Memory is a very useful cognitive tool. After all, where would we be if we had no recall of our family, friends, foods, words, tasks and dangers.
But, it turns our that memory may also help us imagine the future — another very important human trait.
WHEN thinking about the workings of the mind, it is easy to imagine memory as a kind of mental autobiography – the private book of you. To relive the trepidation of your first day at school, say, you simply dust off the cover and turn to the relevant pages. But there is a problem with this idea. Why are the contents of that book so unreliable? It is not simply our tendency to forget key details. We are also prone to “remember” events that never actually took place, almost as if a chapter from another book has somehow slipped into our autobiography. Such flaws are puzzling if you believe that the purpose of memory is to record your past – but they begin to make sense if it is for something else entirely.
That is exactly what memory researchers are now starting to realise. They believe that human memory didn’t evolve so that we could remember but to allow us to imagine what might be. This idea began with the work of Endel Tulving, now at the Rotman Research Institute in Toronto, Canada, who discovered a person with amnesia who could remember facts but not episodic memories relating to past events in his life. Crucially, whenever Tulving asked him about his plans for that evening, the next day or the summer, his mind went blank – leading Tulving to suspect that foresight was the flipside of episodic memory.
Subsequent brain scans supported the idea, suggesting that every time we think about a possible future, we tear up the pages of our autobiographies and stitch together the fragments into a montage that represents the new scenario. This process is the key to foresight and ingenuity, but it comes at the cost of accuracy, as our recollections become frayed and shuffled along the way. “It’s not surprising that we confuse memories and imagination, considering that they share so many processes,” says Daniel Schacter, a psychologist at Harvard University.
Over the next 10 pages, we will show how this theory has brought about a revolution in our understanding of memory. Given the many survival benefits of being able to imagine the future, for instance, it is not surprising that other creatures show a rudimentary ability to think in this way (“Do animals ever forget?”). Memory’s role in planning and problem solving, meanwhile, suggests that problems accessing the past may lie behind mental illnesses like depression and post-traumatic stress disorder, offering a new approach to treating these conditions (“Boosting your mental fortress”). Equally, a growing understanding of our sense of self can explain why we are so selective in the events that we weave into our life story – again showing definite parallels with the way we imagine the future (“How the brain spins your life story”). The work might even suggest some dieting tips (“Lost in the here and now”).