Good timing: Study unravels how our brains track time

Ever hear the old adage that time flies when you're having fun? A new study by a team of UNLV researchers suggests that there's a lot of truth to the trope.

Many people think of their brains as being intrinsically synced to the human-made clocks on their electronic devices, counting time in very specific, minute-by-minute increments. But the study, published this month in the latest issue of the peer-reviewed Cell Press journal Current Biology, showed that our brains don't work that way.

By analyzing changes in brain activity patterns, the research team found that we perceive the passage of time based on the number of experiences we have -- not some kind of internal clock. What's more, increasing speed or output during an activity appears to affect how our brains perceive time.

"We tell time in our own experience by things we do, things that happen to us," said James Hyman, a UNLV associate professor of psychology and the study's senior author. "When we're still and we're bored, time goes very slowly because we're not doing anything or nothing is happening. On the contrary, when a lot of events happen, each one of those activities is advancing our brains forward. And if this is how our brains objectively tell time, then the more that we do and the more that happens to us, the faster time goes."

Methodology and Findings

The findings are based on analysis of activity in the anterior cingulate cortex (ACC), a portion of the brain important for monitoring activity and tracking experiences. To do this, rodents were tasked with using their noses to respond to a prompt 200 times.

Scientists already knew that brain patterns are similar, but slightly different, each time you do a repetitive motion, so they set out to answer: Is it possible to detect whether these slight differences in brain pattern changes correspond with doing the first versus 200th motion in series? And does the amount of time it takes to complete a series of motions impact brain wave activity?

By comparing pattern changes throughout the course of the task, researchers observed that there are indeed detectable changes in brain activity that occur as one moves from the beginning to middle to end of carrying out a task. And regardless of how slowly or quickly the animals moved, the brain patterns followed the same path. The patterns were consistent when researchers applied a machine learning-based mathematical model to predict the flow of brain activity, bolstering evidence that it's experiences -- not time, or a prescribed number of minutes, as you would measure it on a clock -- that produce changes in our neurons' activity patterns.

Hyman drove home the crux of the findings by sharing an anecdote of two factory workers tasked with making 100 widgets during their shift, with one worker completing the task in 30 minutes and the other in 90 minutes.

"The length of time it took to complete the task didn't impact the brain patterns. The brain is not a clock; it acts like a counter," Hyman explained. "Our brains register a vibe, a feeling about time. ...And what that means for our workers making widgets is that you can tell the difference between making widget No. 85 and widget No. 60, but not necessarily between No. 85 and No. 88."

But exactly "how" does the brain count? Researchers discovered that as the brain progresses through a task involving a series of motions, various small groups of firing cells begin to collaborate -- essentially passing off the task to a different group of neurons every few repetitions, similar to runners passing the baton in a relay race.

"So, the cells are working together and over time randomly align to get the job done: one cell will take a few tasks and then another takes a few tasks," Hyman said. "The cells are tracking motions and, thus, chunks of activities and time over the course of the task."

And the study's findings about our brains' perception of time applies to activities-based actions other than physical motions too.

"This is the part of the brain we use for tracking something like a conversation through dinner," Hyman said. "Think of the flow of conversation and you can recall things earlier and later in the dinner. But to pick apart one sentence from the next in your memory, it's impossible. But you know you talked about one topic at the start, another topic during dessert, and another at the end."

By observing the rodents who worked quickly, scientists also concluded that keeping up a good pace helps influence time perception: "The more we do, the faster time moves. They say that time flies when you're having fun. As opposed to having fun, maybe it should be 'time flies when you're doing a lot'."

Takeaways

While there's already a wealth of information on brain processes over very short time scales of less than a second, Hyman said that the UNLV study is groundbreaking in its examination of brain patterns and perception of time over a span of just a few minutes to hours -- "which is how we live much of our life: one hour at a time. "

"This is among the first studies looking at behavioral time scales in this particular part of the brain called the ACC, which we know is so important for our behavior and our emotions," Hyman said.

The ACC is implicated in most psychiatric and neurodegenerative disorders, and is a concentration area for mood disorders, PTSD, addiction, and anxiety. ACC function is also central to various dementias including Alzheimer's disease, which is characterized by distortions in time. The ACC has long been linked to helping humans with sequencing events or tasks such as following recipes, and the research team speculates that their findings about time perception might fall within this realm.

While the findings are a breakthrough, more research is needed. Still, Hyman said, the preliminary findings posit some potentially helpful tidbits about time perception and its likely connection to memory processes for everyday citizens' daily lives. For example, researchers speculate that it could lend insights for navigating things like school assignments or even breakups.

"If we want to remember something, we may want to slow down by studying in short bouts and take time before engaging in the next activity. Give yourself quiet times to not move," Hyman said. "Conversely, if you want to move on from something quickly, get involved in an activity right away."

Hyman said there's also a huge relationship between the ACC, emotion, and cognition. Thinking of the brain as a physical entity that one can take ownership over might help us control our subjective experiences.

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Physical activity reduces stress-related brain activity to lower cardiovascular disease risk

New research indicates that physical activity lowers cardiovascular disease risk in part by reducing stress-related signaling in the brain.

In the study, which was led by investigators at Massachusetts General Hospital (MGH), a founding member of the Mass General Brigham healthcare system and published in the Journal of the American College of Cardiology, people with stress-related conditions such as depression experienced the most cardiovascular benefits from physical activity.

To assess the mechanisms underlying the psychological and cardiovascular disease benefits of physical activity, Ahmed Tawakol, MD, an investigator and cardiologist in the Cardiovascular Imaging Research Center at Massachusetts General Hospital, and his colleagues analyzed medical records and other information of 50,359 participants from the Mass General Brigham Biobank who completed a physical activity survey.

A subset of 774 participants also underwent brain imaging tests and measurements of stress-related brain activity.

Over a median follow-up of 10 years, 12.9% of participants developed cardiovascular disease. Participants who met physical activity recommendations had a 23% lower risk of developing cardiovascular disease compared with those not meeting these recommendations.

Individuals with higher levels of physical activity also tended to have lower stress-related brain activity. Notably, reductions in stress-associated brain activity were driven by gains in function in the prefrontal cortex, a part of the brain involved in executive function (i.e., decision making, impulse control) and is known to restrain stress centers of the brain. Analyses accounted for other lifestyle variables and risk factors for coronary disease.

Moreover, reductions in stress-related brain signaling partially accounted for physical activity's cardiovascular benefit.

As an extension of this finding, the researchers found in a cohort of 50,359 participants that the cardiovascular benefit of exercise was substantially greater among participants who would be expected to have higher stress-related brain activity, such as those with pre-existing depression.

"Physical activity was roughly twice as effective in lowering cardiovascular disease risk among those with depression. Effects on the brain's stress-related activity may explain this novel observation," says Tawakol, who is the senior author of the study.

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Your dog understands that some words 'stand for' objects

It's no surprise that your dog can learn to sit when you say "sit" and come when called. But a study appearing March 22 in the journal Current Biology has made the unexpected discovery that dogs generally also know that certain words "stand for" certain objects. When dogs hear those words, brain activity recordings suggest they activate a matching mental representation in their minds.

"Dogs do not only react with a learned behavior to certain words," says Marianna Boros of the Department of Ethology at the Eötvös Loránd University, Budapest, Hungary, one of the paper's co-first authors. "They also don't just associate that word with an object based on temporal contiguity without really understanding the meaning of those words, but they activate a memory of an object when they hear its name."

