To Improve Memory, Tune It Like an Orchestra

To Improve Memory, Tune It Like an Orchestra

Anyone above a certain age who has drawn a blank on the name of a favorite uncle, a friend’s phone number or the location of a house key understands how fragile memory is. Its speed and accuracy begin to slip in one’s 20s and keep slipping. This is particularly true for working memory, the mental sketch pad that holds numbers, names and other facts temporarily in mind, allowing decisions to be made throughout the day.

On Monday, scientists reported that brief sessions of specialized brain stimulation could reverse this steady decline in working memory, at least temporarily. The stimulation targeted key regions in the brain and synchronized neural circuits in those areas, effectively tuning them to one another, as an orchestra conductor might tune the wind section to the strings.

The findings, reported in the journal Nature Neuroscience, provide the strongest support yet for a method called transcranial alternating current stimulation, or tACS, as a potential therapy for memory deficits, whether from age-related decline, brain injury or, perhaps, creeping dementia.

In recent years, neuroscientists have shown that memory calls on a widely distributed network in the brain, and it coordinates those interactions through slow-frequency, thrumming rhythms called theta waves, akin to the pulsing songs shared among humpback whales. The tACS technology is thought to enable clearer communication by tuning distant circuits to one another.

The tACS approach is appealing for several reasons, perhaps most of all because it is noninvasive; unlike other forms of memory support, it involves no implant, which requires brain surgery. The stimulation passes through the skull with little sensation. Still, a widely available therapy is likely years away, as the risks and benefits are not fully understood, experts said.

“This study suggests that age-related impairment in one particular form of short-term memory largely reflects a failure of synchronization,” said Michael Kahana, a brain scientist at the University of Pennsylvania who was not involved in the research. If the technique can boost other forms of memory, “it could be a game changer for the treatment of age-related memory decline and possibly even dementia,” Dr. Kahana said.

In the new study, Robert M.G. Reinhart and John A. Nguyen, neuroscientists at Boston University, invited two groups of subjects, young adults and people in their 60s and 70s, to the lab for baseline measures of their neural firing rhythms. The scientists tailored the tACS program to optimize rhythmic “coupling” between frontal and temporal cortex areas in each individual’s brain. These brain regions specifically support working memory.

After 25 minutes of gentle stimulation, delivered by electrodes built into a skullcap, the older subjects performed just as well on memory tests as young adults.

The participants tested their own working memories repeatedly, completing 10 sessions on a computer-based program that mimicked the old Highlights magazine game: stare at an image, then decide if subsequent images are identical or have subtle differences.

They performed under several conditions, including without stimulation; with “sham” stimulation, as a placebo control, and with the targeted tACS. The results were striking. Young people reliably outperformed their elders in the no-stimulation and sham conditions. But with the aid of the tACS, the older participants did just as well as their younger counterparts. And their working memory remained sharp for as long as the researchers continued testing it, for 50 minutes.

“We show here that working-memory decline in people in their 60s and 70s is due to brain circuits becoming uncoupled, or disconnected,” said Dr. Reinhart, in a call with reporters. He added that the findings “show us that negative, age-related changes in working memory are not unchangeable. We can bring back the superior function you had when you were much younger.”

The tACS tuning prompted greater improvements in older people than in younger ones, the study found, which suggests that the tool is more a corrective than an enhancer of memory. In another experiment, Dr. Reinhart and Dr. Nguyen found that, by using the tACS technology to decouple key brain regions, they could temporarily muddle the working memory of young participants.

The new findings come at a time when increasing numbers of people are experimenting with brain stimulation at home, placing electrodes on different areas of their skull, depending on how they’re feeling. They share tips online about how best to use stimulation when feeling depressed, or impulsive, or mentally foggy — with mixed results. Experts said that the sort of stimulation used in the new study is far from a do-it-yourself approach.

“Reinhart and Nguyen use a very complex, sophisticated system here in a very carefully controlled environment,” Bradley Voytek, a neuroscientist at the University of California, San Diego, said in an email. “Do not try this at home! This is a promising start, not a panacea for memory problems.”



This article was originally published in The New York Times. Read the original article.

Can a Person Learn While Sleeping?

Can a Person Learn While Sleeping?

