Biological Psychology Links

By Tina Hesman Saey Sea slugs make memories with a twist. Screwing a normal nerve cell protein into a distorted shape helps slugs, and possibly people, lock in memories, new research shows. Notably, the shape change also brings a shift in the protein’s behavior, leading it to form clumps. That kind of behavior is the sort seen in prions, the misshapen, infectious proteins that cause mad cow disease, scrapie and other disorders (SN: 7/31/04, p. 67). But the new study, published February 5 in Cell, shows a possible normal function for the shape-shifting, suggesting that twists and clumps don’t necessarily make prions monsters. In one sense, prions are machines of “molecular memory,” says Yury Chernoff, a biologist at the Georgia Institute of Technology in Atlanta and editor in chief of the journal Prion. The proteins remember what happened to them — changing shapes — and then transmit that change to other proteins. “But the notion of these machines being used for cellular, and therefore organismal, memory is truly amazing,” he says. If further research shows the process works the same way in humans as it does in sea slugs, prionlike proteins might eventually be used in memory-enhancing treatments, Chernoff says. Prions have a bad reputation due to the most famous of the shape-changing proteins, called prion protein or PrP. When PrP switches from its harmless form, which is normally present in nerve cells, into a prion form, it corrupts other PrP molecules that then assemble themselves into nearly indestructible plaques known as amyloids. © Society for Science & the Public 2000 - 2010

By Emily Sohn There may be a simple way to ease the memory lapses and brain slips that typically accompany old age: Eat more blueberries. In a small study, older adults who drank a couple cups of blueberry juice a day improved their scores on a learning and memory task by 20 percent. Studies in animals have linked blueberries with brain function, but this is one of the first such studies in people. The results, while still preliminary, suggest that blueberries might just live up to their reputation as "superfoods." Among other health benefits, adding the tasty little, blue marbles to your diet could help slow the march of memory decline and possibly even prevent memories from slipping in the first place. "We're getting the first signal in humans that this might work," said Robert Krikorian, a neuropsychologist at the University of Cincinnati in Ohio. "There's so much research now suggesting that fruits and vegetables are beneficial. I don't have any qualms about recommending that people eat blueberries." The case for blueberries has been building for more than a decade. In animal studies, older individuals that consume blueberry extract improve their performance on memory tasks, sometimes to the point of being just as sharp as their younger counterparts. © 2009 Discovery Communications, LLC

Fresh research may help explain why regular exercise can improve brain power, say Cambridge scientists. The report, which was published in the Proceedings of the National Academy of Sciences, found mice which exercised performed better on memory tests. These mice also grew more new cells in a part of the brain linked to memory than those which did not exercise. The authors believe the new brain cells were behind the improvement in cognitive performance. The aim of the study, which was carried out by scientists from the Department of Experimental Psychology at the University of Cambridge and researchers at the National Institute on Aging in Baltimore, was to find out why exercise might improve brain function. Previous research had suggested that exercise helps mental performance in both people and animals. Studies had also shown that exercise increases the number of new brain cells in rodents. The new finding in this study is that mice which exercise are better able to distinguish between memories of similar things. The authors believe this is explained by the additional brain cells generated by exercise. The study was conducted on two groups of mice over a period of 105 days. The mice were trained to touch a box on a computer screen to get food pellets. One group were then allowed unlimited access to an exercise wheel. They ran over 20km (12 miles) a day on average. The control group were not able to exercise. Both groups were then repeatedly shown two boxes on a screen, one of which provided a treat when it was touched. The mice learned which box released the treat, and then the boxes were moved around. First the boxes were moved close together, which made it harder for the mice to remember which one to touch to get the food. The exercising mice did better on this task than the non-exercising mice. (C)BBC

