Memories don’t just happen — they’re made. In the brain, the process involves converting working memory — things we’ve just learned — into long-term memories. Scientists have known for years that the noise of everyday life can interfere with the process of encoding information in the mind for later retrieval. Emerging evidence even suggests that forgetting isn’t a failure of memory, but rather the mind’s way of clearing clutter to focus on what’s important.
Other research shows the process of imprinting memories is circular, not linear. “Every time a memory is retrieved, that memory becomes more accessible in the future,” says Purdue University psychologist Jeffrey Karpicke, who adds that only in recent years has it become clear just how vital repeated retrieval is to forming solid memories. This helps explain why people can remember an event from childhood — especially one they’ve retold many times — but can’t remember the name of someone they met yesterday.
Making memories stick
Karpicke and colleagues have shown that practicing retrieval, such as taking multiple quizzes, is far superior in creating solid memories than doing rote memorization. To study this, they had students use different methods to learn the translations of foreign words flashed on a computer screen:
- One group simply studied each word and translation once, with no quizzes.
- A second group was quizzed until they could recall each translation.
- A third group was quizzed until they could recall each translation three times in a row after initial success.
- The fourth group did the same as the third, but their quizzes were spaced out in time.
A week later, all the students were quizzed again. Here’s the amount they remembered via each method:
Based on these findings, Karpicke says self-quizzing — with flashcards or other means — can be an effective way to solidify new knowledge into memories, but the best way is to space those quizzes out, rather than doing them all in one sitting.
For more complicated memory tasks, such as memorizing a long speech, some long-used strategies do appear to hold up today. The ancient Greeks had an elaborate method to remember complex trains of thought. They called it the “Memory Palace,” also known as the method of loci. It works because research suggests people are much better at remembering things they can see, rather than raw facts or abstract concepts.
The way to create a Memory Palace is to walk through a familiar place (like your home) and make offbeat associations between the objects you know well and the things you wish to remember. Let’s say you’re giving a talk about global warming. If you were to use the Memory Palace technique to remember your lines, you might take a walk through your home and associate the fridge with an unusually frigid winter storm. You would then pretend SpongeBob is right there, in your kitchen, eating a Krabby Patty, to represent global warming’s negative effects on sea level and the health of crustaceans. During your talk, you take a mental stroll through your kitchen and let the wacky associations bubble up.
Modern memory competitions, in which participants memorize entire poems or the order of several shuffled card decks, have resurrected the Memory Palace technique. Ben Pridmore, a three-time World Memory Champion, used the practice to memorize the order of 1,528 random digits in one hour, among other feats of mental gymnastics.
Joshua Foer, a science journalist, covered the United States Memory Championship in 2005. Foer figured he’d be better prepared to write about the mind-boggling contestants if he learned a little about their techniques. He spent a year studying the tactics. In a 2012 TED Talk, Foer explains how memorization is all about associating the mundane with the interesting or even the bizarre:
“As bad as we are at remembering names and phone numbers and word-for-word instructions… we have really exceptional visual and spatial memories,” Foer says. “The crazier, weirder, more bizarre, funnier, raunchier, stinkier the image is, the more unforgettable it’s likely to be.”
Foer got pretty good at memorizing. Instead of covering the competition the following year, he entered it. “The problem was, the experiment went haywire,” he says. “I won the contest. Which really wasn’t supposed to happen.”
“Great memories are learned. But if you want to live a memorable life, you have to be the kind of person who remembers to remember.”
In his bestselling book Moonwalking with Einstein, Foer says all memory champions like himself will claim that they actually have average memories. And science backs that claim. Back in 2002, researchers scanned the brains of World Memory Champions while they were memorizing facts and detailed images. The results showed that “superior memory was not driven by exceptional intellectual ability or structural brain differences,” the authors wrote. “Rather, we found that superior memorizers used a spatial learning strategy, engaging brain regions such as the hippocampus that are critical for memory and for spatial memory in particular.”
It’s not that memory champions are smarter than everyone else. They just work hard at remembering, and therefore apply more of their brains to the task.
A couple easier techniques
If creating a Memory Palace seems too involved or absurd, there are simpler strategies you can try, like taking a nap or doing nothing at all for a period of time.
Studies have shown that sleep is important for memory formation, and several studies have indicated that naps function just like overnight sleep. In one study published in the journal Sleep earlier this year, researchers had 84 college students learn some basic facts. One group then napped for an hour, another group just took a break and watched a movie unrelated to the material they’d learned, and the third group crammed, going back over all the material.
“When retention was tested immediately after learning, both napping and cramming produced better retention than taking a break, but only the nap benefit remained significant when tested one week later,” the researchers concluded.
Michael Craig and Michaela Dewar at Heriot-Watt University in the UK have found in several studies that sitting quietly and doing nothing — what they call “awake quiescence” — helps people remember more. The idea is that when you learn something new, what you do next is crucial in helping you retain that information, and taking a pause might be the best choice to let the brain process new information.
In a 2012 study led by Dewar, people ages 61 to 87 heard two short stories and were quizzed on the details of the stories immediately after. Then the people were split up into two groups. For 10 minutes, half the people in the study played a computer game that required some thought, while the others sat in a quiet, dark room, alone, with their eyes closed. Neither group was given any instructions about trying to remember things (they were told the researchers were headed off to prepare for the next test).
The quiz was then repeated a half-hour later and again a week later, and in both retests, the people who sat and did nothing for 10 minutes “remembered much more,” the researchers reported in the journal Psychological Science.
“Our findings support the view that the formation of new memories is not completed within seconds,” says Dewar. “Indeed our work demonstrates that activities that we are engaged in for the first few minutes after learning new information really affect how well we remember this information after a week.”
The biological mechanisms behind awake quiescence haven’t been investigated. But Craig says he thinks that memories are fragile and vulnerable to disruption and that hanging onto them requires sleep or quietude to allow them to consolide or solidify.
“Findings in rodents and humans indicate that the brain consolidates new memories by ‘replaying’ them” in the minutes after initial learning,” he says. “We believe that awake quiescence might be so beneficial to memory because it is conducive to the ‘replay’ of new memories in the brain.”
The replay is not conscious — it’s an automatic biological process, Craig explains. After the memory tests, his team asks people what they were thinking about during their quiescence period. Normally they say their minds were wandering, as happens with anyone not engaged in a task. “People rarely report thinking about the studied materials during these periods,” he says.
Among the most exciting aspects of awake quiescence is that it seems to work for almost anyone. The researchers use the same tests on the young and old, and even people with serious memory problems. Awake quiescence hasn’t been tested on associating names with faces, but it has been found to boost spatial-associative memory, such as binding a landmark to a location. “So, it is possible that quietly resting for a moment after meeting someone new could well help you to remember a person’s name and face better,” Craig says.
The ultimate takeaway is that improvements in recall may require the adoption of a process, even if it’s a conscious effort to spend some time not doing much thinking at all.
“Great memories are learned,” Foer says. “But if you want to live a memorable life, you have to be the kind of person who remembers to remember.”