Word understanding tests with individuals who do not speak, such as infants and animals, usually require active choice, the researchers say. They're asked to show or get an object after hearing its name. Very few dogs do well on such tests in the lab, often fetching objects correctly at a rate expected by chance.

The researchers wanted to look closer at dogs' implicit understanding of object words by measuring brain activity using non-invasive EEG without asking them to act. The idea was that this might offer a more sensitive measure of their understanding of language.

In their studies, they had 18 dog owners say words for toys their dogs knew and then present the objects to them. Sometimes they presented the matching toy, while other times they would present an object that didn't match. For example, an owner would say, "Zara, look, the ball," and present the object while the dog's brain activity was captured on EEG.

The brain recording results showed a different pattern in the brain when the dogs were shown a matching object versus a mismatched one. That's similar to what researchers have seen in humans and is widely accepted as evidence that they understand the words. The researchers also found a greater difference in those patterns for words that dogs knew better, offering further support for their understanding of object words. Interestingly, while the researchers thought this ability might depend on having a large vocabulary of object words, their findings showed that it doesn't.

"Because typical dogs learn instruction words rather than object names, and there are only a handful of dogs with a large vocabulary of object words, we expected that dogs' capacity for referential understanding of object words will be linked to the number of object words they know; but it wasn't," says Lilla Magyari, also of Eötvös Loránd University and University of Stavanger and the other co-first author.

"It doesn't matter how many object words a dog understands -- known words activate mental representations anyway, suggesting that this ability is generally present in dogs and not just in some exceptional individuals who know the names of many objects," Boros added.

The discovery that dogs as a species may generally have a capacity to understand words in a referential way, just as humans do, might reshape the way scientists think about the uniqueness of how humans use and understand language, the researchers say. That has important implications for theories and models of language evolution. For dog owners, it's also an important realization.

"Your dog understands more than he or she shows signs of," Magyari says. "Dogs are not merely learning a specific behavior to certain words, but they might actually understand the meaning of some individual words as humans do."

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Lack of focus doesn't equal lack of intelligence -- it's proof of an intricate brain

Imagine a busy restaurant: dishes clattering, music playing, people talking loudly over one another. It's a wonder that anyone in that kind of environment can focus enough to have a conversation. A new study by researchers at Brown University's Carney Institute for Brain Science provides some of the most detailed insights yet into the brain mechanisms that help people pay attention amid such distraction, as well as what's happening when they can't focus.

In an earlier psychology study, the researchers established that people can separately control how much they focus (by enhancing relevant information) and how much they filter (by tuning out distraction). The team's new research, published in Nature Human Behaviour, unveils the process by which the brain coordinates these two critical functions.

Lead author and neuroscientist Harrison Ritz likened the process to how humans coordinate muscle activity to perform complex physical tasks.

"In the same way that we bring together more than 50 muscles to perform a physical task like using chopsticks, our study found that we can coordinate multiple different forms of attention in order to perform acts of mental dexterity," said Ritz, who conducted the study while a Ph.D. student at Brown.

The findings provide insight into how people use their powers of attention as well as what makes attention fail, said co-author Amitai Shenhav, an associate professor in Brown's Department of Cognitive, Linguistic and Psychological Sciences.

"These findings can help us to understand how we as humans are able to exhibit such tremendous cognitive flexibility -- to pay attention to what we want, when we want to," Shenhav said. "They can also help us better understand limitations on that flexibility, and how limitations might manifest in certain attention-related disorders such as ADHD."

The focus-and-filter test

To conduct the study, Ritz administered a cognitive task to participants while measuring their brain activity in an fMRI machine. Participants saw a swirling mass of green and purple dots moving left and right, like a swarm of fireflies. The tasks, which varied in difficulty, involved distinguishing between the movement and colors of the dots. For example, participants in one exercise were instructed to select which color was in the majority for the rapidly moving dots when the ratio of purple to green was almost 50/50.

Ritz and Shenhav then analyzed participants' brain activity in response to the tasks.

Ritz, who is now a postdoctoral fellow at the Princeton Neuroscience Institute, explained how the two brain regions work together during these types of tasks.

"You can think about the intraparietal sulcus as having two knobs on a radio dial: one that adjusts focusing and one that adjusts filtering," Ritz said. "In our study, the anterior cingulate cortex tracks what's going on with the dots. When the anterior cingulate cortex recognizes that, for instance, motion is making the task more difficult, it directs the intraparietal sulcus to adjust the filtering knob in order to reduce the sensitivity to motion.

"In the scenario where the purple and green dots are almost at 50/50, it might also direct the intraparietal sulcus to adjust the focusing knob in order to increase the sensitivity to color. Now the relevant brain regions are less sensitive to motion and more sensitive to the appropriate color, so the participant is better able to make the correct selection."

Ritz's description highlights the importance of mental coordination over mental capacity, revealing an often-expressed idea to be a misconception.

"When people talk about the limitations of the mind, they often put it in terms of, 'humans just don't have the mental capacity' or 'humans lack computing power,'" Ritz said. "These findings support a different perspective on why we're not focused all the time. It's not that our brains are too simple, but instead that our brains are really complicated, and it's the coordination that's hard."

Ongoing research projects are building on these study findings. A partnership with physician-scientists at Brown University and Baylor College of Medicine is investigating focus-and-filter strategies in patients with treatment-resistant depression. Researchers in Shenhav's lab are looking at the way motivation drives attention; one study co-led by Ritz and Brown Ph.D. student Xiamin Leng examines the impact of financial rewards and penalties on focus-and-filter strategies.

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Study identifies distinct brain organization patterns in women and men

A new study by Stanford Medicine investigators unveils a new artificial intelligence model that was more than 90% successful at determining whether scans of brain activity came from a woman or a man.

The findings, to be published Feb. 19 in the Proceedings of the National Academy of Sciences, help resolve a long-term controversy about whether reliable sex differences exist in the human brain and suggest that understanding these differences may be critical to addressing neuropsychiatric conditions that affect women and men differently.

"A key motivation for this study is that sex plays a crucial role in human brain development, in aging, and in the manifestation of psychiatric and neurological disorders," said Vinod Menon, PhD, professor of psychiatry and behavioral sciences and director of the Stanford Cognitive and Systems Neuroscience Laboratory. "Identifying consistent and replicable sex differences in the healthy adult brain is a critical step toward a deeper understanding of sex-specific vulnerabilities in psychiatric and neurological disorders."

Menon is the study's senior author. The lead authors are senior research scientist Srikanth Ryali, PhD, and academic staff researcher Yuan Zhang, PhD.

"Hotspots" that most helped the model distinguish male brains from female ones include the default mode network, a brain system that helps us process self-referential information, and the striatum and limbic network, which are involved in learning and how we respond to rewards.

The investigators noted that this work does notweigh in on whether sex-related differences arise early in life or may be driven by hormonal differences or the different societal circumstances that men and women may be more likely to encounter.

Uncovering brain differences

The extent to which a person's sex affects how their brain is organized and operates has long been a point of dispute among scientists. While we know the sex chromosomes we are born with help determine the cocktail of hormones our brains are exposed to -- particularly during early development, puberty and aging -- researchers have long struggled to connect sex to concrete differences in the human brain. Brain structures tend to look much the same in men and women, and previous research examining how brain regions work together has also largely failed to turn up consistent brain indicators of sex.

