Posts tagged brain activity
Articles and news from the latest research reports.
Playing computer games makes brains feel and think alike
Scientists have discovered that playing computer games can bring players’ emotional responses and brain activity into unison.
By measuring the activity of facial muscles and imaging the brain while gaming, the group found out that people go through similar emotions and display matching brainwaves. The study of Helsinki Institute for Information Technology HIIT researchers is now published in PLOS ONE.
– It’s well known that people who communicate face-to-face will start to imitate each other. People adopt each other’s poses and gestures, much like infectious yawning. What is less known is that the very physiology of interacting people shows a type of mimicry – which we call synchrony or linkage, explains Michiel Sovijärvi-Spapé.
In the study, test participants play a computer game called Hedgewars, in which they manage their own team of animated hedgehogs and in turns shoot the opposing team with ballistic artillery. The goal is to destroy the opposing team’s hedgehogs. The research team varied the amount of competitiveness in the gaming situation: players teamed up against the computer and they were also pinned directly against each other.
The players were measured for facial muscle reactions with facial electromyography, or fEMG, and their brainwaves were measured with electroencephalography, EEG.
– Replicating previous studies, we found linkage in the fEMG: two players showed both similar emotions and similar brainwaves at similar times. We further observed a linkage also in the brainwaves with EEG, tells Sovijärvi-Spapé.
A striking discovery indicates further that the more competitive the gaming gets, the more in sync are the emotional responses of the players. The test subjects were to report emotions themselves, and negative emotions were associated with the linkage effect.
– Although counterintuitive, the discovered effect increases as a game becomes more competitive. And the more competitive it gets, the more the players’ positive emotions begin to reflect each other. All the while their experiences of negative emotions increase.
The results present promising upshots for further study.
– Feeling others’ emotions could be particularly beneficial in competitive settings: the linkage may enable one to better anticipate the actions of opponents.
Another interpretation suggested by the group is that the physical linkage of emotion may work to compensate a possibly faltering social bond while competing in a gaming setting.
– Since our participants were all friends before the game, we can speculate that the linkage is most prominent when a friendship is ‘threatened’ while competing against each other, ponders Sovijärvi-Spapé.
Shedding new light on learning disorders
A Michigan State University researcher has discovered the first anatomical evidence that the brains of children with a nonverbal learning disability – long considered a “pseudo” diagnosis – may develop differently than the brains of other children.
The finding, published in Child Neuropsychology, could ultimately help educators and clinicians better distinguish between – and treat – children with a nonverbal learning disability, or NLVD, and those with Asperger’s, or high functioning autism, which is often confused with NLVD.
“Children with nonverbal learning disabilities and Asperger’s can look very similar, but they can have very different reasons for why they behave the way they do,” said Jodene Fine, assistant professor of school psychology in MSU’s College of Education.
Understanding the biological differences in children with learning and behavioral challenges could help lead to more appropriate intervention strategies.
Children with nonverbal learning disability tend to have normal language skills but below average math skills and difficulty solving visual puzzles. Because many of these kids also show difficulty understanding social cues, some experts have argued that NVLD is related to high functioning autism – which this latest study suggests may not be so.
Fine and Kayla Musielak, an MSU doctoral student in school psychology, studied about 150 children ages 8 to 18. Using MRI scans of the participants’ brains, the researchers found that the children diagnosed with NVLD had smaller spleniums than children with other learning disorders such as Asperger’s and ADHD, and children who had no learning disorders.
The splenium is part of the corpus callosum, a thick band of fibers in the brain that connects the left and right hemispheres and facilitates communication between the two sides. Interestingly, this posterior part of the corpus callosum serves the areas of the brain related to visual and spatial functioning.
In a second part of the study, the participants’ brain activity was analyzed after they were shown videos in an MRI that portrayed both positive and negative examples of social interaction. (A typical example of a positive event was a child opening a desired birthday present with friend; a negative event included a child being teased by other children.)
