your
memory
brain rule
Remember, it’s never too late
to learn—or to teach
God gave us memory
so that we might have roses in December.
—James M. Barrie
Not only is my short-term memory horrible,
but so is my short-term memory.
—Anonymous
THE TITLE OF THE following true story should be “Amazing Wife to the Rescue.”
I was once introduced to a most engaging fellow at a Seattle reception, and we were soon lost in the thick fog of scientific conversation. My wife, finishing a chat with a friend, started walking my way. I knew proper introductions would soon be in order, and I was immediately confronted with this paralyzing, embarrassing fact: I had completely forgotten my new colleague’s name! My wife glanced at me upon arriving, sensed that my social memory was stuck in tree sap, held out her hand first, and voluntarily introduced herself. The gentleman quickly returned the favour. See? Amazing Wife to the Rescue.
Forgetful moments like these are painfully common as we age, and they only become more frequent. Comedian George Burns riffed on them famously. “First you forget names. Then you forget faces. Next you forget to pull your zipper up, and finally, you forget to pull it down!” he quipped, in one of his ageless routines about growing old.
Burns’s lively flippancies are a terrific example of memory systems that stay vibrant well into old age. How does that jibe with Amazing Wife to the Rescue–style forgetfulness? Our brains have multiple memory systems, and, as we’ll discover, they don’t age at the same rate. So which changes should keep us up at night? Which can we safely ignore? Is there anything we can do about the memory systems we start to lose?
These are the questions we’ll tackle in this chapter, starting with what typically happens to memory as we age. Spoiler alert: we’re going to be doing a fair amount of myth busting.
Many types of memory
As you know, it’s a mistake to think there’s a solitary memory system in the brain, as if a single hard drive were embedded in our foreheads. Rather, there are multiple memory systems within the brain, almost as if the organ were a fancy laptop with twenty or thirty separate hard drives.
Each system is in charge of processing a specific type of memory, each composed of freelancing neural circuits working in a semi-independent fashion. As an example, suppose you remember a high school shop class where your friend Jack got cut while you were all learning how to use a lathe. Learning how to operate a lathe prior to the accident involved a specific memory domain (motor). Recalling that the person who got cut is named Jack and not Brian uses another domain of memory (declarative). Recalling that you watched it in time and space—morning shop class—complete with a cast of characters, you and Jack, uses still another memory domain (episodic).
These systems talk to one another constantly, integrating and updating their findings in tiny fractions of seconds. Yet how they do this is mostly unknown. We mentioned that it’s more complicated than a reel-to-reel tape recorder with a playback button. And just to make matters more complex, we have both short-term and long-term forms of memory systems. For simplicity’s sake, we’ll be focusing on the long-term varieties, except where indicated.
Given how much scientists don’t know about memory, any overarching framework attempting to organise it will have major theoretical fracture lines. But a framework I like—the one we’ll use here—involves organising human memory by whether conscious or unconscious functions are stimulated when processing specific types of information.
One system that involves conscious retrieval is called declarative memory—named for memories that are easy to declare. Declarative memory has two components: semantic memory (which allows you to remember the Pledge of Allegiance) and episodic memory (which allows you to remember what happened in Gilligan’s Island). What do I mean by conscious retrieval? Say I ask you how old you are, and you respond, “None of your business.” You know your age, which you bring up consciously. You use your knowledge of English to respond to my question in an indignant manner, also consciously.
And then there are learned skills that you call up without really being aware of it. Take driving a car. Do you consciously retrieve the skills from long-term memory and whisper to yourself: “I will now open the driver’s door, get into the left seat, grab the key between my thumb and index finger, insert it into the ignition, turn it thirty degrees clockwise, and wait for the engine to start”? Of course not. You simply get in the car and drive it, awareness mostly not required. This type of memory is called procedural memory. One of the distinguishing differences between procedural memory and declarative memory is conscious awareness.
Let’s be clear: all memory systems, conscious-tinged or not, are formed from learned experiences. You weren’t born offended by rude questions any more than you were born able to drive. Nonetheless, these phenomena engage different parts of the brain as you learn them. To describe this variation, we scientists puff out our chests and stuffily declare, “Memory is not a unitary phenomenon.”