In their current study, Menon and his team took advantage of recent advances in artificial intelligence, as well as access to multiple large datasets, to pursue a more powerful analysis than has previously been employed. First, they created a deep neural network model, which learns to classify brain imaging data: As the researchers showed brain scans to the model and told it that it was looking at a male or female brain, the model started to "notice" what subtle patterns could help it tell the difference.

This model demonstrated superior performance compared with those in previous studies, in part because it used a deep neural network that analyzes dynamic MRI scans. This approach captures the intricate interplay among different brain regions. When the researchers tested the model on around 1,500 brain scans, it could almost always tell if the scan came from a woman or a man.

The model's success suggests that detectable sex differences do exist in the brain but just haven't been picked up reliably before. The fact that it worked so well in different datasets, including brain scans from multiple sites in the U.S. and Europe, make the findings especially convincing as it controls for many confounds that can plague studies of this kind.

"This is a very strong piece of evidence that sex is a robust determinant of human brain organization," Menon said.

Making predictions

Until recently, a model like the one Menon's team employed would help researchers sort brains into different groups but wouldn't provide information about how the sorting happened. Today, however, researchers have access to a tool called "explainable AI," which can sift through vast amounts of data to explain how a model's decisions are made.

Using explainable AI, Menon and his team identified the brain networks that were most important to the model's judgment of whether a brain scan came from a man or a woman. They found the model was most often looking to the default mode network, striatum, and the limbic network to make the call.

The team then wondered if they could create another model that could predict how well participants would do on certain cognitive tasks based on functional brain features that differ between women and men. They developed sex-specific models of cognitive abilities: One model effectively predicted cognitive performance in men but not women, and another in women but not men. The findings indicate that functional brain characteristics varying between sexes have significant behavioral implications.

"These models worked really well because we successfully separated brain patterns between sexes," Menon said. "That tells me that overlooking sex differences in brain organization could lead us to miss key factors underlying neuropsychiatric disorders."

While the team applied their deep neural network model to questions about sex differences, Menon says the model can be applied to answer questions regarding how just about any aspect of brain connectivity might relate to any kind of cognitive ability or behavior. He and his team plan to make their model publicly available for any researcher to use.

"Our AI models have very broad applicability," Menon said. "A researcher could use our models to look for brain differences linked to learning impairments or social functioning differences, for instance -- aspects we are keen to understand better to aid individuals in adapting to and surmounting these challenges."

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Human beliefs about drugs could have dose-dependent effects on the brain

Mount Sinai researchers have shown for the first time that a person's beliefs related to drugs can influence their own brain activity and behavioral responses in a way comparable to the dose-dependent effects of pharmacology.

The implications of the study, which directly focused on beliefs about nicotine, are profound.

They range from elucidating how the neural mechanisms underlying beliefs may play a key role in addiction, to optimizing pharmacological and nonpharmacological treatments by leveraging the power of human beliefs.

The study was published in the journal Nature Mental Health.

"Beliefs can have a powerful influence on our behavior, yet their effects are considered imprecise and rarely examined by quantitative neuroscience methods," says Xiaosi Gu, PhD, Associate Professor of Psychiatry, and Neuroscience, at the Icahn School of Medicine at Mount Sinai, and senior author of the study.

"We set out to investigate if human beliefs can modulate brain activities in a dose-dependent manner similar to what drugs do, and found a high level of precision in how beliefs can influence the human brain. This finding could be crucial for advancing our knowledge about the role of beliefs in addiction as well as a broad range of disorders and their treatments."

To explore this dynamic, the Mount Sinai team, led by Ofer Perl, PhD, a postdoctoral fellow in Dr. Gu's lab when the study was conducted, instructed nicotine-dependent study participants to believe that an electronic cigarette they were about to vape contained either low, medium, or high strengths of nicotine, when in fact the level remained constant.

Participants then underwent functional neuroimaging (fMRI) while performing a decision-making task known to engage neural circuits activated by nicotine.

The scientists found that the thalamus, an important binding site for nicotine in the brain, showed a dose-dependent response to the subject's beliefs about nicotine strength, providing compelling evidence to support the relationship between subjective beliefs and biological substrates in the human brain.

This effect was previously thought to apply only to pharmacologic agents.

A similar dose-dependent effect of beliefs was also found in the functional connectivity between the thalamus and the ventromedial prefrontal cortex, a brain region that is considered important for decision-making and belief states.

"Our findings provide a mechanistic explanation for the well-known variations in individual responses to drugs," notes Dr. Gu, "and suggest that subjective beliefs could be a direct target for the treatment of substance use disorders. They could also advance our understanding of how cognitive interventions, such as psychotherapy, work at the neurobiological level in general for a wide range of psychiatric conditions beyond addiction."

Dr. Gu, who is one of the world's foremost researchers in the emerging field of computational psychiatry, cites another way in which her team's research could inform clinical care.

"The finding that human beliefs about drugs play such a pivotal role suggests that we could potentially enhance patients' responses to pharmacological treatments by leveraging these beliefs," she explains.

Significantly, the work of the Mount Sinai team can also be viewed in a much broader context: harnessing beliefs in a systematic manner to better serve mental health treatment and research in general.

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What happens in the brain while daydreaming?

You are sitting quietly, and suddenly your brain tunes out the world and wanders to something else entirely -- perhaps a recent experience, or an old memory. You just had a daydream.

Yet despite the ubiquity of this experience, what is happening in the brain while daydreaming is a question that has largely eluded neuroscientists.

Now, a study in mice, published Dec. 13 in Nature, has brought a team led by researchers at Harvard Medical School one step closer to figuring it out.

The researchers tracked the activity of neurons in the visual cortex of the brains of mice while the animals remained in a quiet waking state. They found that occasionally these neurons fired in a pattern similar to one that occurred when a mouse looked at an actual image, suggesting that the mouse was thinking -- or daydreaming -- about the image. Moreover, the patterns of activity during a mouse's first few daydreams of the day predicted how the brain's response to the image would change over time.

The research provides tantalizing, if preliminary, evidence that daydreams can shape the brain's future response to what it sees. This causal relationship needs to be confirmed in further research, the team cautioned, but the results offer an intriguing clue that daydreams during quiet waking may play a role in brain plasticity -- the brain's ability to remodel itself in response to new experiences.

"We wanted to know how this daydreaming process occurred on a neurobiological level, and whether these moments of quiet reflection could be important for learning and memory," said lead author Nghia Nguyen, a PhD student in neurobiology in the Blavatnik Institute at HMS.

An overlooked brain region

Scientists have spent considerable time studying how neurons replay past events to form memories and map the physical environment in the hippocampus, a seahorse-shaped brain region that plays a key role in memory and spatial navigation.

By contrast, there has been little research on the replay of neurons in other brain regions, including the visual cortex. Such efforts would provide valuable insights about how visual memories are formed.

"My lab became interested in whether we could record from enough neurons in the visual cortex to understand what exactly the mouse is remembering -- and then connect that information to brain plasticity," said senior author Mark Andermann, professor of medicine at Beth Israel Deaconess Medical Center, and professor of neurobiology at HMS.

In the new study, the researchers repeatedly showed mice one of two images, each consisting of a different checkerboard pattern of gray and dappled black and white squares. Between images, the mice spent a minute looking at a gray screen. The team simultaneously recorded activity from around 7,000 neurons in the visual cortex.

