Decorating a Barren Memory Palace

Click here to read an original op-ed from the TED speaker who inspired this post and watch the TEDTalk below.

In my mind's eye, I now have an image of overweight nudists on bicycles. It's not an image I want in my head, but it's vivid and -- my guess is -- enduring. I have science journalist Joshua Foer to thank for this. I have just watched his charming and hugely popular TEDTalk on memory, and he uses this image to illustrate an ancient mnemonic device called the "memory palace" -- a technique he has actually used to memorize the TEDTalk itself.

His own memory palace -- or memory house -- begins at his own front door, where he has pictured the nude cyclists congregating. Then, as he mentally walks through the ground floor of his house, he encounters other vivid images that he has linked to various rooms -- first the Cookie Monster and Mr. Ed, followed by Britney Spears on the coffee table, the Wizard of Oz characters in the kitchen, and so forth. By linking strange and surprising images to a familiar route, he can cue his memory -- and recall the key points he wants to make.

Psychological scientists have long known about this mnemonic technique, which they label the Method of Loci. In his bestselling book, Moonwalking With Einstein, Foer describes how the world's best memorizers use this ancient technique to compete in memory contests -- memorizing multiple decks of shuffled playing cards or hundreds of random binary digits. The book and the TEDTalk take us inside this rather strange world of memory competition.

People who suffer from serious depression have great difficulty calling up vivid memories from their past, and clinicians believe that this meager autobiographical memory may contribute to the mood disorder.

- Wray Herbert

But as Foer notes, these memory competitions are merely exaggerations of the memory challenges we all face every day. Even for those of us with average memories, the key to successful recall is what experts call elaborate encoding: The more vivid and concrete an image is -- the more bizarre or hilarious or raunchy -- the more likely it is to stick in the mind. Elaboration is the key to the memory palace.

Some people's memory palaces are rather barren, however. Notably, people who suffer from serious depression have great difficulty calling up vivid memories from their past, and clinicians believe that this meager autobiographical memory may contribute to the mood disorder. Recently, psychological scientists in the UK have been exploring the idea of using the Method of Loci technique to enrich sufferers' personal memory repositories -- to decorate their palaces -- so that they might have more joy to tap into.

Clinical psychologist Tim Dalgleish, working with colleagues at the MRC Cognition and Brain Sciences Unit in Cambridge, knew that depression often impairs the ability to retrieve positive, self-affirming memories. Even when depressed people do manage to summon up happy memories, they don't seem to improve their mood much. Dalgleish suspected that the quality of the depressives' personal memories is poor -- lacking in concrete detail -- and he wondered if the memory palace technique might be used as a clinical intervention.

Here's the study. He recruited volunteers who had been diagnosed with major depression. About half were currently experiencing a depressive episode, while the others were in remission. About half of each group met face-to-face with a researcher for Method of Loci training. They started off by generating 15 positive, affirming recollections from the past. The memories they first came up with on their own were often vague and general, but with the help of the researcher they elaborated each of them with as much rich and concrete detail as possible. Then they used a familiar mental map -- either their home, just like Foer, or their route to work -- and attached these 15 memories to memorable images placed along the route. For example, one volunteer had fond memories of a conversation with her best friend over coffee in New York, so she pictured the front of her home transformed into a popular American coffee chain, with her friend as the smiling barista. They all did this with all 15 memories, and practiced using them.

The other volunteers, the controls, also received memory training -- but a technique called chunking and rehearsing. With this approach, volunteers group memories into categories -- good times with children, for example -- which they then rehearse. Dalgleish suspected that both of these memory techniques would help the depressed volunteers enrich their repositories of positive memories, but he predicted that the Method of Loci technique would have more enduring effects.

And that's exactly what they found. As reported in the journal Clinical Psychological Science, all the volunteers practiced at home for a week, and when they returned to the lab they had all succeeded in improving access to joyful past experiences. This was true whether they were depressed at the time or in remission. However -- and this is the key finding -- on a surprise follow-up recall test a week later, only those who had learned the Method of Loci technique maintained these recollections. Presumably, these people could draw on this rich repository of good memories in the future, and at will, to help regulate their moods. The controls, by contrast, showed a significant falloff in recall for these happy past experiences.

To continue with Foer's colorful example of a mnemonic residence, those who went through the Method of Loci intervention now live in richly decorated homes, while the others still occupy their Spartan and melancholy quarters.

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