The researchers found that the brains of children with nonverbal learning disability responded differently to the social interactions than the brains of children with high functioning autism, or HFA, suggesting the neural pathways that underlie those behaviors may be different.
“So what we have is evidence of a structural difference in the brains of children with NLVD and HFA, as well as evidence of a functional difference in the way their brains behave when they are presented with stimuli,” Fine said.
While more research is needed to better understand how nonverbal learning disability fits into the family of learning disorders, Fine said her findings present “an interesting piece of the puzzle.”
“I would say at this point we still don’t have enough evidence to say NVLD is a distinct diagnosis, but I do think our research supports the idea that it might be,” she said.
Connections in the brains of young children strengthen during sleep
While young children sleep, connections between the left and the right hemispheres of their brain strengthen, which may help brain functions mature, according to a new study by the University of Colorado Boulder.
The research team—led by Salome Kurth, a postdoctoral researcher, and Monique LeBourgeois, assistant professor in integrative physiology—used electroencephalograms, or EEGs, to measure the brain activity of eight sleeping children multiple times at the ages of 2, 3 and 5 years.
“Interestingly, during a night of sleep, connections weakened within hemispheres but strengthened between hemispheres,” Kurth said.
Scientists have known that the brain changes drastically during early childhood: New connections are formed, others are removed and a fatty layer called “myelin” forms around nerve fibers in the brain. The growth of myelin strengthens the connections by speeding up the transfer of information.
Maturation of nerve fibers leads to improvement in skills such as language, attention and impulse control. But it is still not clear what role sleep plays in the development of such brain connections.
In the new study, appearing online in the journal Brain Sciences, the researchers looked at differences in brain activity during sleep as the children got older and differences in brain activity of each child over a night’s sleep. They found that connections in the brain generally became stronger during sleep as the children aged. They also found that the strength of the connections between the left and right hemispheres increased by as much as 20 percent over a night’s sleep.
“There are strong indications that sleep and brain maturation are closely related, but at this time, it is not known how sleep leads to changes in brain structure,” Kurth said.
Future studies will be aimed at determining how sleep disruption during childhood may affect brain development and behavior.
“I believe inadequate sleep in childhood may affect the maturation of the brain related to the emergence of developmental or mood disorders,” Kurth said.
Glowing Worms Illuminate Roots of Behavior
A research team at Worcester Polytechnic Institute (WPI) and The Rockefeller University in New York has developed a novel system to image brain activity in multiple awake and unconstrained worms. The technology, which makes it possible to study the genetics and neural circuitry associated with animal behavior, can also be used as a high-throughput screening tool for drug development targeting autism, anxiety, depression, schizophrenia, and other brain disorders.
Image: Neurons in the worms (marked by arrows) glow as the animals sense attractive odors.
The team details their technology and early results in the paper “High-throughput imaging of neuronal activity in Caenorhabditis elegans,” published on-line in advance of print by the journal Proceedings of the National Academy of Sciences.
"One of our major objectives is to understand the neural signals that direct behavior—how sensory information is processed through a network of neurons leading to specific decisions and responses," said Dirk Albrecht, PhD, assistant professor of biomedical engineering at WPI and senior author of the paper. Albrecht led the research team both at WPI and at Rockefeller, where he served previously as a postdoctoral researcher in the lab of Cori Bargmann, PhD, a Howard Hughes Medical Institute Investigator and a co-author of the new paper.
To study neuronal activity, Albrecht’s lab uses the tiny worm Caenorhabditis elegans (C. elegans), a nematode found in many environments around the world. A typical adult C. elegans is just 1 millimeter long and has 969 cells, of which 302 are neurons. Despite its small size, the worm is a complex organism able to do all of the things animals must do to survive. It can move, eat, mate, and process environmental cues that help it forage for food or react to threats. As a bonus for researchers, C.elegans is transparent. By using various imaging technologies, including optical microscopes, one can literally see into the worm and watch physiological processes in real time.
