By Susan Milius A dollop of living yellow ooze has aced a test of navigation, showing that you don’t really need a mind to make spatial memories. The egg-yolk-colored slime mold Physarum polycephalum is a single cell without any nervous system. But this blob of a creature uses its slime trails as a form of external spatial memory, says complex systems biologist Chris R. Reid of the University of Sydney. Smears of goo left behind as a slime mold crawls act as records of past paths. Given a choice, slime molds won’t crawl over their old slime, Reid and his colleagues found. These simple external “memories” work quite well. When lured into a U-shaped dead-end in front of a sugar treat, slime molds were able to escape. Instead of just throbbing futilely against the closed end of the U or crawling around in circles, 39 out of 40 managed to ooze their way back out of the blind alley and creep to the treat by an outside route, Reid and his colleagues report October 8 in the Proceedings of the National Academy of Sciences. “It’s the first time any spatial memory system has been found in an organism without a brain,” Reid says. Ants, which Reid also studies, lay trails of scents as they scurry to food sources, and these scents can function as external memories of the whole colony. Ants do have brains though. © Society for Science & the Public 2000 - 2012

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17353 - Posted: 10.11.2012

By GRETCHEN REYNOLDS Can you improve your body’s ability to remember by making it move? That rather odd-seeming question stimulated researchers at the University of Copenhagen to undertake a reverberant new examination of just how the body creates specific muscle memories and what role, if any, exercise plays in the process. To do so, they first asked a group of young, healthy right-handed men to master a complicated tracking skill on a computer. Sitting before the screen with their right arm on an armrest and a controller similar to a joystick in their right hand, the men watched a red line squiggle across the screen and had to use the controller to trace the same line with a white cursor. Their aim was to remain as close to the red squiggle as possible, a task that required input from both the muscles and the mind. The men repeated the task multiple times, until the motion necessary to track the red line became ingrained, almost automatic. They were creating a short-term muscle memory. The term “muscle memory” is, of course, something of a misnomer. Muscles don’t make or store memories. They respond to signals from the brain, where the actual memories of any particular movement are formed and filed away. But muscle memory — or “motor memory,” as it is more correctly referred to among scientists — exists and can be quite potent. Learn to ride a bicycle as a youngster, abandon the pastime and, 20 years later, you’ll be able to hop on a bicycle and pedal off. Copyright 2012 The New York Times Company

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 5: The Sensorimotor System
Link ID: 17304 - Posted: 09.26.2012

By Gary Stix Market researcher SharpBrains has predicted that the brain fitness industry will range anywhere from $2 billion to $8 billion in revenues by 2015. That’s a wide swath, but the companies that sell brain-tuning software could conceivably hit at least the low end of their sales target by then. The question that persists is whether any of these games and exercises actually enhance the way your brain works, whether it be memory, problem solving or the speed with which you execute a mental task. True, study participants often get better at doing an exercise that is supposedly related to a given facet of cognition. But the ability to master a game or ace a psych test often doesn’t translate into better cognition when specific measures of intelligence are assayed later. One area of research that has shown some promise relates to a method of boosting the mental scratchpad of working memory— keeping in your head a telephone number long enough to dial, for instance. Some studies have demonstrated that a particular technique to energize working memory betters the reasoning and problem-solving abilities known as fluid intelligence. Yet two new studies have now called into question the earlier research on working memory. A recent online publication in the Journal of Experimental Psychology led by a group at the Georgia Institute of Technology showed that 20 sessions on a working memory task did not did not result in a later acing of tests of cognitive ability. Similarly, a group at Case Western Reserve University tried the same “dual n-back test” and published a report in the journal Intellgence that found that better scores did not produce higher tallies for working memory and fluid intelligence. An n-back test requires keeping track of a number, letter or image “n” places back. A dual n-back demands the simultaneous remembering of both a visual and auditory cue perceived a certain number of places back. © 2012 Scientific American