For most people, the 16 hours spent awake each day are hardly enough time to get critical tasks done, let alone acquire knowledge. Yet a growing number of neuroscientists believe that sleep not only helps cement memories, but is actually a time to learn something new—even a foreign language.

Sanam Hafeez, a clinical neuropsychologist and professor at Columbia University, explains how this might be possible.

Learn This Word: Hypnopedia

Through decades of research, Dr. Hafeez says, scientists have concluded that while we’re bombarded by stimuli all day, sleep is the time when the brain filters all that information. “I think of it as a computer shuffling process: junk, junk, junk, important, junk,” she says. “As it tunes out all these distractions, the brain encodes information and decides how important a memory or a piece of information is.”

study published in 1965 using electroencephalograms (EEGs) showed that hypnopedia, or sleep-learning, was a real thing. In that and later studies, researchers showed that during certain cycles of sleep that don’t include dreaming, the hippocampus—the primary area of the brain related to memory and learning, as well as in the retrieval of new learning—is activated.

This happens, Dr. Hafeez says, through “neural oscillatory activity,” or the up-and-down of wakefulness that occurs during Stage 2 non-REM sleep, when the heart rate slows and body temperature drops. The “up-down” moments of neural activity, called sleep spindles, last half a second to two seconds and have been shown to play an essential role in sensory processing and long-term consolidation of memory.

“The up spindles of wakefulness help the brain communicate across different areas, transferring data to the correct part of the brain,” she says. Another way to look at it, she says, is the “up” phase is akin to the brain coming up for air for a split second and filing information in the appropriate place for later recall.

‘Guga’ Means ‘Elephant’

In a recent study by researchers at the University of Zurich published in the scientific journal Cerebral Cortex, 68 German students were asked to learn some new Dutch words before 11 p.m. Half the students were allowed to go to sleep while the words were played back to them. The other half stayed awake while listening to the words.

After three hours of sleep or wakefulness, the 68 students were tested on their memory of the new vocabulary at 2 a.m. Researchers found that those who had listened to the words while sleeping retained much more than those who didn’t sleep.

To ensure that the inferior performance of those who stayed awake wasn’t due to sleep deprivation, researchers used EEGs. “The results were clinically significant,” Dr. Hafeez says.

For further evidence that the “up” phase of spindles are the secret to sleep learning, Dr. Hafeez points to another study published in the journal Current Biology by researchers at the University of Bern in Switzerland.

Sleeping participants were exposed to made-up words and their translation while asleep. When the translation was replayed two to four times during the “up” state of a sleep spindle, recall was high, she says. “If they were told that ‘guga’ means ‘elephant’ while sleeping, they were able to remember that ‘guga’ was related to something big when they were awake.”

At least two other studies conditioned subjects to associate smells or sounds with new information while they were asleep. These participants retrieved that new learning when awake, without knowing that they had been exposed to new knowledge as they slept, Dr. Hafeez says.

She notes that people with schizophrenia have few sleep spindles, and women tend to have many more spindles than men, leading many neuropsychologists to infer that brain estrogen production may be important for the consolidation of memory.

Priming Your Spindles

A small industry of YouTube videos has cropped up, aiming to teach new languages that people can listen to while sleeping. Dr. Hafeez isn’t advocating for these sleep-learning language videos, but does believe that good sleep hygiene can help facilitate a higher number of spindles per night. That helps with learning and memory consolidation, both during sleep and while awake.

She recommends cutting back on caffeine by 4 p.m., exercising well before bedtime and using the bed exclusively for sleep. Then, she says, when you listen to that history podcast as you nod off at night, you just might remember a few more details about Henry VIII.



This article was originally published in The Wall Street Journal. Read the original article.

Simple Ways to Be Better at Remembering

Simple Ways to Be Better at Remembering

When the sum total of human knowledge rests an arm’s length away in each person’s pocket, why do we have to remember anything anymore?

On an average day most of us check our smartphones 47 times, and nearly double that if we’re between the ages of 18 and 24, which might explain why some of us have such a hard time processing the information we take in to form memories. Smartphones alter the way we walk, talk and think, and we’re barely keeping up.

“Everything is available through a Google search almost instantaneously, so what motive do you have to store useless info?” said Joseph LeDoux, who directs New York University’s Emotional Brain Institute.