Numerous studies have been done by “worm labs” around the world exploring various neurological processes in C. elegans. These have typically been done using one worm at a time, with the animal’s body fixed in place on a slide. In their new paper, Albrecht’s team details how they imaged, recorded, and analyzed specific neurons in multiple animals as they wormed their way around a custom-designed microfluidic array, called an arena, where they were exposed to favorable or hostile sensory cues.
Specifically, the team engineered a strain of worms with neurons near the head that would glow when they sensed food odors. In experiments involving up to 23 worms at a time, Albrecht’s team infused pulses of attractive or repulsive odors into the arena and watched how the worms reacted. In general, the worms moved towards the positive odors and away from the negative odors, but the behaviors did not always follow this pattern. “We were able to show that the sensory neurons responded to the odors similarly in all the animals, but their behavioral responses differed significantly,” Albrecht said. “These animals are genetically identical, and they were raised together in the same environment, so where do their different choices come from?”
In addition to watching the head neurons light up as they picked up odor cues, the new system can trace signaling through “interneurons.” These are pathways that connect external sensors to the rest of the network (the “worm brain”) and send signals to muscle cells that adjust the worm’s movement based on the cues. Numerous brain disorders in people are believed to arise when neural networks malfunction. In some cases the malfunction is dramatic overreaction to a routine stimulus, while in others it is a lack of appropriate reactions to important cues. Since C. elegans and humans share many of the same genes, discovering genetic causes for differing neuronal responses in worms could be applicable to human physiology. Experimental compounds designed to modulate the action of nerve cells and neuronal networks could be tested first on worms using Albrecht’s new system. The compounds would be infused in the worm arena, along with other stimuli, and the reaction of the worms’ nervous systems could be imaged and analyzed.
"The basis of our work is to combine biomedical engineering and neuroscience to answer some of these fundamental questions and hopefully gain insight that would be beneficial for understanding and eventually treating human disorders," Albrecht said.
(Source: wpi.edu)
Our relationship with food: What drives us to eat and new insights into eating disorders
A growing body of evidence shows the impact of diet on brain function, and identifies patterns of brain activity associated with eating disorders such as binge eating and purging. The findings were presented at Neuroscience 2013, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.
Millions of people worldwide suffer from eating disorders such as anorexia, bulimia, and binge eating. With increased risk for psychiatric and chronic diseases, today’s studies are valuable in helping generate new strategies to treat disorders from obesity to anorexia.
Today’s new findings show that:
- Targeted magnetic stimulation of the brain reduces the symptoms of severe eating disorders, including bingeing and purging. These findings may represent a new treatment tool for patients with eating disorders (Jonathan Downar, MD, PhD, abstract 540.01, see attached summary).
- Rats that are more naturally impulsive tend to consume more calories on a binge. Findings suggest that this may be due to an imbalance in the brain’s serotonin system (Noelle Anastasio, PhD, abstract 547.13, see attached summary).
Other recent findings discussed show that:
- Consuming a diet of red meat and processed foods is linked to a decline in verybal memory in the elderly after just 36 months (Samantha Gardener, see attached summary).
- Consuming cannabis can influence body weight ofoffspring for generations (Yasmin Hurd, PhD, presentation 685.05, see attached speaker summary).
- Eating a sweet, high-fat meal sets off a series of events that includes the release of insulin and suppression of dopamine, leading to less interest in food-related cues in the environment (Stephanie Borgland, PhD, presentation 685.06, see attached speaker summary).
“As scientists uncover the impacts of diet on brain function, the adage ‘You are what you eat,’ takes on new meaning,” said press conference moderator Fernando Gomez-Pinilla, PhD, of the University of California, Los Angeles, an expert in the impact of the environment on brain health. “We cannot separate the nutritional benefits of food for the body from that of the mind. What we put into the body also shapes the brain, for better or for worse.”
