This article was taken from the July 2012 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
We might well curse our memories when they let us down. But we might also be shocked by the results of the decades of work by the psychologist Elizabeth Loftus showing how easy it is to implant false memories into our minds, whether of kissing giant frogs or meeting Bugs Bunny at Disney World Manchester. We might worry about what it means for justice if an eyewitness can be so easily swayed by a leading question.
But there's a good reason for the fallibility of our memories. It allows us to time-travel mentally, at will, in the opposite direction -- into the future.
After more than a century of systematic research into the way our memories work, psychologists are turning their attention to the way we imagine what's coming.
The most significant finding is the degree to which future thinking relies on our memory for the past.
The evidence for this comes from a range of sources.
In addition to forgetting the past, people with amnesia often find it difficult to imagine the future. Endel Tulving, the influential memory theorist, was met with a blank when questioning a patient about what he might do the next day: such patients struggle to imagine a future when asked to do so, but they appear to have no desire to imagine one either. It's since been found that these patients find it particularly hard to imagine the spatial elements of a situation in the future. When asked to imagine a future scenario where they were standing in a museum, they were unable to suggest what features they might see, whereas people without a brain injury might describe a marble floor or domed ceiling.
Likewise, very small children find it hard. In one experiment only a third of three-year-olds could give a plausible answer as to what they might do the next day.
To envisage the future we rely on memory, recombining any relevant recollections to create possible outcomes. This remix of memories allows us to preview future events in a window in the mind. Memory is essentially a reconstructive process; when we want to re-experience an event we don't summon up a tape from the library -- we alter memories as we lay them down in order to make sense of them, then we reconstruct them when we recall an event and even change them again if new information has come to light. A similar process takes place when we imagine the future -- the neural signatures of remembering the past and imagining the future are remarkably alike.
If memories were fixed like videotape recordings, then imagining a new situation would be challenging. For instance, you can picture yourself arriving by double-decker bus at a tropical beach for the wedding of Johnny Depp to your best friend next week. To do so you need to do the equivalent of finding your personally recorded memories of sitting on buses and visiting your best friend, before ordering clips from the mind's archive of films starring Johnny Depp and TV programmes featuring tropical beach weddings -- memories which could be decades apart. Then you splice all these elements together to create the scene. Cognitively it sounds like hard work, but the flexibility of our memories makes it relatively easy to meld these memories together to invent a scene that we've never witnessed before.
This is the key to travelling forwards in time in our minds: millions of fragments of memories from different times of our lives are not set in stone -- they can change, giving us endless, instant imaginative possibilities for the future.
Claudia Hammond presents All In the Mind on BBC Radio 4 and is the author of <span class="s1">Time Warped: Unlocking the Mysteries of Time Perception*(Canongate)*
This article was originally published by WIRED UK
