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September 4, 2012

Amazing Memory

memory brain

Memory is a collaborative effort within the brain. Image courtesy of Flickr user alles-schlumpf

At last count, at least 33 people in the world could tell you what they ate for breakfast, lunch and dinner, on February 20, 1998. Or who they talked to on October 28, 1986. Pick any date and they can pull from their memory the most prosaic details of that thin slice of their personal history.

Others, no doubt, have this remarkable ability, but so far only those 33 have been confirmed by scientific research. The most famous is probably actress Marilu Henner, who showed off her stunning recall of autobiographical minutiae on “60 Minutes” a few years ago.

What makes this condition, known as hyperthymesia, so fascinating is that it’s so selective. These are not savants who can rattle off long strings of numbers, Rainman-style, or effortlessly retrieve tidbits from a deep vault of historical facts. In fact, they generally perform no better on standard memory tests than the rest of us.

Nope, only in the recollection of the days of their lives are they exceptional.

Obsessing over details

How does science explain it? Well, the research is still a bit limited, but recently scientists at the University of California at Irvine, published a report on 11 people with superior autobiographical memory. They found, not surprisingly, that their brains are different. They had stronger “white matter” connections between their mid and forebrains, when compared with the control subjects. Also, the region of the brain often associated with Obsessive-Compulsive Disorder (OCD), was larger than normal.

In line with that discovery, the researchers determined that the study’s subjects were more likely than usual to have OCD tendencies. Many were collectors–of magazines, shoes, videos, stamps, postcards–the type of collectors who keep intricately detailed catalogs of their prized possessions.

The scientists are wary, as yet, of drawing any conclusions. They don’t know how much, or even if that behavior is directly related to a person’s autobiographical memory. But they’re anxious to see where this leads and what it might teach them about how memory works.

Is it all about how brain structures communicate? Is it genetic? Is it molecular? To follow the clues, they’re analyzing at least another three dozen people who also seem to have the uncanny ability to retrieve their pasts in precisely-drawn scenes.

Why our stories change

What about the rest of us? Our personal memories are much more erratic, some powerfully vivid, most frustratingly murky. And fluid.

That’s right, fluid. We like to believe that memories, once created, are like data filed away, constant and enduring. The challenge, we think, is in retrieving the uncorrupted files.

But recent research suggests that memory doesn’t work like that. Personal memories are more like mental reconstructions where the original details are contorted, at least to some degree, by who we are today.

Science writer Charles Fernyhough, author of the new book, Pieces of Light: The New Science of Memory, offered this explanation in The Guardian:

“When we look at how memories are constructed by the brain, the unreliability of memory makes perfect sense. In storyboarding an autobiographical memory, the brain combines fragments of sensory memory with a more abstract knowledge about events, and reassembles them according to the demands of the present.”

Recalling a memory, in fact, appears to be a collaborative effort of different parts of our brains. It also seems to be strengthened and modified each time it’s retrieved. Scientists have a term for this–reconsolidation. And they’ve found that a memory is not only a reflection of the original event, but also a product of each time you call it up. So memories, it turns out, aren’t fixed; they’re dynamic, reshaped by our current emotions and beliefs.

And that’s not a bad thing. As Fernyhough posits, the purpose of memory is about adapting and looking into the future as much as into the past. “There is only a limited evolutionary advantage in being able to reminisce about what happened to you,” he writes, “but there is a huge payoff in being able to use that information to work out what is going to happen next.”

The good and the bad

According to recent research, here are a few of the things that are good or bad for your memory:

  • GOOD: Green tea: A study published in the European Journal of Clinical Nutrition concludes that green tea seems to activate the part of the brain associated with working memory.
  • BAD: Junk food: Research at Brown University led scientists to conclude that a diet heavy in junk food can stop brain cells from responding properly to insulin and and that can hinder one’s ability to create new memories.
  • GOOD: Frequent exercise: According to a study at Dartmouth University, exercise generally enhances the ability to remember. People in the study who exercised regularly improved their memory test scores, and this was particularly true for those who exercised the day they re-took the test.
  • BAD: Frequent eating: A study published in a recent issue of Neurology warned that people over 50 who are obese are more likely to lose memory and cognitive skills during the next decade than their fitter counterparts.
  • GOOD: Piano tuning: A team of British scientists discovered highly specific changes in the hippocampus–which affects memory– within the brains of professional piano tuners. They suggested that the act of playing and listening closely to two notes played simultaneously as they tuned pianos helped make their brains more adaptive.
  • BAD: Working near MRI scanners: Research by Dutch scientists suggests that people with frequent exposure to the magnetic fields used to create MRI images may be at greater risk of diminished working memory.