The researchers found that when a mouse looked at an image, the neurons fired in a specific pattern, and the patterns were different enough to discern image one from image two. More important, when a mouse looked at the gray screen between images, the neurons sometimes fired in a similar, but not identical, pattern, as when the mouse looked at the image, a sign that it was daydreaming about the image. These daydreams occurred only when mice were relaxed, characterized by calm behavior and small pupils.

Unsurprisingly, mice daydreamed more about the most recent image -- and they had more daydreams at the beginning of the day than at the end, when they had already seen each image dozens of times.

But what the researchers found next was completely unexpected.

Throughout the day, and across days, the activity patterns seen when the mice looked at the images changed -- what neuroscientists call "representational drift." Yet this drift wasn't random. Over time, the patterns associated with the images became even more different from each other, until each involved an almost entirely separate set of neurons. Notably, the pattern seen during a mouse's first few daydreams about an image predicted what the pattern would become when the mouse looked at the image later.

"There's drift in how the brain responds to the same image over time, and these early daydreams can predict where the drift is going," Andermann said.

Finally, the researchers found that the visual cortex daydreams occurred at the same time as replay activity occurred in the hippocampus, suggesting that the two brain regions were communicating during these daydreams.

To sit, perchance to daydream

Based on the results of the study, the researchers suspect that these daydreams may be actively involved in brain plasticity.

"When you see two different images many times, it becomes important to discriminate between them. Our findings suggest that daydreaming may guide this process by steering the neural patterns associated with the two images away from each other," Nguyen said, while noting that this relationship needs to be confirmed.

Nguyen added that learning to differentiate between the images should help the mouse respond to each image with more specificity in the future.

These observations align with a growing body of evidence in rodents and humans that entering a state of quiet wakefulness after an experience can improve learning and memory.

Next, the researchers plan to use their imaging tools to visualize the connections between individual neurons in the visual cortex and to examine how these connections change when the brain "sees" an image.

"We were chasing this 99 percent of unexplored brain activity and discovered that there's so much richness in the visual cortex that nobody knew anything about," Andermann said.

Whether daydreams in people involve similar activity patterns in the visual cortex is an open question, and the answer will require additional experiments. However, there is preliminary evidence that an analogous process occurs in humans when they recall visual imagery.

Randy Buckner, the Sosland Family Professor of Psychology and of Neuroscience at Harvard University, has shown that brain activity in the visual cortex increases when people are asked to recall an image in detail. Other studies have recorded flurries of electrical activity in the visual cortex and the hippocampus during such recall.

For the researchers, the results of their study and others suggest that it may be important to make space for moments of quiet waking that lead to daydreams. For a mouse, this may mean taking a pause from looking at a series of images and, for a human, this could mean taking a break from scrolling on a smartphone.

"We feel pretty confident that if you never give yourself any awake downtime, you're not going to have as many of these daydream events, which may be important for brain plasticity," Andermann said.

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Babies as young as four months show signs of self-awareness

Babies as young as four months old can make sense of how their bodies interact with the space around them, according to new research from the University of Birmingham.

The findings, published today (21 November 2023) in Scientific Reports, shed new light on how self-awareness develops.

Experts from the Birmingham BabyLab showed babies a ball on a screen moving towards or away from them.

When the ball was closest to them on the screen, the babies were presented with a 'touch' (a small vibration) on their hands, whilst their brain activity was being measured.

The data collection for the study was conducted at Goldsmiths (University of London).

The researchers found that from just four months old, babies show enhanced somatosensory (tactile) brain activity when a touch is preceded by an object moving towards them.

Dr Giulia Orioli, Research Fellow in Psychology at the University of Birmingham, who led the study said: "Our findings indicate that even in the first few months of life, before babies have even learned to reach for objects, the multisensory brain is wired up to make links between what babies see and what they feel. This means they can sense the space around them and understand how their bodies interact with that space. This is sometimes referred to as peripersonal space.

"Of course, humans do this all the time as adults, using our combined senses to perceive where we are in space and making predictions about when we will touch an object or not. But now that we know that babies in the early stages of their development begin to show signs of this, it opens up questions about how much of these abilities are learnt, or innate."

The researchers also explored how an unexpected 'touch' would affect some of the older babies in the study.

They found that in babies aged eight months old when the touch on their hand was preceded by the ball on the screen moving away from them, the babies' brain activity showed signs that they were surprised.

Andrew Bremner, Professor of Developmental Psychology, commented: "Seeing the older babies show surprise responses suggests that they had not expected the touch due to the visual direction the object was moving in. This indicates that as babies proceed through their first year of life, their brains construct a more sophisticated awareness of how their body exists in the space around them."

Next, the researchers are hoping to follow up this study with younger and older participants.

Research with adults can illuminate the kinds of brain activity which infants are developing towards.

They are also hoping to be able to see if there are early signs of these "multisensory" abilities in newborn babies.

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Rats have an imagination, new research suggests

As humans, we live in our thoughts: from pondering what to make for dinner to daydreaming about our last beach vacation.

Now, researchers at HHMI's Janelia Research Campus have found that animals also possess an imagination.

A team from the Lee and Harris labs developed a novel system combining virtual reality and a brain-machine interface to probe the rat's inner thoughts.

They found that, like humans, animals can think about places and objects that aren't right in front of them, using their thoughts to imagine walking to a location or moving a remote object to a specific spot.

Like humans, when rodents experience places and events, specific neural activity patterns are activated in the hippocampus, an area of the brain responsible for spatial memory. The new study finds rats can voluntarily generate these same activity patterns and do so to recall remote locations distant from their current position.

"The rat can indeed activate the representation of places in the environment without going there," says Chongxi Lai, a postdoc in the Harris and Lee Labs and first author of a paper describing the new findings. "Even if his physical body is fixed, his spatial thoughts can go to a very remote location."

This ability to imagine locations away from one's current position is fundamental to remembering past events and imagining possible future scenarios. Therefore, the new work shows that animals, like humans, possess a form of imagination, according to the study's authors.

"To imagine is one of the remarkable things that humans can do. Now we have found that animals can do it too, and we found a way to study it," says Albert Lee, formerly a Group Leader at Janelia and now an HHMI Investigator at Beth Israel Deaconess Medical Center.

A novel brain-machine interface

The project began nine years ago when Lai arrived at Janelia as a graduate student with an idea to test whether an animal could think. His advisor, Janelia Senior Fellow Tim Harris, suggested Lai walk down the hall to chat with Lee, whose lab had similar questions.

Together, the labs worked to develop a system to understand what animals are thinking -- a real-time "thought detector" that could measure neural activity and translate what it meant.

The system uses a brain-machine interface (BMI), which provides a direct connection between brain activity and an external device. In the team's system, the BMI produces a connection between the electrical activity in the rat's hippocampus and its position in a 360-degree virtual reality arena.

The hippocampus stores mental maps of the world involved in recalling past events and imagining future scenarios. Memory recall involves the generation of specific hippocampal activity patterns related to places and events. But no one knew whether animals could voluntarily control this activity.

The BMI allows the researchers to test whether a rat can activate hippocampal activity to just think about a location in the arena without physically going there -- essentially, detecting if the animal is able to imagine going to the location.

Probing the rat's inner thoughts

Once they developed their system, the researchers had to create the "thought dictionary" that would allow them to decode the rat's brain signals. This dictionary compiles what activity patterns look like when the rat experiences something -- in this case, places in the VR arena.

