The memory is fallible. We misremember and forget the events of our lives all of the time. But a small number of individuals seem to have exceptional recall for the mundane details of their personal lives without even trying. Give them a date, and they can bring to mind the sandwich they ate for lunch, the sneakers they wore, the soft rain that fell in the afternoon.
In 2006, the first clinical case of such a person was identified, and the condition was given a name: Highly Superior Autobiographical Memory, or HSAM. Some experts propose that there may be no more than 100 or so people on Earth with the condition.
Read more: “Faulty Memory is a Feature not a Bug”
Recently, the parents of a young woman in Atlanta who seemed to have such a superior memory brought her to the attention of a team of scientists, who invited her into the lab for study. They found that her exceptional recall seemed to begin at age 12, shortly after the COVID-19 pandemic, and that she scored especially high on standardized tests of involuntary memory. Voluntary and involuntary memory seem to be distinct processes, and this rare form of superior memory, they believe, may be closely linked to the latter. They published their results this year as a case study in the journal Neurocase.
I spoke with study author Anne Cleary, a psychology researcher at Colorado State University, about the memories of the girl from Atlanta, what her condition has to do with COVID, déjà vu, and creativity, and what impact her remarkable memory has had on her life.
Can you tell me about the woman you studied?
She was 16 years old at the time I met her. Her parents realized that her memory was truly phenomenal, so they started looking into it, and they came across some of the blog posts and publications that are out there on this phenomenon known as HSAM. Her parents learned about what that was, thought that she might have it, and wanted to have her tested for it. They wanted to make sure that it wasn’t going to affect her wellbeing. I heard about her through a colleague at Emory University in Atlanta, and I ended up traveling to Atlanta in 2024 to meet with the girl, who we called EE, as well as her mother.
It was the summer of 2024. There’s no great standardized method of testing for HSAM, but James McGough, one of the authors of the very first case report on HSAM that had come out in 2006, let me know his method at that time and over the years. That method was to give the person a set of dates, to see what they can remember from those dates, and then go back and look at whether there were objectively verifiable details such as what was in the news that day, the weather.
It turned out, the teenager that we were interviewing never watched the news, ever, so public events were not really in her realm of experiences. But I gave her a set of dates that I had come prepared with. Some were pre-planned based on public events that were noteworthy that my colleague’s teenager, who was similar in age, had suggested.
The first date that I gave to her was November 5th, 2021. Without hesitation, she said, “Oh, that was a Friday. and we didn’t have school that day because the Atlanta Braves were going to the World Series, and there was a local parade to celebrate it, and we had off of school.” And then she went on to describe what she was wearing that day, a sleepover she had at a friend’s house that night, with pizza and the movie she watched.
She also told me that night there was this really beautiful sunset. As I was trying to verify the details later, I just happened to come across this picture on the internet of a beautiful sunset from that day in Marietta, Georgia, where she had been for the sleepover. I remember getting chills, from head to toe.
You believe that this form of memory overload is involuntary. Why?
That’s what we’re arguing in our case report. In the 20 years since the first case was identified, researchers have tried neuropsychological assessments, laboratory tasks, analyzing different aspects of memory and cognitive performance to see what is different about people who have this HSAM. But they haven’t been able to pinpoint anything.
It occurred to us to ask a different question. We’ve been thinking about involuntary forms of memory as a research group for a while because I also study a phenomenon known as déjà vu, that puzzling, eerie feeling of having lived through something before. If you think about it, déjà vu is an involuntary form of memory, right? It just happens to you. You don’t get to decide when it’s going to happen.
If you look at the case reports of people with HSAM, at least anecdotally, the person often reportedly claims they’re not trying. They’re different from so-called memory athletes, or competitive memorizers, who will strategize and come up with elaborate intentional strategies to remember enormous amounts of information.
We decided to give EE an inventory known as the IAMI, the Involuntary Autobiographical Memory Inventory, which was developed relatively recently. It’s a survey tool for assessing the frequency with which a person has involuntary memories that just kind of pop into mind, for no reason. You may think, “Why did I just think of that vacation? I was trying to type an email.” And it’s totally normal.
This inventory came out as a publication in 2015 as a way of trying to assess individual differences. We hypothesized that maybe she would have really high involuntary autobiographical memory frequency. And sure enough, that is exactly what we found. She was off the charts.
It may be putting us on a path toward finally understanding what really is different in these people. We’re hypothesizing that maybe if someone has involuntary memories pop into mind at a greater frequency than average, because they come to mind repeatedly and over time, they get consolidated better. Maybe that is why you have a remarkable memory for past events that happened to you.
Was it already understood that involuntary and voluntary memory are entirely different beasts?
