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Brain Stores Multiple Copies of Single Memory - Neuroscience News

First to arrive during development, the early-born neurons are responsible for the long-term persistence of a memory. In fact, even though their memory copy is initially too weak for the brain to access, it becomes stronger and stronger as time passes. Also in humans, the brain might have access to such memory only some time after its encoding. In contrast, the memory copy of the same event created by the late-born neurons is very strong at the beginning but fades over time, so that if one waits long enough, such a copy becomes inaccessible to the brain. In the middle ground, among neurons emerging in between the two extremes during development, a more stable copy could be observed. Surprisingly, which copy is used might also be linked to how easy it is to change a memory – or to use it to create a new one.
#memory #hippocampus - neurosciencenews.com

Are your earliest childhood memories still lurking in your mind—or gone forever? | Science | AAAS

Research with young rats and mice suggests they, too, can access suppressed memories with a little help. In a 2016 study, Cristina Alberini, a neuroscientist at New York University, and her colleagues gave juvenile rats a foot shock when they stepped into a dark compartment within a white box. The young animals learned to stay out of the dangerous compartment, but forgot soon after. Once the animals were older, the researchers found they could jog their memory by showing them the white box and shocking them in a different colored box. Then, when the researchers returned the rats to the original white box, the combination of the two cues made the rodents remember to stay out of its dark compartment.
#psychology #memory #children - science.org

Brain ripples may help bind information across the human cortex: Ubiquitous bursts of brain waves appear to synchronize disparate and distant elements of memory, unifying them upon recollection -- ScienceDaily

The UC San Diego team, led by Halgren, found that ripples also occur in all areas of the human cortex, in waking as well as sleep. The ripples were brief, lasting roughly one-tenth of a second, and had a consistent narrow frequency close to 90 cycles per second. The authors calculated that a typical brief ripple event may involve approximately 5,000 small modules becoming active simultaneously, distributed across the cortical surface. This work is part of the doctoral thesis in neurosciences by first author Charles W. Dickey. "Remarkably, the ripples co-occurred and synchronized across all lobes and between both hemispheres, even at long distances," said Dickey. "Cortical neurons increased firing during ripples, at the ripple rhythm, potentially supporting interaction between distant locations. "There were more co-occurrences preceding successful memory recall. All of which suggests that distributed, cortical co-ripples promote the integration of different elements that may comprise a particular experiential memory."
#synchronize #brain #memory #ripples - sciencedaily.com

Conceptual knowledge increases infants' memory capacity | PNAS

For example, adults are better at remembering the letter string PBSBBCCNN after parsing it into three smaller units: the television acronyms PBS, BBC, and CNN. Is this chunking a learned strategy acquired through instruction? We explored the origins of this ability by asking whether untrained infants can use conceptual knowledge to increase memory. In the absence of any grouping cues, 14-month-old infants can track only three hidden objects at once, demonstrating the standard limit of working memory. In four experiments we show that infants can surpass this limit when given perceptual, conceptual, linguistic, or spatial cues to parse larger arrays into smaller units that are more efficiently stored in memory. This work offers evidence of memory expansion based on conceptual knowledge in untrained, preverbal subjects.
#narratives #memory #children - pnas.org

Why do we forget? New theory proposes 'forgetting' is actually a form of learning -- ScienceDaily

"Memories are stored in ensembles of neurons called 'engram cells' and successful recall of these memories involves the reactivation of these ensembles. The logical extension of this is that forgetting occurs when engram cells cannot be reactivated. The memories themselves are still there, but if the specific ensembles cannot be activated they can't be recalled. It's as if the memories are stored in a safe but you can't remember the code to unlock it. "Our new theory proposes that forgetting is due to circuit remodelling that switches engram cells from an accessible to an inaccessible state. Because the rate of forgetting is impacted by environmental conditions, we propose that forgetting is actually a form of learning that alters memory accessibility in line with the environment and how predictable it is."
#memory #engram - sciencedaily.com

Signal coupling between neuron-glia super-network may lead to improved memory formation -- ScienceDaily

