Why is it that you can perfectly recite the words to *NSYNC’s “Bye Bye Bye,” but can’t remember the title of the new TV show you started watching on Netflix and wanted to tell your coworker about?
We remember things because they either stand out, they relate to and can easily be integrated in our existing knowledge base, or it’s something we retrieve, recount or use repeatedly over time, explains Sean Kang, PhD, assistant professor in the Department of Education at Dartmouth College, whose research focuses on the cognitive psychology of learning and memory. “The average layperson trying to learn nuclear physics for the first time, for example, will probably find it very difficult to retain that information." That's because he or she likely doesn’t have existing knowledge in their brain to connect that new information to.
And on a molecular level neuroscientists suspect that there’s actually a physical process that needs to be completed to form a memory — and us not remembering something is a result of that not happening, explains Blake Richards, DPhil, assistant professor in the Department of Biological Sciences and Fellow at the Canadian Institute for Advanced Research.
In the same way that when you store a grocery list on a piece of paper, you are making a physical change to that paper by writing words down, or when you store a file on a computer, you’re making a physical change somewhere in the magnetization of some part of your hard drive — a physical change happens in your brain when you store a memory or new information.
“So the ultimate question, at the cellular level, as to whether or not a memory gets stored [in the brain] is does that process actually complete properly,” he explains. “Do all of the molecular signals get transmitted to ensure that that cell changes physically?”
So there are strategies for better organizing what may at first glance appear to be unrelated information to connect it to what we already know to help us better remember things, according to Kang and others. But as far as changing the physical processes in the brain that make memories stick, there’s likely not much you can do now to affect that, Richards says.
And that’s probably a good thing, he adds.
In a recent paper, Richards and his colleague Paul Frankland, PhD, senior scientist at The Hospital for Sick Children and Fellow at the Canadian Institute for Advanced Research, looked at previous studies that have investigated the physical changes in the brain associated with memory — and why sometimes that process completes and sometimes it does not. “We found that there’s a variety of mechanisms the brain uses — and actually invests energy in — that undo and override those connections, ultimately cause us to forget information,” Richards says.
And that would mean that some “forgetting” is actually a very natural and normal process, rather than a “failure” of our memory, Richards says. “Our brains may want us to remember the gist of what we’ve experienced because that will be most adaptive for making decisions in the real world.”
For example, let’s say you remember a friend’s phone number, but that friend moves away and gets a new phone number. Remembering the old number becomes useless and may make it more difficult to remember your friend’s new number.
“It’s not the case that as much forgetting as possible is good, obviously,” he says. “But at the same time it may not be the case that as much remembering as possible is always the best course either.”