The rat is harnessed in the VR system, designed by Shinsuke Tanaka, a postdoc in the Lee Lab. As the rat walks on a spherical treadmill, its movements are translated on the 360-degree screen. The rat is rewarded when it navigates to its goal.

At the same time, the BMI system records the rat's hippocampal activity. The researchers can see which neurons are activated when the rat navigates the arena to reach each goal. These signals provide the basis for a real-time hippocampal BMI, with the brain's hippocampal activity translated into actions on the screen.

Next, the researchers disconnect the treadmill and reward the rat for reproducing the hippocampal activity pattern associated with a goal location. In this "Jumper" task -- named after a 2008 movie of the same name -- the BMI translates the animal's brain activity into motion on the virtual reality screen. Essentially, the animal uses its thoughts to navigate to the reward by first thinking about where they need to go to get the reward. This thought process is something humans experience regularly. For example, when we're asked to pick up groceries at a familiar store, we might imagine the locations we will pass along the way before we ever leave the house.

In the second task, the "Jedi" task -- a nod to Star Wars -- the rat moves an object to a location by thoughts alone. The rat is fixed in a virtual place but "moves" an object to a goal in the VR space by controlling its hippocampal activity, like how a person sitting in their office might imagine taking a cup next to the coffee machine and filling it with coffee. The researchers then changed the location of the goal, requiring the animal to produce activity patterns associated with the new location.

The team found that rats can precisely and flexibly control their hippocampal activity, in the same way humans likely do. The animals are also able to sustain this hippocampal activity, holding their thoughts on a given location for many seconds -- a timeframe similar to the one at which humans relive past events or imagine new scenarios.

"The stunning thing is how rats learn to think about that place, and no other place, for a very long period of time, based on our, perhaps naïve, notion of the attention span of a rat," Harris says.

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Bat study reveals how the brain is wired for collective behavior

The same neurons that help bats navigate through space may also help them navigate collective social environments, finds a new study published today in the journal Nature.

Many mammals -- including bats and humans -- are believed to navigate with the help of a brain structure called the hippocampus, which encodes a mental "map" of familiar surroundings. For example, as you walk around your neighborhood or commute to work, individual "place" neurons in the hippocampus fire to indicate where you are.

In the new study, researchers at the University of California, Berkeley, used wireless neural recording and imaging devices to "listen in" on the hippocampal brain activity of groups of Egyptian fruit bats as they flew freely within a large flight room -- often moving among tightly clustered social groups -- while tracking technology recorded the bats' movements.

The researchers were surprised to find that, in this social setting, the bat's place neurons encoded far more information than simply the animal's location. As a bat flew toward a landing spot, the firing of place neurons also contained information about the presence or absence of another bat at that spot. And when another bat was present, the activity of these neurons indicated the identity of the bat they were flying toward.

"This is one of the first papers to show identity representation in a non-primate brain," said study senior author Michael Yartsev, an associate professor of bioengineering and neuroscience at UC Berkeley. "And surprisingly, we found it in the hub of what was supposed to be the brain's GPS.We found that it still acts as a GPS, but one that is also tuned to the social dynamic in the environment."

While not as visually stunning as a school of fish or a murmuration of birds, highly social animals like humans and bats also exhibit forms of collective behavior, said study first author Angelo Forli, a postdoctoral fellow in Yartsev's NeuroBat lab.

"Social animals, like humans, will coordinate in space to achieve different goals," Forli said. "It might be just visiting others. It might be moving together, as in the case of classical collective behaviors or playing a soccer match. Or it might be other forms of cooperation or conflict."

Due to the complexity of the experiment, Forli initially had doubts about whether allowing groups of bats to fly and interact freely would yield results about the neural basis of collective behavior. He was concerned that the movements of the bats and their social interactions might be too random to uncover robust relationships between their neural activity and their behavior.

So he was pleasantly surprised when the bats spontaneously established a handful of specific resting spots within the flight room and followed very similar trajectories when traveling among them. The bats also showed strong preferences for flying toward specific "friend" bats, often landing very close to or even on top of each other.

"We found that if you put together a small group of bats in a room, they would not actually behave randomly, but would show precise patterns of behavior," Forli said. "They would spend time with specific individuals and show specific and stable places where they liked to go."

These precise patterns of behavior allowed Forli to identify not only the neural activity associated with different flight trajectories, but also how the neural activity changed depending on the identity of the bat present at the target location and the movements of other bats.

"By recording just a handful of those neurons from this brain structure, we can really know what the bats were doing in their social space," Yartsev said. "We could find out if they were going to an empty location or to a location where there were other individuals, which is really surprising."

In recent years, Yartsev and his NeuroBat Lab have used a variety of wireless neural recording devices and flight tracking technologies to uncover a number of surprising details about the brain, including how bats' neural activity syncs up while they socialize; how activity in the frontal cortex helps bats identify self vs. others during vocal interactions; how bats' hippocampus maps not only specific locations, but full flight trajectories; and even how stable spatial memories might be stored in the brain.

This new study brings together the team's work on navigation and social behavior, showing how these two things are fundamentally intertwined within the brain. The findings also help illuminate why damage to the hippocampus in humans has been linked to both social and spatial aspects of memory loss in neurodegenerative diseases like Alzheimer's.

"Our episodic memories are a combination of the environment where we are located and our experiences within it -- including, of course, our social experiences," Yartsev said. "Our results are surprising, in the sense that no one has observed this connection before in groups of animals and at the individual neuron level. But they also make sense in that they are very consistent with deficits that people with damage to the hippocampus experience."

Finally, this study highlights a very important point, Yartsev said. While most of the neuroscientific community examines the brain under "simplified" or "artificial" conditions that are often far removed from the natural behavior the brain has evolved to promote, this work demonstrates the power of the natural approach to neuroscience research.

"For half a century, people have been studying place neurons, but 99% of that work has been done in single animals moving in an empty box," Yartsev said. "Our findings suggest that there is a lot that can be learned when neuroscience research focuses on natural behavior."

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Elephant seals drift off to sleep while diving far below the ocean surface

For the first time, scientists have recorded brain activity in a free-ranging, wild marine mammal, revealing the sleep habits of elephant seals during the months they spend at sea.

The new findings, published April 20 in Science, show that while elephant seals may spend 10 hours a day sleeping on the beach during the breeding season, they average just 2 hours of sleep per day when they are at sea on months-long foraging trips. They sleep for about 10 minutes at a time during deep, 30-minute dives, often spiraling downward while fast asleep, and sometimes lying motionless on the seafloor.

First author Jessica Kendall-Bar led the study as a UC Santa Cruz graduate student working with Daniel Costa and Terrie Williams, both professors of ecology and evolutionary biology at UCSC.

"For years, one of the central questions about elephant seals has been when do they sleep," said Costa, who directs UCSC's Institute of Marine Sciences. Costa's lab has led the UCSC elephant seal research program at Año Nuevo Reserve for over 25 years, using increasingly sophisticated tags to track the movements and diving behavior of the seals during their foraging migrations, when they head out into the North Pacific Ocean for as long as 8 months.

"The dive records show that they are constantly diving, so we thought they must be sleeping during what we call drift dives, when they stop swimming and slowly sink, but we really didn't know," Costa said. "Now we're finally able to say they're definitely sleeping during those dives, and we also found that they're not sleeping very much overall compared to other mammals."

In fact, during their months at sea, elephant seals rival the record for the least sleep among all mammals, currently held by African elephants, which appear to sleep just two hours per day based on their movement patterns.

