people, again, these kids created false memories. An example was my brother Colin was trying to get a blowtorch or something for me and I wouldn't let him take it from me. So he pushed me into a wood pile where the mousetrap was and then my finger got caught in it. So this kid has fabricated this complete story simply by the suggestion of the image. There's some even crazier things. In one example of this research, they actually used advertisements. They prompted kids with pictures of Mickey Mouse or Donald Duck and said, you know, have you ever met this person? Right? And again, if they suggested that and then said something, have you ever shaken hands with a character at a theme resort? Kids would come up that they had done that if they'd seen this previous prompt of this ad where Mickey Mouse or whoever was in it. So again, these children were creating false memories and they

were confident that it actually happened. So let's talk a little bit more about how this is actually working and get to the neuroscience part of this. Basically, memories for personal experience traumatic events can be altered by new experiences. Entire events, even impossible ones that never happened can enter into memory. And as we know, entire events can be forgotten. Anyone from the preschool age to adulthood is susceptible to this. And even when a memory is vivid and compelling, it does not necessarily mean it's accurate. Now, what's actually happening here? Well, your episodic memories, that are your memories for events in your life, they're imperfect

and they are subject to error and reconstruction, distortion, dissociations from confidence and accuracy. Now, the way it's supposed to work is false memories are actually constructed by combining actual events with the content suggestions received from others. And those suggestions might be from other memories. So your memories are interacting all the time. And sometimes your brain puts it together as something that never happened. Now all of the scenarios I've given you, the examples of research, are pretty artificial. But this is proposed to happen even without experiments happening. You do this naturally.

So right now, as you're sitting there listening to this, there's a chance that half of what you remember never actually happened to you. Or probably more accurately, that it was distorted. And modern theories of this suggest that imagination plays a role in this as well. I've talked about the default mode network in the past, and the idea is when you get into the default network headspace, this is where imagination might run a bit wild and start biasing your memories. What I'll leave you with if you're still thinking about how does this really, really work. Imagine you have two memories for events, right? One is

going to a dinner party and one is going dancing. Well, your memory of the dinner party might be combined with a taste of the food, topic of conversation, who was at the table, something you smelled. And you might also have a memory of going dancing where there was something you smelled and there was other things going on, but these common items between these two memories might interact and flip and bias each other. And even the ones that aren't as common, because the way our memories truly work is your memory is a network. So a memory for an event, if you recall me talking about this in the past, isn't just one little spot in your brain. It's distributed across your brain. So the motor stuff is in motor regions. The visual stuff is in visual

regions. The smell stuff is in olfactory regions and so on and so forth. So your brain is trying to tie all this together, but sometimes when it's trying to tie it all together or when it's trying to recall it, it simply gets it wrong. The wrong brain regions get connected and that creates this new false memory. All right, well hopefully you found that interesting. I've always found false memories to be incredibly compelling or just get my attention because if half of what I remember isn't true, what does that really mean? And what, you know, what really happened in my life? Okay. Don't forget, check out the website, thatneuroscienceguy.com. There's links to Patreon where you can support us at our Etsy store. Of course, if you've got ideas like this

one, this was a request for more on false memories, just follow me on X or threads at that neuroscience guy and message me. Or of course you can email us at that neuroscience guy at gmail.com. And finally, thank you for listening to the podcast. Thank you so much. And please subscribe if you haven't already. My name is Olive Craig Olson, and I'm that neuroscience guy. I'll see you soon for another full episode of the podcast.