And neither is the ageing of those memory systems. George Burns, the comedian we met earlier, is a good guy to help me explain. He signed a lifetime contract to do stand-up at a Las Vegas casino.
At the tender age of ninety-six.
Oh, God! It’s George Burns
“You know you’re getting old when you stop to tie your shoes and wonder what else you can do while you’re down there,” the comedian quipped. He joked about his fifteen-cigar-a-day habit: “At my age, I have to hold on to something” and about sex being like trying to play pool with a rope. “I’d go out with women my age,” he said, “but there are no women my age.” He was asked to portray the Almighty in the popular Oh, God! series of movies. When asked how the casting director selected him for the title role, Burns joked, “I was the closest to Him in age.” He’d already won an Academy Award at age eighty.Such was their belief in his vitality, the executives at Caesars Palace inked a contract with this funny ninety-six-year-old just so they could have broadcast rights to his hundredth-birthday performance. Here’s why his comedic instinct was still going strong.
Semantic memory, a memory for facts, doesn’t erode with age. Access to its supporting memorised database—your vocabulary—actually increases with the passing years. You score a 25 on performance tests in your twenties. By the time you reach your late sixties, your score is just north of 27 (!). That might not sound like a big deal, but given the elderly brain’s reputation for memory loss, few people expected it to show increases. Yet that’s exactly what is observed.
Procedural memory isn’t priced for quick sale, either. Procedural memory (nonconscious retrieval, remember, falling under the umbrella of motor memory) remains steady as the years go by, although some studies also demonstrate a slight improvement. One experiment, for example, taught a visuomotor task to both younger and older populations, then tested memory performance two years later. Motor memory, as measured by mean performance times, improved 10 per cent in younger populations. When the older populations were measured, their motor memories had improved 13 per cent.
The fact that these types of memories stay robust over the years adds up to good news: you really do get wiser with age, depending on how you define wiser (and age). These findings come from the obvious insight that we seniors have brains chock-full of experience, which provides two measurable benefits: First, older people have access to a larger fund of knowledge. This gives us a broader array of options for decision making. That’s handy when the issues are as complex, confusing, and nuanced as a Middle East peace process. Or our adult children.
Second, our decision making is less impulsive, more thoughtful. It takes longer, simply because we have more options to weigh (it’s the load of all those extra memory traces). Senior brains are still flexible and plastic, but decision making becomes more metabolically costly to the brain the more stuffed it is with information. The upshot: seniors tend not to make stupid mistakes. Here’s how one paper describes the phenomenon: “The brains of healthy older adults are less likely, and may have less need, to react to environmental challenges with a plastic response than the brains of children and adolescents. In other words, older adults have a richer model of the world that enables deployment of established behavioural repertoires.”
You might call this richer model, as some researchers do, “wisdom.”
Here again, George Burns’s life is instructive. From vaudeville to radio, television to movies, Burns was one of the few comedians to work in every entertainment medium the twentieth century offered. By age ninety-six, his brain had grown fat from the accumulated wisdom of almost eight decades of steady work.
No wonder they asked him to play God.
Now for the bad news
Not all memory systems are preserved with age. One type that declines might best be illustrated not by an old comic but by an old Pixar movie.
Our family has always loved Pixar’s delightful Finding Nemo. In the story, Nemo’s dad (a clownfish) watches his son get kidnapped by a group of divers. Dad runs smacks into Dory, a cobalt blue tang fish voiced by Ellen DeGeneres. She excitedly reveals she’s seen the divers’ boat, exclaiming: “It went this way! Follow me!” They both start swimming furiously in the direction of the wake.
But not for long. Dory soon slows down, then meanders in a zigzag, looking back at Nemo’s dad in an increasingly suspicious manner. She doesn’t seem to recognise him anymore. “Will you quit it!” she exclaims, turning on the suddenly surprised clownfish. “What are you talking about?” Nemo’s dad exclaims. “You’re showing me which way the boat went!”