"Elephant seals are unusual in that they switch between getting a lot of sleep when they're on land, over 10 hours a day, and two hours or less when they're at sea," said Kendall-Bar, who is currently a postdoctoral fellow at UC San Diego's Scripps Institution of Oceanography.

Elephant seals are most vulnerable to predators such as sharks and killer whales when they are at the surface in the open ocean, so they only spend a minute or two breathing at the surface in between dives.

"They're able to hold their breath for a long time, so they can go into a deep slumber on these dives deep below the surface where it's safe," Kendall-Bar said.

Kendall-Bar developed a system that can reliably record brain activity (as an electroencephalogram or EEG) in wild elephant seals during their normal diving behavior at sea. With a neoprene headcap to secure the EEG sensors and a small data logger to record the signals, the system can be recovered when the animals return to the beach at Año Nuevo.

"We used the same sensors you'd use for a human sleep study at a sleep clinic and a removable, flexible adhesive to attach the headcap so that water couldn't get in and disrupt the signals," Kendall-Bar said.

In addition to the EEG system, the seals carried time-depth recorders, accelerometers, and other instruments that allowed the researchers to track the seals' movements along with the corresponding brain activity. The recordings show diving seals going into the deep sleep stage known as slow-wave sleep while maintaining a controlled glide downward, then transitioning into rapid-eye-movement (REM) sleep, when sleep paralysis causes them to turn upside down and drift downwards in a "sleep spiral."

"They go into slow-wave sleep and maintain their body posture for several minutes before they transition into REM sleep, when they lose postural control and turn upside down," Kendall-Bar said.

At the depths at which this happens, the seals are usually negatively buoyant and continue to fall passively in a corkscrew spiral "like a falling leaf," Williams said. In shallower waters over the continental shelf, elephant seals sometimes sleep while resting on the seafloor.

"It doesn't seem possible that they would truly go into paralytic REM sleep during a dive, but it tells us something about the decision-making processes of these seals to see where in the water column they feel safe enough to go to sleep," said Williams, who directs the Comparative Neurophysiology Lab at UCSC.

In developing the new EEG instrument, Kendall-Bar first deployed it on elephant seals housed temporarily in the marine mammal facilities at UCSC's Long Marine Laboratory. The next step was to deploy it on animals in the elephant seal colony at Año Nuevo Reserve north of Santa Cruz, where researchers could observe the animals on the beach.

"I spent a lot of time watching sleeping seals," Kendall-Bar said. "Our team monitored instrumented seals to make sure they were able to reintegrate with the colony and were behaving naturally."

Some of those seals took short excursions into the water, but to observe diving behavior the researchers used a translocation procedure developed by Costa's lab. Juvenile female elephant seals outfitted with the EEG sensors and trackers were transported from Año Nuevo to Monterey and released on a beach at the southern end of Monterey Bay. Over the next few days, the animals would swim back to Año Nuevo across the deep Monterey Canyon, where their dive behavior is very similar to that seen during much longer foraging trips in the open ocean.

With data on brain activity and dive behavior from 13 juvenile female elephant seals, including a total of 104 sleep dives, Kendall-Bar developed a highly accurate algorithm for identifying periods of sleep based on the dive data alone. This enabled her to estimate sleep quotas for 334 adult seals using dive data recorded over several months during their foraging trips.

"Because of the dataset that Dan Costa has curated over 25 years of working with elephant seals at Año Nuevo, I was able to extrapolate our results to over 300 animals and get a population-level look at sleep behavior," said Kendall-Bar, who now plans to use similar methods to study brain activity in other species of seals and sea lions and in human freedivers.

Williams called Kendall-Bar's work on the project a tour de force. "It's an amazing feat to pull this off," she said. "She developed an EEG system to work on an animal that's diving several hundred meters in the ocean. Then she uses the data to create data-driven animations so we can really visualize what the animal is doing as it dives through the water column."

The results may be helpful for conservation efforts by revealing a "sleepscape" of preferred resting areas, Williams said. "Normally, we're concerned about protecting the areas where animals go to feed, but perhaps the places where they sleep are as important as any other critical habitat," she said.

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Corporal punishment affects brain activity, anxiety, and depression

Don't spank your kids. That's the conventional wisdom that has emerged from decades of research linking corporal punishment to a decline in adolescent health and negative effects on behavior, including an increased risk for anxiety and depression. Now, a new study explores how corporal punishment might impact neural systems to produce those adverse effects.

Corporal punishment can be simply defined as the "intentional infliction of physical pain by any means for the purpose of punishment, correction, discipline, instruction, or any other reason." This violence, particularly when inflicted by a parent, evokes a complex emotional experience. The researchers, led by Kreshnik Burani, MS, and working with Greg Hajcak, PhD, at Florida State University, wanted to understand the neural underpinnings of that experience and its downstream consequences.

The study appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, published by Elsevier.

The researchers conducted a longitudinal study on 149 boys and girls ages 11 to 14 from the Tallahassee, FL, area. Participants performed a video game-like task and a monetary guessing game while undergoing continuously recorded electroencephalography, or EEG -- a noninvasive technique to measure brain-wave activity from the scalp. From the EEG data, the researchers determined two scores for each participant -- one reflecting their neural response to error and the other reflecting their neural response to reward.

Two years later, participants and their parents completed a series of questionnaires to screen for anxiety and depression and to assess parenting style. As expected, kids who had experienced corporal punishment were more likely to develop anxiety and depression.

"Our paper first replicates the well-known negative effect that corporal punishment has on a child's wellbeing: we found that corporal punishment is associated with increased anxiety and depressive symptoms in adolescence. However, our study goes further to demonstrate that corporal punishment might impact brain activity and neurodevelopment," said Burani.

That was reflected by larger neural response to error and a blunted response to reward in the adolescents who received physical punishments.

"Specifically," Burani added, "our paper links corporal punishment to increased neural sensitivity to making errors and decreased neural sensitivity to receiving rewards in adolescence. In previous and ongoing work with Dr. Hajcak, we see that increased neural response to errors is associated with anxiety and risk for anxiety, whereas decreased neural response to rewards is related to depression and risk for depression. Corporal punishment, therefore, might alter specific neurodevelopmental pathways that increase risk for anxiety and depression by making children hypersensitive to their own mistakes and less reactive to rewards and other positive events in their environment."

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Musical tests can detect mental deterioration in old age

Researchers at Tel Aviv University have developed a method that employs musical tests and a portable instrument for measuring brain activity to detect cognitive decline in old age. According to the researchers, the method, which is based on the measurement of 15 minutes of electrical activity in the brain while performing simple musical tasks, can be easily implemented by any staff member in any clinic, without requiring special training.

The researchers: "Our method enables routine monitoring and early detection of cognitive decline in order to provide treatment and prevent rapid, severe deterioration. Prophylactic tests of this kind are commonly accepted for a variety of physiological problems such as diabetes, high blood pressure or breast cancer; however, to date no method has yet been developed to enable routine, accessible monitoring of the brain for cognitive issues." The researchers further note that tests of this kind are particularly important in light of increasing longevity and associated growth of the elderly population.

The study was led at Tel Aviv University by PhD student Neta Maimon from the School of Psychological Sciences and the Buchmann-Mehta School of Music, and Lior Molcho from Neurosteer Ltd, headed by Prof. Nathan Intrator from the Blavatnik School of Computer Science and the Sagol School of Neuroscience. Other participants included: Adi Sasson, Sarit Rabinowitz, and Noa Regev-Plotnick from the Dorot-Netanya Geriatric Medical Center. The article was published in the journal Frontiers in Aging Neuroscience.

