A highly superior memory

Lynne Malcolm: You're with All in the Mind on RN, I'm Lynne Malcolm.

What's your earliest memory? Could it possibly go back to when you were a newborn baby?

Becky Sharrock: It was 23 December 1989 when I was 12 days old. I was lying down on the sheepskin car cover of the four-wheel-drive and my parents were taking a picture of me, and I was just looking up at the camera wondering what it was, looking up at the steering wheel of the car because I was on the driver's seat wondering what it was. And at that age, every sight I heard, every scent I smelled, just everything was a novelty then, and I was just curious to keep learning.

Lynne Malcolm: Are you really feeling and experiencing that 12th day as you are speaking to me?

Becky Sharrock: Yes, just emotionally and just how busy my mind was back then when I was a 12-day-old baby.

Lynne Malcolm: Do you think you remember anything about, say, your birth?

Becky Sharrock: I don't remember leaving the womb, but I remember being in a bed with glass walls around me and I was on a cotton blanket and my head was up, just looking, at just mainly the ceiling above me and the heads of the people who were putting blankets on me and dressing me. And I can't say for certain if that was the day I was born because I didn't know calendars at that young age but I'm guessing that it was on or around that time.

Lynne Malcolm: Becky Sharrock remembers every one of her 28 birthdays. In fact, she can't forget any single day of her life. She is one of approximately 60 people in the world, and the only known person in Australia with this kind of exceptional memory. It's known as Highly Superior Autobiographical Memory or HSAM.

Gail Robinson: Yes, this is a very rare and very selective type of memory ability. And really it's that skill that allows someone to accurately recall an exceptionally high number of personal experiences and perhaps dates from events occurring throughout their life. So this is the autobiographical or personal memories that one holds. So this is not very common, and often people are unaware that they have an exceptional ability to do this until they hear about it, say on the radio or perhaps on a TV program.

Lynne Malcolm: Associate Professor Gail Robinson, in Health and Behavioural Sciences at the University of Queensland. HSAM was first identified in 2006 at the University of California Irvine. This group is still working to understand the underlying neural basis of the condition. Gail Robinson is conducting HSAM research in Australia with a single participant, Becky Sharrock.

Becky thought her memory was completely normal until she was in her early twenties and she and her family saw a TV doco describing HSAM. Then they realised that this is what Becky has.

I asked Becky how good she is at linking dates to events throughout her life.

Becky Sharrock: Every morning since I was 14 years old I have crossed dates off on my calendar each morning. So I know what days of the week certain dates fell on. Any date from 2004 onwards I can tell you what day of the week it fell on.

Lynne Malcolm: Can I give you some dates and you let me know what you remember about those dates?

Becky Sharrock: Yes.

Lynne Malcolm: The first one, 4 September 2006.

Becky Sharrock: 4 September 2006 was a Monday, and on that particular day I was going to my therapist who I was seeing for my autism. I was on my way to see him when my stepdad called my mum and said, 'Did you hear Steve Irwin died from a stingray?' And I couldn't believe it. I said, 'No, I didn't hear of that,' because Steve Irwin, I looked at him as invincible to any animal attack. He'd done so many daring things with crocodiles, I thought there's no way on earth Steve Owen could have died. But then I saw the news afterwards and it was true, and it was sad, and especially since he had two young children and the time and it was sad for…it was sad for Terri, and it was sad that little Robert who was only two years old at the time, that he didn't get a chance to spend a lot of time with his dad, yeah.

Lynne Malcolm: It is a Monday too. So what about 24 June 2010?

Becky Sharrock: 24 June 2010 was a Thursday.

Lynne Malcolm: Yes.

Becky Sharrock: I didn't come across any new news that day, but when I was reading the papers it was still all over the headlines, it was the oil spill in America, it was the eruption of the volcano in Iceland, that was still going on. Even though it happened months before they were still talking about the oil spill, they were still talking about the Iceland volcano eruption, but I didn't come across any new news that day.

Lynne Malcolm: What about 22 January 2008?

Becky Sharrock: 22 January 2008 was a Tuesday. And on that day, again I didn't watch the news but it was feeling so strange to me because it was the first year in a very long time that I wasn't returning to school because I graduated in 2007. So all of my younger siblings were getting ready for school and I just felt so disorganised because I didn't have any of my books ready. It's just felt so strange.

Lynne Malcolm: Becky Sharrock is a big fan of Harry Potter. Could she really remember and recite every chapter of every book?