Dory stops and suddenly smiles: “Hey, I’ve seen a boat. It passed by not too long ago.” With the vigor of an igniting rocket, her brain reenergises. “It went this way! This way! Follow me!” She blasts off in the same direction as before. Nemo’s dad, frustrated, confronts her head-on about this obvious memory lapse, and they stop swimming. “I’m so sorry—I suffer from short-term memory loss,” she explains. “I forget things almost instantly. Runs in the family.”
That’s a terrific example of a cognitive work space scientists call working memory. We used to call it short-term memory, believing it to be a simple, passive storage locker for temporarily storing information. But that was only a long-distance cousin of the truth. We still think it’s a temporary work space, but one that is nowhere near simple. Or passive.
Alan Baddeley is the British researcher who first coined the term “working memory.” He posited that this work space was dynamic, composed of subprocesses, functioning like shifting piles of manila file folders atop a busy office desk. He was right on all counts. One folder in the working memory work space is useful for temporarily holding visual information (the visuospatial sketch pad). Another folder is useful for temporarily holding verbal information (the phonological loop). Still another folder is in charge of coordinating all the others, appropriately termed the central executor. This last subprocess doesn’t hold anything except a program that keeps track of what the others are doing.
Working memory deficits can show up in the most embarrassing ways. You begin to lose your keys more often. You forget what you were about to say, or do, or you lose track of what somebody else says or does. You mention something to a friend, only to have them stop you and say you’d told them before. We’ve all had these experiences.The decline can be dramatic. One research paper showed that in our twenties, we score on a normalised scale for working memory at about 0.6 (for the particulars of the test, see the references on brainrules.net). That’s pretty high. As we get older, unfortunately, the numbers go south. At age forty the score is about 0.2 (not so high) and by age eighty, it has plummeted to a –0.6 (really low). Forgetfulness settles on our brain like a net floating down from above. Working memory is part of a larger network called executive function (EF), which experiences a decline I’ll spend some time detailing in a later chapter. Suffice it to say, working memory dysfunction, Dory’s enduring—and endearing—quality, will eventually gift us the same way, too.
By the way, Dory was right. Working-memory abilities really do run in families. Which means if you want to preserve it, you must choose your parents wisely. Or, short of that, follow the suggestions in this book.
I’ll have much more to say about what to do, but right now, I need to deliver some more bad news. It involves one of the most famous prizefighters who ever lived.
Down for the count
Short-term memories aren’t the only ones swimming in troubled waters. Certain long-term-memory gadgets encounter turbulence, too.
A case in point is nicely illustrated by an episode of an old TV show called This Is Your Life. It starred one of the most celebrated athletes of all time, Muhammad Ali, the late, great, TV-friendly boxer as famous for his mouth as for his fists. And for his self-confidence, bright with quotes like “I’m so mean, I make medicine sick” and “I should be a postage stamp. That’s the only way I’ll ever get licked.”
This Is Your Life functioned as part biographical sketch, part interpersonal ambush. It often featured famous guests, and the hook was to surprise them with appearances from people in their past, flown in just for the show, some not seen for decades. Ali’s 1978 spot featured visits from his parents, brother, wife, and other legendary boxers. And one particularly moving segment, a taped interview from legendary entertainer Tom Jones (Who knew they were friends?), in which he recalls when they first met.
“I’m sitting here in Las Vegas, in the dressing room, between shows … the time, I think it was about ten years ago, in the Latin Casino, in Cherry Hill, New Jersey, knocking at the door, I looked up, and you were standing there . . .” The most amazing part is Ali’s reaction as Jones begins speaking. He looks stunned. As Jones continues, Ali wipes his eyes and nose. “And we’ve been friends ever since,” Mr. Jones finishes. Ali just sits there for a moment. In a life ringed with past glory, the champ appears KO’d not by an opponent but by a memory.
Episodic memory, that lively, previously mentioned subdivision of declarative memory, is just what it sounds like. It is a memory for episodes, the information about events occurring in a certain context and—this is important—interacting through time. Casts of characters are usually interacting in these events. If the character happens to be you, we call it autobiographical episodic memory. Episodic memory is in charge of answering questions like “what, where, and when”—standard fare in a typical This Is Your Life installment.
