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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."

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.

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.

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.

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.

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."

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.

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.

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."

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.

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.”

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.

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."

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."

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.

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.

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.

A December Night in Chapel Hill

The gathering took place on a bristly cold December night for Chapel Hill. The evening started with a group of carolers, including James and his girlfriend of the moment—yes, it was Joni Mitchell—lighting out from the Taylors’ and rambling through the neighborhood from house to house. Ike went along, too, his voice resonant and booming. It would have been just like my parents to join in such a sing-along. My mother had a beautiful voice, and as my father used to say about singers like himself: If you can’t sing, at least sing loud.  I can imagine the smell of that night, woodsmoke flirting with the December air, the scent of pine and fallen leaves. David was seventeen. His older brother Louis was there, too. So was his friend Isabelle Patterson, whom he had picked up on his motorcycle, much to her dad’s distress. The other Taylor siblings were away, probably up north. As the carolers circled around Morgan Creek, David lip-synched his way through “Silent Night,” in part so that he could listen to James and Joni sing. Why listen to himself when such beautiful voices were ringing out behind his ears? Plus he was Jewish and didn’t know the lyrics.  David had treasured James’s friendship from childhood. When David was seven or eight, he’d been helping a group of older boys build a tree house in the woods near Morgan Creek. When they finished, the boys shooed him away. “This is our clubhouse,” they said. He slunk home, head down. James, then thirteen, walking up the road, saw him. “What’s wrong?” he asked. David told him. “Come with me,” James said. They went to the Taylor house, picked up hammers and nails, and proceeded to build David a tree house of his own.  The carolers stopped by the UNC basketball coach Dean Smith’s midcentury modern. He wasn’t quite as exalted in 1970 as he would become, but he was still local royalty. They sang to Dean and his then-wife, Ann. In the years after that, Smith would sometimes drive players he was recruiting through the neighborhood in one of his Carolina-blue Cadillacs. “That’s James Taylor’s house,” he’d tell them. Late in Smith’s career (and well along in Taylor’s), he said that to a recruit, who responded, “Who’s James Taylor?” “He’s a local musician,” Smith said.  When everyone finished caroling, they went back to the Taylors’, gathering upstairs around the fire in the open living room. Nearby stood a Christmas tree that Ike and James had gone into the woods and cut down. Decades later, Isabelle Patterson would tell David that whenever she hears Joni Mitchell’s song “River” (“It’s coming on Christmas, they’re cutting down trees”), she’s convinced that the song was inspired by that visit. That evening, David plopped down on the floor next to Joni. She struck him as shy but very kind and very beautiful. “Is this your dulcimer?” he asked.  “Yes, would you like to see it?” she said. She took the dulcimer out of the case and talked a little about it. When she did that, James pulled his guitar out and they began to play together, as they had in London at the Paris Theatre earlier that fall in a concert broadcast by the BBC. They performed “A Case of You,” “California,” and “Carey,” from Joni Mitchell’s forthcoming album, the epochal Blue, which would be released in the summer of 1971.  James and Joni also played “You’ve Got a Friend,” “Fire and Rain,” and a song-in-progress called “Long Ago and Far Away.” David had already been privileged to hear perhaps the first finished version of “Fire and Rain,” which Taylor completed in Chapel Hill after returning from London. He and James’s youngest brother, Hugh, had been hanging out at the Taylors’ when James asked if they wanted to hear a new song. They listened. “Yeah, I think that’ll be a hit,” David told him. That night, when the gathering finally came to a close and the guests got up to leave, James stood up and sang them off with his version of “Happy Trails,” originally performed by Roy Rogers and Dale Evans. The guests sang along, my parents included, as they disappeared into the night and the rest of their lives.

Touch can produce detailed, lasting memories -- ScienceDaily

Participants showed almost perfect recall on the test that followed the exploration period, correctly identifying the object they had explored 94% of the time. Remarkably, participants still showed robust memory for the original objects 1 week later, with 84% accuracy. But would they still remember objects so well if they weren't intentionally memorizing them? And could objects that were explored by touch be recognized via a different sensory modality? In a second experiment, a new group of participants explored the same 168 objects without knowing they would be tested on them. Instead, the experimenters said that they were investigating aesthetic judgments, and they asked the participants to rate the pleasantness of each object based on texture, shape, and weight. Participants returned 1 week later for a surprise memory test, completing a blindfolded touch-based recognition task for half of the objects. For the rest of the objects, they completed a visual recognition task, in which they saw the original object and a similar object placed on a table, and indicated which one they previously explored. After each trial, the participants also reported if they answered based on recalling details of their touch-based exploration, feeling a vague familiarity, or simply guessing. Again, the results showed that participants remembered the objects with high accuracy. In the blindfolded test, participants answered correctly on 79% of the trials. In the cross-modal visual test, participants identified the correct object 73% of the time.