Now, I believe that you're a very big fan of the Harry Potter books series…

Becky Sharrock: Yes, definitely!

Lynne Malcolm: I wondered if I could start a chapter of a book and see if you can tell me the next few lines?

Becky Sharrock: Yes.

Lynne Malcolm: Okay. 'October arrived, spreading a damp chill over the grounds…'

Becky Sharrock: '…over the grounds and into the castle. Madam Pomfrey the matron was kept busy by a sudden spate of colds amongst the staff and students.'

Lynne Malcolm: Exactly. So tell me, what book was that from?

Becky Sharrock: That was Harry Potter and the Chamber of Secrets, which is the second in the series, and it was chapter 8, 'The Deathday Party'.

Lynne Malcolm: That's right, that's amazing. Let me give you another one. 'Harry went down to breakfast the next morning to find the three Dursleys already…'

Becky Sharrock: '…already sitting around the kitchen table. They were watching a brand-new television, a welcome-home-for-the-summer present for Dudley, who had been complaining about the long walk between the television and the fridge in the living room.' That's Harry Potter and the Prisoner of Azkaban, which is the third in the series, and it's chapter 2, 'Aunt Marge's Big Mistake'.

Lynne Malcolm: Yes, that's amazing, okay.

Gail Robinson: That's one part of Becky. Another component is really just having very detailed memories of mundane events. So what she was doing in the family home on certain days, or what the family did or what the conversation was. And I think her mother finds that a little daunting on occasion because Becky might ask her mother an opinion or ask her to give advice, and a year later she might ask the same question, and of course her mother doesn't remember what she said, whereas Becky has very good recollection of word-for-word what her mother said. So it actually is quite an interesting ability from that respect as well.

Lynne Malcolm: Gail Robinson from the University of Queensland.

Gail Robinson: In terms of HSAM, one of the diagnostic questionnaires really is that 10 dates are randomly generated for that individual. So it's a 10-dates quiz. And HSAM individuals like Becky have a very high consistency in what they say happened on those days, and very routine things that you and I would probably never dream of even trying to remember.

Lynne Malcolm: Gail Robinson.

Becky's autobiographical memory is truly impressive, but her recollections also trigger associated emotions.

Becky Sharrock: Emotions attached to memories, that's what makes them most difficult because the memory itself is just a file you go over, but it's when the emotions return, that's what makes them either a pleasure or a discomfort. With negative memories I don't like re-living them because if it was from a time when I was depressed I re-live depression. But with a positive memory I re-live all the happy things. There was one particularly troubling one that I re-lived 5 years ago now, it's when I was walking down a path and I saw a leaf on the ground which was at a similar angle to how it was at a time when I was walking home from school, and when I re-lived that time, on that particular day after I walked home from school I had been bullied that day. So the emotions when that memory was formed, I was depressed because a bully said something to me. Then years later when I saw a leaf that was similar to one that I saw on the path walking home, I again re-lived just the depression and the feeling of hopelessness that I experienced back at that time.

Lynne Malcolm: So this must become overwhelming to you. How do you live with so much information and so much emotion in your head all the time?

Becky Sharrock: I must say, it is very tiring. I have never known life differently but I get a lot of headaches. I have trouble sleeping each night. And when I'm sleeping I have to have my brain stimulated to enable me to fall asleep. I'll have my television on or some music on because if it's dark and quiet I'll be kept awake by all of these involuntary busy memories that are going through my head. So I have learned ways to adapt to it, but it can get really overwhelming at times.

Lynne Malcolm: I believe you can also re-feel physical pain and re-taste food, for example.

Becky Sharrock: Yes, that works positively and negatively. Positively is especially the case for re-tasting food because if I see the words Black Forest cake gateaux, that's my favourite, that's my favourite desert, so whenever I see that word or think of Black Forest I can re-taste the cream, the chocolate and the cherries. And I really like that, especially if I'm eating a bland food like potato, but if it's a food that I really don't like, not even a memory can cover the taste.

Re-living physical pain, I could remember grazing myself as a three-year-old, grazing my knee. As a three-year-old it hurts so much more than it does when you are an adult, and it just burns and stings, and I just remember crying in my grandparents' living room because the sensation was…it's the same as now as an adult if I burn myself on something, just the stinging. And now if I get a graze on my knee I won't even notice it, but back then it just hurt so much.