Mr. LeDoux, whose work focuses on how the brain forms memories, said this instant-fact setup clouds our judgment on what information to filter and store. Since we’re no longer weighed down by having to retain trivial data, we are left with greater cognitive space. But how do we select what we remember?

He said there are two main kinds of memories: explicit, which are created through conscious experience, and implicit, which form when past experiences affect us, sometimes without our knowledge, as in reacting with fear in dangerous situations or getting sweaty palms when you see a dog if you were once bitten.

Memory is a fallible thing, changing over time. Recalling a long-term memory brings it back into our short-term memory, which essentially gives it new context. Memory is therefore a reconstruction, not a photographic recording, and for economic purposes, our brains — unlike computers — are forever rerecording those memories, making them far more error prone.

On top of that, we now live inside dual screens and endless browser tabs, headphones streaming music, smartphones buzzing, co-workers chatting with us on Slack — all while we should be performing the actual jobs we’re paid to be doing.

“Many people seem unaware that they might accomplish more with sustained, uninterrupted attention to one task,” said Nelson Cowan, a specialist in working memory at the University of Missouri. “It can be exhilarating to flit from one conversation to another on Facebook, but people don’t realize what’s missing in the process. It’s like having a delicious soup poured on your head. Often the people who think they’re the best at sharing attention between tasks are actually missing the most.”

Mr. LeDoux added: “The brain does have limitations to what it can process or handle.”

They’re both right, but there are still things we can do to improve our memories.

As simple as it sounds, the repetition of tasks — reading, or saying words over and over — continues to be the best method for transforming short-term memories into long-term ones. To do that, we have to retrain our minds to focus on one task at a time. Sadly, most bypass this formula because we’re already convinced we’re productive.

New connections are made in your brain when you learn. To remember what you learn, do what you probably did in your youth: Repeat words, thoughts and ideas over and over until you get them right. It’s the easiest brain game there is.

Forget cramming. It didn’t work in college, it doesn’t work now. Spaced repetition might be the best way.

Robert Bjork, the chair of U.C.L.A.’s psychology department, said that quickly stuffing facts into our brains leads us to forget them in the long term (he even filmed a YouTube video series on the subject). When you rehearse knowledge and practice it often, it sticks, research has shown. So if you can incorporate what you’re trying to remember into daily life, ideally over time, your chances of retaining it drastically improve.

But once you stop rehearsing that knowledge, the retention drops profoundly. Researchers call this the “forgetting curve.”

To get past it, space out your repetition over a few days and test the effect yourself. But be careful: Spacing out sessions or scheduling them too concurrently seem to slow gains, so find a healthy medium that works. This is a good way to effectively start tackling a new language.

Memory and focus go hand-in-hand. Dr. Cowan suggests rearranging our office setup as one way to improve focus. He believes the collaborative start-up design and open offices touted by Silicon Valley’s hoodied C.E.O.s actually make us far less productive because they create added distractions. How do you stay on task if your co-worker is piloting a drone or endlessly, and loudly, snacking just inches away

“The rebirth of the open workplace cannot be helping this situation,” Dr. Cowan said, alluding to work spaces without desks, physical barriers and privacy, but with a plethora of playthings. Yoga rooms, rock climbing and gardens can be great perks, but they can make it difficult to deliver on deadline with so much stimuli.

Multiple studies have found that procrastination leads to stress and downright kills focus. Stop engaging in useless tasks like surfing the web and just tackle whatever it is you need to work on. Then watch your focus soar and your memory improve. Dr. Cowan said both perform better when they aren’t cheating on each other pursuing so-called “life hacks.”

Minds wander constantly. For students, adding frequent tests incentivizes focus because they know they’ll be quizzed. Harvard researchers report this approach decreases daydreaming by 50 percent, improving the result.

Daniel Schacter, a psychologist and a co-author of the Harvard study who also wrote “The Seven Sins Of Memory,” said the trick is focus. For some tasks, like online surfing, divided attention sounds harmless, but when we’re behind the wheel, it’s anything but. That forgetfulness can change the course of entire lives, the most serious vulnerability of memory, he added.

