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Near bottom: focus triggered by new activity or movement?

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

Synchronizing Gait with Cardiac Cycle Phase Alters Heart Rat... : Medicine & Science in Sports & Exercise

Finally, if diastolic stepping is truly advantageous for exercise performance, we wondered if there is any natural tendency for elite runners to step diastolically without prompting. We observed that 3 of the 10 subjects stepped accurately at the diastolic target timing (45% ± 15% RRI) during a substantial portion of their final, unprompted (silent) control period (e.g., see Fig. 2B). In one of those cases, the subject was guided to systolic step timing during the final prompted period but naturally reverted to stepping during diastole when the auditory prompt was removed. By comparison, none of the subjects stepped at a consistent systolic phase during the free stepping control stages. These anecdotal observations are also consistent with the findings of earlier authors, including Niizeki (10), which suggested that the heart automatically adjusts its timing, when HR = SR, to prevent ventricular systole from coinciding with maximal peripheral skeletal muscle contraction.

Could consciousness all come down to the way things vibrate?

The central thesis of our approach is this: the particular linkages that allow for large-scale consciousness – like those humans and other mammals enjoy – result from a shared resonance among many smaller constituents. The speed of the resonant waves that are present is the limiting factor that determines the size of each conscious entity in each moment. As a particular shared resonance expands to more and more constituents, the new conscious entity that results from this resonance and combination grows larger and more complex. So the shared resonance in a human brain that achieves gamma synchrony, for example, includes a far larger number of neurons and neuronal connections than is the case for beta or theta rhythms alone. What about larger inter-organism resonance like the cloud of fireflies with their little lights flashing in sync? Researchers think their bioluminescent resonance arises due to internal biological oscillators that automatically result in each firefly syncing up with its neighbors.

Could consciousness all come down to the way things vibrate?

Gamma waves are associated with large-scale coordinated activities like perception, meditation or focused consciousness; beta with maximum brain activity or arousal; and theta with relaxation or daydreaming. These three wave types work together to produce, or at least facilitate, various types of human consciousness, according to Fries. But the exact relationship between electrical brain waves and consciousness is still very much up for debate. Fries calls his concept “communication through coherence.” For him, it’s all about neuronal synchronization. Synchronization, in terms of shared electrical oscillation rates, allows for smooth communication between neurons and groups of neurons. Without this kind of synchronized coherence, inputs arrive at random phases of the neuron excitability cycle and are ineffective, or at least much less effective, in communication.

An Amygdala-Hippocampus Subnetwork that Encodes Variation in Human Mood: Cell

The most common subnetwork, found in 13 of 21 subjects, was characterized by β-frequency coherence (13-30 Hz) between the amygdala and hippocampus. Increased variability of this subnetwork correlated with worsening mood across these 13 subjects. Moreover, these subjects had significantly higher trait anxiety than the 8 of 21 for whom this amygdala-hippocampus subnetwork was absent.

Brain signature of depressed mood unveiled in new study: Direct recordings of human brain activity link memory, emotion, and anxiety during bouts of low mood -- ScienceDaily

Then, to compare results across the unique brains and distinct electrode placements of all 21 research participants, the researchers mapped each subject's ICNs onto neural connectivity diagrams. Comparing these standardized records of network activity across subjects revealed several "cliques" -- groups of brain regions that repeatedly became synchronized at specific frequencies, and were therefore likely to represent functional brain networks. One such clique was highly active and coordinated in 13 research participants, all of whom had also scored high on a psychological assessment of baseline anxiety conducted prior to the start of the study. In these same individuals, changes in the activity of this brain network were also highly correlated with day-to-day bouts of low or depressed mood. This mood-related network was characterized by so-called beta waves -- synchronized oscillations between 13 and 30 cycles per second -- in the hippocampus and amygdala, two deep brain regions which have long been linked, respectively, to memory and to negative emotion. Sohal said the research team was at first taken aback by the clarity of the finding. "We were quite surprised to identify a single signal that almost completely accounted for bouts of depressed mood in such a large set of people," said Sohal. "Finding such a powerfully informative biomarker was more than what we'd expected at this stage of the project." Surprisingly, this powerful link between of mood-associated beta waves in the amygdala and hippocampus was entirely absent from eight other research participants, all of whom had comparatively low preexisting anxiety, suggesting new questions about how the brains of people prone to anxiety may differ from others in how they process emotional situations.

