Time Warped

by Claudia Hammond

  In terms of time perception, the Holiday Paradox in reverse was definitely at work here. The hours passed very, very slowly. The marker of time, the big clock, hung over us psychologically as well as physically. We could talk all day and listen to our Walkmans while we worked, but time crawled by at such a snail’s pace that we often wondered whether the clock had stopped. Now that I’m lucky enough to work in a job that’s never boring, I only ever look at the clock in dread of an approaching deadline and never in the hope of finding more time has passed. Although we wished away the hours in the factory, when we finally reached the weekend and looked back, with so few new memories to fill it, the week occupied little space in the memory and it felt as though it had been short.

  I’ve illustrated how the Holiday Paradox and its opposite can account for some of the contradictions in the sensation of time passing when you are ill, bored, caring for small children or on holiday, but the same principle of our dual perspective on time can also expand on the explanations I have covered so far for that other big mystery we have been considering – why time speeds up as we get older.

  Let’s take a child of seven who is living a life filled with new experiences. We know that time feels slower for that child than it does for an adult. To understand the reason, once again we need to look at their prospective and retrospective estimations of time passing. Here there’s less of a paradox than there is for adults because even prospectively some hours can drag. Children have far less control over their lives and spend more hours doing things they don’t want to. Think back to those endless car journeys or the doodles you did while aching for a dull lesson to end. Conversely, when they’re doing something they enjoy children become very absorbed, with an apparent ability to live more in the moment than adults do. They can entertain themselves in a paddling pool for hours longer than any adult could, constantly innovating and experimenting. For them this time passes quickly, too quickly. They are shocked when they’re called away to have their lunch. The watching parent has probably found time dragging, but for the rapt child time has sped by. As bedtime approaches, the minutes rush by even faster as they beg for just one more game/go/story. What the child is experiencing is a variation on the Holiday Paradox, an effect that is complicated by their relatively poor skills at prospective time estimation. The days are full of new experiences and while their parents rush them to school they want to take every opportunity to explore the world. They will stop and stare at workers digging up the road; they will pause to pat a dog; they will notice anything that’s different; they will try new things. Why walk along the pavement when you can hopscotch along avoiding the cracks in the paving stones or pick your way up and down the crenellations on a wall? This means that overall, despite a few slow hours where they’re forced to do something boring, on the whole days for children, just like ours on holiday, are all-absorbing, and packed with new memories which, looking back retrospectively, makes the months and years seem to stretch out.

  By the time a child reaches the mid-teens, the reminiscence effect begins to come into play. The demands of school and exams mean that the hours can still sometimes drag, but gradually there is less routine, more freedom, and novelty in spades – first sex, first drinks, first love, first time away from home, first chance to have some real choice about what they do and who they are. The formation of identity makes these events stand out as we’ve discussed, giving rise to the reminiscence effect. It’s already been suggested that these memories might be extra-strong in order to help reinforce that new identity, but I propose that this time of entering adulthood also becomes the benchmark for our judgements of retrospective time. This plethora of new events continues until at least our mid-twenties, by which time we’ve become accustomed to a certain number of memories representing a certain amount of time passing.

  In middle age prospective estimation of time tells us that the hours are passing at an average speed and so are the days. It is the elapsing of the months and years that people say they find shocking, never the hours. Markers of time constantly remind us that the years are moving on. We are shocked when we hear that it is already the twentieth anniversary of the Berlin wall coming down. We see items we own in vintage shops. Most shocking of all, we have work colleagues born in the 1990s – surely they should still be at school! These markers in time conflict sharply with our retrospective judgements, through which we gauge time passing via the number of new memories we have made. With fewer new experiences, and thus fewer new memories, we repeatedly experience a disconnection between the information we are getting from prospective and retrospective time estimation.

  This dual process of prospective and retrospective time estimation is key to many of time’s mysteries. Once again this is not something to which we become accustomed or ever will; it is simply a consequence of the dissonance between the two methods we have for estimating time. We can’t stop judging time in this way, but we can make use of the features of time estimation to make time feel as though it’s passing slower or faster, depending on how we would like it to be. This is something I’ll be exploring in the final chapter of this book. Before that, we’re going to move forward into the future. We have seen the way our memories of the past affect our view of time. Next we will see how our ability to time-travel mentally into the future has a bigger impact on the present than we have ever realised.