Mr. Schacter suggests employing cues — visual or verbal for items like keys — to associate places and things. And our electronic devices can help remind us, everything from mobile vaccination and immunization alerts to apps like Waze that can remind you that you left your baby in the car. It can sound silly, but it’s also tragic when we fail.

“Memory is very cue dependent,” he said, referring to something he calls absent-minded memory failure. “Most say it could never happen to me, but it’s a very long list of responsible people that it has happened to. When you don’t have that cue, you can forget almost anything.”

He added: “The really tricky thing about absent-minded memory failure is it can affect almost anything if the cue is not present at the moment you need to catch a reaction.”

A simple way around that is to set reminders. Even better, combine a few of these techniques: Write your reminder on a Post-it and put it on your desk so you’re forced to repeatedly look at it over a prolonged period, incorporating the practice of spaced repetition. Build on your memory by combining these approaches. Modern life offers few guarantees, but using even one of these tips is surely an improvement.

“A lot of people are overconfident that they can handle distractions,” Mr. Schacter said. “Doing two things at once always has an effect. Be aware of the situation you’re in and understand when you let attention divide you, you’re likely to pay the price. In some situations it may not matter, but in others it could change everything.”



This article was originally published in The New York Times. Read the original article.

How Exercise May Help Keep Our Memory Sharp

How Exercise May Help Keep Our Memory Sharp

A hormone that is released during exercise may improve brain health and lessen the damage and memory loss that occur during dementia, a new study finds. The study, which was published this month in Nature Medicine, involved mice, but its findings could help to explain how, at a molecular level, exercise protects our brains and possibly preserves memory and thinking skills, even in people whose pasts are fading.

Considerable scientific evidence already demonstrates that exercise remodels brains and affects thinking. Researchers have shown in rats and mice that running ramps up the creation of new brain cells in the hippocampus, a portion of the brain devoted to memory formation and storage. Exercise also can improve the health and function of the synapses between neurons there, allowing brain cells to better communicate.

In people, epidemiological research indicates that being physically active reduces the risk for Alzheimer’s disease and other dementias and may also slow disease progression.

But many questions remain about just how exercise alters the inner workings of the brain and whether the effects are a result of changes elsewhere in the body that also happen to be good for the brain or whether the changes actually occur within the brain itself.

Those issues attracted the attention of an international consortium of scientists — some of them neuroscientists, others cell biologists — all of whom were focused on preventing, treating and understanding Alzheimer’s disease.

Those concerns had brought a hormone called irisin into their sphere of interest. Irisin, first identified in 2012 and named for Iris, the gods’ messenger in Greek mythology, is produced by muscles during exercise. The hormone jump-starts multiple biochemical reactions throughout the body, most of them related to energy metabolism.

Because Alzheimer’s disease is believed to involve, in part, changes in how brain cells use energy, the scientists reasoned that exercise might be helping to protect brains by increasing levels of irisin there.

But if so, they realized, irisin would have to exist in human brains. To see if it did, they gathered tissues from brain banks and, using sophisticated testing, found irisin there. Gene expression patterns in those tissues also suggested that much of this irisin had been created in the brain itself. Levels of the hormone were especially high in the brains of people who were free of dementia when they died, but were barely detectable in the brains of people who had died with Alzheimer’s.

Those tests, however, though interesting, could not tell scientists what role irisin might be playing in brains. So the researchers now turned to mice, some healthy and others bred to develop a rodent form of Alzheimer’s.

They infused the brains of the animals bred to have dementia with a concentrated dose of irisin. Those mice soon began to perform better on memory tests and show signs of improved synaptic health.

At the same time, they soaked the brains of the healthy animals with a substance that inhibits production of irisin and then pumped in a form of beta amyloid, a protein that clumps together to form plaques in the brains of those with Alzheimer’s. In effect, they gave the mice dementia. And, without any irisin in their brains, the once-healthy mice soon showed signs of worsening memory and poor function in the synapses between neurons in their hippocampus.

The scientists also looked inside individual neurons from healthy mice and found that, when they added irisin to the cells, gene expression changed in ways that would be expected to lessen damage from beta amyloid.

Finally and perhaps most important, the scientists had healthy mice work out, swimming for an hour almost every day for five weeks. Beforehand, some of the animals also were treated with the substance that blocks irisin production.

