Changing the context of memories can help to us ‘decide’ to forget them, new research shows.
By intentionally pushing related things out of our mind, we can also get rid of a target memory.
The technique relies on the fact that our memories are highly contextual.
Our memories are organised based on where we are, who is there and what else is going on at the time.
Dr Jeremy Manning, the study’s first author, explained:
“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.
We were able to physically measure and quantify that process using brain data.”
For the study people were given a list of words to memorise.
At the same time they were shown random scenes such as pictures of mountains and beaches.
Dr Manning explained the reasoning:
“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.
We used fMRI to track how much people were thinking of scene-related things at each moment during our experiment.
That allowed us to track, on a moment-by-moment basis, how those scene or context representations faded in and out of people’s thoughts over time.”
Sometimes people were told to intentionally forget the list of words that were interspersed with the pictures of mountains and beaches.
The brain scans showed that people were ‘flushing out’ the scene-related images from their minds.
In other words: to get rid of the word from memory, they were also getting rid of the context in which they had learnt the word (the picture of the mountain, for example).
When people were not told to forget the words, this ‘flushing’ was not seen on the brain scans.
Dr Manning underlined the importance of forgetting:
“…forgetting is typically viewed as a ‘failure’ in some sense, but sometimes forgetting can be beneficial, too.
For example, we might want to forget a traumatic event, such as soldiers with PTSD [post-traumatic stress disorder].
Or we might want to get old information ‘out of our head,’ so we can focus on learning new material.
Our study identified one mechanism that supports these processes.”
The study was published in the journal Psychonomic Bulletin & Review (Manning et al., 2016).
Image credit: kozumel