"Glial cells appear to have the capacity of coding information," says professor Ko Matsui of the Super-network Brain Physiology lab at Tohoku University, who led the research. "However, the role of the added layer of signals encoded in the glial circuit has always been an enigma." Using patch clamp electrophysiology techniques in acute brain slices from mice, Dr. Kaoru Beppu, Matsui, and their team show that glial cells in the cerebellum react to excitatory transmitter glutamate released from synapses of neurons. The glial cells then release additional glutamate in return. Therefore, these glial cells effectively function as excitatory signal amplifiers.
#memory #glia - sciencedaily.com

Sleep is vital to associating emotion with memory, study finds -- ScienceDaily

The researchers found that when they disrupted sleep after they showed the subjects an image and had given them a mild foot shock, there was no fear associated with the visual stimulus. Those with unmanipulated sleep learned to fear the specific visual stimulus that had been paired with the foot shock. "We found that these mice actually became afraid of every visual stimulus we showed them," Aton said. "From the time they go to the chamber where the visual stimuli are presented, they seem to know there's a reason to feel fear, but they don't know what specifically they're afraid of." This likely shows that, in order for them to make an accurate fear association with a visual stimulus, they have to have sleep-associated reactivation of the neurons encoding that stimulus in the sensory cortex, according to Aton. This allows a memory specific to that visual cue to be generated.The researchers think that at the same time, that sensory cortical area must communicate with other brain structures, to marry the sensory aspect of the memory to the emotional aspect.
#memory #sleep #fear - sciencedaily.com

Sport and memory go hand in hand -- ScienceDaily

To test the effect of sport on motor learning, scientists asked a group of 15 young and healthy men, who were not athletes, to take a memory test under three conditions of physical exercise: after 30 minutes of moderate cycling, after 15 minutes of intensive cycling (defined as 80% of their maximum heart rate), or after a period of rest. "The exercise was as follows: a screen showed four points placed next to each other. Each time one of the dots briefly changed into a star, the participant had to press the corresponding button as quickly as possible," explains Blanca Marin Bosch, researcher in the same laboratory. "It followed a predefined and repeated sequence in order to precisely evaluate how movements were learnt. This is very similar to what we do when, for example, we learn to type on a keyboard as quickly as possible. After an intensive sports session, the performance was much better."
#exercise #memory - sciencedaily.com

Exercise improves memory, boosts blood flow to brain: Study: 1-year workout program shows benefits for older people at risk of dementia -- ScienceDaily

The study, published in the Journal of Alzheimer's Disease, documented changes in long-term memory and cerebral blood flow in 30 participants, each of them 60 or older with memory problems. Half of them underwent 12 months of aerobic exercise training; the rest did only stretching. The exercise group showed 47 percent improvement in memory scores after one year compared with minimal change in the stretch participants. Brain imaging of the exercise group, taken while they were at rest at the beginning and end of the study, showed increased blood flow into the anterior cingulate cortex and the hippocampus -- neural regions that play important roles in memory function.
#exercise #brain #memory #hippocampus - sciencedaily.com

Specific neurons that map memories now identified in the human brain -- ScienceDaily

"Our study demonstrates that neurons in the human brain track the experiences we are willfully recalling, and can change their activity patterns to differentiate between memories. They're just like the pins on your Google map that mark the locations you remember for important events," Qasim says. "This discovery might provide a potential mechanism for our ability to selectively call upon different experiences from the past and highlights how these memories may influence our brain's spatial map."
#neurons #memory #maps #hippocampus - sciencedaily.com

Human brains reorganize experiences while resting to find new solutions - Neuroscience News

They also found that replay is factorized – that is, multiple representations of different aspects of events are replayed simultaneously, and these different representations can be recombined to make new events. This is important because factorized representations are a powerful means of generalizing knowledge. ‘With factorized representations, individual experiences can be decomposed into parts and these parts can be meaningfully recombined in a vast number of ways – which has the potential to dramatically improve learning,’ said lead author Yunzhe Liu, a PhD student in the Max Planck UCL Centre for Computational Psychiatry & Ageing Research and Wellcome Centre for Human Neuroimaging at UCL.
#memory #learning - neurosciencenews.com