New links between social status and brain activity
New studies released today reveal links between social status and specific brain structures and activity, particularly in the context of social stress. The findings were presented at Neuroscience 2013, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.
Using human and animal models, these studies may help explain why position in social hierarchies strongly influences decision-making, motivation, and altruism, as well as physical and mental health. Understanding social decision-making and social ladders may also aid strategies to enhance cooperation and could be applied to everyday situations from the classroom to the boardroom.
Today’s new findings show that:
- Adult rats living in disrupted environments produce fewer new brain cells than rats in stable societies, supporting theories that unstable conditions impair mental health and cognition (Maya Opendak, abstract 85.11, see attached summary).
- People who have many friends have certain brain regions that are bigger and better connected than those with fewer friends. It’s unknown whether their brains were predisposed to social engagement or whether larger social networks prompted brain development (Maryann Noonan, PhD, abstract 667.11, see attached summary).
- In situations where monkeys can potentially cooperate to improve their mutual reward, certain groups of brain cells work to accurately predict the responses of other monkeys (Keren Haroush, PhD, abstract 668.08, see attached summary).
- Following extreme social stress, enhancing brain changes associated with depression can have ananti-depressant effect in mice (Allyson Friedman, PhD, abstract 504.05, see attached summary).
Other recent findings discussed show that:
- Defeats heighten sensitivity to social hierarchies and may exacerbate brain activity related to social anxiety (Romain Ligneul, presentation 186.12, see attached speaker summary).
“Social subordination and social instability have been associated with an increased incidence of mental illness in humans,” said press conference moderator Larry Young, PhD, of Emory University, an expert in brain functions involved with social behavior. “We now have a better picture of how these situations impact the brain. While this information could lead to new treatments, it also calls on us to evaluate how we construct social hierarchies — whether in the workplace or school — and their impacts on human well-being.”
Looking for a needle in a haystack: new research shows how brain prepares to start searching
Many of us have steeled ourselves for those ‘needle in a haystack’ tasks of finding our vehicle in an airport car park, or scouring the supermarket shelves for a favourite brand.
A new scientific study has revealed that our understanding of how the human brain prepares to perform visual search tasks of varying difficulty may now need to be revised.
When people search for a specific object, they tend to hold in mind a visual representation of it, based on key attributes like shape, size or colour. Scientists call this ‘advanced specification’. For example, we might search for a friend at a busy railway station by scanning the platform for someone who is very tall or who is wearing a green coat, or a combination of these characteristics.
Researchers from the School of Psychology at the University of Lincoln, UK, set out to better explain how these abstract visual representations are formed. They used fMRI scanners to record neural activity when volunteers prepared to search for a target object: a coloured letter amid a screen of other coloured letters.
Their findings, published in the journal ‘Brain Research’, are the first to fully isolate the different areas of the human brain involved in this ‘prepare to search’ function. Surprisingly, they show that the advanced frontal areas of the brain, usually key to advanced cognitive tasks, appear to take a backseat. Instead it is the basic back areas of the brain and the sub-cortical areas that do the work.
Dr Patrick Bourke from the University of Lincoln’s School of Psychology, who led the study, said: “Up until now, when researchers have studied visual search tasks they have also found that frontal areas of the brain were active. This has been assumed to indicate a control system: an ‘executive’ that largely resides in the advanced front of the brain which sends signals to the simpler back of the brain, activating visual memories. Here, when we isolated the ‘prepare’ part of the task from the actual search and response phase we found that this activation in the front was no longer present.”
This finding has important implications for understanding the fundamental brain processes involved. It was previously thought that the Intra-parietal region of the brain, which is linked to visual attention, was the central component of the supposed ‘front-back’ control network, relaying useful information (such as a shape or colour bias) from frontal areas of the brain to the back, where simple visual representations of the object are held. If the frontal areas are not activated in the preparation phase, this cannot be the case.