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17303 - Posted: 09.26.2012

Remember the game "telephone"? Someone starts by saying a sentence to the person next to them. That person then turns to someone else and repeats what they heard. Somehow, by the time the sentence gets to the last person in line, it's all mixed up and barely resembles the original. Apparently our memories operate in the same way. A study published recently in the Journal of Neuroscience looks at how we retrieve memories. It's a well-known phenomenon that retrieval is good for memory - the more you remember something, the longer you'll remember it for. The catch, researchers have discovered, is that each time you retrieve a memory you forget or add small things to it, and the next time you recall the information, you'll remember what you remembered. "Our memories aren’t like a photograph," says lead study author Donna Bridge. "We mix up details, we forget things. We’re likely to remember this incorrect information just as much as we are the correct (memory)." In other words, the more you recall an event, the more distorted your memory of that event may be. Bridge, a postdoctoral fellow at Northwestern University's Feinberg School of Medicine, asked 12 participants to take a memory test on three subsequent days. The first day, study participants repeatedly placed 180 objects in an assigned location - different for each one - on a computer screen grid. The second day they were asked to place those objects in the same positions. Twenty-four hours later, they did it again. © 2012 Cable News Network

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17282 - Posted: 09.22.2012

By BENEDICT CAREY Scientists have designed a brain implant that sharpened decision making and restored lost mental capacity in monkeys, providing the first demonstration in primates of the sort of brain prosthesis that could eventually help people with damage from dementia, strokes or other brain injuries. The device, though years away from commercial development, gives researchers a model for how to support and enhance fairly advanced mental skills in the frontal cortex of the brain, the seat of thinking and planning. The new report appeared Thursday in The Journal of Neural Engineering. In just the past decade, scientists have developed brain implants that improve vision or allow disabled people to use their thoughts to control prosthetic limbs or move computer cursors. The new paper, led by researchers at Wake Forest Baptist Medical Center and the University of Southern California, describes a device that improves brain function internally, by fine-tuning communication among neurons. Previous studies have shown that a neural implant can do this for memory in rodents, but the new report extends that work significantly, experts said — into brains that are much closer to those of humans. In the study, researchers at Wake Forest trained five rhesus monkeys to play a picture-matching game. The monkeys saw an image on a large screen — of a toy, a person, a mountain range — and tried to select the same image from a larger group of images that appeared on the same screen a little while later. The monkeys got a treat for every correct answer. After two years of practice, the animals developed some mastery, getting about 75 percent of the easier matches correct and 40 percent of the harder ones, markedly better than chance guessing. © 2012 The New York Times Company

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 14: Attention and Consciousness
Link ID: 17262 - Posted: 09.15.2012

Sandrine Ceurstemont, Most of us would probably find it difficult to remember everything we did yesterday. But for a small group of people with near-perfect memory, autobiographical events from decades ago can be recalled just as easily as scrolling through a DVD. Sean Conlon, a food and beverages director from Baltimore, Maryland, and Frank Healy, a counsellor based in Pennsylvania, are two of about 30 people now confirmed to possess highly superior autobiographical memory. In this video, you can watch them recall life events from specific dates without prior preparation. Since the dates coincide with historical events, we were able to check that they weren't making it up. The two men recently had their brain scanned by memory researcher James McGaugh and colleagues from the University of California, Irvine, whose work is now revealing differences in certain memory regions for people with the ability. The team also found that super-memorisers share some of the hallmarks of obsessive compulsive disorder (OCD). Conlon claims that he doesn't have obsessive tendencies, other than being preoccupied with his past. Healy, however, admits that he's quite germ-phobic: at restaurants he will go and wash his hands as soon as he places his order. Both men have found their memory to be advantageous in their jobs. "It helps me if I have a client who stops therapy for a year or two and then returns," says Healy. "I'm instantly able to remember their birthday, their issues and everything about them." © Copyright Reed Business Information Ltd.

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 17179 - Posted: 08.18.2012

by Michael Marshall Big and strong predators are dangerous enough, but clever ones are the worst. There's nothing more annoying than realising you've been outwitted in the seconds before you're disembowelled. Killer whales are some of the smartest predators on Earth. They can climb onto beaches to catch sea lions, stun fish by slapping them with their tails, and create waves to knock seals off ice floes. That might be because they learn from each other. They are one of the few animals that can imitate behaviours that they haven't seen before, and they are ferociously quick students. Despite their name, killer whales are actually dolphins – albeit rather large ones. Populations in different areas are quite dissimilar, and genetic evidence suggests that there are actually several species. A key difference between populations is that they target different prey, using different techniques. In the Crozet Islands in the Indian Ocean, whales strand themselves on beaches to hunt southern elephant seals. In Patagonia, they hunt sea lions in the same way. Beaching oneself on purpose is unusual, and it takes young killer whales years to get the hang of it. Even at five or six years old, they often need their mothers' help to get back off the beach. © Copyright Reed Business Information Ltd.