Video bonus: See what researchers learned about memory from the brains of London taxi drivers.

More from Smithsonian.com

How Our Brains Make Memories

The Brain Is Full of Surprises




August 17, 2012

Brain Science: 10 New Studies That Get Inside Your Head

brains research neuroscience

Brain research is now part of the daily news. Image courtesy of National Institute of Mental Health

We know so much more about our brains than we once did. Some would suggest too much.

Because neuroscience, once a subject confined to academia and research labs, now belongs to all of us. Every day, it seems, there’s a story in the mainstream media about a study providing fresh insights on how our brain functions or what we do to make it perform better or worse. Scientists can caution all they want that this is a maddeningly complex subject, but in our search to understand why we do the things we do, we more often look for overly simple answers deep inside our heads.

So we tend to take quite seriously any neurological evidence that would seem to explain behavior. Just yesterday, in fact, the journal Science published a study which found that judges–not juries, but judges–presented with a hypothetical case gave lighter sentences to a man convicted of a vicious beating if his file included a statement from a neurobiologist that he had a genetic predisposition to violent behavior.

Most neuroscientists aren’t happy that brain scans are now routinely used to help convicted murderers try to avoid death sentences. The science isn’t that clearcut, they’ll argue. And they’re right.

But the more we learn about the brain, the more captivated we become. This is where science gets personal, where it helps us make sense of ourselves. These days you don’t hear many people say, “The devil made me do it.” More likely they’ll blame their amygdala.

Brain salad

To get a sense of how much brain science is weaving into our daily lives, here are 10 studies published in just the past month:

1) Never gonna give you up: A new study suggests that hoarding is a brain disorder all its own. It long had been characterized as a variant of obsessive compulsive disorder (OCD). But no more. When hoarders in the study were asked to keep or destroy an object belonging to them–in this case junk mail–the region of their brains associated with decision-making became unusually active. That’s a different part of the brain than what’s usually activated with OCD.

2) Send grandpa a vat of chocolate: Here’s yet another reason chocolate is awesome. Italian researchers have found that a cocoa drink rich in flavanols–the antidioxidants found in chocolate–can help sharpen the brains of people with memory problems. The antidioxidants are believed to protect brain cells and improve blood flow.

3) But make sure he lays off the microwave popcorn: According to another study, this one at the University of Minnesota, the chemical that provides the fake butter taste in microwave popcorn may actually speed up the mental decline of Alzheimer’s disease. The chemical, diacetyl, can lead to the same kind of clumping of beta-amyloid proteins in the brain that causes Alzheimer’s.

4) Why the nose is king of the face: When you have a bad head cold or allergy and your nose is stuffed up, your brain kicks into gear to make sure your sense of smell snaps back to normal as soon as your health does. The brain isn’t able to do that with other senses–when sight is lost temporarily, for instance, it takes much longer for it to be restored.

5) Teenage wasteland: New research concludes brain scans may help predict if a teenager will become a problem drinker. Experts say the findings suggest that heavy drinking may affect young people’s brains right at the time when they need to be working efficiently.

6) And while we’re on the bottle: Alcoholism apparently affects women’s brains differently than it does men’s. A team of researchers in Boston found that heavy drinking over a number of years destroys white brain matter in a different part of the brain for women than it does for men. They also found that women’s brains recover more quickly when they quit drinking than men’s do.

7) Pep talk is cheap: No matter how good your intentions may be, you won’t necessarily help someone by giving him or her encouragement before they make a big decision. In fact, according to a study at Queen Mary University in London, when people received either positive or negative feedback about their performance on complex decision-making tasks, they made worse decisions. Put simply, it’s too much information for their brain to process under stress. So just keep quiet.

