Remembering the past can wipe out competing memories, new study suggests

When we forget things we often chalk it up to our memory failing us, but new research suggests that this brain process is really just a way for us to wipe out irrelevant information information that is cluttering our minds.

“It’s an active mechanism to get rid of memories that distract us from remembering the truly relevant things,” lead author Maria Wimber from the University of Birmingham said in an interview with Yahoo Canada News.

“And in our study we have been able to even watch individual memories while they are being ‘wiped out’ in the brain.”

A team of British researchers who published their findings this week in the journal of Nature Neuroscience, developed a method that allows them to identify the “neural fingerprints” of individual memories as they return to the brains of human volunteers who were monitored using an MRI scanner.

Each participant’s brain images were divided into tiny three-dimensional pixels. Researchers could then observe detailed patterns of brain activity that pictures like those of Albert Einstein, or the Eiffel Tower elicit.

The very same patterns repeat in the brain when subjects are merely asked to recall Albert Einstein from memory. This allowed Wimber and her team to decode the brain patterns and clearly identify which memories drew the strongest responses.

“Even more interestingly, when a reminder word triggered two competing memories to become active — only one of which was the correct answer — we observed that the neural fingerprint of the ‘true’ memory grew more detailed over time, while the neural fingerprint of the competing memory was actively degraded,” Wimber said. “This degradation made our participants more likely forget the competing memories on a later test.”

Wimber believes that the underlying mechanism involved in forgetting allows our brains to prioritize the information that we frequently use, only to eventually throw out competing memories that might simply distract us from the important stuff.

So in a practical sense, it lets our brain focus on memories we need to recall frequently and remain highly accessible.

Wimber offers the example of opening a new bank account on how important memory wiping and prioritizing can be for us on a daily basis.

“Many of us have probably experienced the situation of standing at an ATM being unable to remember the new PIN code, because the old one keeps popping up in our mind,” Wimber said. “The forgetting mechanism we observed ensures that the more often we actively use our new PIN, the weaker the old PIN will become, and the easier it will get every time to recall the new one.”

Researchers are now hoping to see if these findings can be applied to help with disorders associated with unwanted memories like those seen with post-traumatic stress disorder, anxiety or depression.

But is there any way we could prevent this wiping effect from happening in the first place?

Wimber said actively using our memories by frequently recalling them is a good way to make they last in the long term.

We may be able to avoid the pitfall of forgetting as a side effect of remembering by always testing our memory and recalling as many details as we can.

When studying for exams for instance, students may want to use flashcards. Integration of knowledge is known to protect against forgetting.

“The more links you build to connect different pieces of information, the more resistant to forgetting this information becomes,” Wimber said.