The study also showed that the pattern of brain activation varied depending on the anticipated difficulty of the search task, even when the target object was the same. This indicates that rather than holding in mind a single representation of an object, a new target is constructed each time, depending on the nature of the task.
Dr Bourke added: “While consistent with previous brain imaging work on visual search, these results change the interpretations and assumptions that have been applied previously. Notably, they highlight a difference between studies of animals’ brains and those of humans. Studies with monkeys convincingly show the front-back control system and we thought we understood how this worked. At the same time our findings are consistent with a growing body of brain imaging work in humans that also shows no frontal brain activation when short term memories are held.”
(Source: lincoln.ac.uk)
What do bullies and sex have in common? Based on work by scientists at the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, it seems that the same part of the brain reacts to both. In a study published today in Nature Neuroscience, the researchers found that – at least in mice – different types of fear are processed by different groups of neurons, even if the animals act out those fears in the same way. The findings could have implications for addressing phobias and panic attacks in humans.
“We found that there seems to be a circuit for handling fear of predators – which has been described anatomically as a kind of defence circuit – but fear of members of the same species uses the reproductive circuit instead,” says Bianca Silva, who carried out the work, “and fear of pain goes through yet another part of the brain.”
Working in the lab of Cornelius Gross at EMBL, Silva exposed mice to three threats: another mouse (chosen for being particularly aggressive), a rat (the mouse’s natural predator) or a mild electric shock to the feet. The mice showed the same typical fearful behaviours – running away, freezing – in response to all threats, but their brains painted a different picture. When the scientists mapped the brain activity of mice exposed to the aggressive mouse and the rat, they saw that different parts of a region called the ventromedial hypothalamus (VMH) ‘lit up’ depending on the threat. Fear of the mouse seemed to activate the bottom and sides of the VMH, while fear of the rat seemed to be processed by the VMH’s central and upper areas. This was confirmed when the scientists used drugs to block only the neurons in those ‘rat fear’ areas: mice were no longer afraid of the rat, but were still afraid of the mouse, showing that mice need this brain circuit specifically to process fear of predators.
The human brain has similar circuits, and we too experience different kinds of fear, so the results hint at the possibility of developing more efficient treatments for specific phobias or panic attacks, by targeting only the relevant region of the brain.
For their part, the EMBL scientists plan to probe these fears further.
“What we’re interested in, in the long-run, is if these results represent a kind of mental state,” says Cornelius Gross, who led the work. “If so, mice should be able to be in that state without expressing it in their behaviour – do they re-live that fear, for example? These are not easy questions to ask in the mouse, but we’re looking into them.”
Gross’s lab are also looking at how these different fears – and the neural circuits that process them – may have evolved. Working with Detlev Arendt’s group at EMBL Heidelberg, they have discovered a similar brain region in a marine worm thought to closely resemble our ancestors from 600 million years ago. Now the team is exploring the possibility that this represents an ancestral core fear circuit that those ancestors handed down to us all, from worms to man.
Exercise during pregnancy gives newborn brain development a head start
As little as 20 minutes of moderate exercise three times per week during pregnancy enhances the newborn child’s brain development, according to researchers at the University of Montreal and its affiliated CHU Sainte-Justine children’s hospital. This head-start could have an impact on the child’s entire life. “Our research indicates that exercise during pregnancy enhances the newborn child’s brain development,” explained Professor Dave Ellemberg, who led the study. “While animal studies have shown similar results, this is the first randomized controlled trial in humans to objectively measure the impact of exercise during pregnancy directly on the newborn’s brain. We hope these results will guide public health interventions and research on brain plasticity. Most of all, we are optimistic that this will encourage women to change their health habits, given that the simple act of exercising during pregnancy could make a difference for their child’s future.” Ellemberg and his colleagues Professor Daniel Curnier and PhD candidate Élise Labonté-LeMoyne presented their findings today at the Neuroscience 2013 congress in San Diego.