8) Thinking small: New research has confirmed that stress and depression actually makes your brain smaller. Yale scientists found that deactivation of a single genetic switch can instigate a cascading loss of brain connections and that’s more likely to happen in brains of depressed people.

9) At last, something good about migraines: As painful and debilitating as they can be, migraines do not cause the kind of cognitive decline that often leads to dementia or Alzheimer’s. That’s according to a new study at Brigham and Women’s Hospital in Boston, which gathered data gathered from more than 6,300 women.

10) Who knew brains packed a punch?: And finally, research suggests that the punching power of karate black belts has more to do with how their brain functions than how strong their bodies are. The key, says scientists at Imperial College London, is the fine tuning of neural connections in the cerebellum, allowing them to synchronize their arm and trunk movements more precisely.

Video bonus: Dr. Charles Limb is a surgeon. He’s also a musician. So it probably was inevitable that he wanted to find out how the brain works during improvisation. He shares what he learned about the science of creativity in this TED talk.

More on Smithsonian.com

The Allure of Brain Scans

Building a Human Brain




July 19, 2012

An Answer for Alzheimer’s?

alzheimer's disease brain

What a deteriorating brain looks like. Image courtesy of National Institute on Aging

It’s been called the holy grail of medical research, a discovery that could profoundly change what it means to grow old. The personal costs of Alzheimer’s disease to its victims, and the family and friends who have to watch its insidious assault on their loved ones, is enormous.

The financial costs are equally staggering. The cost of caring for the more than 5 million Americans with Alzheimer’s–there are 35 million worldwide–already is estimated to be $200 billion a year. By 2050, it’s expected to top a trillion dollars.

But the search for a treatment that cures Alzheimer’s, or even slows it down, has not gone well. Over the past 20 years drug companies have seen one trial after another end in failure. Nothing, it seemed, could kill the beast. Two more big studies of new drugs–one developed by Pfizer and Johnson & Johnson, the other by Lilly–will be completed this fall. And while the drugmakers hope that this time they’ve found an answer, there’s been much speculation that if they haven’t, they may throw in the towel.

Earlier this week, though, thousands of the world’s leading Alzheimer’s researchers and experts at an international conference in Vancouver, heard some heartening news for a change. A cure for Alzheimer’s remains as elusive as ever, but scientists seem to be making headway in slowing down the horrific mental deterioration that makes the disease so terrifying.

In one study, for instance, researchers were able to stabilize the conditions of four Alzheimer’s patients for three years. That may not sound like much–only 16 people were in the study–but any indication that the downward spiral could be stopped offers no small promise. The four patients who didn’t decline mentally were the only ones in the study who received the same dosage of the same drug–an intravenous immune system treatment called Gammagard–for all three years.

Whether or not this turns out to be another splash of false hope won’t be known until a larger trial is completed next year. And even if the results are positive, plenty of challenges would remain, including the cost. In its current form, Gammagard, created by Baxter International, costs between $3,000 and $6,000 a month.

Preventive medicine?

While the Gammagard research involves patients already reflecting the effects of Alzheimer’s, another proposed study, announced at the conference, would focus on people who are showing no symptoms, but who have an abnormal protein in their brains believed to be an indicator of the disease.

Most Alzheimer’s experts now believe the reason attempts to fight it with drugs haven’t succeeded is that they’ve been started too late. It’s thought that more than 50 percent of critical brain cells are already lost by the time a patient displays even mild cognitive impairment.

So the key may be to battle the disease long before it makes its presence known. In fact, according to an Alzheimer’s timeline developed at Washington University Medical School in St. Louis, the first effects can be detected in the body 25 years before the onset of cognitive decline.

To see if drugs can be more effective on people who haven’t yet been formally diagnosed with Alzheimer’s, the planned study will involve 1,000 people over the age of 70 who have buildup of amyloid beta plaques in their brains but have shown only a minor loss of cognitive skills.

Half of the participants will be given a still-to-be-determined drug, the other half a placebo. They also will be provided with counseling to reassure them that having amyloid in their brains doesn’t guarantee that they’ll develop Alzheimer’s. The Boston scientists who would do the research won’t know until this fall if they’ll receive the federal funding they need.