Human brains reorganize experiences while resting to find new solutions - Neuroscience News

Human replay occurs while the brain is resting between exercises, and reverses direction after a reward has been given for making the correct choice. They also showed that human replay spontaneously reorganizes experience based on learned structure. This enables us to spontaneously re-order sequences to integrate past knowledge with current experiences.
#memory #learning - neurosciencenews.com

Pink noise boosts deep sleep in mild cognitive impairment patients: Sound stimulation in deep sleep improved recall for some in small pilot study -- ScienceDaily

Each participant received sounds on one of the nights and no sounds on the other. The order of which night had sounds or no sounds was randomly assigned. Participants did memory testing the night before and again in the morning. Scientists then compared the difference in slow-wave sleep with sound stimulation and without sounds, and the change in memory across both nights for each participant. The participants were tested on their recall of 44 word pairs. The individuals who had 20% or more increase in their slow wave activity after the sound stimulation recalled about two more words in the memory test the next morning. One person with a 40% increase in slow wave activity remembered nine more words. The sound stimulation consisted of short pulses of pink noise, similar to white noise but deeper, during the slow waves. The system monitored the participant's brain activity. When the person was asleep and slow brain waves were seen, the system delivered the sounds. If the patient woke up, the sounds stopped playing.
#memory #sleep #noise - sciencedaily.com

Hippocampus and memory development

The Geneva team has been following 275 patients aged 6 to 35 years for 18 years: a control groups of 135 individuals -- i.e. individuals without genetic problems -- and 140 people with deletion syndrome, including 53 with moderate to severe psychotic symptoms. "They underwent an MRI every three years so that we could observe their brain development," says Valentina Mancini, a researcher in UNIGE's Department of Psychiatry. "This has helped us create a statistical model that measures and compares the development of the hippocampus in both groups of patients." It was discovered that the hippocampus of the group affected by deletion syndrome, although smaller from the beginning, followed a growth curve identical to that of the control group. "This meant that we could hypothesise that the smaller size of the hippocampus originates in utero during its development in the womb." The UNIGE scientists also observed the subfields of the hippocampus in detail, discovering that one of them -- called CA3 -- was not affected by the decrease in size. "This subfield plays a crucial role in the work of memorisation and seems stronger than the other sub-parts," adds professor Eliez.
#memory #DNA #psychosis #hippocampus - sciencedaily.com

Memories form 'barrier' to letting go of objects for people who hoard -- ScienceDaily

Dr Stewart explains: "We can all relate to the experience of being flooded with positive memories when we hold valued possessions in our hands. However, our findings suggest that it's the way in which we respond to these object-related memories that dictates whether we hold onto an object or let it go. The typical population appears to be able to set aside these memories, presumably to ease the task of discarding the objects, and so manage to avoid the accumulation of clutter. The hoarding participants enjoyed the positive memories but reported that they got in the way of their attempts to discard objects."
#memory #home - sciencedaily.com

Allen Neuringer's Many Decades of Self-Experimentation - Quantified Self

Allen proceeded to test the effects of movement on his cognitive abilities. He tested memory at first. He had flashcards with faces on one side and names on the other. His A condition would be to run two miles or swim 20 laps and then review 20 of the cards recording how many he got right. The B condition would be to spend the same amount of time working at his desk before reviewing the cards. The effect was clear. His ability to memorize was better after activity. But how does one test idea generation? Allen’s method was to spend 15 minutes moving around in a “quasi-dance” manner and noted any ideas he had on a notecard, writing the date and the condition on the back side, in this case, “move”. He then compared those cards to ones generated during a 15 minute period sitting at a desk. He repeated these AB intervals over the course of weeks, accumulating piles of cards. Months later he went through the cards and evaluated the quality of the ideas, looking at whether or not they were good and how creative they were. He didn’t know which conditions they were, since “sit” and “move” were written on the back side. He calculated the number of subjectively judged “good” ideas for each condition. Again, he noticed there were clear differences. Movement helped. Movement also helped with reading. Allen rigged a book holder out of an old backpack and through his testing found out that he surprisingly reads faster while moving and retains more. But was moving always better? Allen looked at his problem solving abilities in the move and sit conditions, using a similar method that he used for testing idea generation. He found that moving tended to make problem solving easier, with one significant exception: problems involving mathematical reasoning were more difficult to do while moving.
#exercise #brain #memory #creativity #mind-body #movement #qs - quantifiedself.com