By Sujata Gupta Always stunk at video games? Perhaps you've been cursed with a small striatum, a region of the brain involved in learning and memory. Researchers have found that college students with relatively large striatums learned how to play a challenging video game faster than their small-striatum peers. Large-striatum individuals were also better at shifting priorities from, say, shooting a target to outrunning an enemy--abilities that could translate to the real world. The game isn't exactly Halo or Assassin's Creed. Instead, Space Fortress looks a lot like the very first arcade games, with geometric shapes subbing for spaceships and buildings. "The graphics stink," admits Arthur Kramer, a psychologist at the University of Illinois, Urbana-Champaign, who designed the game in the early 1980s. Gameplay is fairly complex, however: Players must shoot down a fortress with their ship while avoiding enemies, the bad guys look a lot like the good guys, and the ship has no brakes. Over the years, researchers have used the game to study memory, motor control, and learning speed. The U.S. Air Force and the Israeli air force have even changed their training regimens based on how cadets fared as players. Recent studies have suggested that players appear to heavily utilize their striatum during gameplay. So Kramer and Kirk Erickson, a psychologist at the University of Pittsburgh in Pennsylvania, decided to investigate whether the size of the striatum alone might be responsible for these abilities. © 2010 American Association for the Advancement of Science.

Sleeping is known to help humans commit information to memory and learn skills, but now researchers say the same is true of birds. Researchers at the University of Chicago have found that sleep helps starlings remember how to perform a specific task. The birds were trained to distinguish two five-second birdsong clips using what the researchers called a "go-no go" procedure. When the "go" birdsong was played, the bird was given a food pellet if it poked its beak through a hole in its cage. When the "no go" song was played, the bird poking its beak through the hole didn't release a food pellet and caused the lights in the cage to briefly turn off. Groups of starlings were trained in the task at different times of day and tested later to see how well they learned. In all the groups, the birds' performance at the task improved after the birds slept. "We really wanted to behaviourally show that these types of sleep-dependent memory benefits are occurring in animals," said graduate study and lead author Timothy Brawn, in a statement. "What was remarkable was that the pattern here looks very similar to what we see in humans. There wasn't anything that was terribly different," . Previous studies have shown that humans can perform a learned task better after a night's sleep. Brawn and his colleagues demonstrated this in a 2008 study involving people learning to play a first-person shooter game. © CBC 2010

By Jacqueline Stenson If you’re trying to motivate yourself to get moving in the new year, here’s some added inspiration: Mounting research shows that exercise isn’t just good for the body, it’s also good for the brain — and not just the brains of older folks. While much of the research on the effects of exercise on the mind has focused on countering dementia in seniors, recent studies show that kids and young to middle-aged adults can get a brain boost as well. One large new study, for instance, found that teenage males in the best cardiovascular shape performed better on various cognitive tests at age 18 than their less fit counterparts. And those who improved their fitness levels between the ages of 15 and 18 achieved higher test scores than those who decreased their fitness during that time. What’s more, the fittest 18-year-olds were more likely to achieve both higher educational and socioeconomic status later in life, according to results published in December in the Proceedings of the National Academy of Sciences. “We cannot determine from this study alone that physical fitness causes better cognitive functioning,” says study author Georg Kuhn, a professor at the Center for Brain Repair and Rehabilitation at the University of Gothenburg in Sweden. “But taken together with other studies, we can assume that better cardiovascular fitness may optimize cognitive performance and academic achievements.” © 2010 msnbc.com

By BENEDICT CAREY That most alarming New Year’s morning question — “Uh-oh, what did I do last night?” — can seem benign compared with those that may come later, like “Uh, what exactly did I do with the last year?” Or, “Hold on — did a decade just go by?” It did. Somewhere between trigonometry and colonoscopy, someone must have hit the fast-forward button. Time may march, or ebb, or sift, or creep, but in early January it feels as if it has bolted like an angry dinner guest, leaving conversations unfinished, relationships still stuck, bad habits unbroken, goals unachieved. “I think for many people, we think about our goals, and if nothing much has happened with those then suddenly it seems like it was just yesterday that we set them,” said Gal Zauberman, an associate professor of marketing at the Wharton School of Business. Yet the sensation of passing time can be very different, Dr. Zauberman said, “depending on what you think about, and how.” In fact, scientists are not sure how the brain tracks time. One theory holds that it has a cluster of cells specialized to count off intervals of time; another that a wide array of neural processes act as an internal clock. Either way, studies find, this biological pacemaker has a poor grasp of longer intervals. Time does seem to slow to a trickle during an empty afternoon and race when the brain is engrossed in challenging work. Stimulants, including caffeine, tend to make people feel as if time is passing faster; complex jobs, like doing taxes, can seem to drag on longer than they actually do. Copyright 2010 The New York Times Company