In the untreated animals, irisin levels in the brain blossomed during the exercise training and later, after the animals’ brains were exposed to beta amyloid, they seemed to fight off its effects, performing significantly better on memory tests than sedentary control mice that likewise had been exposed.

But the animals that had been unable to create irisin did not benefit much from exercise. After exposure to beta amyloid, they performed about as poorly on memory tests as sedentary animals with beta amyloid in their brains.

Taken as a whole, these experiments suggest that exercise may protect against dementia in part by triggering an increase in the amount of irisin in the brain, says Ottavio Arancio, a professor of pathology and cell biology at Columbia University, who conducted the research along with two dozen colleagues from the Federal University of Rio de Janeiro in Brazil, Queen’s University in Canada and other institutions.

But the experiments, although elaborate and multipronged, used mice, and so cannot tell us if exercise and irisin will work similarly in people, or how much and what types of exercise might be best for brain health. The results also do not show whether exercise and irisin can prevent Alzheimer’s, but only that they seem to allay some of the effects of the disease in mice once it begins.

The scientists involved in the study hope soon to test a pharmaceutical form of irisin as a treatment for dementia in animals and eventually people, especially those who have lost the ability to exercise, Dr. Arancio says.

But for now, he says, the overarching lesson of the study would seem to be that “if you can, go for a walk.”


This article was originally published in The New York Times. Read the original article.

Train Your Brain Like a Memory Champion

Train Your Brain Like a Memory Champion

You slide the key into the door and hear a clunk as the tumblers engage. You rotate the key, twist the doorknob and walk inside. The house is familiar, but the contents foreign. At your left, there’s a map of Minnesota, dangling precariously from the wall. You’re certain it wasn’t there this morning. Below it, you find a plush M&M candy. To the right, a dog, a shiba inu you’ve never seen before. In its mouth, a pair of your expensive socks.

And then it comes to you, 323-3607, a phone number.

If none of this makes sense, stick with us; by the end of this piece you’ll be using the same techniques to memorize just about anything you’ve ever wanted to remember.

The “memory athlete” Munkhshur Narmandakh once employed a similar combination of mnemonics to commit more than 6,000 binary digits to memory in just 30 minutes. Alex Mullen, a three-time World Memory Champion, used them to memorize the order of a deck of cards in just 15 seconds, a record at the time. It was later broken by Shijir-Erdene Bat-Enkh, who did it in 12.

We’re going to aim lower, applying these strategies to real-world scenarios, like remembering the things we often forget at dinner parties or work-related mixers.

At the start of this piece, we employed two mnemonic strategies to remember the seven digits of a phone number. The first, called the “Major System,” was developed in 1648 by historian Johann Winkelmann.

In his book “Moonwalking With Einstein,” the author Joshua Foer described this system as a simple cipher that transforms numbers to letters or phonetic sounds. From there we can craft words and, ultimately, images. Some will, no doubt, be crude or enigmatic. Others may contain misspellings and factual errors. It doesn’t matter. This system is designed to create rich imagery, not accurate representations.


The number 19, for example, is TP, TB, DP, or DB. From those two letter combinations, there are a host of visuals we can come up with to match words like toilet paper, tuberculosis, DPepper, or dubstep. Our visuals followed the same logic. MN/Minnesota (32), MM/M&M (33), SH/shiba inu (6), SK/socks (07).

One could argue that, on its own, the Major System is as complicated as just remembering the seven digit phone number, or perhaps more than. That’s why you’ll often see memory athletes combine the system with another mnemonic, like the “method of loci,” or MoL.

The method was first developed in ancient Greece, but popularized in “The Art of Memory,” by Frances A. Yates, in 1966. Also called a “memory palace,” MoL involves placing items throughout a familiar place. In this case, your home. Mr. Foer in his book suggested walking through the front door and then letting your eyes gaze from left to right, top to bottom. In our example, we started with a map, placed a plush figure below it, and then a dog with a pair of socks in its mouth.

Seven digits, though, is child’s play. Gary Shang once used MoL to memorize pi to 65,536 digits.

