The best memory system may not be the one inside your head. Scientists are learning more every day about the fragile nature of memories, including the rather sci-fi fact that they can be functionally erased. Once you know that, it might make you wonder just how much you can trust the wet stuff you use every day.
The answer is that you can’t really trust it, unless you really know how to use it. So take a moment to reflect on the critical flaws in your onboard wetware–and how to troubleshoot it.
Your temporary storage is generally less than 10 things
How many things can you remember at any one time? The most-cited number is “seven, plus or minus two,” as George Miller put it in a classic research paper. It was a stab at determining exactly how many things–digits, shapes, names, what have you–can be stored in what’s called “working memory.” Working memory is where your brain puts things that it’s holding and processing temporarily. As soon as you’re on to the next thing–conversation, browser tab, street block–our brain dumps those previous seven things to work on the next set. Some people can store nine things, some people just five, but the big median curve, as Miller saw it at the time, was around seven items.
Since its publication and spread, the idea of a common number of things for every human has been refuted and moved past. But the fact remains that your brain isn’t the place to keep anything you can’t act on very quickly.
The most accessible way of optimizing your short set of things is to “chunk” those things, or compress many things into single things related to things stored in your long-term memory. It’s hard to remember a string of letters: FABOTWTRFOSQINGR. It’s much easier to remember “Four each from Facebook, Twitter, Foursquare, and Instagram.” It’s why phone numbers are usually broken into three and four-digit sequences.
It sounds simple, goofy, and more like a party trick than a real strategy. But as Joshua Foer notes in his book Moonwalking with Einstein, that exact chunking is the major (and maybe the only) difference in the thinking of chess grandmasters and the innumerable amateurs. When grandmasters look at a board, they’re looking at whole clusters of pawns and compressing them into “structures” and arrangements they know, making whole swaths of the board into single parts of their seven-item working memory. They could, therefore, remember entire boards at a time on a remarkably consistent basis. But show those chess masters random arrangements on a board, and they’re only slightly better at recalling them than brand-new players. Chunking matters.
False memories can be as strong as true memories
When something happens that’s notable and unique, or emotional and stressful, our brain tends to write it to our long-term memory. That’s good, but the way it’s written can lead to confusion later on. It’s something that police detectives and prosecutors know all too well.
Dr. Caroline Racine, a clinical neuropsychologist at the University of California San Francisco, says that our brains organize their neurons around associated features. If you recite a list of related words to a group–”dream, bed, midnight, tired”–and give it some time, most people will report they heard the word “sleep” in the list.
“We base many of our memory judgements on information that seems familiar, even if we can’t specifically recall detaills from a particular fact or event,” Racine wrote in an email. “[So] if related information is introduced when discussing a particular memory, that information can be co-opted into that previous memory, because neurons that are firing together get wired as a specific memory.” The more that bundle of neurons is accessed, either for recalling or hearing the story again, the more real the fake parts will seem, according to Racine.
It’s the same principle as to why memories can be “erased,” why memoirs are so rife with falsities, and it’s why you should (hopefully) remember to check your facts and archives, especially on the things you think you have down cold.
Your mental library has a faulty card catalog
That said, your context-obsessed brain can recall information it learned just a short while ago, or sometimes farther back. It just needs the right reminder, but more importantly, it needs it at just the right time.
Sunil Vemuri, PhD graduate of the MIT Media Lab, studied the effectiveness of what’s called spaced repetition, or feeding someone reminders and hints about something at specific intervals. It powered his personal studying on “personal long-term memory aids,” and it’s what eventually became reQall, an app that works on iPhone, Android, and BlackBerry, but also through email, IM, voicemail messages, and nearly anywhere you can type or say anything.
“The case we’re really driving toward is … having a computer system handle your day-to-day reminders, so your biological memory can stay in its optimal state,” Vemuri said.
When you can’t recall anything about that guy Ken you met with before, and whom you’re meeting with again at 3 p.m., the memory’s usually not lost, Vemuri said. “It’s like losing the card for your memory in a massive card catalog.” Vemuri’s app and other spaced reminders work best by giving you clues about that person in staggered intervals leading up to the meeting. Ken is from Dallas. You met with Ken last in March, when you were in San Francisco. Ken last emailed you one week ago–and, suddenly, everything about that cab ride you shared with Ken after the conference comes into focus.
For specific sets of knowledge to nail down, you could turn to flash-card-like spaced repetition software, or fill out a calendar with specifically spaced reminders. But even if you fail to remember something crucial, look on the bright side–the event might be so traumatic, you’ll definitely remember the next time.