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 11: Emotions, Aggression, and Stress
Link ID: 17177 - Posted: 08.18.2012

By Dwayne Godwin and Jorge Cham In 1953, Henry Molaison underwent radical surgery in an attempt to stop his epileptic seizures... © 2012 Scientific American,

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 17046 - Posted: 07.16.2012

By Laura Sanders In a paradoxical twist, people with amnesia can get bogged down by too many memories. Unwanted, irrelevant information crowds in and prevent amnesiac patients from recognizing objects, scientists report in the July 12 Neuron. The finding suggests that amnesia isn’t strictly a memory problem, and it may even point out ways to help people with the disorder live more normally. Most people consider amnesia a breakdown of memory that leaves people unable to recall a conversation they had minutes earlier, says study coauthor Morgan Barense of the University of Toronto. While it’s true that people with amnesia have striking memory deficits, “the real picture is more complicated,” she says. People with amnesia caused by damage to a brain region near the ears called the perirhinal cortex also have problems recognizing objects, Barense and colleagues found. In the study, two people with this form of amnesia assessed a series of pictures of two objects — squiggly blobs with distinctive patterns of lines. The objects, shown at different rotations, were either identical or slightly different. At first, people with amnesia were just as good as people with functioning recall at deciding whether the two objects were the same. But as the experiment wore on, participants’ performance started to crash. “They’re doing fine, they’re doing fine — and then all of a sudden, it was like a switch flipped,” says Barense. After ruling out other possibilities, the researchers landed on what Barense calls a “wildly paradoxical conclusion” to explain the crash: too many memories. © Society for Science & the Public 2000 - 2012

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17030 - Posted: 07.12.2012

By Kara Rogers The honeybee brain is dynamic and full of surprises. For instance, much like the human brain, its neurons not only modulate their activity in response to sensory stimuli but also alter their gene and protein expression patterns—changes that in bees are so dramatic as to essentially rewire the brain. And even more remarkable is that this plasticity is strongly influenced by social environment, a feature that was underscored recently by the discovery that bees who changed social roles effectively reversed the aging of their brains. The reversal, described in terms of recovery of learning ability, occurred when older honeybees reverted from foraging tasks to caring for newborn bees and was linked to increased brain levels of stress response and antioxidant proteins, which serve important cellular maintenance and repair functions. One of the proteins was similar to the mammalian enzyme peroxiredoxin-6 (Prx6). In humans, Prx6 defends against oxidative stress and inflammation associated with Alzheimer disease and Huntington disease, indicating that a better understanding of the molecules involved in brain plasticity and cognitive recovery in honeybees could inform research on dementia and related conditions. The new findings are especially intriguing for what they suggest about the influence of social environment on cognitive function. Studies in humans have linked strong social relationships with increased likelihood for survival and declining social engagement in mid- to late-life with increasing risk of dementia. However, relatively little is known about the significance of social environment in the context of human cognitive function and aging. © 2012 Scientific American,

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 13: Memory, Learning, and Development
Link ID: 17027 - Posted: 07.12.2012

by Krystnell A. Storr For California ground squirrels, survival against rattlesnakes often comes down to one basic question: Are you willing to "shake it?" By holding their tails upright and thrashing them from side to side, the animals notify predators that any attempt to turn them into a meal is likely to end in failure. Now researchers have discovered that this tail-waving behavior has a dual purpose. Not only does it ward off predators, but it also warns other squirrels of potential danger, forcing rattlesnakes to find new hunting grounds. Pacific rattlesnakes (Crotalus oreganus oreganus) are patient hunters. They wait for hours in or around the burrows of California ground squirrels (Otospermophilus beecheyi). When an unsuspecting squirrel gets close enough, the snake delivers a venomous bite, releases the animal, and hunts for the dead body later. Scientists knew that some squirrels avoid attack by shaking their tails after seeing a snake, but sometimes squirrels did this even when they didn't detect a predator. Were they clued into some sort of alarm call or just waving at random? Matthew Barbour and Rulon Clark decided to investigate things from a snake's perspective. Armed with snake tongs and bags, the San Diego State University ecologists trekked into the California wilderness and captured and anesthetized 22 rattlesnakes, surgically implanting them with small tracking devices. As soon as the snakes recovered, the duo released them back into the wild, keeping tabs on them with the tracking devices and security cameras set up around several squirrel burrows. © 2010 American Association for the Advancement of Science.