A low risk mutation

Just before the conference, there was more positive news. A study published a week ago in the journal Nature by a team of Icelandic researchers identified a genetic mutation that greatly reduces a person’s risk of getting Alzheimer’s.

The scientists found that people with the mutation, which is very rare, produced about 40 percent less of the proteins that become the amyloid plaques linked to Alzheimer’s and other memory loss. For some researchers, this confirms that plaques are the culprit. Rudolph Tanzi, of Harvard Medical School and a scientist who helped discover the gene mutation, thinks a path has been drawn.

He believes researchers need to attack amyloid plaques as aggressively as heart disease experts have gone after high cholesterol.

“We’ve got to have that same focus with Alzheimer’s disease,” he told NPR, “and I’m hoping that this paper will galvanize us to say, ‘OK, this is our target.”

Cause and effects

Here’s more that recent research has learned about Alzheimer’s:

  • Both too little and too much sleep can raise your risk of Alzheimer’s. A study of 15,000 women 70 or older had worse brain functioning if they typically slept five hours or nine hours a night than women who averaged seven hours a night.The researchers also discovered that if the amount of time a woman slept changed by two or more hours per day as she progressed from mid-life to old age, her brain functioning deteriorated more than those who didn’t change their sleep patterns.
  • So does binge drinking. People 65 and over who say they binge drink at least twice a month are two and a half times more likely to suffer cognitive declines than those who don’t drink that much. Binge drinking, as defined for this research, is consuming four or more drinks on one occasion.
  • If your walk is slower, so’s your brain. A number of studies presented at the conference concluded that an older person’s slowing gait can reflect a parallel decline in memory and thinking skills.
  • Pumping iron can help stave off dementia. While all exercise helped women between 70 and 80 hold on to their memory and cognitive skills in several studies, those who did strength training–lifting weights or using resistance bands–seemed to benefit the most.
  • Soon you could be screened for Alzheimer’s with a blood test. Two separate reports published in the Archives of Neurology say that markers have been found in blood that distinguish those with Alzheimer’s from those who don’t have it. Currently, testing is both expensive and invasive–it involves brain scans and spinal punctures.

Video bonus: Enough with all this talk about memory loss. Take a break and watch how a “World Memory Champion” trains his brain. Be very jealous.

More from Smithsonian.com

The Race for an Alzheimer’s Miracle

Building a Human Brain




July 12, 2012

10 Ways Tech Makes Old Age Easier

technology elderly health care

Taizo the robot gets seniors to exercise. Photo courtesy of General Robotix

Yesterday the Republican-controlled House of Representatives, as it had 32 times before, voted to repeal what’s become known as Obamacare. There is no chance the Democratic Senate will follow suit.

So, until the November election, it looks like health care at the national level will pretty much live in the Land of Swirling Rhetoric and Symbolic Gestures.

This is unfortunate because it’s a slice of our future that’s pockmarked with some ugly realities. Here’s a personal favorite: Two years ago, more than 40 million people 65 years or older lived in the U.S. By mid-century, more than twice that many people–roughly 88 million–will be that old. That’s one out of every five Americans.

In other countries, particularly in Europe, it will be even worse, with a stunningly high percentage of their populations expected to be on the downhill side of 60. In Spain, 37 percent of the people will be that old. In Japan, it will be even higher, maybe as high as 43 percent.

No question that a whole lot more people in the world are going to need help taking care of themselves. Which is why there’s a big push now to see how much of that load can be handled by technology–from wearable sensors to helper robots.

Here are 10 tech tools that are making it easier for old folks to avoid spending their final years in nursing homes:

1) One day we will all be Kinected: Researchers at the University of Missouri are testing to see if they can use Kinect motion sensors—yes, the ones originally designed for xBox games–to monitor elderly residents in another state. This is considered less intrusive than using actual video cameras since they’d be seeing only silhouette images. The system’s already being used at an independent living facility near the Missouri campus; now, with the help of a National Science Foundation grant, the scientists are going to see how well it works in keeping in touch with old people in Cedar Falls, Iowa.