  In case you have resisted looking until now, here are the correct dates for the list of events:

  John Lennon is shot dead – December 1980

  Margaret Thatcher becomes British Prime Minister – May 1979

  Chernobyl nuclear power plant explodes – April 1986

  Michael Jackson dies – June 2009

  The film Jurassic Park is released in the USA – June 1993

  Argentina invades the Falkland Islands – April 1982

  Morgan Tsvangirai is sworn in as Prime Minister of Zimbabwe – February 2009

  Hurricane Katrina strikes New Orleans – August 2005

  Indira Gandhi is assassinated – October 1984

  A car bomb explodes next to Harrods in London – December 1983

  The first cases of swine flu hit Mexico – March 2009

  The Berlin Wall comes down – November 1989

  Prince William marries Kate Middleton – April 2011

  An IRA bomb explodes at the Grand Hotel in Brighton – October 1984

  Barack Obama is inaugurated as President of the USA – January 2009

  Princess Diana dies – August 1997

  Bombs explode on the London Underground – July 2005

  Saddam Hussein is executed – December 2006

  33 miners become trapped in a mine in Chile – August 2010

  The first Harry Potter book is published – June 1997

  AN ELDERLY MAN, apparently very ordinary, died late one December afternoon in Windsor Locks, Connecticut, in 2008. He was 82. In normal circumstances, the passing of such a man would have provoked little interest beyond his family and friends. But in this instance, a team of internationally eminent research scientists from across the USA immediately sprang into action. The care home where the man lived – and died – phoned Suzanne Corkin, a neuroscientist at MIT in Boston, who – for once – was not away at a conference. She alerted one of her colleagues, based in California, who was also in the country – and he too picked up the call. So keen were the scientists to get hold of the man’s body as soon as he died that they had even taken the precaution, years in advance, of contacting every funeral home in the area. If his mortal remains were delivered to them, they must on no account proceed with cremation.

  Why were they so insistent? In order to stop the scientific calamity of the most famous brain in neuroscience being incinerated.

  This outcome averted, ice blankets were packed around the elderly man’s head and his body was driven in a hearse to Boston a hundred miles away. Meanwhile Jacopo Annese, a neuroanatomist was on a plane from California. He had been selected by Suzanne as the perfect pe
rson for the job – someone advanced enough in their career to be highly skilled, yet prepared to devote the necessary time to the project. By midnight scans of the brain while it remained inside the skull had been completed. Next morning Suzanne watched through the viewing window of the pathology department while Jacopo and two colleagues carefully extracted the brain from the body. The following day Jacopo flew back to San Diego and ‘Henry’, as he couldn’t help saying, occupied the seat next to him.

  It might seem rather tasteless to give a brain, hanging upside down in formaldehyde in a plastic vat inside a cooler, a name. But for the scientists it was somehow appropriate. Professor Corkin had taken responsibility for Henry Molaison, a vulnerable soul in life, and ensured he was well looked after at the Bickford Nursing Home. She had protected his identity – for decades in text books he was known only as ‘H.M.’ – and grown very fond of him. But in scientific terms, it was his brain that made Henry so special. For more than 45 years, Suzanne had thought more about the workings of this brain than any other – what it could remember, what it could learn, what it could predict. Now finally she and Jacopo were to have the opportunity to see inside it.

  Why were they so excited? Because Henry had lived two-thirds of his life locked in an eternal present.

  When he was 27 years old, Henry underwent brain surgery to try to prevent the multiple epileptic seizures he experienced daily – seizures that would probably have killed him within a few years if no action had been taken. The surgeon, Dr William Scoville, took a silver straw, inserted it into Henry’s brain and slowly sucked out part of the hippocampus, the tiny seahorse-shaped area deep inside. The operation appeared to be a success. Henry recovered well and the seizures ceased. But Scoville gradually realised that something had gone very wrong. Henry could not remember anything new that happened to him. Although he could recall incidents from his childhood, people he had met the previous day were like strangers to him. Every face was new. Every experience was new. He had no idea what he had been doing even an hour before. The surgery had caused anterograde amnesia. Henry had his old memories, but he could never again make any new ones.

  Although Henry’s case features in many neuroscience and psychology textbooks, it usually appears in the chapter on memory. There is, though, another aspect to amnesia, one that’s less well-known: the loss of the ability to imagine the future. Henry exhibited just these twin symptoms: no sense of a past after the accident, but no sense of a future either.

  As I’ve illustrated throughout this book, we construct our own sense of time in our minds, but nowhere is this clearer than with our mental images of the future. At will, we can choose to imagine tomorrow, next week or 1,000 years hence. This ability has nothing to do clairvoyance. The chances are that the future we imagine will not turn out exactly that way. Indeed, such is the power of our imagination that we can clearly picture a future that not only won’t happen, but could never happen. This strange ability to pitch ourselves forward in time – called future thinking – is the opposite of memory. But as I’ll show in this chapter, it is connected to it. For the mind uses both our sense of space and our memories to create a sense of the future.

  On average people think about the future 59 times a day or once every 16 minutes during waking hours.77 Indeed research in this field reveals a staggering finding: contemplating the future could be the brain’s default mode of operation. But this is not wasteful daydreaming or, as the phrase goes, a case of ‘wishing our lives away’.

  Mental time-travel into the future matters – and is useful. It affects our judgements, our emotional states and the decisions we make, sometimes for the worse. And my explorations of future thinking will also reveal something rather surprising about the reasons for the fallibility of our memories of the past.