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17024 - Posted: 07.11.2012

by Andy Coghlan One of the key elements of memory – how we store and retrieve words according to what they mean – has been unravelled by analysing electrical signals from people's brains while they recalled lists of words. Although the discovery cannot identify the individual words being filed, which could effectively make a very basic form of mind-reading possible, it does for the first time reveal the electrical circuitry vital for storing words according to what they mean, rather than where they came in a sequence, for example. "Our main focus is on how people organise their memories," says Jeremy Manning, currently at Princeton University. "So we looked at the degree to which people organised their memories according to the meanings of words." Calling Roget The researchers recruited 46 patients with epilepsy who had already had electrodes implanted in their brains for treatment purposes. The electrodes allowed the researchers to measure electrical activity in the brain as the participants viewed lists of 15 to 20 words. A minute later, the patients were asked to recall aloud as many as possible, in any order. Collectively, the participants viewed 1550 lists, including a total of 24,760 words. The researchers included within each list words with similar meanings or associations, such as "goose" and "duck", to see if recall of one prompted recollection of the other. © Copyright Reed Business Information Ltd.

Related chapters from BP6e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 15: Language and Our Divided Brain; Chapter 13: Memory, Learning, and Development
Link ID: 16987 - Posted: 06.30.2012

By Laura Sanders A dreamland ditty played softly during a nap helps people hit the right notes while awake. Soft tones during sleep creep into the napping brain and strengthen playing skills, researchers report online June 24 in Nature Neuroscience. The results don’t mean that after a nighttime Beethoven sonata, a piano novice will wake up with the ability to play it. But the results do suggest that an existing skill can be sharpened during a nap, says study coauthor Ken Paller of Northwestern University in Evanston, Ill. Earlier work by Paller and others has found that sound and odor cues during sleep can improve a person’s memory for the locations of objects. The new study extends those results by showing that a learned skill — in this instance, playing music — can also be influenced during sleep. Although these sorts of experiments are just getting started, “the door is wide open,” Paller says. Musical ability, athletic prowess and other talents that normally require a lot of practice may be amenable to boosts during sleep. Before the easy job of having a nap, 16 right-handed participants in the study had to do some actual work. Volunteers learned two different not-very-catchy tunes, played with their left hands on the a, s, d and f keys of a computer. In an arrangement similar to that of Guitar Hero, circles that floated up the screen told participants which key to hit and when. © Society for Science & the Public 2000 - 2012

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 16963 - Posted: 06.25.2012

By Madeline Haller Prepping for a big presentation but can't seem to remember any of the content? Blame your sweet tooth. A diet high in sugar may hamper your memory and ability to learn, says a study published in the Journal of Physiology. Researchers had two groups of rats drink water mixed with fructose, a type of sugar. One of the groups also received omega-3 fatty acids as a part of their diet. After 6 weeks, the rats who drank only sugar water completed a maze slower than the omega-3-fed mice. (We know you're not a mouse -- but you can still take steps to navigate the maze of life. Check out these 27 Ways to Power Up Your Brain.) Not only were they slower in the maze, the rats who drank only sugar water had higher triglyceride, glucose, and insulin levels. It appears that they entered a state of insulin resistance, which is where the hormone insulin becomes less effective at lowering your blood sugar, says Fernando Gomez-Pinilla, Ph.D., lead study author and a professor of neurosurgery at the David Geffen School of Medicine at UCLA. Here's how it works: Insulin, in addition to controlling blood sugar, also influences the ways in which your brain cells operate. And within the hippocampus -- the part of the brain responsible for short-term and long-term memory -- insulin signaling actually facilitates memory. Therefore, an insulin resistance may be what's causing a disruption in the rats' ability to recall the route they'd learned 6 weeks ago, the researchers hypothesize. © 2012 msnbc.com

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 13: Homeostasis: Active Regulation of Internal States
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 16959 - Posted: 06.25.2012

