JUL 13, 2017

Why the Brain Needs to Forget

WRITTEN BY: Brenda Kelley Kim

One of the crucial parts of the brain's function is to learn things and store what's necessary, so it's available for recall. It wouldn't do to keep forgetting how to make a cup of coffee or which roads lead the way home or to work. In a process that isn't fully understood yet, the brain seems to realize what needs remembering and what can be forgotten.

Recent research at the University of Toronto and the Hospital for Sick Children (SickKids), however, suggests that the ability of the brain to forget information is just as important as what it stores in permanent long-term memories.

U of T Scarborough Assistant Professor Blake Richards is the author of a new study on memory and what its purpose is. He explained, "The real goal of memory is to optimize decision-making. 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." So much for retaining lots of pop culture or sports facts, right? That might make you a formidable opponent on a quiz show, but for actual life skills, it might not be the most efficient use of your brain power.

In neuroscience, the function of memory in the brain, at the cellular level, is called "persistence" which happens when the neurons, via certain mechanisms, will store important memories long-term. It's a common focus in research. Forgetting something, which is also a cellular process in the brain is called "transience, " and it doesn't get much notice in research studies. What the latest research shows is that forgetting something isn't just a lapse in the memory-making process, but a separate process all its own. Study co-author Paul Frankland, U of T associate professor and senior scientist of neurosciences and mental health at SickKids explained, "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."

Frankland's lab found in a recent study that new neurons that grow in the hippocampus are involved in the brain forgetting some details. That finding is significant because these new neurons are often prevalent in younger people, which could be why many people have a difficult time remembering events that happened in early childhood. Forgetting some things is a necessary process in the brain, however. Our environment is constantly changing, when we change jobs, move to a new neighborhood or have some other life change. Without forgetting old patterns, it would be difficult to learn new ones; there simply isn't room for everything. Also, some information needs to be sifted out when developing artificial intelligence, so computers can make decisions the way humans can. Prioritizing different facts and using only the ones relevant requires that some fall by the wayside.

Summarizing the results of the study, Richards stated, "We always idealize 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." The video below explains more, don't forget to check it out.

Sources: University of Toronto, The Independent, Neuron