New research reveals that humans can choose what they remember, writes Ailin Quinlan
WE’RE brought up to believe our memories are infallible — but they’re actually the opposite. In fact, not only do we unconsciously ‘select’ what we want to actually remember — we routinely ‘massage’ certain memories to show ourselves in a better light.
‘Forgetting’ an uncomfortable or distressing incident, in fact, can be something we do very deliberately. “We usually talk about forgetting as something that happens later in life, or for example, in terms of the onset of Alzheimer’s disease,” says Dr Sabina Brennan, Research Assistant Professor at Trinity College and an expert on brain health and dementia prevention.
However ‘forgetting’, she explains, is more common than that. Throughout our daily lives we have the ability to select what we actually remember or forget — think of the phenomenon of mothers who forget the agony of childbirth.
“It’s all about survival,” she says. “It can be an instinctive way of protecting ourselves, by feeling better about ourselves — it is about resilience and survival.”
It’s simply not possible to remember everything we do every day across our lives, explains Brennan, a research psychologist and co-director of the NEIL (NeuroEnhancement for Independent Lives) Dementia Research Programme at the Institute of Neuroscience at Trinity College.
So we have to choose what we do remember — and the memories we most need to hang on to are those which help us to function, feel good about ourselves and survive in our day to day lives.
Here’s how it works. The first step in making a memory is to pay attention to what you want to remember. Next you ‘encode’ it, then consolidate it through a process in the brain after the memory has been acquired. On top of that, we can instinctively, or unintentionally, ‘create’ a new memory of an incident in a way that throws our own past actions in a better light.
So if we say or do something stupid or embarrassing, we can quite literally massage or ‘re-shape’ the memory of that comment or action to make ourselves appear less foolish in retrospect.
We do this by replaying such incidents in a more positive way, either by thinking about or telling a slightly different version of the story.
“We can replay something that happened to make ourselves look better than we did,” says Brennan. “A person can tell a story a little bit differently, making himself or herself look better than they were,” she explains.
Once we start to replay this more pleasing version of a particular incident in our minds, we can eventually have difficulty in distinguishing between what actually happened, and our personal ‘recall’ of what happened.
That’s because if you tell the story with the slightly enhanced version of yourself often enough, she says, it eventually becomes re-consolidated as a memory — and, years later, that’s the version you’ll remember.
Memory re-consolidation is the process of previously consolidated memories (as above) being recalled and then actively consolidated all over again in order to maintain, strengthen and modify memories that are already made. “It makes adaptive sense to focus on the positive and make ourselves feel good,” she says.
“It’s the constant remembering and re-imagining of an event that causes the reinforcement and re-consolidation of memory.
“Then that memory becomes so strong and so realistic that it can actually become the memory we retrieve,” she says.
In other words, the modified memory is encoded while the old memory starts to fade away because it’s not being retrieved.
Another way to ‘select’ what we want to remember is to suppress a memory, explains Brennan.
“We have the capacity to suppress memory.”
In other words, if we consciously refuse to think about a negative thing, the memory of it may gradually fade.
For example, maybe you’ve had a bad day at work, and when you come home you refuse to talk or think about it.
You gradually suppress the memory by simply not paying attention to it and it may not get consolidated, she explains.
However, other factors can impinge on our memory — stress, for example, can impair our memory function in everyday life.
“It can make it hard for us to remember things — so, for example, some people get stressed out when they have to make a speech in public and cannot remember what they want to say,” she explains. Any type of stress impairs memory function. Our brains can also decide that we don’t want to remember something, says Dr Marian Tsanov of the Neuroscience Institute at Trinity College.
“It’s not a case of ‘I am deliberately forgetting’,” he says. “More a case of ‘I simply don’t want to remember’.”
A classic example is where people who have been in the army will fondly remember the joking and camaraderie, he says — but may not recall the fear, the stresses and the difficulties they encountered during that time.
“The brain is wired to remember more positive things. It’s easier to recollect positive things in day to day life than negative things, simply because it makes us feel better to recollect things that are nice.”
However, the way we view memories is also down to our brain hormones, such as dopamine or serotonin, he adds.
“The level of dopamine in your brain can determine whether you will look more positively at something you said or whether you will be more self-critical,” explains Dr Tsanov
“People with healthy dopamine levels are more likely to focus on the positive and recollect positive things,” he says, adding that serotonin and dopamine can control whether your memory of something will be in a positive or negative light.
Dr Sabina Brennan and Dr Marian Tsanov are participating in ‘The Science of Memory’ event which is part of this year’s free public programme of events for Trinity Week (April 11-15) which takes place place at Trinity College. For the full programme of public talks, seminars, poetry and other events visit www.tcd.ie/trinityweek/
© Irish Examiner Ltd. All rights reserved