The Human Brain Is a Time Traveler - The New York Times

In 2001, Randy Buckner’s adviser at Washington University, Marcus Raichle, coined a new term for the phenomenon: the “default-mode network,” or just “the default network.” The phrase stuck. Today, Google Scholar lists thousands of academic studies that have investigated the default network. “It looks to me like this is the most important discovery of cognitive neuroscience,” says the University of Pennsylvania psychologist Martin Seligman. The seemingly trivial activity of mind-wandering is now believed to play a central role in the brain’s “deep learning,” the mind’s sifting through past experiences, imagining future prospects and assessing them with emotional judgments: that flash of shame or pride or anxiety that each scenario elicits.

The Human Brain Is a Time Traveler - The New York Times

In her 1995 paper, Nancy Andreasen included two key observations that would grow in significance over the subsequent decades. When she interviewed the subjects afterward, they described their mental activity during the REST state as a kind of effortless shifting back and forth in time. “They think freely about a variety of things,” Andreasen wrote, “especially events of the past few days or future activities of the current or next several days.” Perhaps most intriguing, Andreasen noted that most of the REST activity took place in what are called the association cortices of the brain, the regions of the brain that are most pronounced in Homo sapiens compared with other primates and that are often the last to become fully operational as the human brain develops through adolescence and early adulthood. “Apparently, when the brain/mind thinks in a free and unencumbered fashion,” she wrote, “it uses its most human and complex parts.”

Exercise and memory mechanisms

Mice were given cocaine injections over four days in special chambers with a distinctive floor texture to produce a drug association with that environment. The animals were then housed for 30 days in cages, some of which included a running wheel. The researchers found that mice that exercised on these wheels had lower levels of brain peptides related to myelin, a substance that is thought to help fix memories in place. Re-exposure to the cocaine-associated environment affected running and sedentary mice differently: Compared with sedentary mice, the animals with running wheels showed a reduced preference for the cocaine-associated environment. In addition, the brains of re-exposed runners contained higher levels of hemoglobin-derived peptides, some of which are involved in cell signaling in the brain. Meanwhile, peptides derived from actin decreased in the brains of re-exposed sedentary mice. Actin is involved in learning and memory and is implicated in drug seeking. The researchers say these findings related to peptide changes will help to identify biomarkers for drug dependence and relapse.

'Nested sequences': An indispensable mechanism for forming memories -- ScienceDaily

Which of these sequences, slow or nested, is necessary for the appearance of sequence reactivations, and therefore causes the consolidation of memories during sleep? Using an ingenious system, the researchers discovered what deactivates nested sequences, without affecting slow sequences: the animals are transported on an electric train, in a car with a treadmill (see image). When the treadmill is stopped, the nested sequences disappear; they return when the treadmill starts again. The researchers then observed that after several circuits in the train with the treadmill stopped, place cells in the rats' hippocampi did not reactivate during sleep in the same order as when awake. On the contrary, after one train circuit with the treadmill on, the sequence reactivations are indeed present. So it is these nested theta sequences during movement that are indispensable for the consolidation of memory during sleep.

Memory palaces aren't a metaphor

Electroencephalography readings were taken as 24 participants performed a visual working memory task while at rest and during exercise involving different postures: seated on or pedalling a stationary bicycle, as well as standing or walking on a treadmill. (Visual working memory is the ability to maintain visual information to serve the needs of ongoing tasks.) The investigators found that both aerobic exercise and upright posture improved visual working memory compared with passive and seated conditions. Their analyses also suggest where the neural origins of these observed effects take place.

Hippocampus maps relationship of scenes?

Aya Ben-Yakov and Richard Henson found that the hippocampus responded most strongly to the films at the points that independent observers identified as the end of one event and the beginning of a new one. The researchers found a strong match between these event boundaries and participants’ hippocampal activity, varying according to the degree to which the independent observers agreed on the transition points between events. While watching the two-hour long Forrest Gump, hippocampal response was more strongly influenced by the subjective event boundaries than by what the filmmaker may consider a transition between scenes, such as a change in location.

Working Memory May be More Flexible than Previously Thought - Neuroscience News

They turned this idea into a computational model and tested it on data from nine previously published experiments. In those experiments, human subjects memorized the colors of varying numbers of objects. When asked to reproduce these colors as precisely as possible, the quality of their responses was negatively affected by the number of objects in memory. The model by Van den Berg and Ma accurately mimics this set size effect in all nine datasets. Moreover, their model simulations predict that the objects most relevant for a task are stored more accurately than less important ones, a phenomenon also observed in participants. Lastly, their simulation predicts that the total amount of resources devoted to working memory varies with the number of objects to be remembered. This too is consistent with the results of previous experiments. Working memory thus appears to be more flexible than previously thought. The amount of resources that the brain allocates to working memory is not fixed but could be the result of balancing resource cost against cognitive performance. If this is confirmed, it may be possible to improve working memory by offering rewards, or by increasing the perceived importance of a task.