As part of the study, the researchers developed a groundbreaking method combining a portable device for the measurement and innovative analysis of electroencephalography (EEG), developed by Neurosteer, and a short musical test of about 12-15 minutes, developed by Neta Maimon. During the test, the subject is connected to the portable EEG device by means of a adhesive band with only three electrodes attached to the forehead. The subject performs a series of musical-cognitive tasks according to audible instructions given automatically through earphones. The tasks include short melodies played by different instruments, with the subjects instructed to perform various tasks on them at varying levels of difficulty. For example, pressing a button each time any melody is played or pressing it only when the violin plays. In addition, the test includes several minutes of musically guided meditation designed to bring the brain to a resting state, as this state is known to indicate cerebral functioning in various situations.

Neta Maimon, who specializes in musical cognition, explains that music has great influence on different centers in the brain. On the one hand, music is known to be a quick mood stimulant, particularly of positive emotion. On the other hand, in different situations, music can be cognitively challenging, activating the frontal parts of the brain, especially if we try to concentrate on different aspects of the music, and at the same time perform a particular task.

According to Maimon, if we combine these two capabilities, we can create cognitive tests that are quite complex, yet also pleasant and easy to perform. Furthermore, music that is positive and reasonably rhythmic will enhance concentration and performance of the task. Thus, for example, the famous "Mozart effect," showing improved performance on intelligence tests after listening to Mozart's music, actually has nothing to do with Mozart's music, but rather the fact that music creates a positive mood and stimulates us to a state that is optimal for performing intelligence and creativity tests.

Accordingly, the researchers hypothesized that with musical tools, it would also be possible to challenge the subjects to an extent that would enable testing of the brain's frontal activity as well as raising their spirits, thus enhancing their performance on the test while the overall experience is pleasant.

The study included an experiment at the Dorot-Netanya Geriatric Medical Center. Neta Maimon: "Anyone hospitalized at Dorot, or any other geriatric rehabilitation institution, undergoes a standard test called "mini-mental," designed to evaluate their cognitive condition as a routine part of the intake process. The test is conducted by an occupational therapist specially trained for it, and includes a variety of tasks. For example, enumerating the days of the week or months of the year backwards. In this test, up to 30 points can be accrued. A high score indicates normal cognition.

The experiment included the testing of 50 elderly people hospitalized at Dorot who scored 18-30 on the mini-mental test, indicating various levels of cognitive functioning. The participants performed the musical-cognitive tasks, administered automatically. The EEG device registered the electrical activity in the brain during the activity, with the results analyzed using machine learning technology. This allowed mathematical indices to be identified that were precisely correlated with the mini-mental test scores; in other words, we obtained new neuro-markers (brain markers) that may stand alone as indices of the subject's cognitive status.

Maimon adds: "We have actually succeeded in illustrating that music is indeed an effective tool for measuring brain activity. The brain activity and response times to tasks correlated to the subjects' cerebral conditions (correlating to the mini-mental score assigned to them). More importantly, all those who underwent the experiment reported that, on the one hand, it challenged the brain, but on the other it was very pleasant to perform."

The researchers conclude: "Our method enables the monitoring of cognitive capability and detection of cognitive decline already in the early stages. all by simple and accessible means, with a quick and easy test that can be conducted in any clinic. This method is of special importance today due to the increase in longevity and accelerated population growth, particularly among the elderly. Today, millions of people around the world already suffer or are liable to suffer soon from cognitive decline and its dire consequences, and their number will only increase in the coming decades. Our method could pave the way towards efficient cognitive monitoring of the general population, and thus detect cognitive decline in its early stages, when treatment and prevention of severe decline are possible. It is therefore expected to improve the quality of life of millions around the world."

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Video game players show enhanced brain activity, decision-making skill study

Frequent players of video games show superior sensorimotor decision-making skills and enhanced activity in key regions of the brain as compared to non-players, according to a recent study by Georgia State University researchers.

The authors, who used functional magnetic resonance imaging (FMRI) in the study, said the findings suggest that video games could be a useful tool for training in perceptual decision-making.

"Video games are played by the overwhelming majority of our youth more than three hours every week, but the beneficial effects on decision-making abilities and the brain are not exactly known," said lead researcher Mukesh Dhamala, associate professor in Georgia State's Department of Physics and Astronomy and the university's Neuroscience Institute.

"Our work provides some answers on that," Dhamala said. "Video game playing can effectively be used for training -- for example, decision-making efficiency training and therapeutic interventions -- once the relevant brain networks are identified."

Dhamala was the adviser for Tim Jordan, the lead author of the paper, who offered a personal example of how such research could inform the use of video games for training the brain.

Jordan, who received a Ph.D. in physics and astronomy from Georgia State in 2021, had weak vision in one eye as a child. As part of a research study when he was about 5, he was asked to cover his good eye and play video games as a way to strengthen the vision in the weak one. Jordan credits video game training with helping him go from legally blind in one eye to building strong capacity for visual processing, allowing him to eventually play lacrosse and paintball. He is now a postdoctoral researcher at UCLA.

The Georgia State research project involved 47 college-age participants, with 28 categorized as regular video game players and 19 as non-players.

The subjects laid inside an FMRI machine with a mirror that allowed them to see a cue immediately followed by a display of moving dots. Participants were asked to press a button in their right or left hand to indicate the direction the dots were moving, or resist pressing either button if there was no directional movement.

The study found that video game players were faster and more accurate with their responses.

Analysis of the resulting brain scans found that the differences were correlated with enhanced activity in certain parts of the brain.

"These results indicate that video game playing potentially enhances several of the subprocesses for sensation, perception and mapping to action to improve decision-making skills," the authors wrote. "These findings begin to illuminate how video game playing alters the brain in order to improve task performance and their potential implications for increasing task-specific activity."

The study also notes there was no trade-off between speed and accuracy of response -- the video game players were better on both measures.

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New window system allows for long-term studies of brain activity

Bilal Haider is studying how multiple areas of the brain work together for visual perception. This could help researchers understand if neural activity "traffic jams" underlie all kinds of visual impairments: from running a red light when visual attention is elsewhere, to shedding light on the autism-affected brain.

To do this kind of work, researchers need a reliable "map" of all the visual brain areas with specific coordinates for each unique brain. Drawing the map requires monitoring and recording data from an active, working brain, which usually means creating a window in the skull to watch blood flow activity.

Haider's team has developed a better approach -- a new kind of window that's more stable and allows for longer-term studies. The assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University explains how in a paper published in February in Scientific Reports, an open access forum of Nature publishing.

To get a clear image of the brain's visual network, Haider's lab uses an established technique called blood flow imaging, which tracks oxygen in the blood, measuring the active and inactive areas of a mouse brain while the animal views visual stimuli. To capture a strong blood flow signal, researchers typically create a cranial window by thinning the skull or removing a piece of it altogether. These procedures can diminish stability in the awake, pulsing brain -- detrimental conditions for delicate electrophysiological measurements made in the same visual areas after imaging.

"Standard windows give really good pictures of the vasculature," Haider said. "But the downside is, if you're working with an animal learning how to perform a sophisticated task that requires weeks of training, and you want to do neural recordings from the brain later, that area has been compromised if the skull is missing or thinned out."

