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What is it? -

Hyperthymesia is also known as highly superior autobiographical memory (HSAM). People with hyperthymesia can accurately and readily recall details about events that occurred in their life, from what they ate to what the weather was like on any given day.

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It’s personal -

These details can include exact dates and seemingly mundane information, but the catch is that the ability is limited to autobiographical memory, meaning people can only recall information about themselves and their own experiences.

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Average memory in impersonal ways -

People with HSAM fascinatingly seem to have an average (and even sometimes less than average) memory recall when it comes to impersonal information, such as random lists of words.

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Short term vs. long term -

People with HSAM likely process short-term memories in a similar way to most others, however a 2016 study suggests that these individuals have better long-term memory, Medical News Today reports.

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No tricks -

HSAM is different from just having a good memory, even when it comes to those who win memory contests. That’s because people with HSAM do not use mnemonic devices or other techniques to remember information. Rather, memory for people with HSAM is encoded involuntarily and retrieved automatically, according to a report in Wisconsin Medical Society.

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HSAM and OCD -

Some researchers have noted that individuals with HSAM share some characteristics with people who have obsessive-compulsive disorder (OCD), like demonstrating obsessive tendencies.

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HSAM and OCD -

There is no definitive link between the two, but some studies found that people with both conditions also tend to have certain structural differences in particular regions of the brain.

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Unable to forget -

A key part of the experience of HSAM is that people are unable to forget their life experiences. While further research is required to make definitive statements about the long-term effects, we can all probably guess how difficult it is to not be able to forgive and forget, or to let go of your worst memories.

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What causes it? -

As there are relatively few cases of hyperthymesia, there isn’t enough research to determine the causes. But theories suggest that the cause of HSAM may be biological, genetic, or psychological.

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Biological cause -

After scanning the brains of those with HSAM, one study suggests there might be links to hyperactivity in certain parts of the brain, like the amygdala. Another study suggests that people with HSAM have increased activity within different regions of the brain, like the superior and inferior parietal lobe.

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Chicken or the egg dilemma -

Craig Stark at the University of California, Irvine found additional wiring between the frontal lobes, which are involved in analytical thought, and the hippocampus, which is an area considered to be our memory's "printing press,” the BBC reports. But that may be a result of the skill strengthening the neural networks as opposed to the cause. “It’s a chicken or egg kind of thing,” said Stark.

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Genetic cause -

Another, much less substantiated, theory is that hyperthymesia may be genetic.

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Psychological cause -

Some researchers believe that HSAM may have psychological causes, due to certain behaviors that cause people to obsessively think about their previous experiences—as we mentioned with the suspected link with OCD. Regularly thinking about memories increases the ability to recall them.

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No formal diagnosis exists -

As hyperthymesia is a rare ability, there is currently no formal way of diagnosing it. Since hyperactivity in certain parts of the brain is a suspected characteristic of HSAM, doctors have tried assessing the condition through an MRI scan while getting the individual to undergo a memory test.

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Memory tests -

Complex memory tests have also been used to help confirm if someone has HSAM, and those include assessing a person’s ability to recall specific events and facts from their life—and thus also retrieving this personal information beforehand.

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It’s not photographic memory -

People who claim to have a photographic memory say that they can remember an image for a long period of time in the same detail as when they first saw it, but the entire existence of photographic memory remains a subject of scientific debate.

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Nor eidetic memory -

Eidetic memory is the ability to accurately recall an image after only seeing it once for a short period, but the key here is that the eidetic memories tend to fade after a short while. Similarly to people with HSAM, however, people with eidetic memory do not rely on memory devices like mnemonics.

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Landmark example: Jill Price -

HSAM first came to light in the early 2000s, with a young woman named Jill Price who contacted neuroscientist and memory researcher Jim McGaugh at the University of California, Irvine one day, claiming she could recall every day of her life since the age of 12. He soon tested her and found it to be true, and Price became the first person to receive the hyperthymesia diagnosis. Very soon, her condition caught the media’s attention and others came forward, spurring more research.

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Nima Veiseh’s trigger -

Nima Veiseh, a painter known as the Enigma of New York, is another person who came forward with his ability to recall the minutiae of every day. “My memory is like a library of VHS tapes, walk-throughs of every day of my life from waking to sleeping,” he explained to BBC in 2016. But, interestingly, it all started on a specific date, which he can also remember: December 15, 2000, when he met his first girlfriend at his best friend’s 16th birthday party. There’s no way to say if young love triggered this involuntarily memory response, but it’s a nice story.

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Bill’s short-term struggle -

People with HSAM have a strange difference between long-term and short-term memory. “Sometimes I don’t remember what happened five minutes ago, but I can remember a detail from January 22, 2008,” explains “Bill,” who asked the BBC not to use his name to avoid unwanted attention. His desire for anonymity also highlights a negative aspect of people with hyperthymesia in the modern world…

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Treated as a spectacle -

Because the ability is so fascinating and rare, and it seems like a superpower to the general public, people with HSAM are often treated as a spectacle, which could perhaps stop them from coming forward and contributing to modern research.

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The ability is susceptible to mistakes -

In 2013, Lawrence Patihis, currently at the University of Portsmouth, and colleagues found that people with HSAM, like all of us, still suffer from “false memories.” Their personal bias can, like us, interfere with their memory of world events, and they can be primed to remember events that never actually occurred, for instance.

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There’s no such thing as “perfect” memory -

This is a good thing to remember in case you ever get into an argument with a person who has HSAM: there is no such thing as a “perfect” memory, and their extraordinary minds still use the same flawed tools that we do.

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It's not about picking up more details -

In Stark’s research, he questioned HSAM and regular subjects one week, one month, and one year after events in their lives to see how their memories of events change over time. He thought that HSAM subjects might begin with more detailed accounts of the events, but the only difference between the two began months down the line, after the details for regular subjects began to fade and turn vague while the same details for HSAM subjects remained fresh.

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It’s more about holding information -

Scientists suspect that it’s not about the way that people with HSAM register or record information in their mind, but rather about how they retain it.

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Fantasy proneness and absorption -

Patihis found two behavioral traits that may contribute to HSAM. He profiled around 20 people with the ability and found that they scored particularly highly on “fantasy proneness” and “absorption.” The former could be considered a tendency to daydream, and the latter a tendency to allow your mind to become immersed in an activity or experience and all its sensations.

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A combination that helps recall -

According to Patihis, the absorption helps to first establish strong foundations for a memory, and the fantasy proneness means that they revisit those memories repeatedly, strengthening them with each replay.

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“I remember it like it was yesterday” -

We all have certain memories of moments in which we were completely absorbed, and which we replayed again and again afterward—from the perfect wedding to the most terrible embarrassment. That’s a slice of what researchers suspect happens with HSAM subjects, though they are thought to be doing it every day and without much conscious effort.

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Stuck in the past -

The irrepressible stream of memories has reportedly been a source of significant distress to some people with HSAM. Jill Price described her recollection as "non-stop, uncontrollable and totally exhausting" and as "a burden" because she was prone to getting lost in remembering, which made it hard to be in the present moment.

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It can be a curse -

Being unable to let go of vivid memories of the past makes it difficult to get over pain and regret. Nicole Donohue, someone with HSAM who has taken part in many studies, told BBC of the embarrassing moments, “You feel the same emotions—it is just as raw, just as fresh… You can’t turn off that stream of memories, no matter how hard you try.” Veiseh agreed: “It is like having these open wounds—they are just a part of you.”

Sources: (BBC) (Medical News Today) (Wisconsin Medical Society)

See also: Understanding Alzheimer's disease

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