Gail Robinson: So Becky has something that we call synaesthesia, where if she is thinking about certain objects or even colours, it has an association with something different. So she might think about the colour yellow and then she can taste chalk in her mouth. I think there was another example with Black Forest cake. So her perception of stimuli is heightened.

Lynne Malcolm: Gail Robinson.

You're with All in the Mind on RN. I'm Lynne Malcolm. I'm speaking with Becky Sharrock who can remember details of every single day of her life since she was a newborn. She has a rare condition called Highly Superior Autobiographical Memory or HSAM.

Becky has also been diagnosed with obsessive compulsive disorder and autism.

Becky Sharrock: They are very different conditions but I think the OCD has more links to my HSAM than the autism does. It's slightly different from the stereotypes. When we have OCD it's not that we have to have everything in straight lines, we have to have everything in perfect order, but it's more a case of whenever events and experiences happen to us we just fixate on them and we can't get them out of our mind, and it can become a problem if we just can't let go of emotions or let go of an issue, and that's where I have to do therapy and I take medication for that. But the difference between OCD and HSAM though is that remembering things isn't an obsession, it's just something your brain does, you remember something, and the memories that I remember don't have any…most of them don't have any emotional significance to me. I don't have any fixation or obsession with that event, it just comes back in my mind.

Lynne Malcolm: And Becky also has a diagnosis of autism and obsessive-compulsive disorder. Are these conditions related to her superior autobiographical memory?

Gail Robinson: Well, that's obviously one of the questions. So really we are trying to look at the source of this highly superior autobiographical memory. And there are several ideas about why that might come about. One of them is related to the OCD, the obsessive compulsive disorder, the idea being that this passive rumination which is obsessive, so she thinks about the these events a lot, if one does that, does that actually strengthen the memory the more that you ruminate on that. So that certainly has been found by the group in California, they have actually shown that the stronger or the better the highly superior autobiographical memories, the higher they rate on an OCD scale. So they have more features consistent with obsessive compulsive disorder. So there seems to be a little bit of truth with that.

With regards to the autism, we haven't seen that in the literature really supported at all yet, but one of the features in the autism individuals is there tends to be a comorbidity of high anxiety. Becky does have quite severe anxiety and she manages that with psychological strategies. But one of the other ideas about why the autobiographical memory is so good is that the high anxiety means there's a high level of arousal, so there is a highly intense personal experience that is associated with all these memories. And if you actually also ruminate or think about those again, the emotional arousal is higher than the average individual. So that could contribute to some sort of heightened encoding and consolidation of these memories. So those two diagnoses that Becky certainly has had, they possibly could be contributing. But it's very difficult to disentangle that.

Lynne Malcolm: So you're studying Becky, she is your only subject because it's such a rare condition. What are some of the other theories that you are investigating in terms of why some people have this amazing ability?

Gail Robinson: That's an interesting question, and really we are following up sort of on two avenues. And it's really related to the personality or the natural innate abilities of these individuals, the idea being that there is a higher level of absorption. So when somebody is thinking or encoding a memory, there's attention to the detail where their memory encoding is stronger. So we are looking at the imagination and also fantasy proneness, because if you are absorbed in a memory and there's a fantasy about that in the sense of you are thinking about it and vividly reimagining and really going into all the details in their richness in terms of the perception…so we've already talked about her sensory and exceptional perception of information, but perhaps also the emotional component or a deeper or a richer ability to really see the details when she is thinking about that event, is her recollection of that, is that actually just richer in terms of the colours or the temporal sequencing or the spatial relationships of all the details? So basically there's an idea here that it may be that her autobiographical memories are richer, or that she has this increased tendency to fantasy, as in to really reimagine all the different bits to their extreme, whereas we probably wouldn't bother quite so much. So we are following those things up by looking at her autobiographical memory, both past episodes as well as into the future. This relates to memory and time travel. Do HSAM individuals actually have a greater ability to imagine the events of tomorrow or next year?

Lynne Malcolm: What are you finding about her ability to look into the future?

Gail Robinson: I must also say that we are very tentative at this stage because we are still gathering and analysing data. But it appears to me that there's not a great difference in terms of going into the future, but there is certainly a deep richness and a vividness about how she describes her own personal experiences, those autobiographical memories.

Lynne Malcolm: And what about other cognitive abilities such as intelligence, attention? Are they superior as well?