By Laura Sanders In what seems like a blow for humanity, a very smart chimpanzee in Japan crushes any human challenger at a number memory game. After the numbers 1 through 9 make a split-second appearance on a computer screen, the chimp, Ayumu, gets to work. His bulky index finger flies gracefully across the screen, tapping white squares where the numbers had appeared, in order. So far, no human has topped him. Ayumu’s talent caused a stir when researchers first reported it in 2007 (SN: 12/8/2007, p. 355). Since then, the chimp’s feat has grown legendary, even earning him a starring role in a recent BBC documentary. But psychologist Nicholas Humphrey says the hype may be overblown. In an upcoming Trends in Cognitive Sciences essay, Humphrey floats a different explanation for Ayumu’s superlative performance, one that leaves humans’ memory skills unimpugned: Ayumu might have a curious brain condition that allows him to see numbers in colors. If Humphrey’s wild idea is right, the chimpanzee’s feat has nothing to do with memory. “When you get extraordinary results, you need to look for extraordinary ideas to explain them,” says Humphrey, of Darwin College at Cambridge University in England. The idea came to him after listening to two presentations at a consciousness conference in 2011. Tetsuro Matsuzawa of the Primate Research Institute at Kyoto University in Japan described his research on the memory skills of Ayumu, his mother Ai, and two other mom-offspring pairs. And neuroscientist David Eagleman of Baylor College of Medicine in Houston talked about the brain condition known as synesthesia, which causes people to attach sensory experiences to letters or numbers. A synesthete might always see the number four as blue, for instance. © Society for Science & the Public 2000 - 2012

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 5: The Sensorimotor System
Link ID: 16918 - Posted: 06.16.2012

By PERRI KLASS, M.D. Like many other pediatricians, I do not wear a white coat. Many of us believe that babies and small children suffer from a special form of “white coat syndrome,” that mix of trepidation and anxiety that some adults experience — to the point of high blood pressure — in a medical setting. The pediatric version is easy to diagnose: Doctor in white coat walks into room, kid starts to cry. I worry that a child like this has recalled shots or an unpleasant ear check and has connected that memory to a particular garment, rather than to my face, or my exam room, or my stethoscope. But how realistic is that? Do babies remember past events? Starting when? Recent investigations of memory formation raise fascinating questions about how young children store and retrieve experiences and information. In some ways, I believe we tend to exalt the memory-related feats of the infant and the toddler. True, they can learn language, even more than one; sorting out words and syntax from the surrounding noise is in many ways a defining human use of memory. Nora Newcombe, a professor of psychology at Temple University, points out that there may be evolutionary reasons that this kind of memory — semantic memory — is so strong in the early years of life, when babies are faced with learning so many facts about the world. And yet, every adult lacks memories from the very early years. Freud called it “infantile amnesia,” describing “the peculiar amnesia which veils from most people (not from all!) the first years of their childhood.” Not surprisingly, he felt we repress those early childhood memories because they contain the beginnings of sexual feeling. Copyright 2012 The New York Times Company

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 13: Memory, Learning, and Development
Link ID: 16904 - Posted: 06.12.2012

by Dan Hurley Marilyn 
Monroe and Jane Russell appeared 
outside Grauman’s Chinese Theatre 
to write their names and leave imprints 
of their hands and high heels in the 
wet concrete. Down on their knees, 
supported by a velvet-covered pillow for their elbows, they wrote “Gentlemen 
Prefer Blondes” in looping script, followed by their signatures and the date, 6-26-53. But how did those watching the 
events of that day manage to imprint a memory trace of it, etching the details with neurons and synapses in the soft cement of the brain? Where and how are those memories written, and what is the molecular alphabet that spells out the 
rich recollections of color, smell, and sound? After more than a century of searching, an answer was recently found, strangely enough, just eight miles from Grauman’s. Although not located on any tourist map, the scene of the discovery can be reached easily from Hollywood Boulevard by heading west on Sunset to the campus of UCLA. There, amid one of the densest clusters of neuroscience research facilities in the world, stands the Gonda (Goldschmied) Neuroscience and Genetics Research Center. And sitting at a table in the building’s first-floor restaurant, the Café Synapse, is the neuroscientist who has come closer than anyone ever thought possible to finding the place where memories are written in the brain. That spot, the physical substrate of a particular memory, has long been known in brain research as an engram. Decades of scientific dogma asserted that engrams exist only in vast webs of connections, not in a particular place but in distributed neural networks running widely through the brain. Yet a series of pioneering studies have demonstrated that it is possible to lure specific memories into particular neurons, at least in mice. If those neurons are killed or temporarily inactivated, the memories vanish. If the neurons are reactivated, the memories return. These same studies have also begun to explain how and why the brain allocates each memory to a particular group of cells and how it links them together and organizes them—the physical means by which the scent of a madeleine, the legendary confection that sparked Marcel Proust’s memory stream, leads to remembrance of things past. © 2012, Kalmbach Publishing Co.