Not so long ago, obstetricians would tell women to take it easy and rest during their pregnancy. Recently, the tides have turned and it is now commonly accepted that inactivity is actually a health concern. “While being sedentary increases the risks of suffering complications during pregnancy, being active can ease post-partum recovery, make pregnancy more comfortable and reduce the risk of obesity in the children,” Curier explained. “Given that exercise has been demonstrated to be beneficial for the adult’s brain, we hypothesized that it could also be beneficial for the unborn child through the mother’s actions.”
To verify this, starting at the beginning of their second trimester, women were randomly assigned to an exercise group or a sedentary group. Women in the exercise group had to perform at least 20 minutes of cardiovascular exercise three times per week at a moderate intensity, which should lead to at least a slight shortness of breath. Women in the sedentary group did not exercise. The brain activity of the newborns was assessed between the ages of 8 to 12 days, by means of electroencephalography, which enables the recording of the electrical activity of the brain. “We used 124 soft electrodes placed on the infant’s head and waited for the child to fall asleep on his or her mother’s lap. We then measured auditory memory by means of the brain’s unconscious response to repeated and novel sounds,” Labonté-LeMoyne said. “Our results show that the babies born from the mothers who were physically active have a more mature cerebral activation, suggesting that their brains developed more rapidly.”
The researchers are now in the process of evaluating the children’s cognitive, motor and language development at age 1 to verify if these differences are maintained.
(Source: nouvelles.umontreal.ca)
New Study Decodes Brain’s Process for Decision Making
When faced with a choice, the brain retrieves specific traces of memories, rather than a generalized overview of past experiences, from its mental Rolodex, according to new brain-imaging research from The University of Texas at Austin.
Led by Michael Mack, a postdoctoral researcher in the departments of psychology and neuroscience, the study is the first to combine computer simulations with brain-imaging data to compare two different types of decision-making models.
In one model — exemplar — a decision is framed around concrete traces of memories, while in the other model — prototype — the decision is based on a generalized overview of all memories lumped into a specific category.
Whether one model drives decisions more than the other has remained a matter of debate among scientists for more than three decades. But according to the findings, the exemplar model is more consistent with decision-making behavior.
The study was published this month in Current Biology. The authors include Alison Preston, associate professor in the Department of Psychology and the Center for Learning and Memory; and Bradley Love, a professor at University College London.
In the study, 20 respondents were asked to sort various shapes into two categories. During the task their brain activity was observed using functional magnetic resonance imaging (fMRI), allowing researchers to see how the respondents associate shapes with past memories.
According to the findings, behavioral research alone cannot determine whether a subject uses the exemplar or prototype model to make decisions. With brain-imaging analysis, researchers found that the exemplar model accounted for the majority of participants’ decisions. The results show three different regions associated with the exemplar model were activated during the learning task: occipital (visual perception), parietal (sensory) and frontal cortex (attention).
While processing new information, the brain stores concrete traces of experiences, allowing it to make different kinds of decisions, such as categorization information (is that a dog?), identification (is that John’s dog?) and recall (when did I last see John’s dog?).
To illustrate, Mack says: Imagine having a conversation with a friend about buying a new car. When you think of the category “car,” you’re likely to think of an abstract concept of a car, but not specific details. However, abstract categories are composed of memories from individual experiences. So when you imagine “car,” the abstract mental picture is actually derived from experiences, such as your friend’s white sedan or the red sports car you saw on the morning commute.
“We flexibly memorize our experiences, and this allows us to use these memories for different kinds of decisions,” Mack says. “By storing concrete traces of our experiences, we can make decisions about different types of cars and even specific past experiences in our life with the same memories.”
Mack says this new approach to model-based cognitive neuroscience could lead to discoveries in cognitive research.
“The field has struggled with linking theories of how we behave and act to the activation measures we see in the brain,” Mack says. “Our work offers a method to move beyond simply looking at blobs of brain activation. Instead, we use patterns of brain activation to decode the algorithms underlying cognitive behaviors like decision making.”
(Source: utexas.edu)