Hyperthymesia, also known as piking or hyperthymestic syndrome, is a condition in which an individual possesses a superior autobiographical memory, meaning he or she can recall the vast majority of personal experiences and events in his or her life. The term “hyperthymesia" is derived from the Greek words thymesis meaning "remembering," and hyper meaning "excessive". Individuals with hyperthymesia can recall almost every day of their lives in near perfect detail, as well as public events that hold some personal significance to them. Those affected describe their memories as uncontrollable associations, when they encounter a date, they "see" a vivid depiction of that day in their heads. Recollection occurs without hesitation or conscious effort. It is important to draw a distinction between those with hyperthymesia and those with other forms of exceptional memory, who generally use mnemonic or similar rehearsal strategies to memorise long strings of subjective information. Memories recalled by hyperthymestic individuals tend to be personal, autobiographical accounts of both significant and mundane events in their lives. This extensive and highly unusual memory does not derive from the use of mnemonic strategies; it is encoded involuntarily and retrieved automatically. Despite being able to remember the day of the week on which a particular date fell, hyperthymestics are not calendrical calculators like some people with autism or savant syndrome. Rather, hyperthymestic recall tends to be constrained to a person’s lifetime and is believed to be an unconscious process. Although hyperthymestics are not autistic, and likewise savants do not memorise autobiographical information, there are certain similarities between the two conditions. Like autistic savants, individuals with hyperthymesia have an unusual and obsessive interest in dates. Scientists have not yet been able to explain this mysterious ability but a new paper in the peer-reviewed journal, Neurobiology of Learning & Memory's July issue, offers the first scientific findings about nearly a dozen people with this uncanny ability. Scientists researching this remarkable kind of memory - that they previously did not believe humans could possess - have discovered intriguing differences in the brains and mental processes of this extraordinary group of people who can effortlessly recall every moment of their lives since about age 10. Everyone in the study had variations in nine structures of their brains compared to those of control subjects, including more robust white matter linking the middle and front parts. Most of the differences were in areas known to be linked to autobiographical memory, "so we're getting a descriptive, coherent story of what's going on," said lead author Aurora LePort, a doctoral candidate at UCI's Centre for the Neurobiology of Learning & Memory. Surprisingly, the people with stellar autobiographical memory did not score higher on routine laboratory memory tests or when asked to use rote memory aids. Yet when it came to public or private events that occurred after age 10½, "they were remarkably better at recalling the details of their lives," said Dr James McGaugh, senior author on the new work. "These are not memory experts across the board. They're 180 degrees different from the usual memory champions who can memorize pi to a large degree or other long strings of numbers," LePort noted. "It makes the project that much more interesting; it really shows we are homing in on a specific form of memory." She said interviewing the subjects was "baffling. You give them a date, and their response is immediate. The day of the week just comes out of their minds; they don't even think about it. They can do this for so many dates, and they're 99 per cent accurate. It never gets old." The study also found statistically significant evidence of obsessive-compulsive tendencies among the group, but the authors do not yet know if or how this aids recollection. Many of the individuals have large, minutely catalogued collections of some sort, such as magazines, videos, shoes, stamps or postcards. UCI researchers and staff have assessed more than 500 people who thought they might possess highly superior autobiographical memory and have confirmed 33 to date, including the 11 in the paper. Another 37 are strong candidates who will be further tested. "The next step is that we want to understand the mechanisms behind the memory," LePort said. "Is it just the brain and the way its different structures are communicating? Maybe it's genetic; maybe it's molecular." McGaugh added: "We're searching for clues in a very new area of research." Superior Autobiographical Memory is a fairly newly discovered phenomenon. People with this ability appear able to remember most days of their past in great detail. When given a date they are usually able to recall precisely what they did on that day, who they were with, and even details of conversations, programmes they saw on television or what they ate for their lunch. Some of these individuals claim to be able to remember every day of their life since childhood. The inability to forget anything - and therefore move on with their lives -means that some people find it extremely traumatic to live with this condition. The phenomenon was first described by a memory research group in California a few years ago. A handful of Americans have been identified with this very rare skill but no cases had been reported in the UK until now. A 20 year old Cardiff-born, Durham university student called Aurelien, is the first person in Britain to come forward claiming to possess this ability. He was featured in the recent Channel 4 programme: “The Boy Who Can’t Forget”. Aurelien claims to be unaware of how he is able to remember the days of his life with such precision. He says: “It’s like someone saying to you what’s your name? You just know that it’s your name, it’s just something that comes straight to you.” He has lived with this ability all his life but only recently realised how rare it was. He admitted: “I’ve never met anyone who can do what I do”. Aurelien submitted to an MRI scan which showed considerable activity in the occipital lobe, located in the back of the brain and responsible for processing visual information. This would seem to reinforce Aurelien’s belief that he “sees” his memories as distinct pictures. He has filled his room with hundreds of photographs that he has taken over the years and admits that he has an inherent need to have every event he attends photographed for posterity. Scientists have not been able to explain this mysterious ability. Professor Giuliana Mazzoni from the Department of Psychology at the University of Hull is trying to learn more about what enables it and whether it is something of which we might all be capable. She said: “It is these exceptional cases that give the first clue to something that might change the way we think about how personal memory works, so it is really an exciting moment”. Professor Mazzoni believes that there may be other people in the country who also have this ability. She would like anyone who might be able to help her with her research to contact her at the University of Hull.