Suppressing Negative Memories May Weaken Them
Many of us have had a few unpleasant or
negative experiences. Things we would rather forget. Unfortunately,
those unpleasant episodes can keep coming back to us from time to time.
But what if you were told that there’s a way to forget them?
According to a study published in the
journal eLife, actively suppressing negative experiences may help
prevent intrusive thoughts and ruminations.
Our unwanted memories can often be triggered by seemingly harmless
objects: a shirt that belonged to a lover that passed away or a scar
from a horrific accident, for instance. Earlier research had discovered
that if such unpleasant memories are deliberately pushed away from one’s
consciousness, the related scenes become more difficult to remember
later on and are forgotten. However, it wasn’t clear what happens to the
stored scenes and whether or not they ‘faded away.’
This new study sheds more light on the
subject.
“If you actively suppress a memory and then try to recall it again, the
images appear less vividly than before,” says Ann-Kristin Meyer, a
doctoral student at MPI CBS.
How the Study Worked
To investigate whether the unwanted memories really 'fade away' after
being suppressed, the researchers closely studied 33 participants who
were taught to relate pictures of negative experiences with neutral
objects, such as a car accident with a lost shoe or a flood disaster
with a rubber boot. They were shown the scenes with the respective
objects several times. Eventually, the objects began to automatically
evoke bad images.
While being observed via magnetic resonance imaging (MRI), the
participants were then shown the objects and were asked to either recall
the negative experiences or suppress them. This helped the research
team know if the suppressed memories had actually faded. In the final
step, the participants were shown the objects once again and were asked
to recall each scene associated with them.
Using a pattern classifier, the researchers observed how suppression
diffused the neural reactivation of scene information both globally
across the brain and locally in the parahippocampal cortices. The
results revealed that suppressing memories earlier made them less vivid
when recalled later on. According to the team, this happens because
subduing memories weakens them “by causing a sustained reduction in the
potential to reactivate their neural representations.” They argue that
continued suppression exerts a sustained influence on memories by
weakening their neural representations. This makes them less clear and
eventually causes them to fade away.
Is Deliberately Forgetting Memories a Good Thing?
“Forgetting has a largely bad reputation,”
says Dr. Roland Benoit, study leader and head of the Adaptive Memory
Research Group at Max Planck Institute for Human Cognitive and Brain
Sciences.
However, the scientists involved in this new study believe that active
forgetting may be a helpful tool in preventing memories of bad
experiences from continually plaguing us. They state that we can weaken
our memories and even get rid of their neural traces in the brain by
controlling our thoughts.
For now, it isn’t clear why some people forget more easily than others.
According to the research team, depression or post-traumatic stress
disorder (PTSD) tend to find it difficult to forget unpleasant memories
and this isn’t the case for people without the conditions.
The researchers now insist that future studies must investigate whether
and how deliberate forgetting contributes to mental health.