Memories are strengthened via brainwaves produced during sleep, new study shows: Researchers use medical imaging to map areas involved in recalling learned information while we slumber -- ScienceDaily

The researchers found that during spindles of the learning night, the regions of the brain that were instrumental in processing faces were reactivated. They also observed that the regions in the brain involved in memory -- especially the hippocampus -- were more active during spindles in the subjects who remembered the task better after sleep. This reactivation during sleep spindles of the regions involved in learning and memory "falls in line with the theory that during sleep, you are strengthening memories by transferring information from the hippocampus to the regions of the cortex that are important for the consolidation of that specific type of information," he says.
#synchronize #brain #memory #fMRI #eeg - sciencedaily.com

Unexplored neural circuit modulates memory strength -- ScienceDaily

"We know with flies, just like in mammals, there are neurons involved in positive reinforcement, there are neurons involved in negative reinforcement -- the valence neurons -- and then there are this third set," Tomchik says. "Nobody really knew what they did." The fruit fly brain contains eight groups of neurons that produce dopamine. Three of them can be found in what's known as the fly brain's "mushroom body." Humans don't have an exact analogous brain section, but other brain regions perform similar functions. In Drosophila melanogaster, aka the fruit fly, the mushroom body is an area highly responsive to odors. Past fly brain studies have shown that one of the dopamine-producing groups projecting into the mushroom body handles desire-inducing memories connected to odors. ("Mmmm, rotten bananas!") while another guides avoidant behavior related to negative experiences. ("Yikes, dangerous banana smell!") To find out the role of the third group, referred to as PPL2, research associate and first author Tamara Boto, PhD, trained the flies with an experiment that involved exposing them to fruit-like odors while simultaneously giving them a mild electric shock. Their conditioned response could be visualized under a microscope by adding a green fluorescent protein that releases light upon reacting to calcium. Calcium ions are released when neurons communicate. Stimulating the PPL2 neurons during the odor experiments changed the brightness of the fluorescence when presented with the odor, an indication that the structures involved in learning and memory had altered the degree of response. "When we activated this PPL2 set of neurons, it would actually modulate the strength of that memory," Tomchik says. "So we see there are dopaminergic neurons that encode the aversive stimulus itself, and then there is this additional set that can turn the volume up or down on that memory."
#neurons #memory #dopamine #complexity - sciencedaily.com

Exercise activates memory neural networks in older adults: Study shows acute exercise has the ability to impact brain regions important to memory -- ScienceDaily

Dr. Smith's research team measured the brain activity (using fMRI) of healthy participants ages 55-85 who were asked to perform a memory task that involves identifying famous names and non famous ones. The action of remembering famous names activates a neural network related to semantic memory, which is known to deteriorate over time with memory loss. This test was conducted 30 minutes after a session of moderately intense exercise (70% of max effort) on an exercise bike and on a separate day after a period of rest. Participants' brain activation while correctly remembering names was significantly greater in four brain cortical regions (including the middle frontal gyrus, inferior temporal gryus, middle temporal gyrus, and fusiform gyrus) after exercise compared to after rest. The increased activation of the hippocampus was also seen on both sides of the brain. "Just like a muscle adapts to repeated use, single sessions of exercise may flex cognitive neural networks in ways that promote adaptations over time and lend to increased network integrity and function and allow more efficient access to memories," Dr. Smith explained.
#exercise #memory #hippocampus # - sciencedaily.com

Auschwitz Memorial Asks Visitors to Stop Taking Playful Photos

“When you come to @AuschwitzMuseum remember you are at the site where over 1 million people were killed. Respect their memory,” the memorial tweeted. “There are better places to learn how to walk on a balance beam than the site which symbolizes deportation of hundreds of thousands to their deaths.”
#memory #RIP #central-europe #instagram - dailydot.com

