Time Warped (19 page)

Something similar can happen with insurance questions. We are asked for a history of car accidents within the past three years. We even sign a form saying we’ve told the truth, but since dating events is difficult, whatever our intentions, we might not have done. Car accidents are events that are both unusual and alarming, so you could expect them to stick in the memory; but since we already know that
negative memories lose their power over time, it shouldn’t surprise us to learn that people often forget about accidents altogether. By checking records against drivers’ recollections one study found that as many as a quarter of road accidents are forgotten.
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Add this to the impact of telescoping and many a survey could have inaccurate results that then go on to influence policy. The provision of GP services, for example, relies not only on records of actual visits, but on asking people how often they have visited in the past three years. If everyone includes a few extra visits by mistake, this could skew the data considerably. When 200 students at the University of Alberta were asked how many times they had seen a doctor during the previous two months, many of them included appointments which happened far longer ago.
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And one of the reasons (and of course there are others) why people fail to visit the dentist as regularly as recommended is that each trip feels fairly recent.

The chief dentist at the Winter Olympics in Canada in 2010, Dr Chris Zed, told me that considering Olympians are elite athletes who take very good care of their bodies, they have surprisingly poor teeth. Part of the reason that 75 dentists were present at the games was to deal with the inevitable accidents – anyone who missed that second Wu-Tang on the ski cross could easily smash their jaw and need a dentist – but they were also there to take the opportunity to get inside the mouths of the athletes. Their itinerant schedules make regular check-ups difficult and because they are hardened to withstand pain, they continue training with the kinds of abscesses that would leave the rest of us howling. It wouldn’t surprise those 75 dentists if the next
time some of those competitors see a dentist is during the 2014 winter Olympics in Russia. These skiers and skaters will probably intend to have a check-up between now and then, but they’re busy people and the time will pass quickly. It is only in 2014, reclined in the dentist’s chair, that they will realise that not only have they not seen a dentist since Vancouver in 2010, but also that four years have passed. Only then will the marker in time provided by the games alert them to the years which have passed since their last check-up. But it’s these kinds of markers that can help solve the problem of skewed surveys.

Think back to the last two months and count the number of friends you have spent an evening with.

The chances are you will include friends whom it feels as though you’ve seen recently, when in fact you saw them several months ago. It’s easily done. But it’s also easily avoided; this method improves the accuracy of surveys and our own time estimates by changing the wording of the question to include an explicit landmark in time. So instead of asking, ‘How many times in the last year have you been to see your doctor?’ you ask, ‘How many times since New Year’s Day have you been to see your doctor?’ The landmark, in this case New Year’s Day, gives people a firm anchor in time, making it easier for them to calculate which events came before it and which after. When reconstructing memories we make a minimal cognitive effort, but if we’re asked for an actual date we are forced to compare a memory with other landmarks and are more likely to get the answer right.

TIME-STAMPING THE PAST

Bob Petrella is a middle-aged American television producer who remembers everything. He remembers every conversation he’s ever had and everywhere he’s ever visited. When he lost his mobile phone he wasn’t concerned about losing his contact numbers: he knows them all off by heart. This is because he is one of only 20 people in the world who have been diagnosed with a newly discovered condition called hyperthymesia, or Superior Autobiographical Memory. It was discovered accidently by an American neuroscientist called James McGaugh, who had spent his career studying memory. In the year 2000 he was contacted by a woman who wanted to tell him about the problem she had. He was accustomed to this, and patiently explained that his department at the University of California Irvine researched memory problems, but wasn’t a treatment facility. But hers wasn’t exactly a memory problem – more the opposite – as she told him she doesn’t forget anything. Intrigued, he agreed to meet her and soon realised she was telling the truth. She could remember everything. Since then another 19 people have been found to have this rare ability, including Bob Petrella. Never mind naming the dates of a list of famous events like the one at the start of this chapter; he can do it the other way round too. Give him a random date and Bob will be able to tell you the event that happened that day. When he was at school he found exams easy and didn’t really understand why other people felt the need to revise. He seemed to know everything, except the fact that his mind was rather exceptional. James McGaugh
is now studying the brains and genetic make-up of Bob and the other nine individuals who share his abilities, to try to discover how they do it. He has already seen structural differences in both their grey and white matter and hopes that in the long-term their remarkable abilities might shed light on memory processes that can in turn help those who suffer with memory problems.

Bob remembers the date of every football match he has ever seen. He excels at getting dates
exactly
right. Although the rest of us get plenty of dates wrong, we can identify approximately 10 per cent of dates correctly. Sometimes we can work them out through reconstruction, linking them to other memories from that month or year. Occasionally we simply know an exact date is correct, without having to trawl through our memories to prove it. The mystery is how we do this. One theory is that on occasion we create a memory that comes with some kind of time-tag attached. This time-stamp tells us when it happened and could explain this sporadic accuracy. What it doesn’t explain is why the other 90 per cent of memories should fail to have this time-stamp.

If I’d asked you to put the list of news stories at the beginning of this chapter into chronological sequence instead of guessing the actual months and years they took place, you would have found the task much easier. However, people with damage to the parts of the brain associated with remembering new facts find the sequencing of past events very difficult, illustrating once again how crucial memory is to our perception of time. The neurologist Antonio Damasio has found that people with amnesia also lose these time-tags,
finding it impossible to distinguish which events happened in which decade. This deficit presents a real problem; if we can’t create and store memories, we are unable to get a sense of the chronology of our own lifetimes and our place in the world. When Damasio asked healthy people to lay out personal and public events from the past along a time line, they were on average two years out. When people with amnesia due to damage to the basal forebrain did the same task, they were wrong by an average of just over five years. But, and this is where it gets interesting, people whose amnesia was caused by damage to a different area, the temporal lobe, remembered the events less well, but could still time-stamp. This suggests that the details of the memory itself and the time-stamping of that memory rely on different processes. Damasio has found that this corresponds with his observations of patients; those with damage to the basal forebrain can still learn new facts, but might get those facts in the wrong order.