By BARBARA STRAUCH I LOVE reading history, and the shelves in my living room are lined with fat, fact-filled books. There’s “The Hemingses of Monticello,” about the family of Thomas Jefferson’s slave mistress; there’s “House of Cards,” about the fall of Bear Stearns; there’s “Titan,” about John D. Rockefeller Sr. The problem is, as much as I’ve enjoyed these books, I don’t really remember reading any of them. Certainly I know the main points. But didn’t I, after underlining all those interesting parts, retain anything else? It’s maddening and, sorry to say, not all that unusual for a brain at middle age: I don’t just forget whole books, but movies I just saw, breakfasts I just ate, and the names, oh, the names are awful. Who are you? Brains in middle age, which, with increased life spans, now stretches from the 40s to late 60s, also get more easily distracted. Start boiling water for pasta, go answer the doorbell and — whoosh — all thoughts of boiling water disappear. Indeed, aging brains, even in the middle years, fall into what’s called the default mode, during which the mind wanders off and begin daydreaming. Given all this, the question arises, can an old brain learn, and then remember what it learns? Put another way, is this a brain that should be in school? As it happens, yes. While it’s tempting to focus on the flaws in older brains, that inducement overlooks how capable they’ve become. Over the past several years, scientists have looked deeper into how brains age and confirmed that they continue to develop through and beyond middle age. Copyright 2010 The New York Times Company

By Darold A. Treffert and Daniel D. Christensen Editor's Note: The main text of this story, originally published in the December 2005 issue of Scientific American, is being made available in light of the recent death of Kim Peek. When J. Langdon Down first described savant syndrome in 1887, coining its name and noting its association with astounding powers of memory, he cited a patient who could recite Edward Gibbon’s The Decline and Fall of the Roman Empire verbatim. Since then, in almost all cases, savant memory has been linked to a specific domain, such as music, art or mathematics. But phenomenal memory is itself the skill in a 54-year-old man named Kim Peek. His friends call him “Kim-puter.” He can, indeed, pull a fact from his mental library as fast as a search engine can mine the Internet. He read Tom Clancy’s The Hunt for Red October in one hour and 25 minutes. Four months later, when asked, he gave the name of the Russian radio operator in the book, referring to the page describing the character and quoting several passages verbatim. Kim began memorizing books at the age of 18 months, as they were read to him. He has learned 9,000 books by heart so far. He reads a page in eight to 10 seconds and places the memorized book upside down on the shelf to signify that it is now on his mental “hard drive.” Kim’s memory extends to at least 15 interests—among them, world and American history, sports, movies, geography, space programs, actors and actresses, the Bible, church history, literature, Shakespeare and classical music. He knows all the area codes and zip codes in the U.S., together with the television stations serving those locales. He learns the maps in the front of phone books and can provide Yahoo-like travel directions within any major U.S. city or between any pair of them. He can identify hundreds of classical compositions, tell when and where each was composed and first performed, give the name of the composer and many biographical details, and even discuss the formal and tonal components of the music. Most intriguing of all, he appears to be developing a new skill in middle life. Whereas before he could merely talk about music, for the past two years he has been learning to play it. © 1996-2009 Scientific American Inc.

By Philip Yam The man who could recite whole books by heart but could not button his own shirt has died. Kim Peek, born November 11, 1951 (on a Sunday, he will tell you) passed away last weekend from a heart attack. The inspiration for Dustin Hoffman's autistic character in the movie Rain Man, Peek provided scientists with an extraordinary window into the human brain and the nature of memory. Peek suffered from many developmental problems--besides the inability to button up, he also walked with a sideways gait, could not handle the mundane tasks of everyday life and had trouble with abstraction: once told as a child to lower his voice, he slumped deeper into his chair to move his voice box physically lower. Yet he displayed phenomenal abilities. He memorized thousands of books, could read a page in 10 seconds or less and could recite passages verbatim after just one reading. Peek's brain had several abnormalities, the strangest being the lack of a corpus callosum, the bundle of nerve fibers that enable the left and right hemispheres of the brain to communicate with each other. Just how that abnormality may have conferred savant syndrome to Peek is not known. An absent corpus callosum is not unique, and some people lacking the structure suffer no disabilities. In savant cases, it's not clear if brain damage stimulates compensatory development in some other neural area or whether it enables otherwise latent abilities to emerge. © 1996-2009 Scientific American Inc.

