- We can intentionally forget memories by changing the context
- This could help people suffering with Post Traumatic Stress Disorder
- Scientists could track how scene images faded in and out of the mind
- Memory studies often focus on how we remember rather than forget
For some, a certain song or smell makes them feel postively nostalgic while for someone else it reminds them of a love lost.
But a new study has shown people can intentionally forget past experiences by changing how they think about the context of those memories.
The findings could help in the development of new educational tools, or even help to diminish harmful memories, especially in people with post-traumatic stress disorder.
Theorists have known since the Ancient Greek era the importance of context in retrieving our memories, such as being reminded by a particular person, sight or smell.
But the team from Dartmouth and Princeton wanted to find out about whether memories could be intentionally forgotten.
To do this, they scanned the brains of participants using MRI technology to track the thoughts related to memories’ contexts, while putting a new twist on the traditional psychological research technique of having subjects memorise and recall a list of unrelated words.
In the new study, researchers showed participants images of outdoor scenes, such as forests, mountains and beaches, as they studied two lists of random words.
The volunteers deliberately manipulated whether the participants were told to forget or remember the first list prior to studying the second list.
Jeremy Manning, a psychology professor at Dartmouth who led the study, said, ‘Our hope was the scene images would bias the background, or contextual, thoughts that people had as they studied the words to include scene-related thoughts.’
The brain data allowed them to track, moment-by-moment, how scene or context representations faded in and out of people’s thoughts over time.
The participants were told to either forget or remember the random words presented to them interspersed between scene images.
Right after they were told to forget, the scans showed they ‘flushed out’ the scene-related activity from their brains.
‘It’s like intentionally pushing thoughts of your grandmother’s cooking out of your mind if you don’t want to think about your grandmother at that moment,’ Manning said.
‘We were able to physically measure and quantify that process using brain data.’
But when the participants were told to remember the studied list rather than forget it, this flushing out of scene-related thoughts didn’t occur.
The amount people flushed out scene-related thoughts predicted how many of the studied words they would later remember, which shows the process is effective at facilitating forgetting.