2) But there’s still no curmudgeon meter: They were introduced in Japan two years ago and now wireless sensors that attach to your chest and track heart beat, body surface temperature, stress levels and movements have a good chance of becoming a standard part of the senior wardrobe. All that data, gathered on what’s called a “human recorder system,” is then transmitted to a mobile phone or PC.

3) A bed that gets up with you: Here’s another invention from Japan, where already more than 20 percent of the population is over 65. Panasonic has developed a bed that easily converts into a wheelchair so that an elderly person can become mobile without actually having to get up out of bed. But Panasonic hasn’t stopped there. It also has created a robot that shampoos and blow-dries your hair. As yet, it doesn’t give advice.

4) Smell the virtual grapes: You can’t expect seniors to do a lot of cycling in traffic, but those trying to stay in shape by using stationary bikes can get bored pretty quickly. A study in Schenectady, New York earlier this year, though, found that elderly people not only were more likely to get back on the bike if they had virtual reality images of France or California or outer space in front of them, but also that the faux scenery kept their brains sharper.

5) The nurse is always in: It’s not exactly a magic pendant, but Nurse Alert can do a pretty decent job of protecting people. The device, which you can wear around your neck or carry in your pocket, gives you 24-hour access to nurses. There’s an emergency button that connects a person directly to a monitoring center and also a non-emergency button that patches you through to a “Nurse Triage Call Center.” Another feature can detect if the person with the pendant falls down. It automatically alerts the nurse center. If the person doesn’t respond to a nurse, emergency crews are called.

6) Robots with helper people: Now here’s a different spin on outsourcing. Willow Garage, a California robotics company, is exploring the idea of having human workers remotely help robots take care of elderly people. Called the Heaphy Project, it would involve having a person remotely control a robot using just a Web browser. Say an elderly person dropped something; the worker, who could be on the other side of the planet, would be able to see what happened through a video feed, then guide the robot to pick it up.

7) Only my phone really knows me: It wasn’t designed specifically for seniors, but a new Android-based smartphone called LifeWatch V will be able to help them let their doctors know how they’re doing between checkups. By holding his finger over sensors on the phone, a person can get an electrocardiogram reading or data on their stress levels, heart rate, body fat and temperature. The phone can also be used to help diabetics monitor their blood sugar levels. All of the info is automatically stored in the cloud and can easily be forwarded to a doctor’s office.

8) But he doesn’t do zumba: When you’re 80, you’re not looking for buff in a fitness instructor. So who cares if Taizo the robot looks like the the Michelin Man after bariatric surgery? Japan’s National Institute of Advanced Industrial Science and Technology and a spin-off called General Robotix created the small humanoid bot a few years ago to lead classes of seniors in stretching and light exercises. He can bust 30 moves.

9) Beware of cuteness overload: While we’re talking robots, you can’t leave out Kabochan, a doll-like robot that’s been a big hit with elderly folks in Japan since it went on the market late last year. It’s modeled after a three-year-old boy–one that knows 400 phrases, responds to light, sound and movement and never throws a fit. What’s not to like?

10) Your memory cheat sheet: When people talk about Google glasses, no one mentions old people. But can you imagine how much sweeter old age could be if you never had to worry about remembering a name or place or anything else? Who needs a memory when you can augment reality?

Video bonus: Here’s a demo clip of Kabochan, the little robot doll that’s become so popular among seniors in Japan. Be prepared, though, it may make you very afraid of your future.

More from Smithsonian.com

Better Sleep in the Golden Years

Robots Get the Human Touch




June 18, 2012

The Allure of Brain Scans

brain scans neuroimaging

More clues than answers? Image courtesy of the National Institute of Mental Health

Science is rarely pretty. Stunning, yes. Provocative and enlightening, of course. But pretty? Not so much.

But brain scans are a different story. Once they’ve been splashed with vibrant purples and reds and yellows, they can look downright ravishing. Makes you want you want to pat yourself on the head and say, “Stay beautiful in there.”

Alas, therein lies a problem. Not only has technology made it possible to see our brains as something they’re not–a fiesta of technicolor–but it also has made it easier to draw absurdly simple conclusions about a ridiculously complex organ.