By BENEDICT CAREY SAN DIEGO — On a gray Wednesday afternoon here in early December, scientists huddled around what appeared to be a two-gallon carton of frozen yogurt, its exposed top swirling with dry-ice fumes. As the square container, fixed to a moving platform, inched toward a steel blade mounted level with its surface, the group held its collective breath. The blade peeled off the top layer, rolling it up in slow motion like a slice of pale prosciutto. “Almost there,” someone said. Off came another layer, another, and another. And then there it was: a pink spot at first, now a smudge, now growing with every slice like spilled rosé on a cream carpet — a human brain. Not just any brain, either, but the one that had belonged to Henry Molaison, known worldwide as H. M., an amnesiac who collaborated on hundreds of studies of memory and died last year at age 82. (Mr. Molaison agreed to donate his brain years ago, in consultation with a relative.) “You can see why everyone’s so nervous,” said Jacopo Annese, an assistant professor of radiology at the University of California, San Diego, as he delicately removed a slice with an artist’s paintbrush and placed it in a labeled tray of saline solution. “I feel like the world is watching over my shoulder.” And so it was: thousands logged on to view the procedure via live Webcast. The dissection marked a culmination, for one thing, of H. M.’s remarkable life, and of more than a year of preparation for just this moment, orchestrated by Suzanne Corkin, a memory researcher at the Massachusetts Institute of Technology who had worked with Mr. Molaison for the last five decades of his life. Copyright 2009 The New York Times Company

By Olga Kuchment Imagine planning your schedule for the week and seeing the days on the calendar appear before you as a spiral staircase so real you feel like you could touch it. That's what it's like to have spatial-sequence synesthesia, a condition in which people perceive numbered sequences as visual patterns. Now researchers have shown that individuals with the condition have superior memories, recalling dates and historic events much better than can the average person. Spatial-sequence synesthesia is one of several types of synesthesia, neural conditions in which senses combine in unusual ways. Grapheme-color synesthetes, for example, associate letters and numbers with colors; the number six might always look red to them. In other types of synesthesia, the word "cat" may create the taste of tomato soup, or the sound of a flute may appear as a blue cloud. Recently, scientists have wondered if synesthesia--especially spatial-sequence synesthesia--might be linked to a superior ability to form memories. So psychologist Julia Simner of the University of Edinburgh in the United Kingdom tested for unusual mnemonic skills or other mental talents in 10 spatial-sequence synesthetes. Subjects had to quickly recall the dates of 120 public events occurring between 1950 and 2008, such as the year Nelson Mandela was freed from jail in South Africa (1990) or the year My Fair Lady won the Academy Award for best picture (1965). On average, non-synesthetic volunteers were off by about 8 years for each date, but the synesthetes were wrong by only about 4 years. They could also name almost twice as many events from specified years in their own lives than could the controls. "They have this subtle extra gift," says Simner. © 2009 American Association for the Advancement of Science.

By Katherine Harmon Many people living with HIV report having memory loss or other cognitive problems that can sound a lot like early-onset Alzheimer's disease. Unlike their senior counterparts, however, cognitively impaired people with HIV are often in their 40s and 50s—and the early decline can make it difficult to hold jobs and maintain personal lives. Researchers have been looking for similarities between the two diseases for years. And new findings, published online today in the journal Neurology, have confirmed a key commonality: abnormal distribution of a protein known as amyloid beta. "I really did not expect the biology of HIV cognitive dysfunction to be related to Alzheimer's," David Clifford, a professor of neurology and medicine at Washington University School of Medicine in St. Louis and lead study author, said in a prepared statement. But that is just what his team found, backing up results from smaller studies that had posited the link a few years ago. Sampling brain and spinal fluid from Alzheimer's, HIV-infected and control volunteers, researchers found that both people with HIV showing cognitive decline and people with Alzheimer's have strikingly low amounts of amyloid beta protein in their spinal fluid compared to the healthy, control volunteers and those with HIV who had normal cognitive function. (In those with Alzheimer's, amyloid beta levels dip in the spinal fluid as they increase in the brain, where it is suspected to contribute to some of the physical damage seen in post-mortem studies.) © 1996-2009 Scientific American Inc.