Episodic memory marries two components: the information being retrieved and the context in which the information is recalled. The former is probably just good old semantic memory—the memory for facts. But the latter is unique to episodic memory and gets its own name: “source memory.” Think of it like a person giving a speech. Semantic memory recalls the content of the speech. Source memory remembers who said it.
Though episodic memory dips into the deep wells of your semantic reservoirs (Ali is not an “episode,” after all), episodic memory in the brain is structurally distinct. How do we know this? Some people are born with ridiculously powerful episodic memories, but they have average-to-poor semantic memories. One famous case concerned a woman who remembered virtually everything that had happened to her since childhood, without fail and without error. Her autobiographical episodic memory appeared flawless. Yet she was a below-average student in school. She had a fairly hard time memorising run-of-the-mill facts, and she had to make lists to remember certain mundane things. Her declarative memory was flawed. She could remember exactly what she had for dinner eight years, seven days, and four hours ago, yet could not remember her times tables. Distinct systems, indeed.
Now for the bad news: episodic memory, like working memory, gets worse with age. Research shows there’s a 33 per cent drop in the ability from your twenties to your seventies. (The peak is around age twenty.) A grandfather has a much harder time remembering what he had for breakfast than his granddaughter does.
We even know the type of information that goes down for the count: source memory. One test measured younger and older test subjects as they watched people giving speeches. The subjects were later asked to recall the content of these speeches, then to match which content was said by which speaker. Older people and younger people could identify the content just fine (semantic memory), but older people had much greater difficulty in identifying who said it (source memory). They failed even to remember the gender of the speaker, a much less cognitively taxing task called partial-source memory.
What’s going on with episodic memory from a neurological perspective? Episodic memory involves electrical connections between the hippocampus, which we’ve discussed before, and something called the default mode network (DMN), which we haven’t discussed before. Hippocampal involvement makes sense; it helps mediate many types of memory. DMN involvement will, too, once you know a bit about its functions.
The DMN is a group of far-flung neural networks: regions behind your forehead connecting to regions arcing between your ears. It’s called “default” because it’s active when you’re inactive—bored, daydreaming. The DMN is deeply involved in episodic memory, too, particularly with neurons on the right side of the prefrontal cortex. It makes sense that the neurons generating daydreams might also help construct narratives, as both involve episodic features.
As we age, both the hippocampus and DMN begin to erode. You can see this structurally (volumetric loss) and functionally (connectivity changes). It’s here that things get nightmare-like. The brain cannot marshal enough forces to overcome it. Unless you do something intentionally, these changes will become permanent. A moderate loss is typical—happens to everybody—but a severe loss is not. It’s one of the signature features of Alzheimer’s disease.
Unfortunately, working memory and episodic memory are not the only systems suffering age-related decline. I bet you’ve experienced the third one already.
It’s on the tip of my tongue
Two older married couples are walking home from a movie, goes an old joke. The women are chatting in front, men tarrying in back. One man announces, “We went to a really fine restaurant last night. You should go.” His friend replies, “What was its name?” The man begins to respond, then becomes frustrated. “I’m afraid I don’t remember,” he says. “What is the name of that lovely flower everybody likes? You know, the kind you give on Valentine’s Day?” “Do you mean a rose?” his friend says, puzzled. “Yep, that’s it,” says the man, and then calls out to his wife walking ahead.
“Rose? Hey, Rose! What was the name of that restaurant we went to last night?”
Most everybody I know suffers from a variation of the memory loss described in this joke. You want to recall a word, and you have the distinct feeling it’s rolling around in your memory like some invisible marble. But it soon it circles down the inexorable cognitive drain, lost forever until noon the next day, when you suddenly recall it. This is the Tip of the Tongue phenomenon (its actual scientific name!). As we age, the frustrating experience becomes more common. On average, Tip of the Tongue irritations increase fourfold when you compare seventy-year-olds to thirty-year-olds.
One of the most intriguing aspects of this loss is what’s not lost. In the joke, the older man knew he’d gone to a restaurant, really enjoyed it, and wanted to share that with his friend. And he did share something about it verbally, showing his language comprehension was fine. What got him in trouble was finding a specific word.
Here’s the upshot. Language comprehension and general word production are well preserved into old age, like canned peaches. Losing access to phonological representation, like fruit that sat in the sun too long, is not.