We’re understandably desperate for a neurological Rosetta Stone, something that can help us decipher the magical call and response of electrochemical impulses inside our thick skulls. But when, with that purpose, we conjure up notions of a “love center” or “God spot” inside our brains, we insult our own intelligence.

It’s far more complex than that, particularly when it comes to such matters as spirituality. A recent study concluded that it involves not one, but many parts of the brain. But a larger issue centers on how brain scans are interpreted. As writer Vaughan Bell pointed out recently in The Guardian, false positives are a big concern, resulting in scans suggesting that parts of the brain are linked to certain activities when, in fact, other factors may be responsible. A few years ago, a Dartmouth scientist with a sense of humor made this point by reporting that scans reflected activity in the brain of a salmon shown photos of humans. He also noted that the fish was dead.

Can they predict behavior?

Most neuroscientists have become more cautious about drawing definitive conclusions about what scans show. But, as is often the case with innovative technology that captures the public’s imagination, neuroimmaging is headed in unexpected directions, spreading beyond scientific research into legal tactics and commercial ventures. In a way, it’s become the new DNA testing, science that’s seen as a nifty tool, in this case to predict or explain behavior.

Earlier this year, defense attorneys for a convicted double murderer in Mississippi submitted his brain scans in a last-minute, albeit unsuccessful, attempt to show he was mentally ill and not suitable for the death penalty. Last year the French parliament was moved to update its bioethics law so that it now reads: “Brain-imaging methods can be used only for medical or scientific research purposes or in the context of court expertise.”

Scientists were not happy about that last phrase. Many, such as Olivier Oullier, think it’s too soon to give the technology legal standing. As he wrote in the journal Nature, “Brain scientists may not be oracles, but our research, responsibly interpreted, can help policy-makers to make informed decisions. As such, it should be given the opportunity to progress. Law and science have something in common — both can be misinterpreted.”

On the flip side

That said, neuroimaging has given scientists the first real look inside the brain at work. You can’t underestimate the value of that. And it has allowed them to start making tenuous connections between blood flow to certain areas of the brain and particular behavior. But the more they learn, the more they realize that no matter what “lights up” in an image–and keep in mind, that reflects blood flow, not actual mental activity–it likely tells only part of the story.

Psychiatrists have begun using brain imaging data to try to predict who might develop neurological or psychiatric disorders. It’s a start. But as Kayt Sukel, author of Dirty Minds: How Our Brains Influence Love, Sex and Relationships, wrote recently on Big Think.com, “At best, most of these studies can only offer predictions slightly higher than chance. Better than a coin flip–but only just.”

So while they can create beautiful 3-D images of the brain in action, scientists are still working the surface, still in the realm of educated guesses. The brain, it seems, refuses to be dumbed down.

Brain puzzlers

Despite their limitations, neuroimages are helping scientists get a clearer picture of how brains function and why they malfunction. Here’s some of the latest research.

  • Think good thoughts: A study in Wales found that patients with depression could learn to control aspects of their brain activity by getting “neurofeedback” while their brains were being scanned. Scientists described to them how trying different ways of creating positive thoughts was affecting their brains, based on continuous measurements.
  • The dope on dopamine: Researchers in Germany discovered a link between low dopamine levels in the brain and aggressive behavior. It was just the opposite result from what they expected.
  • Running on empty: A University of Iowa neuroscientist says that based on MRI imaging in his research, self-control is a commodity in limited supply and that a brain can truly run out of patience.
  • Early warning system: This month doctors in southern Florida will be able to start using a new brain imaging radioactive dye that will help them detect plaques of the toxic protein that builds up in the brains of Alzheimer’s victims. It will help confirm an Alzheimer’s diagnosis and also rule it out in cases where something else might be causing memory loss. And scientists hope that these scans will help doctors spot Alzheimer’s much earlier, when there still are no symptoms and treatment can be more effective.
  • Either I need sleep or barrels of Doritos: According to a study at Columbia University using brain scans, subjects getting only four hours of sleep a night were more likely to develop cravings for junk food than those who got a full eight hours.

Video bonus: Okay, so we’ve reached the point where we’ve started to put dogs in MRI machines. Researchers at Emory University are trying to get a bead on what dogs are thinking. Good luck with that.



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