The Art and Science of Remembering
Key techniques for creating a
lasting memory
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Robert
Roy Britt / Jul 2
Cramming
for the exam, repeating someone¡¯s name: Some experts say they¡¯re not that
effective at solidifying a memory.
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
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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:
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One group simply studied
each word and translation once, with no quizzes.
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A second group was
quizzed until they could recall each translation.
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A third group was
quizzed until they could recall each translation three times in a row after
initial success.
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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.
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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(±â¾ïÀÇ ±ÃÀü),¡± 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.¡±
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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
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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.¡±
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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.
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¡°We believe that awake quiescence might be so beneficial
to memory because it is conducive to the ¡®replay¡¯ of new memories in the
brain.¡±
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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.
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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.¡±