Like any area of cognitive science or neuroscience, there are controversies over exactly how these things differ. But they tend to be thought of as having some different underlying mechanisms. Some more voluntary forms of memory involve more intentionality and what we would call top-down processing. With involuntary memory, there are mechanisms under the surface that are causing memories to just come to mind without you trying.
Now is there overlap? That’s something scientists still need to work out. But there is something fundamentally different about the two. And there are many hypotheses about what that difference is.
One thing I found really fascinating was that EE said her memory became more clear around age 12, which corresponded with COVID. Do you think that life circumstances could play any role in HSAM?
I don’t think we have the answer to that yet. But at least anecdotally, if you look at other reports, including that first report from 2006, people identified as having HSAM often report noticing that their memory was better than most of the people around them at that same age of around 12, or in adolescence. Is there something that happens around that point in human development that’s critical?
Partly because it’s so rare, it’s hard to find a large number of people to follow and study. But EE was 16 at the time that we identified her. Shortly after our report came out, another report came out of Europe arriving at the same conclusion as us with another 16-year-old, who I believe was from Poland.
So now we’re starting to identify people in their teens who seem to have it around the world. There was also someone in Italy who was maybe 13 or so who was recently identified, as well. It would be interesting to be able to examine what memory was like in these people before adolescence.
Another thing that surprised me is that people with HSAM don’t appear to differ on measures of creativity or forgetting, which seems so counterintuitive.
This ties back to how are we measuring it and what are we measuring. There are so many different facets of memory: the ability to recall something over the short term, the ability to intentionally recall something when given a cue, associative memory, familiarity-based memory or recognition memory. And they all may have slightly different underlying mechanisms. It boils down to how are we trying to measure things like forgetting? That may be why we weren’t in the past yet getting at, well, what is different in people with HSAM? Because if you give them standard tasks, they seem to perform very comparably to the young adult college students that are typically participating in memory studies or other comparable control participants.
It may be we were going at it wrong. If you measure forgetting of just life experiences, they clearly are going to score lower than average. But for other things, like lists of items, they exhibit the same rate of success versus forgetting as a comparable control group. They don’t excel at these standard kinds of memory tests. It seems to be their specific autobiographical memory, their personal life experiences that they can’t forget.
You mentioned that you study déjà vu. Does this particular case of HSAM suggest anything to you about the nature of déjà vu or memory more broadly?
We were very interested in that question, in part because some researchers in Europe have suggested that autobiographical memory and déjà vu may themselves be linked. These researchers argue that both are essentially involuntary types of memory. They both kind of just happen to you without you willing them to happen. And it may be that déjà vu is a sense of familiarity with an experience followed by retrieval of a past autobiographical experience that might be responsible for why you’re feeling déjà vu in a current situation.
And based on that assessment, we hypothesized that maybe someone with HSAM would experience déjà vu at a higher rate than average in the world. Other colleagues hypothesized that someone with HSAM would never have déjà vu because they’re just so good at retrieving autobiographical memories, they wouldn’t have this in-between kind of experience.
We actually gave EE an inventory known as the IDEA, which stands for Inventory for Déjà Vu Experiences Assessment. It’s been around since about 1994, and while there’s not a huge amount of research happening on déjà vu, among people who do study it, it’s the most common assessment for tallying how often people experience it on a daily or monthly basis. Every now and then you’ll see people with extremely frequent déjà vu. But EE fell in the average range: about one to two times a year. It’s definitely worth exploring in future cases of HSAM that emerge.
The group out of Europe that I mentioned published a different case report about a few weeks after ours came out. They also gave that person with HSAM the IME, and they found something similar to what we found, where the person seemed to be higher than average on involuntary autobiographical memory frequency.
That group also gave their person a task that’s meant to try to tap into involuntary autobiographical memory. It’s kind of a boring task that’s conducive to daydreaming, and these seemingly random probes come on asking, “Hey, what was your mind doing just now?” Their person with HSAM also ranked higher than the control group. There does seem to be converging evidence for this idea that HSAM may be involuntary.
Did the ability to retrieve these autobiographical memories interfere with EE’s life at all?
Her parents were afraid maybe it would in the future. And they just wanted to check, should we be concerned about anything or how can we help her to thrive if she does have this? But EE does not seem to experience distress from it. It doesn’t seem like it has any negative impacts on her life. If anything, it seems like it’s been mostly a positive for her. Her friends always enjoy being able to ask her what happened on this day or her family can go to a restaurant with her and ask, “Okay, how many times have we been in this restaurant before?” And she can go through in her head and rattle off every single time they’ve ever been in that same restaurant. And she’s very interested in participating in research and contributing to our understanding of memory and of HSAM.
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Lead Image: Nanzeeba Ibnat / Adobe Stock