  TIME-TRAVELLING INTO THE FUTURE

  There has been more than a century of research into the way our memories work, but future thinking is a far newer area of study. The most significant finding is the degree to which future thinking relies on mental time-travel in the opposite direction – into the past. This can even explain one of the mysteries of memory – why it so often lets us down, why researchers like Marigold Linton found studying her own memory to be so painful. We need our memory to be a reconstructive process, and one that’s flexible and even unreliable, to allow us to imagine the future. The evidence for this idea comes from a range of sources, beginning with patients like Henry. Hundreds of cases of amnesia have been reported in the medical literature and their doctors have often noted that these patients found it difficult not only to remember the past, but to imagine the future. They are unable to picture what they might do the following day, let alone in a decade’s time. Although many doctors have made this observation, future thinking has only been studied systematically in a handful of these patients, compared with the copious amount of research done on memory skills.

  There once was a man known in the medical literature as ‘N.N.’, which stood for ‘No Name’. He was driving up the exit slip-road from a motorway in 1981 when he came off his motorbike and sustained a serious head injury. Like Henry, N.N. doesn’t remember new information and still reacts with horror every time he hears what happened on 9/11.78 He later became known by his real initials K.C. and was visited by the influential memory theorist Endel Tulving. Tulving was famous for differentiating between semantic memory – our memory for knowledge, so for example that Canberra is the capital of Australia; and episodic memory – the memory for the personal events that happen to us, for example visiting Canberra. Tulving asked K.C. some simple questions: ‘What are you going to do tomorrow?’ and ‘What are your plans for the summer?’ K.C. was unable to answer either. When Tulving asked him what was in his mind, he replied that it was blank. Hard as he tried, he could not hold ideas of the future in mind, and 30 years later he still can’t. Some patients, such as one known as D.B., can imagine political events in the future, but find personal future events particularly difficult to envisage.79 It’s striking that not only do these patients struggle to imagine a future when asked to do so, but they appear to have no desire to imagine one either.

  Just as semantic memory and episodic memory are different, a similar distinction applies to the way we think of the future. There is a difference between sitting in midwinter knowing the fact that it will be warmer when summer comes and imagining yourself sitting in the sunshine next summer feeling the heat on your skin. This latter mental time-travel into the future through imagination has been defined as episodic future thinking, which for simplicity I refer to here as future thinking. It is part of a more general system of mental time-travel that Endel Tulving said makes up our autonoetic consciousness. This is the sense we have of ourselves as persisting across time, and it is manifest in our ability to re-experience or pre-experience events. This pre-experiencing involves imagining what an activity might feel like, not merely intending to do it. So you might notice in your diary that you’re meeting some friends for a pub lunch. It is your prospective memory that reminds you to turn up at the right time, but it is future thinking that means you can picture yourself ordering a drink, finding a table and reading the blackboard to see what specials they have. With future thinking you project yourself forwards mentally to imagine the actual experience. This is different from actively planning, and it is this skill that seems to set us apart from other animals.

  Mental time-travel need not involve vast stretches of time. Often it will concern what you have just done or are about to do. If you take the example of a job interview, there’s the mental rehearsal of the questions beforehand, followed afterwards by the agonising, repeated replaying of the worst moments, coupled with the imagination of a possible past, of the things you wished you’d said. These were possible futures. Now they are part of an impossible past.

  Demis Hassabis and Eleanor Maguire were the first neuroscientists to carry out a structured investigation of future thinking in people with brain injuries. They found that even when they gave
them suggestions for all the sensory details that might be present in a future scenario – the sights, the smells and the sounds – they were still unable to imagine the scene.80 These five patients had a range of scores on tests of IQ and memory skills, but when it came to imagining the future four of them did very poorly, despite the fact that the scenarios used were everyday enough not to appear to necessitate access to detailed memories.

  It is not only people with brain injuries who find future thinking difficult. Anyone with a poor autobiographical memory will also find it harder to project themselves into the future. This includes very young children, people with schizophrenia, Alzheimer’s disease or depression and those who are feeling suicidal.81 The more delusions and hallucinations a person with psychosis experiences, the harder it is for them to hold an idea of the future in mind, depriving them of the agency that mental time-travel can bring.82 As the decades pass we discuss our failing memories, but this is accompanied by something we tend to notice less – a decline in our ability to imagine the future. This lends weight once again to the idea that we rely on past memories in order to conjure up ideas of time yet to come.

  The part of Henry’s brain that was most damaged was the hippocampus. It gets its name from its shape – it curls around in a narrow arc similar to a seahorse. Not long ago I stood on an old converted squash court that now houses a brain bank. There were shelves and shelves of brains in vats. The neuroscientist carefully handed me one of their six thousand brains and pointed out the hippocampus. It was extraordinary to think that an area that is only four centimetres long and formed so delicately could hold the key to the lifetime of memories that form a person’s identity. We know this area to be crucial to memory, but the experiences of the patients with amnesia would suggest that it also plays a part in imagining the future. The evidence from these people begins to build up a picture of the way the brain holds ideas of the future in mind, one which is backed up by scans of living brains.