Data Mining Reveals the Six Basic Emotional Arcs of Storytelling - MIT Technology Review

The idea behind sentiment analysis is that words have a positive or negative emotional impact. So words can be a measure of the emotional valence of the text and how it changes from moment to moment. So measuring the shape of the story arc is simply a question of assessing the emotional polarity of a story at each instant and how it changes. Reagan and co do this by analyzing the emotional polarity of “word windows” and sliding these windows through the text to build up a picture of how the emotional valence changes. They performed this task on over 1,700 English works of fiction that had each been downloaded from the Project Gutenberg website more than 150 times.
#narratives #memory #history #AI #RIP #emotion - technologyreview.com

A new way by which the human brain marks time: Novel findings may further understanding of age-related dementia -- ScienceDaily

In the UCI study, participants sat with their heads inside a high-resolution fMRI scanner while watching the TV show and then viewing still frames from the episode, one at a time. The researchers found that when subjects had more precise answers to questions about what time certain events occurred, they activated a brain network involving the lateral entorhinal cortex and the perirhinal cortex. The team had previously shown that these regions, which surround the hippocampus, are associated with memories of objects or items but not their spatial location. Until now, little had been known about how this network might process and store information about time. "The field of neuroscience has focused extensively on understanding how we encode and store information about space, but time has always been a mystery," said Yassa, a professor of neurobiology & behavior. "This study and the Moser team's study represent the first cross-species evidence for a potential role of the lateral entorhinal cortex in storing and retrieving information about when experiences happen." "Space and time have always been intricately linked, and the common wisdom in our field was that the mechanisms involved in one probably supported the other as well," added Maria Montchal, a graduate student in Yassa's lab who led the research. "But our results suggest otherwise."
#memory #hippocampus #fMRI - sciencedaily.com

Near bottom: focus triggered by new activity or movement?

Research has shown that the electrical activity of the neocortex of the brain changes, when we focus our attention. Neurons stop signalling in sync with one another and start firing out of sync. This is helpful, says Williams, because it allows individual neurons to respond to sensory information in different ways. Thus, you can focus on a car speeding down the road or on what a friend is saying in a crowded room. It's known that the cholinergic system in the brain plays an important role in triggering this desynchronization. The cholinergic system consists of clusters of special neurons that synthesise and release a signalling molecule called acetylcholine, he explains, and these clusters make far reaching connections throughout the brain. Not only does this cholinergic system act like a master switch, but mounting evidence suggests it also enables the brain to identify which sensory input is the most salient -- i.e. worthy of attention -- at any given moment and then shine a spotlight on that input. "The cholinergic system broadcasts to the brain, 'this thing is really important to be vigilant to'," says Williams. He adds that the cholinergic system has been proposed to have a far-reaching impact on our cognitive abilities. "Destruction of the cholinergic system in animals profoundly degrades cognition, and the formation of memory," he says. "Importantly, in humans a progressive degeneration of the cholinergic system occurs in devastating diseases that blunt cognition and memory, such as Alzheimer's disease." But precisely which neurons in the cortex are being targeted by this master switch and how it's able to influence their function was unknown. Williams and QBI researcher Lee Fletcher wondered if layer 5 B-pyramidal neurons, the 'output' neurons of the neocortex, might be involved, because they are intimately involved in how we perceive the world. "The output neurons of the neocortex perform computations that are thought to underlie our perception of the world," says Williams. Williams and Fletcher wanted to know if the cholinergic system is able to influence the activity of these output neurons. Using a technique called optogenetics, they modified neurons in the cholinergic system in the brains of mice so that they could be activated with a flash of blue light, triggering a sudden release of acetylcholine. This allowed the researchers to closely monitor the interaction between the cholinergic system and the output neurons. They discovered that if the output neurons were not currently active, not much happened. But when those neurons received excitatory input to their dendrites, the cholinergic system was able to massively increase their activity. "It's as if the cholinergic system has given a 'go' signal," says Fletcher, enabling the output neurons of the neocortex to powerfully respond. Importantly, this change was selective, and only apparent when excitatory input was being processed in the dendrites of the 'output' neurons. "We have known for some time that the dendrites of the output neurons of the neocortex only become active when animals are actively performing a behaviour, and that this activity is correlated with perception and task performance," says Williams. This new work demonstrates that the cholinergic system is critical to this transition in mice and rats, allowing the output neurons to perform computations in a state-dependent manner. "We suggest that this switch also occurs in the human neocortex, allowing us to rapidly switch our state of vigilance and attention," says Williams. "Our work therefore provides important insight into how the progressive degeneration of the cholinergic system in disease blunts human cognition."
#synchronize #memory #focus #cognition #touch - sciencedaily.com