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 16895 - Posted: 06.11.2012

by Zoë Corbyn If you want to enhance your memory, consider moving up a mountain. The spatial recall of mountain chickadees – tiny songbirds that inhabit high regions of the western US – is better the higher up they live. Vladimir Pravosudov of the University of Nevada, in Reno, and his colleagues collected 48 juvenile birds (Poecile gambeli) from three different elevations in the Sierra Nevada mountains. Chickadees that lived just 600 metres higher than others had larger hippocampi – a part of the brain strongly linked to memory. Not only that, they were also better at remembering where food was hidden in lab tests. It makes sense that birds living higher up would have a better memory, says Pravosudov. Mountain chickadees are "scatter hoarders", storing their favourite winter food of pine seeds in thousands of different spots among the trees. At higher altitudes, where it stays cold for longer, birds must store more seeds, and remember where they cached them. The effect could apply to other scatter-hoarding species, says Pravosudov, though he rules out most squirrels and rodents, which are either not active during the winter or put everything in one place and so do not need a better memory. Could global warming change things? Very possibly. "The selection pressure that the winter provides will be less, so the birds are going to get dumber," says Pravosudov. Time to consider a simpler pantry? Journal reference: Animal Behaviour, DOI: 10.1016/j.anbehav.2012.04.018 © Copyright Reed Business Information Ltd.

Related chapters from BP6e: Chapter 6: Evolution of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 0: ; Chapter 13: Memory, Learning, and Development
Link ID: 16867 - Posted: 06.02.2012

By Julian De Freitas What did you eat for dinner one week ago today? Chances are, you can’t quite recall. But for at least a short while after your meal, you knew exactly what you ate, and could easily remember what was on your plate in great detail. What happened to your memory between then and now? Did it slowly fade away? Or did it vanish, all at once? Memories of visual images (e.g., dinner plates) are stored in what is called visual memory. Our minds use visual memory to perform even the simplest of computations; from remembering the face of someone we’ve just met, to remembering what time it was last we checked. Without visual memory, we wouldn’t be able to store—and later retrieve—anything we see. Just as a computer’s memory capacity constrains its abilities, visual memory capacity has been correlated with a number of higher cognitive abilities, including academic success, fluid intelligence (the ability to solve novel problems), and general comprehension. For many reasons, then, it would be very useful to understand how visual memory facilitates these mental operations, as well as constrains our ability to perform them. Yet although these big questions have long been debated, we are only now beginning to answer them. Memories like what you had for dinner are stored in visual short-term memory—particularly, in a kind of short-term memory often called “visual working memory.” Visual working memory is where visual images are temporarily stored while your mind works away at other tasks—like a whiteboard on which things are briefly written and then wiped away. We rely on visual working memory when remembering things over brief intervals, such as when copying lecture notes to a notebook. © 2012 Scientific American

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 16853 - Posted: 05.31.2012

By Meehan Crist For decades researchers have known that our ability to remember everyday experiences depends on a slender belt of brain tissue called the hippocampus. Basic memory functions, such as forming new memories and recalling old ones, were thought to be performed along this belt by different sets of neurons. Now findings suggest that the same neurons in fact perform both these very different functions, changing from one role to another as they age. The vast majority of these hippocampal neurons, called granule cells, develop when we are very young and remain in place throughout our lives. But about 5 percent develop in adulthood through the birth of new neurons, a process known as neurogenesis. Young granule cells help form new memories, but as they get older they switch roles to helping recall the past. Newer granule cells pick up the slack, taking on the role of helping to form new memories. Susumu Tonegawa of the Massachusetts Institute of Technology and his colleagues published the findings on March 30 in the journal Cell. Tonegawa’s team tested the role of these adult-born cells by genetically engineering mice in which the old cells could be selectively turned off. They then put the mice through a series of mazes and fear-conditioning tests, which demonstrated that young granule cells are essential to forming separate memories of similar events, whereas old granule cells are essential to recalling past events based on small cues. This discovery suggests that memory impairments common in aging and in post-traumatic stress disorder may be connected to an imbalance of old and new cells. “If you don’t have a normal amount of young cells, you may have a problem distinguishing between two events that would be seen as different by healthy people,” Tonegawa says. At the same time, the presence of too many old cells would make it easier to recall traumatic past experiences based on current cues. © 2012 Scientific American,

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 13: Memory, Learning, and Development
Link ID: 16849 - Posted: 05.29.2012