It’s obvious that memory is uneven in its decline. Is there a generalisable time line scientists use to track its aggravating progress? This is an important question. Many seniors fear that the dark shadow of dementia has claimed another few square inches of their brains every time they can’t remember their favourite wine. Fortunately, most of these memory losses are normal and not indicative of anything except a large backlog of birthdays. And there are things you can do to slow—even reverse—the decline. Only in a few cases are such losses indicative of something more serious, like dementia. We’ll describe in a later chapter how to tell the difference between the typical and the terrifying.
In the meantime, you might find perverse comfort in knowing there’s lots of disagreement in the scientific community about exactly what declines, by how much, and when. The problem? Ageing is so very individually experienced. Pair that with the fact that scientific understanding of how memory works is incredibly incomplete. To stay on the sunny side of peer-reviewed literature, we’re reduced to the following two statements:
Working memory, for example, peaks at age twenty-five for most people, stays steady until thirty-five, then begins its long slow journey into the night.
Episodic memory peaks five years earlier than working memory, then takes the same slow slog as its working cousin.
Contrast these findings with data showing overall vocabulary scores don’t peak until you reach your sixty-eighth birthday. That may sound positive, but on closer inspection may also sound contradictory. How can that possibly be—especially when your Tip of the Tongue exasperations become annoyingly noticeable soon after you turn twenty-five? You appear to have a Cadillac database for vocabulary, but your ability to access it seems to corrode to a Model T.
Will these puzzles be solved if we pop open the hood of an ageing brain and peer inside its whirring retrieval gadgetry? They might—and so we will boldly go where neuroscientists have gone before. To get some help, we’re going to enlist an officer of the USS Enterprise, its legendary skipper, Captain James T. Kirk, and a battle he once fought with something named a Gorn. No kidding.
By hook or by crook
The Gorn was a reptilian alien in a really cheesy costume, starring in a Star Trek episode titled “Arena.” The installment begins with Captain Kirk and the Gorn, previously locked in a space fight over territorial rights, who are suddenly whisked to an alien planet by some advanced race. This race strips Gorn and Kirk of their fancy-schmancy space weapons, then forces them to work out their differences by fighting a duel with just their hands and wits.
Of course Captain Kirk is going to win. He finds, lying around the planet, the basic ingredients needed to create a crude ballistic weapon, complete with small-bore cannon (bamboo stalk), diamond-like projectiles, and the components of gunpowder. He fires his makeshift cannon at his reptilian competitor, severely wounds him, and then decides, Shakespearean-like, not to kill him. It was a lesson in creative workarounds, damn the photon torpedoes, with Kirk to the rescue in all his moralising glory.
(Discovery Channel’s show MythBusters tried to replicate the technology described in the episode. They found that the bamboo cannon, no matter how well reinforced, always exploded the instant it was lit. Conclusion: Kirk would have been killed no matter how his weapon was designed.)
You can quibble with the scriptwriter’s knowledge of physics, but you can’t argue with Kirk’s compensatory creativity. And that’s what our ageing brains are providing, as parts of our memory decline.
An example is syntactic processing, the ability to arrange words into cohesive sentences. Scientists investigating older people’s brains found that though the verbal skill did not change, the way the brain went about accomplishing it did.
A younger brain normally accomplishes syntactic processing by activating Broca’s speech center. The area is named for a nineteenth-century French physician (who was once denounced as a “materialist and a corruptor of youth”), Pierre-Paul Broca. It’s a garden patch of neural networks on one side of your brain, just above your left ear (in the inferior frontal cortex and posterior middle temporal gyrus, left lateralised, for you anatomy geeks). Spoken language flows from two regions there, designated BA 45 and BA 44. How do we know that? If you damage those networks, you can’t speak in grammatically correct sentences. Your language sounds like gibberish. Your speech comprehension also suffers.
Like an ageing celebrity, these networks begin to fade as the brain gets older, the neural pathways connecting separate areas of the brain slowly losing their ability to communicate with one another. This loss of connectivity often predicts loss of function. And that’s what was puzzling to researchers, because syntactic processing is well preserved in the ageing brain.
