According to a new research, bouts of forgetfulness could be caused by a safety mechanism in the brain designed to make sure we are not overloaded with information. In other words, it’s a healthy part of the brain’s operation.
That might come as a relief if you’re always forgetting where you left your house keys. Also it could teach us more about how the brain operates, something scientists are still trying to figure out.
Memory isn’t intended to help transmit the most accurate information, but rather the most useful information that can help us make smart decisions in the future, according to the two researchers from the University of Toronto in Canada.
“It’s important that the brain forgets irrelevant details and instead focuses on the stuff that’s going to help make decisions in the real world,” says one of the researchers, Blake Richards.
Richards and his colleague Paul Frankland reviewed previously published papers by taking different approaches to the idea of memory. Some looked at the neurobiology of remembering, or persistence, while others looked at the neurobiology of forgetting, or transience.
“We find plenty of evidence from recent research that there are mechanisms that promote memory loss, and that these are distinct from those involved in storing information,” says Frankland.
The researchers have found evidence of deliberate weakening of the synaptic connections between neurons that help to encode memories. They also have found signs new neurons overwriting existing memories, to make them harder to access.
So, why is the brain spending time trying to make us forget?- According to Richards and Frankland, there are two reasons.
First one, forgetting helps us adjust to new situations by letting go of memories we actually don’t need – so if your favorite coffee shop has moved to the other side of town, forgetting its old location helps you remember the new one.
Second thing is that forgetting allows us to generalise past events to help us make decisions about new ones, a concept known in artificial intelligence as regularization. If you remember the main gist of your previous visits to the coffee shop rather than every little detail, then it’s less work for your brain to work out how to behave the next time you go in.
“If you’re trying to navigate the world and your brain is constantly bringing up multiple conflicting memories, that makes it harder for you to make an informed decision,” Richards says.
They also think that the amount of forgetting we do depend on the environment, with a faster pace of change requiring a faster pace of forgetting too.
One experiment mentioned in the paper that Frankland was also a part of involved mice looking for a maze. When the location of the maze was moved, mice that were drugged to forget the old location found the new one more quickly.
There’s no doubt forgetting information we need to remember too often is a frustrating experience, and maybe the sign of more serious problems, but the new research suggests a certain level of forgetfulness is actually a built-in mechanism designed to make use smarter.
Richards says: “We always idealise the person who can smash a trivia game, but the point of memory is not being able to remember who won the Stanley Cup in 1972.”
“The point of memory is to make you an intelligent person who can make decisions given the circumstances, and an important aspect in helping you do that is being able to forget some information.”