When you’re trying to gauge when certain events happened, you might be able to work out one time-frame, but not another. You could have no idea of the year, but be certain that it happened on a Saturday. Time does not have a linear hierarchy in the same way that other types of memory do. With faces, for example, if you are given a picture of an actor you may or may not remember his name, but you will most likely remember his job. This is because his job exists at a higher level in your memory. People don’t say, ‘That’s Ethan Hawke, but I can’t remember what he does,’ they say, ‘That’s an actor, but I can’t remember his name.’ With time it’s different. Take, for
example, the death of Princess Diana. This has become one of those flashbulb memories, like the assassination of John F. Kennedy, where everyone can tell you exactly what they were doing when they heard the news. People don’t necessarily know the exact date, but they will probably remember the day of the week – because Diana died late in the middle of a Saturday night most people didn’t find out until they woke up on Sunday morning, and for many people Sundays are distinctively different from other day, making them more memorable. If it had happened on a weekday, they would find it harder to remember which weekday it might have been. You are also better at remembering news events that happened on a day that held a personal meaning for you, so the events you never forget are where the personal and the public cross over. If Michael Jackson died on your thirtieth birthday, and people were discussing his death at your party and requesting his songs, the chances are you will forever remember the date of his death.

To sum up, you are most likely to remember the timing of an event if it was distinctive, vivid, personally involving and is a tale you have recounted many times since.

EVERYTHING SHOOK

On the morning of Friday, 31 January 1986 a woman was shopping at a mall in Mentor, Ohio. At 11.48 a.m. she was wondering what to buy. Everything seemed normal. But one minute later nothing seemed normal at all. Goods were falling off the shelves, the clothes racks were swaying and the whole place seemed to shudder. She didn’t
understand what was going on. People began rushing for the nearest exit and just as she started to move she felt something smack on her head. Putting her hand up to her face she felt blood and as soon as she saw the ceiling tile that had hit her on the head, she knew what this was – an earthquake.

The rumours soon began – people had been killed; houses were wrecked. In fact there were no fatalities and no one’s home was destroyed. The earthquake was relatively mild – only 4.96 on the Richter scale. Some 15 people were treated for anxiety or for the effects of the cold; a little girl had stitches after she was cut by a broken window; and doctors were soon able to deal with the bleeding head-wound of the woman who had been out shopping. In earthquake terms this wasn’t serious, but for thousands of people this did become a day that was in a small way unique. They might have been one of the dozens who phoned the local geological society; one of the hundreds evacuated from the nearby nuclear power station; one of those who noticed that the water in their local well had changed colour; or Betty, the school bus driver who told the local paper,
The Spokesman
, that she’d lived through tornadoes and floods, but had never seen anything like this; or the Mayor of the town of Sharon, who watched his staff flee as a four-foot crack appeared in the wall of the municipal building.

There is a long history of psychologists grabbing unusual opportunities to study situations they could never recreate in an artificial experiment. There was the eminent expert in visual perception, Richard Gregory, who was reading the newspaper one day back in 1958 and discovered that
surgeons had restored the sight of a man who had been blind for 50 years. Here was the perfect chance for him to study whether eyesight automatically lets you watch and comprehend the world or whether the brain has to spend many years learning to make sense of the input from the eyes. He filled his car with the instruments needed for the assessments he wanted to carry out and drove to the hospital to find the man, known in the literature as S.B. The resulting case study became world-famous (answer: for full vision we do need to
learn
to see). More recently there was Barbara Frederickson, who happened to have tested the psychological resilience of a group of students several months before 9/11. She found herself with a unique opportunity to explore how a shocking episode affected levels of optimism and how this linked to a person’s underlying levels of resilience (a surprising answer: the most resilient people actually felt
more
optimistic after 9/11 than before).
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It was a psychologist called William Friedman who spotted the potential of the earthquake in Mentor, Ohio, as a way of studying time perception. As I’ve already mentioned, the problem with testing people on the timing of news events is that – like the Ethiopian plane hijacking – not everyone has heard of every event and even when they do it can be hours, days or months afterwards. But all the people in the earthquake were instantly aware of it.

Nine months after the earthquake, Friedman sent a questionnaire to every employee of the nearby Oberlin College, to ask them to guess the time, date, day, month and year it happened. Most people could guess the time to within an hour, but they found it very hard to name
the day of the week.
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Once again this gives us some insight into how we reconstruct time in the past using fragments of information, clues which are absent on weekdays. Friedman found that even four-year-olds can tell him the time of day of an event, but it’s not before they are about six that abstract concepts like months start to make sense to them. On occasions, we use indirect elements of a situation to attempt to come up with a date – what was the weather like, was it dark? Or we link it to something that has a firm date in our minds already – did it happen near Christmas? You might work out the year of the Falklands War by remembering that Margaret Thatcher was in power or that you were at school or college. Researchers Alex Fradera and Jamie Ward (the same Jamie Ward who works on synaesthesia) found that when people were encouraged to map out timelines of their own life events on paper and then add the news events to the same timeline, they did better than when they guessed the dates without reference to their personal lives, regardless of whether they considered the news story to be striking. This is a strategy you can adopt deliberately when you need to work out the date of a news event – think of as many links as possible to the details of your personal life at the time.