Here’s where your brain transforms into William Shatner. It grabs that bamboo shoot and improvises. It senses loss, looks around for brain regions not normally used in language, and starts parasitising their functions. Scientists have observed two such compensatory changes: First, ageing brains begin stimulating neurons on the brain’s wrong side (the right hemisphere) during language production, recruiting regions not normally associated with syntactic processing. Second, this recruiting drive extends into the prefrontal cortex, activating certain neurons also not normally associated with language. (This recruitment occurs only when the participant is also performing some task. We have no idea why.)
In addition to co-opting, the brain also reorganises the electrical relationships between the neurons remaining in the language production centers of our youth. Thus your brain appears to be starring in its own version of “Arena,” using material lying around its dusty neural corners to battle back the advances of ageing.
Captain Kirk would be proud.
The power of the new
“What’s this stuff?” a little boy demands, addressing his brother at breakfast. He’s pointing to a bowl of Life cereal. The brother shrugs, “Some cereal. Supposed to be good for you.” Neither wants to try it and they push the bowl back and forth. Suddenly one gets an idea: “Let’s get Mikey!” “Yeah,” the other continues. “He won’t eat it. He hates everything.” They shove the bowl over to their younger brother, Mikey, and watch eagerly. To their complete astonishment, Mikey digs in, relishes the experience, and enthusiastically eats more. “He likes it! Hey, Mikey!” the brother cries, amazed. The screen cuts to a shot of the product and sales pitch.
This thirty-second spot is regularly voted one of the top ten commercials of all time and was responsible for gazillions of sales for the Quaker Oats Company. Though it’s hard to believe you could make an indelible impression simply by trying something new—and taking only thirty seconds to do it—Mikey is living proof that you can.
Draw a circle around this signature idea, that trying something new can produce benefits, because it’s nearly everything science knows about how to improve ageing memory systems.
That’s right. Even though memory naturally declines (and most memory types don’t have naturally occurring neural rescuers), we’re not left hopeless. We can treat the corrosive effects of time with a one-sentence prescription: “Go back to school.”
Yes, I am putting on my stern professorial hat, thrusting my finger into the air, and demanding that your brain take up the habit of lifelong learning. Enroll in a class. Pick up a new language. Read until you can’t see anything anymore. An ageing brain is fully capable of learning new things. To keep that talent healthy, you have to plunge yourself into the deep end of learning environments every day. No exceptions. You take up Mikey’s willing spoon and swipe away the cobwebs of age-related memory decline.
Researchers even know the type of learning that’s most nutritious. It’s based on the psychological concept of “engagement,” which has two types. The first is receptive engagement, where you learn things passively, leisurely, stimulating areas of knowledge with which you are already familiar. This has been shown to improve memory in ageing populations.
Yet there’s a better way. If you want the Energiser Bunny of memory improvement, go for “productive engagement.” Here you experience a novel idea and actively, even aggressively, engage it. The best exercise is to find people with whom you do not agree and regularly argue with them. Productive engagement involves experiencing environments where you find your assumptions challenged, your perspective stretched, your prejudices confronted, your curiosity inspired. Productive engagement is one of the clearest ways to keep your memory batteries from draining.
How do we know this works? Consider research examining the effects of productive engagement on episodic memory. Researchers at the University of Texas at Dallas developed a program called the Synapse Project, which included two types of learning: receptive and productive. Seniors were exposed to one of the two conditions for fifteen hours a week, for three months. The productive-engagement group learned a demanding skill such as digital photography or quilting. The receptive group socialised. After a period of time, both styles were found to improve episodic memory—dramatically, actually—but scores for the productive learners went through the roof. In a 2014 article, lead author Denise Park wrote: “The findings suggest that sustained engagement in cognitively demanding, novel activities enhances memory function in older adulthood . . .”
She’s being modest. Episodic memory improved 600 per cent above those in the receptive group.
Episodic memory isn’t the only function that improves with aggressive learning, nor is the Synapse Project the only concept that works. Teaching other people works beautifully, too. Seniors who taught elementary schoolchildren basic skills, like literacy, library usage, or proper behaviour in a classroom, showed dramatic improvements in specific memory domains (and other cognitive functions as well). This is consistent with plenty of research demonstrating that one of the most effective ways to keep your brain sharp over a fund of knowledge is to continually teach it to others.
