London - A good memory is essential for any aspiring actress struggling with her lines. But in the case of Marilu Henner - a Broadway star who rose to fame in the 1970s sitcom Taxi - her memory isn’t just good, it’s incredible. For her, the past is simply unforgettable.
Give her any date from the past 40 years and she can instantly tell you the day of the week, what she was wearing, what the weather was like and what was on TV.
If that isn’t impressive enough, the 59-year-old Hollywood star, who most recently appeared on British TV screens in Celebrity Apprentice, can even recall with complete clarity events that happened when she was just 18 months old.
Marilu Henner is one of a handful of people with a rare condition called hyperthymesia, or “superior autobiographical memory” - the ability to remember everything that happened on every day of their lives.
Their cases don’t just highlight the incredible power of the mind. They are also shaking some of the basic understanding about the nature of memory and what the limits of the brain really are.
Henner regards her supercharged memory as a gift. “It was never a trauma for me - it was just who I was,” she says. “I was very good at remembering things: I was the family historian. People would come to me and ask me stuff, and it was never a problem.”
Her earliest memory is playing with her older brother in her family’s Chicago home aged one and a half. This has stunned scientists, who had assumed that it was virtually impossible to recall events before the age of two.
And that’s just the start. Most people can remember about 250 faces during a lifetime: Henner remembers thousands.
It is impossible for most of us to imagine what it is like to have a memory of every single day. She describes sifting through memories as “looking for a scene on a DVD before me.
“In a second I’m back there, looking through my own eyes at the scene as I saw it in 1980 or whenever.”
Hyperthymesia (hyper means excessive while thymesia means memory in Greek) is a new concept in psychology. It was first identified in 2006 by a team of researchers at the University of California.
In a ground-breaking paper in the journal Neurocase, they introduced the world to a 40-year-old woman - known at the time only by the initials AJ, but who has since “come out” as school administrator Jill Price.
Just like Marilu Henner, Price can recall with accuracy what she was doing on any date, and on what day of the week it fell.
In 2003 she was asked by researchers to list every date of Easter since 1980. Within ten minutes, and with no prior warning, Price wrote all 24 dates and added what she was doing on each date. All but one of the dates was right: the other was off by two days.
When she repeated the experiment two years later, she got all the dates correct. Crucially, too, the personal information she gave about what she was doing each Easter matched her earlier answers. No wonder she was nicknamed the human calendar by friends.
After her extraordinary case was published, other people with hyperthymesia came forward. Today, between six and 20 people are thought to have the condition.
More are expected to emerge in the new few weeks with the start of a new American TV series, Unforgettable, which stars a detective with perfect recall. Marilu Henner is one of the advisers on the show.
So what is going on in the brains of these super-recallers? There is nothing new about people with exceptional memories. Memory acts were a staple of Edwardian music halls, while their 21st-century counterparts compete every year in World Memory Championships.
Modern-day Mr Memories include Ben Pridmore, an accountant from Derby who can memorise a randomly shuffled deck of cards in under 25 seconds, and Dominic O’Brien, who can recall the order of 2,808 playing cards after looking at them.
But Pridmore and O’Brien use memory techniques pioneered by the Ancient Romans to remember long chains of numbers, cards or shapes. These techniques usually involve visualising numbers or playing cards as characters or objects, and then creating a story in which they appear in order along a familiar geographical journey, such as a route to work.
Marilu Henner and Jill Price are different. Their powers are out of their control. Instead of actively remembering events, their brains appear to be like video recorders - taking note of everything that happens to them and storing it away.
Psychologists admit to being baffled by their talents. But they are also uncertain how an ordinary person’s memory works.
Most accept that there are at least two types of memory - the short and the long-term. The short-term holds a small amount of information which can be quickly recalled - but only for a brief period of time. Some believe it acts as a “sorting office”, sending some information to the long-term memory and discarding the rest.
The long-term memory is where information is kept over months and years. It includes information on things we know how to do without thinking, such as tying shoelaces or changing gears, as well as events we can recall.
But how things move from the short-term to the long-term memory is a matter of debate - and where the mystery of hyperthymesia may lie.
In the 1950s, psychologists argued that everything that happens to us passes from the short to the long-term memory - and that the brain has a limitless ability to remember. Everything that happened to us is there, if only we knew how to reach it. But in the past few decades, memory researchers challenged this view, arguing that the brain is more selective in what it locks away for keeps. Rather than keeping a record of all events, only some memories are transferred - and then not often very accurately.
Some information is passed from the short to long-term memory though active choice or repetition. Other events are moved to the long-term through the “flash bulb” effect, where sudden shock, such as a bereavement or news of the death of a celebrity like Princess Diana or John Lennon, crystallises vivid memories.
Cases such as Marilu Henner now suggest that our long-term memory may not be selective after all. If she recalls everything that happens to her, maybe the rest of us could do it too - if only we knew how to access that information.
One of Britain’s top experts, Professor Giuliana Mazzoni of Hull University, believes hyperthymesia could challenge the established view of memory.
“This condition is amazing,” she says. “If a woman in her 40s or 50s can remember every single day of her life, then the capacity of our memory is more or less infinite. And that suggests there is a lot more to discover.
“The other big surprise from this type of condition is that it confirms a very old view of memory - that it is reproductive; that events are encoded in memory in a literal way.”
Henner sees hyperthymesia as a blessing - but not all view it that way. Jill Price described her condition as “non-stop, uncontrollable and totally exhausting”.
“Most have called it a gift, but I call it a burden,” she said. “I run my entire life through my head every day and it drives me crazy.”
While most people approaching old age might welcome the bright, agile memories of youth, psychologists say the ability to forget unhappy experiences can make the difference between a life of contentment, and one of regret and bitterness.
“For some people with hyperthymesia, it is a curse because it makes it impossible to live,” says Professor Mazzoni. “They spend their day remembering, and it doesn’t help get on with life.
“Forgetting can be a blessing.” - Daily Mail