Why We Forget and Why It Matters to Teachers

It’s early in the morning and not many people have managed to get a second cup of much-needed coffee. But that’s not why people’s brains are a little fuzzy. This is the third of the four-part series, Perspectives on Teaching, Learning, and the Brain and Dr. Christian Jernstedt, Professor Emeritus of Psychological and Brain Sciences at Dartmouth College, has just asked these aspiring teachers to recall a meaningful portion of the content of his last session. Everyone is clearly struggling. Dr. Jernstedt is looking at one young man in the back row and waiting patiently for an answer.

“Can I use a lifeline?” Ethan, an aspiring English teacher, asks playfully, and many in the room chuckle.

Dr. Jernstedt specializes in human learning. And he knows exactly why everyone is struggling and furiously flipping through notebooks, searching for their notes from the last class.

“It’s disappointing,” he said later, that people can’t remember a very crucial point from the last session. But Dr. Jernstedt knows a teachable moment when one presents itself. He tells the room that the disappointment he feels is a reality that teachers need to grapple with. Teachers can deliver what they think is a good lesson, but students will not necessarily learn or remember.

The reason we forget, he tells us, is not that the idea or answer has gone from our minds. Interference is why we forget. New information interferes with previously stored information. Our brains are very smart, and crammed with an enormous amount of information. Forgetting happens when we can’t retrieve a memory. And trying to retrieve memories is not analogous to searching in a file cabinet for the information. “It's more like an archeological dig,” says Jernstedt.

Have you ever tried to remember something, been frustrated at the inability to recall, and then the memory comes to you at another time, such as when you’re in the shower? That’s the amazing power of the brain -- to continue to work in the background to retrieve a memory, even when you think you’re not working on the problem.

So what does this all mean for teachers? Well, the answer is complicated. Learning often depends on the ability of a student's brain to retrieve information. Research, Dr. Jernstedt says, tells us that when subjects take a nap immediately after learning new information, they can recall more than those who remain awake. Since most of our students won’t be napping after our lessons, we’ll have to try a different approach.

There are many things teachers can do to minimize interference. Teachers can use structure, elaboration and imagery to maximize meaningfulness. Teachers can chunk information into the small, meaningful bits. And teachers can help students rehearse and remember.

But at the moment, the fuzzy brains in the room are still working on the problem at hand: What was the important information Dr. Jernstedt said at the last session that we should have remembered?

Perhaps we all need to sleep in it. Or get that second cup of coffee.

Commentary by Kristen Downey

Kristen Downey is UVEI’s Associate Director for Teacher Education and a member of the program faculty. Kristen’s commentary on participation strategies can be found here. You can follow her on Twitter @UVEIDowney