The results of aggressive learning are so powerful, they even reduce a senior’s probability of getting Alzheimer’s disease, a notion we’ll explore in the chapter on dementia. This simply underscores the clarity of the findings. Even if you hate everything, lift your spoon to try something new. It is one of the best experiences you can give your brain.
Saints be praised
Here’s another good thing you can give your ageing organ. It’s illustrated by a quote that is surprising, mostly because of its source: “Stupidity is also a gift of God, but one mustn’t misuse it.”
That quote was uttered by none other than Pope John Paul II (now Saint Pope John Paul II). This startled me, because I knew it was a gift his mind never opened.
I swear Pope John Paul’s brain was as big as the Vatican library. He spoke at least eight different languages fluently (accounts vary) and may have had a working knowledge of dozens more. He had a love affair with music, cutting an album called Pope John Paul II Sings at the Festival of Sacrosong, which sold enough to have actually charted (peaking at No. 126). He even hired his own musical adviser when he moved to the Vatican. He was apparently a voracious reader, too, exuding an enthusiasm for books second only to the other great secular love in his life, the outdoors. He was an accomplished hiker, kayaker, and skier, earning the moniker “Daredevil of the Tatras” (a mountain range in Poland) from his skiing buddies before he became the pope. It must have done some good, for he became the second-longest-serving pope in modern history. He died at eighty-four—full of years, controversy, and adulation.
Whether Saint John Paul knew this or not, most of his lifestyle habits were neural fertiliser, directly in line with what science knows about nurturing one’s memory, especially if performance is what you’re after.
We know, for example, that bilingual people perform significantly better on cognitive tests than monolingual controls. This includes memory, especially working memory, regardless of the age at which the language is learned. There’s a minor dose-dependent relationship: people who know three languages outscore people who know two, and both score higher than those who know only one. Fluid intelligence, a measure of creativity and problem solving, is better in bilinguals, too.
Language turns out to be a friend with many long-term benefits. Normal cognitive decline is less steep for bilinguals. Same with their risk for general dementia. The onset of dementia is delayed more than four years compared with monolinguals. These associations are robust enough to warrant a suggestion: when you collect your first Social Security check, use it as tuition to enroll in a foreign language class.
Another saintly example involves exposure to music—even for those with little prior experience outside of listening to the weekly Top 40. One experiment took musically naive seniors and exposed them to a four-month music-training program. They not only learned to play the piano but also were taught music theory and sight-reading. Tests of executive function (which includes working memory) improved dramatically. Participants were happier, as shown by quality-of-life assessments, including measures of depression and acute psychological stress. The control group for this study experienced “other leisurely activities,” ranging from computer classes to painting lessons. The results were clear: it was music that did most of the heavy cognitive lifting.
Voracious reading, another papal habit, also turns out to be good for ageing brains and, surprisingly, even better for longevity. One twelve-year study showed that if seniors read at least 3.5 hours a day, they were 17 per cent less likely to die by a certain age than controls who didn't read. Read more than that and you increase the number to 23 per cent. The reading has to be of books, long form. While reading mostly newspaper articles did something positive, the effects were smaller.
A smattering of other habits, sounding like Pope John Paul’s daily to-do list, reveals more memory-boosting treasure. Exercise (mountain climbing with the Daredevil, anyone?) is great for both short- and long-term forms of memory. So is meditating. The usual my-parents-already-told-me lifestyle habits apply here, too, like getting enough sleep, eating healthy foods, and hanging around good people. Plus something your parents didn’t know to tell you: staying away from the blue light of electronic devices.
This is where our David Attenborough Amazon River analogy is useful. Many tributaries contribute to improving the flow of our ageing memory. Taken together, the effects on cognition generally, and memory specifically, are robust enough to be a formula. The more you lift weights in the mental gym, the more you postpone your otherwise natural memory decline. We even know the rate. Every day you exercise your brain above what you do typically delays that deterioration by 0.18 years.