In an evolutionary sense, our memory hasn’t quite become a powerhouse for nonvisual information. Early hominids had little need to remember dates or phone numbers. They did, however, require an acute sense of what times of the year were best to plant crops, what flora were edible, and when they might need to pack up and move to keep pace with nomadic food sources.

“From an evolutionary prioritization perspective, I think most of this comes down to gating mechanisms we have in place for denoting and ‘tagging’ incoming stimuli as important for the continuation of our existence,” Nicco Reggente, Ph.D., a cognitive neuroscientist at the Tiny Blue Dot Foundation, said.

Even today, sensory representations drive memory in ways mere memorization can’t touch. Dr. Reggente explained that this is best seen in the hippocampus, a part of the brain that originally evolved to support movement. “In order for this movement to be purposeful, it must be guided via prediction,” he said. “It is the same region that is now, in our modern age, repurposed for non-spatial (non-movement based) memories as well.”

It’s why visual mnemonics, like MoL, are so effective; we’re piggybacking on a cognitive system that was fine-tuned over millions of years to work best with visual and spatial representation. “Visualization is typically beneficial due to its translation of the abstract form of the object (or concept) into a spatial medium,” Dr. Reggente said.

Names are actually best remembered by focusing on the text as it’s spoken and then using it immediately. “The most useful trick isn’t a trick at all,” Mr. Mullen, the memory champion, noted. “It’s focus.”

As mnemonics go, all the experts we spoke with suggested the same technique for remembering names. It involves singling out a particular trait of the person you’re speaking with. For Mr. Mullen, in a made-up example, that was hair color. The trait most noticeable about “Karen” was her orange hair, about the same shade as a carrot. He’d then imagine Karen with carrots for hair, perhaps munching on them as they spoke.

In the psychology world, there’s a strange example of how these tricks work, called the “Baker/baker paradox.” After showing subjects the same photograph of a man’s face, the researchers tell half the participants his surname, Baker, and the other half his occupation, a baker. Days later, the subjects were more likely to remember the man’s occupation than his name. This plays to the sensory nature of memory. Upon hearing the man was a baker, the brain immediately springs into action, creating or recalling vast neural networks of what we’ve associated with the title: fresh bread, a white hat and apron, or perhaps someone standing in front of a patisserie, greeting children with delicious sweets.

When incomplete, this sensation is also responsible for the tip of your tongue feeling where you can’t quite recall a memory. According to Mr. Foer: “It’s likely because we’re accessing only part of the neural network that ‘contains’ the idea, but not all of it.”

For competitors, the Major System, often in conjunction with the memory palace, is the most common way to remember hundreds, or even thousands, of numbers.

In our example, a phone number, it may have been overkill. A more useful trick is a simple one, called chunking, you’ve been using for years without even realizing.

Phone numbers, for example, come pre-chunked. We don’t write, or recite, phone numbers as a single digit. 3419108550 is more manageable when written, or recited, as 341-910-8550. Credit card numbers are also chunked, as is your Social Security number.

Mr. Foer detailed an acquaintance that had never formally been taught to chunk information, but used the technique to remember numbers by associating them with his hobby, running. “For example, 3,492 was turned into ‘3 minutes and 49 point 2 seconds, [a] near world-record mile time.’” For most of us, this is probably no easier than remembering the number itself. But for a runner, it’s a different story.

Or, it’s possible to use the Major System to remember smaller number combinations, even without placing visual representations inside a memory palace, as we did above. The phone number 341-910-8550, for example, becomes “MRT PTS FLLS” after consulting the chart. For me, the oddest, most memorable phrase, as Mr. Foer suggested using, is “Mr. T pities fools.” Granted, it’s misspelled, but the image is highly memorable.

In training like a memory champion, it’s really the visual that’s most important. Each technique we covered capitalizes on the ability to visualize memories rather than simply attempting to recall them. This, as our team of experts notes, is an exercise in futility.

There’s nothing, physiologically speaking, separating memory athletes from people who forget where their keys are or can’t remember what they had for breakfast this morning. The difference is in the training methods, and the time spent in mastering them.

“Overall, I’d say you definitely don’t need to be a savant to have a great memory,” Mr. Mullen said. “If you’re sincerely engaged with a few tricks up your sleeve, you might surprise yourself.”



This article was originally published in The New York Times. Read the original article.