How the brain reacts to loss of vision: Going blind affects all senses, and disrupts memory ability -- ScienceDaily

Before any changes had developed in the sensory cortices, the researchers observed that loss of vision was first followed by changes in the density of neurotransmitter receptors and impairments of synaptic plasticity in the hippocampus. In subsequent months, hippocampal plasticity became more impaired and spatial memory was affected. During this time the density of neurotransmitter receptors also changed in the visual cortex, as well as in other cortical areas that process other sensory information. "After blindness occurs, the brain tries to compensate for the loss by ramping up its sensitivity to the missing visual signals," explains Denise Manahan-Vaughan, who led the study. When this fails to work, the other sensory modalities begin to adapt and increase their acuities. "Our study shows that this process of reorganisation is supported by extensive changes in the expression and function of key neurotransmitter receptors in the brain. This is a major undertaking, during which time the hippocampus' ability to store spatial experiences is hampered," says Manahan-Vaughan.
#memory #hippocampus #vision - sciencedaily.com

Ant Colonies Retain Memories That Outlast the Lifespans of Individuals | Science | Smithsonian

Colonies live for 20-30 years, the lifetime of the single queen who produces all the ants, but individual ants live at most a year. In response to perturbations, the behavior of older, larger colonies is more stable than that of younger ones. It is also more homeostatic: the larger the magnitude of the disturbance, the more likely older colonies were to focus on foraging than on responding to the hassles I had created; while, the worse it got, the more the younger colonies reacted. In short, older, larger colonies grow up to act more wisely than younger smaller ones, even though the older colony does not have older, wiser ants. Ants use the rate at which they meet and smell other ants, or the chemicals deposited by other ants, to decide what to do next. A neuron uses the rate at which it is stimulated by other neurons to decide whether to fire. In both cases, memory arises from changes in how ants or neurons connect and stimulate each other. It is likely that colony behavior matures because colony size changes the rates of interaction among ants. In an older, larger colony, each ant has more ants to meet than in a younger, smaller one, and the outcome is a more stable dynamic. Perhaps colonies remember a past disturbance because it shifted the location of ants, leading to new patterns of interaction, which might even reinforce the new behavior overnight while the colony is inactive, just as our own memories are consolidated during sleep. Changes in colony behavior due to past events are not the simple sum of ant memories, just as changes in what we remember, and what we say or do, are not a simple set of transformations, neuron by neuron. Instead, your memories are like an ant colony’s: no particular neuron remembers anything although your brain does.
#brain #neurons #memory #history #community #metaphors - smithsonianmag.com

Ant Colonies Retain Memories That Outlast the Lifespans of Individuals | Science | Smithsonian

From day to day, the colony’s behavior changes, and what happens on one day affects the next. I conducted a series of perturbation experiments. I put out toothpicks that the workers had to move away, or blocked the trails so that foragers had to work harder, or created a disturbance that the patrollers tried to repel. Each experiment affected only one group of workers directly, but the activity of other groups of workers changed, because workers of one task decide whether to be active depending on their rate of brief encounters with workers of other tasks. After just a few days repeating the experiment, the colonies continued to behave as they did while they were disturbed, even after the perturbations stopped. Ants had switched tasks and positions in the nest, and so the patterns of encounter took a while to shift back to the undisturbed state. No individual ant remembered anything but, in some sense, the colony did.
#memory #history #community #socializing #evolution - smithsonianmag.com