The team's new cranial window system allows for high-quality blood flow imaging and stable electrical recordings for weeks or even months. The secret is a surgical glue called Vetbond -- which contains cyanoacrylate, the same compound that's in Krazy Glue -- and a tiny glass window.

Basically, a thin layer of the glue is applied to the skull with a micropipette and a curved glass coverslip is placed on top of that. The cyanoacrylate creates a "transparent skull" effect. Haider's team developed the new window system and then vetted the accuracy of the resulting visual brain maps.

"Sometimes the simplest things work. The glue creates a barrier allowing all of the normal physiological processes underneath to carry on, but leaving the bone transparent," Haider said. "It's like putting a protector on your smartphone. The protector is over the glass surface, but everything underneath stays crystal clear and functioning."

Haider's approach will help his team accomplish their larger goals -- to measure the activity of neurons in the brain's visual pathways and understand how neural traffic jams diminish our visual attention, and how these processes may contribute to visual impairments in people with autism. It's work that's getting a boost, thanks to recent support of the Simons Foundation Autism Research Initiative.

Haider said proper study of brain function requires repeatable measurements of neural activity, so he has made the new window system publicly available.

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Think about this: Keeping your brain active may delay Alzheimer's dementia 5 years

Keeping your brain active in old age has always been a smart idea, but a new study suggests that reading, writing letters and playing card games or puzzles in later life may delay the onset of Alzheimer's dementia by up to five years. The research is published in the July 14, 2021, online issue of Neurology, the medical journal of the American Academy of Neurology.

"The good news is that it's never too late to start doing the kinds of inexpensive, accessible activities we looked at in our study," said study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago. "Our findings suggest it may be beneficial to start doing these things, even in your 80s, to delay the onset of Alzheimer's dementia."

The study looked at 1,978 people with an average age of 80 who did not have dementia at the start of the study. The people were followed for an average of seven years. To determine if they had developed dementia, participants were given annual examinations, which included a number of cognitive tests.

When the study began, people rated their participation in seven activities on a five-point scale. The questions included: "During the past year, how often did you read books?" and "During the past year, how often did you play games like checkers, board games, cards or puzzles?"

Participants also answered questions about cognitive activity in childhood, adulthood and middle age.

Researchers then averaged each person's responses, with a score of one meaning once a year or less and score of five meaning every day or almost every day. People in the group with high cognitive activity scored an average of 4.0 which meant activities several times per week, compared to an average score of 2.1 for those with low cognitive activity, which meant activities several times per year.

During the study follow-up period, 457 people with an average age of 89 were diagnosed with Alzheimer's dementia. People with the highest levels of activity, on average, developed dementia at age 94. The people with the lowest cognitive activity, on average, developed dementia at age 89, a difference of five years. The results were similar when researchers adjusted for other factors that could affect dementia risk, such as education level and sex.

To test the idea that low cognitive activity may be an early sign of dementia, not the other way around, researchers also looked at the brains of 695 people who died during the study. Brain tissue was examined for markers of Alzheimer's like amyloid and tau protein deposits, but researchers found no association between how active they were cognitively and markers of Alzheimer's disease and related disorders in their brains.

"Our study shows that people who engage in more cognitively stimulating activities may be delaying the age at which they develop dementia," Wilson said. "It is important to note, after we accounted for late life level of cognitive activity, neither education nor early life cognitive activity were associated with the age at which a person developed Alzheimer's dementia. Our research suggests that the link between cognitive activity and the age at which a person developed dementia is mainly driven by the activities you do later in life."

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Measurable changes in brain activity during first few months of studying a new language

 A study with first-time learners of Japanese has measured how brain activity changes after just a few months of studying a new language. The results show that acquiring a new language initially boosts brain activity, which then reduces as language skills improve.

"In the first few months, you can quantitatively measure language-skill improvement by tracking brain activations," said Professor Kuniyoshi L. Sakai, a neuroscientist at the University of Tokyo and first author of the research recently published in Frontiers in Behavioral Neuroscience.

Researchers followed 15 volunteers as they moved to Tokyo and completed introductory Japanese classes for at least three hours each day. All volunteers were native speakers of European languages in their 20s who had previously studied English as children or teenagers, but had no prior experience studying Japanese or traveling to Japan.

Volunteers took multiple choice reading and listening tests after at least eight weeks of lessons and again six to fourteen weeks later. Researchers chose to assess only the "passive" language skills of reading and listening because those can be more objectively scored than the "active" skills of writing and speaking. Volunteers were inside a magnetic resonance imaging (MRI) scanner while taking the tests so that researchers could measure local blood flow around their brain regions, an indicator of neuronal activity.

"In simple terms, there are four brain regions specialized for language . Even in a native, second or third language, the same regions are responsible," said Sakai.

Those four regions are the grammar center and comprehension area in the left frontal lobe as well as the auditory processing and vocabulary areas in the temporo-parietal lobe. Additionally, the memory areas of the hippocampus and the vision areas of the brain, the occipital lobes, also become active to support the four language-related regions while taking the tests.

During the initial reading and listening tests, those areas of volunteers' brains showed significant increases in blood flow, revealing that the volunteers were thinking hard to recognize the characters and sounds of the unfamiliar language. Volunteers scored about 45% accuracy on the reading tests and 75% accuracy on the listening tests (random guessing on the multiple choice tests would produce 25% accuracy).

Researchers were able to distinguish between two subregions of the hippocampus during the listening tests. The observed activation pattern fits previously described roles for the anterior hippocampus in encoding new memories and for the posterior hippocampus in recalling stored information.

At the second test several weeks later, volunteers' reading test scores improved to an average of 55%. Their accuracy on the listening tests was unchanged, but they were faster to choose an answer, which researchers interpret as improved comprehension.

Comparing results from the first tests to the second tests, after additional weeks of study, researchers found decreased brain activation in the grammar center and comprehension area during listening tests, as well as in the visual areas of the occipital lobes during the reading tests.

"We expect that brain activation goes down after successfully learning a language because it doesn't require so much energy to understand," said Sakai.

Notably during the second listening test, volunteers had slightly increased activation of the auditory processing area of their temporal lobes, likely due to an improved "mind's voice" while hearing.

"Beginners have not mastered the sound patterns of the new language, so cannot hold in memory and imagine them well. They are still expending a lot of energy to recognize the speech in contrast to letters or grammar rules," said Sakai.

This pattern of brain activation changes -- a dramatic initial rise during the learning phase and a decline as the new language is successfully acquired and consolidated -- can give experts in the neurobiology of language a biometric tool to assess curricula for language learners or potentially for people regaining language skills lost after a stroke or other brain injury.

"In the future, we can measure brain activations to objectively compare different methods to learn a language and select a more effective technique," said Sakai.

Until an ideal method can be identified, researchers at UTokyo recommend acquiring a language in an immersion-style natural environment like studying abroad, or any way that simultaneously activates the brain's four language regions.

This pattern of brain activation over time in individual volunteers' brains mirrors results from previous research where Sakai and his collaborators worked with native Japanese-speaking 13- and 19-year-olds who learned English in standard Tokyo public school lessons. Six years of study seemed to allow the 19-year-olds to understand the second language well enough that brain activation levels reduced to levels similar to those of their native language.

The recent study confirmed this same pattern of brain activation changes over just a few months, not years, potentially providing encouragement for anyone looking to learn a new language as an adult.

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