REMEMBERING THE PAST AND IMAGINING THE FUTURE.
What is going on in the brain as we create and understand narratives? Imaging studies have identified areas of the brain that appear crucial to this ability. The medial and lateral prefrontal cortex are responsible for working memory, something that helps sequence information and represent story events. The cingulate cortex is evolved in visuospatial imagery and may be connecting personal experience with the story to add understanding. Identification of characters’ mental states seems to be the responsibility of regions such as the prefrontal cortex, temporoparietal junction, and temporal lobes. Patterns for story processing differ from those of other related mental tasks, such as paying attention or stringing together sentences for language comprehension.
Sometimes, the brain shows very little difference in patterns of activity, even when one would think it would. Apart from people with certain forms of dementia, we all have the ability to recall the past and imagine the future. We also have the ability to tell one from the other. If I imagine a birthday party, for instance, I do not confuse this fantasy with an actual party I attended. Conversely, if I recall a party that I did attend in the past, I know that what I see in my mind’s eye really happened and is not just imaginary.
The fact that we can so easily distinguish memory of the past from imagining the future might lead one to expect different patterns of activity associated with the past and the future. Indeed, that is what a team lead by Kathleen McDermot expected to see when they recorded the brain activity of subjects as they recalled or imagined a common experience. But, what they found was that both tasks produced very similar brain activity. McDermot remarked, “we really thought we were going to see a region that was more active in memory than in future thought. We didn’t find that”. This evidence suggests that our personal past and future are closely linked in the brain.
Why is that? Well, in and of itself, the ability to recall the past is not evolutionarily useful. It only becomes so once you can also plan for the future. Remembering how hungry you were last winter is advantageous only if it convinces you to store away food you find in a current season of abundance in preparation for the coming winter. Our capacity to remember the past evolved to help us imagine and plan for the future. One of the main functions of memory, therefore, is to shuffle scraps of the past around in novel ways to project possible futures.
This constructive nature of memory is believed to be the reason why we are prone to false memories. Professor Elizabeth Loftus wrote, “I’ve spent three decades learning how to alter people’s memories. I’ve even gone as far as planting entirely false memories into the minds of ordinary people — memories such as being lost in a shopping mall… all planted through the power of suggestion”. A simple way to demonstrate false memories is to show a person a list of words such as ‘pillow’, ‘doze’, and ‘sleep’. S/he can be easily tricked into remembering that the word ‘dream’ appeared on the list as well. However, people do not make the same mistake with unrelated words.
What this type of fallibility shows is that your memory is not a flawless action replay of an event that really happened. Instead, we only have the ability to remember bits and pieces of our past; to recall the outline of things rather than exhaustive details. We may feel as though we remember certain events fully, but what the mind actually does is imaginatively fill in missing details to construct plausible — but not necessarily accurate — accounts of what happened. Earlier, I asked whether the child a person remembered was ‘real’, or whether it was the character that person anticipated roleplaying tomorrow. We can see now that both are a blend of fact and fiction. A memory is not a flawless action replay, but merely something that captures the gist of what happened. The future, meanwhile, is created in the mind by shuffling scraps of the past around in novel ways.