Gail Robinson: Well actually of course as a neuropsychologist that's the first thing we do, is we investigate the HSAM and confirm that actually she does classify for that, but then we look at the whole cognitive profile, so the intelligence, the other aspects of memory, her language skills, her perception, her complex or higher complex thinking and problem solving. And what we actually find is there's really no difference. So it seems that the HSAM individuals are not having a selective exceptional autobiographical memory due to exceptional other cognitive abilities. So for Becky in particular, she very much performs and is scoring on these cognitive tests in sort of broadly the average range. So something exceptional is going on but it's not explained by her other cognitive skills.

Lynne Malcolm: And is there any evidence that there are structural differences in the brains of people with HSAM?

Gail Robinson: Yes, there is some evidence. So there's been some limited studies using MRI brain scans to look at the structures, and it does appear that the autobiographical memory network, which tends to be considered as including the temporal lobes as well as the temporal pole, as well as the hippocampus which is very much associated with the memories, and the insula. It seems like there's some changes there, as well as increased areas in the caudate and putamen. But I think at the moment these are very tentative. And Becky has had a brain scan here in Brisbane, but on the surface it appears that it really isn't that different.

Lynne Malcolm: Apart from the research Gail Robinson is doing with Becky on HSAM, she's involved with the Australian government's Boosting Dementia Initiative. She sees working with Becky on her superior memory may give some valuable insights into memory disorders such as dementia.

Gail Robinson: My approach really is that when we have a greater understanding of memory and why is it that she has this amazing ability to retrieve her personal episodic or autobiographical memories, if we can get a handle on what she's doing differently, then that helps us devise and develop specific interventions. And one of the biggest areas in terms of dementia for memory loss particularly, and there's lots of different types of dementia but particularly for this memory, is reminiscing. So if you reminisce about your personal memories, there is some evidence that this helps hold the memories a little bit longer. So what I hope is that if we can pan out what is it about the narratives and the way she describes her memories, is there a couple of key things in terms of this richness? And that's going to directly feed into what we are saying would be useful, and then taking that to an intervention level to test out with people with memory loss. So it's very important to look at the theoretical aspect to understand how this memory is working in order to devise treatments and interventions that can help maintain memory as long as possible while there is no cure for dementia.

Lynne Malcolm: Gail Robinson from the University of Queensland.

So for Becky, has having a remarkable memory for every day of her life been a gift or a curse for her?

Becky Sharrock: 10 years ago and especially seven years ago when I found out about it I looked at it completely as a curse because I thought that I was broken, there was something wrong with me for not being able to get over past events that happened so many years ago and I'd be too embarrassed to mention to people when I re-live a memory of a child taking my lollipop as a seven-year-old, I'd feel so embarrassed telling people why I'd be upset about that. But as I'm doing therapy and as I'm moving on with my career I'm beginning to see that it's half a blessing, half a curse, it's a perfect balance of pros and cons, and it's making me feel really happy within myself.

Lynne Malcolm: Becky is now in the process of writing a book called My Life is a Puzzle, and you guessed it, it's an autobiography.

Becky Sharrock: It's just an autobiography of my life, my personal accounts of what it was like from being a newborn child right through to a 28-year-old. So it's just my daily life, what I did, what I thought, what I felt at different ages.

Lynne Malcolm: That's funny, I was going to ask you would you ever think of writing an autobiography, and you are writing one. You remember every single thing, so it must be a bit of a tough editing process.

Becky Sharrock: Yes, because I re-live the emotions as I write it. So as I'm writing to I'm going through all these emotions, and the hardest chapter to write was when I was 14 and I was going through depression, because as I was writing it I was re-living the emotions I was feeling then. But as I wrote different years when I was happier, when I have written about holidays I've had as an adult, the same thing happens except it's with positive memories, so I love writing those chapters. But then going back over them and editing them, that's when I feel the emotions again, but once they are edited they are just down in print and set until I read it again.

Lynne Malcolm: Thanks to Becky Sharrock for sharing her story with us today.

Gail Robinson: Becky has really worked on overcoming so many of her psychological difficulties in terms of the autism and the OCD and her anxiety to almost start to enjoy now this area of HSAM and trying to get a better understanding of herself and to contribute where she can. So we love working with Becky and she seems to love being involved with different studies, and I guess the message is watch this space, hopefully we have more to say in a few months or by the end of the year.

Lynne Malcolm: Associate Professor Gail Robinson from the School of Psychology at the University of Queensland.

You'll find further details on the All in the Mind website.

Thanks today to producer Diane Dean and sound engineer Mark Don. I'm Lynne Malcolm, it's been great to have your company, until next time.

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