We are slicing the brain of the amnesic patient H.M. into giant histological sections. The whole brain specimen has been successfully frozen to -40C and will be sectioned during one continuous session that we expect will last approximately 30 hours (+ some breaks and some sleep in between). The procedure was designed for the safe collection of all tissue slices of the brain and for the acquisition of blockface images throughout the entire block. The procedure will mark the completion of Phase 1 of the project which will include ex vivo MR-imaging, blockface imaging, tissue slicing and cryogenic storage of all histological sections. We will be streaming the video live through 12.04.09

By BENEDICT CAREY SAN DIEGO — The man who could not remember has left scientists a gift that will provide insights for generations to come: his brain, now being dissected and digitally mapped in exquisite detail. The man, Henry Molaison — known during his lifetime only as H.M., to protect his privacy — lost the ability to form new memories after a brain operation in 1953, and over the next half century he became the most studied patient in brain science. He consented years ago to donate his brain for study, and last February Dr. Jacopo Annese, an assistant professor of radiology at the University of California, San Diego, traveled across the country and flew back with the brain seated next to him on Jet Blue. Just after noon on Wednesday, on the first anniversary of Mr. Molaison’s death at 82 from pulmonary complications, Dr. Annese and fellow neuroscientists began painstakingly slicing their field’s most famous organ. The two-day process will produce about 2,500 tissue samples for analysis. A computer recording each sample will produce a searchable Google Earth-like map of the brain with which scientists expect to clarify the mystery of how and where memories are created — and how they are retrieved. “Ah ha ha!” Dr. Annese said, as he watched a computer-guided blade scrape the first shaving of gray matter from Mr. Molaison’s frozen brain. “One down, 2,499 more to go.” Dr. Annese carefully dropped the shaving into fluid. The procedure is being shown live online: thebrainobservatory.ucsd.edu/hm_live.php. Copyright 2009 The New York Times Company

By BENEDICT CAREY If a friend is someone who laughs at our stories, then a good friend is one who enjoys them even the second time around. But anyone who gasps with delight on hearing a story for the third time is faking it. Or, it’s a relative: some poor nephew Will or aunt Emily, sitting captive at the holiday table, being polite, perhaps covering a shudder of dread that life is caught in some endless loop where the punch lines never change. It is not an entirely irrational fear, either, according to new research published in the journal Psychological Science. “You hear people of all ages, not just elderly people, say, ‘Stop me if I’ve told you this before,’ ” said Nigel Gopie, a postdoctoral fellow at the Rotman Research Institute, in Toronto, who has a paper in the current issue of the journal on these memory lapses. “We often have a hard time remembering who we told things to, and clearly it starts early.” In their long study of memory, psychologists have made important distinctions between the short-term and long-term varieties. They have documented crucial differences between explicit memories, like for faces and vocabulary, and the implicit kind, like for driving skills. They have published hundreds of studies on autobiographical memory, false memories and so-called source memory — the ability to recall where a fact was learned, whether from the radio or a book, from a work colleague or the neighborhood gossip. Copyright 2009 The New York Times Company

By R. Douglas Fields Practice makes perfect, but how? Two groups of neuroscientists using MRI brain imaging announced last month that they were able to see changes inside the brains of people after mastering a new skill. The big surprise is that the part of the brain that changed has no neurons or synapses in it! The cerebral remodeling during learning was seen in the mysterious and still largely unexplored “white matter” region of the brain. “Grey matter” is synonymous with smarts, but in fact only half of the human brain is grey matter. White matter, the “other brain tissue”, is rarely mentioned. Neurons in the cerebral cortex are packed into in the top layers of the brain, where they are connected together through synapses. Learning takes place in the grey matter by linking neurons together into new circuits by strengthening synapses or forming new ones. But beneath the topsoil of the brain lies a dense network of fibers packed into a spaghetti-like snarl that is so complicated it is difficult to study or comprehend. These fibers are the wire-like axons projecting out from neurons in grey matter that transmit electrical impulses. Like buried telephone lines, these tightly bundled cables transmit information over long distances to communicate between distant regions of the cerebral cortex that are specialized to carry out different aspects of a complex cognitive function. © 1996-2009 Scientific American Inc.