That’s an extraordinary thing to say. And it’s a scientific result that has the unusual luxury of being backed by heaven. Or at least by the lifestyle of one of the smartest saints to ever wear papal robes.
A private reserve
Why does such a prefrontal—and full-frontal—educational assault work so well? We think it involves something called cognitive reserve. I’d like to introduce to you eighty-two-year-old John Hetlinger, who will help us explain the concept. Hetlinger is a spry, goofy-looking old man, and—from an appearance on the show America’s Got Talent—a YouTube sensation. When the judges asked him what he did for a living, Hetlinger replied that he’d been an aerospace engineer: former program manager for a Hubble Space Telescope repair project. The judges sat openmouthed for a moment. And this was only the beginning of their collective jaws dropping to the floor.
What completely dislocated their mandibles was when Hetlinger started performing. Drums ticking out the time, Hetlinger whispered the words “Let the bodies hit the floor” with increasing intensity until he was roaring with the irrational energy of a heavy metal front man, screaming “LET THE BODIES HIT THE FLOOOOOOOOR!!!”
Perhaps channeling Black Sabbath from an earlier era, Hetlinger did a take-no-prisoners’ version of the hit song “Bodies” from the metal band Drowning Pool. He immediately got a standing ovation. Later, one of the judges asked him, “Is there a mosh pit where you work?” Hetlinger replied, laughing, “No, but there’s a lot of beer.”
I can’t think of experiences separated by more occupational light-years than an energetic heavy metal performance and repairing the Hubble telescope. And from an eighty-two-year-old! Hetlinger seemed to draw from some mysterious unseeable store of energy, enthusiasm, and humor. Brain scientists would agree, though we don’t believe it’s mysterious—or unseeable. We call Hetlinger’s store “cognitive reserve.”
Cognitive reserve was birthed from a concept called brain reserve. Brain reserve is a physical measurement involving (a) overall brain size and (b) a census of how many neurons are still available for work. Cognitive reserve measures your ability to use what brain reserve you possess. It was originally hypothesised to explain the observation that some people recover from brain injury failure quickly, and some not at all. The difference turned out to be the amount of cognitive reserve carried prior to injury. If you could increase it, you were more likely to go through life like John Hetlinger than, say, Ozzy Osbourne.
Research shows that pelting your brain with a rainstorm of productive cognitive experiences—in other words, everything we’ve talked about in this chapter—fills up the cognitive reserve cistern. You can even measure it. For every year of education experienced, cognitive decline is delayed by 0.21 years. (This rate is remarkably similar to the numbers seen delaying memory decline. How, or if, they’re related is unknown.) As lead author Mark Antoniou summarises it: “Cognitive reserve is defined as resilience to neuropathological damage of the brain, and is thought to be the result of experience-based neural changes that are a consequence of a physically and mentally stimulating lifestyle.”
Two prominent mechanisms have been proposed to explain these neural changes, each with their own peer-reviewed cheering sections.
The first has the indelible ink of “nature” stamped all over it. Some people are hardwired with a deep cognitive reserve, and are probably born with it. Such people have certain brain regions structurally different from people with poor cognitive reserve. To increase your chance of recovering from some mental injury, it would be wise to have intact neural populations in your frontal, parietal, and temporal cortices.
The second mechanism has the more washable ink of “nurture” stamped all over it. People who’ve spent a lifetime in mentally and physically demanding environments are much more efficient at using whatever brains they carry into their elder years. They’re also more neuroanatomically “nimble,” more flexibly able to create alternative neural circuitry when the originals become injured.
Given these inky prequalifications, you might predict the biological bank would deny your request for additional reserve loans once you’ve reached a certain age. That’s where you’d be wrong. It’s settled neuroscientific law that you can take up learning at any age. The only closing costs are that you have to start. Consider these reassuring words from Alzheimer’s researchers at Columbia: “Even late-stage interventions hold promise to boost cognitive reserve and thus reduce the prevalence of Alzheimer’s disease and other age-related problems.”
I’m sure Hetlinger would agree that it is never too late to learn anything. The only bodies that really need to hit the floor are the prejudiced ones saying you can’t.
SUMMARY
Remember, it’s never too late to learn—or to teach