By PAM BELLUCK Science has never given much credence to claims that you can learn French or Chinese by having the instruction CDs play while you sleep. If any learning happens that way, most scientists say, the language lesson is probably waking the sleeper up, not causing nouns and verbs to seep into a sound-asleep mind. But a new study about a different kind of audio approach during sleep gives insight into how the sleeping brain works, and might eventually come in handy to people studying a language, cramming for a test or memorizing lines in a play. Scientists at Northwestern University report that playing specific sounds while people slept helped them remember more of what they had learned before they fell sleep, to the point where memories of individual facts were enhanced. In a study published online Thursday by the journal Science, researchers taught people to move 50 pictures to their correct locations on a computer screen. Each picture was accompanied by a related sound — meow for a cat, whirring for a helicopter, for example. Then, 12 subjects took a nap, during which 25 of the sounds were played along with white noise as they slept. When they awoke, none realized that the sounds had been played or could guess which ones had been used. Yet, almost all remembered more precisely the computer locations of the pictures associated with the 25 sounds that had been played while they slept, doing less well placing the other 25 pictures. Copyright 2009 The New York Times Company

Frequent use of ketamine - a drug popular with clubbers - is being linked with memory problems, researchers say. The University College London team carried out a range of memory and psychological tests on 120 people. They found frequent users performed poorly on skills such as recalling names, conversations and patterns. Previous studies said the drug might cause kidney and bladder damage. The London team and charity Drugscope said users should be aware of the risks. Ketamine - or Special K as it has been dubbed - acts as a stimulant and induces hallucinations. It has been increasing in popularity, particularly as an alternative to ecstasy among clubbers, as the price has fallen over recent years. A gram now costs about £20 - half the price of cocaine. In response, the drug was made illegal three years ago - it is currently graded class C - although it still remains legal for use as an anaesthetic and a horse tranquiliser. The study split the participants into five groups - those using the drug each day, recreational users who took the drug once or twice a month, former users, those who used other drugs and people who did not take any drugs. All of the people took part in a series of memory tests as well as completing questionnaires and were then followed up a year later, the Addiction journal reported. Researchers found the frequent users group performed significantly worse on the memory tests - in some they made twice as many errors. The study also showed performance worsened over the course of the year. There was no significant difference between the other groups. However, all groups of ketamine users showed evidence of unusual beliefs or mild delusions, such as conspiracy theories, the psychological questionnaires showed. (C)BBC

By Kay Lazar The word teasers flashing on his computer screen seemed tuned to his personal abilities. And the accompanying voice track prodded or consoled - “it actually congratulates you,’’ he said - based on his answers. Now, the 92-year-old former management executive, an engineer by training and crossword puzzler by hobby, is scheduling computer time for fellow residents at the Fox Hill Village retirement community in Westwood. The facility just purchased a couple of these newfangled brain games and residents are lining up for 20-minute sessions. The products are spreading like kudzu through retirement communities and senior centers, as older Americans search for ways to stay mentally sharp. Researchers, however, have yet to determine whether these brain games, targeted to seniors and now an $80 million-a-year market, deliver what they promise. “The jury is still very much out,’’ said Peter Snyder, a brain researcher at Brown University’s Alpert Medical School, who analyzed 10 studies on the issue and came away unimpressed by the quality and quantity of research. In an article published earlier this year in the journal Alzheimer’s & Dementia, Snyder concluded there was no evidence the products, typically computer software costing several hundred to a couple of thousand dollars, stave off dementia in healthy elders. Snyder did not delve into the effect of brain exercises on adults who already have cognitive impairments. © 2009 NY Times Co

Chapters 17-18. Learning and Memory