If pigeons were brilliant, would they flock? Study finds people flock, or behave similarly to others, despite reasoning abilities -- ScienceDaily

Frey explained that flocking, in life, can be good or bad. It can be good for schools of fish, flocking birds, or team cyclists in a race -- where in each case group members gain a greater ability to obtain food, be safe or to win. But flocking can be undesirable in a stock market fall or a riot, for instance, where safety, survival or "winning" can be jeopardized. ." ..These games show that sophisticated human reasoning processes may be just as likely to drive the complex, often pathological, social dynamics that we usually attribute to reactive, emotional, nondeliberative reasoning," the researchers conclude. "In other words, human intelligence may as likely increase as decrease the complexity and unpredictability of social and economic outcomes."

Resynchronizing Neurons to Erase Schizophrenia - Neuroscience News

he Geneva neuroscientists chose to focus on neural networks of the hippocampus, a brain structure notably involved in memory. They studied a mouse model that reproduces the genetic alteration of DiGeorge syndrome as well as some behavioural changes associated with schizophrenia. In the hippocampus of a control mouse, the thousands of neurons that make up the network coordinate according to a very precise sequence of activity, which is dynamic in time and synchronized. However, in the neural networks of their mouse models, the scientists observed something completely different: the neurons showed the same level of activity as in control animals, but without any coordination, as if these cells were incapable of communicating properly with each other. “The organization and synchronization of neural networks is achieved through the intervention of subpopulations of inhibitory neurons, including parvalbumin neurons,» says Carleton. “However, in this animal model of schizophrenia, these neurons are much less active. Without proper inhibition to control and structure the electrical activity of other neurons in the network, anarchy rules. ”

How attention orchestrates groups of nerve cells to enrich the brain's symphony -- ScienceDaily

Silence in the concert hall. The conductor raises the baton and the strings begin. They play the first four bars of Mozart's "A Little Night Music." All together they play a single melody, which is probably one of the best known in the music world. Then the voices divide. Different string instruments play separate melodies and the "Little Night Music" thus becomes a complex work of art. Scientists from the German Primate Center (DPZ) -- Leibniz Institute for Primate Research in Göttingen and Institute for Research in Fundamental Sciences in Tehran, Iran, recently discovered in a study with rhesus monkeys that nerve cells assume the role of musicians in visual perception in our brain. Usually many cells are active together (synchronously) when they process simple stimuli from our environment. The researchers were able to show that visual attention desynchronizes these nerve cells' activity and thus enables more complex information processing. Such insights into the neural mechanisms of attention in the healthy state may provide evidence of mechanisms underlying neuronal diseases such as attention deficit hyperactivity disorder (ADHD) or autism (BMC Biology).

Tight-knit teammates may conform to each other's behavior -- ScienceDaily

After analyzing the data, the researchers found that participants who felt more closely connected to their teammates and identified strongly as part of the team were more likely to engage in risky behaviors like binge drinking, marijuana use and hazing if they believed their teammates were already doing these activities. Additionally, athletes who belonged to teams that as a whole reported being especially close were more likely to say they would conceal a concussion to remain in play. Graupensperger said the findings -- recently published in the Journal of Sport and Exercise Psychology -- suggest that teams should try to find positive ways to encourage bonding between players. "The silver lining is that we did find that conforming does also work similarly for positive behaviors," Graupensperger said. "This finding also generalizes to behaviors like volunteering. So our challenge going forward would be to try to reduce pressures to conform to negative behaviors while still encouraging identifying closely with your teammates."

The heart: Digital or analog? Researchers shed dramatic light on heart bioelectricity disorders -- ScienceDaily

"Sodium channels are literally stuck together between cells in way that seems to ensure that the firing of channels in one cell sparks partnering channels in the neighboring cell," Gourdie said. "The molecular machinery seems to be in place for bioelectrical signals to step between heart cells, not wholly unlike how impulses jump between nerve cells in a stepping-stone-like manner at neural synapses."

The spotlight of attention is more like a strobe light -- ScienceDaily

"Our subjective experience of the visual world is an illusion," said Sabine Kastner, a professor of psychology and the Princeton Neuroscience Institute (PNI). "Perception is discontinuous, going rhythmically through short time windows when we can perceive more or less." The researchers use different metaphors to describe this throb of attention, including a spotlight that waxes and wanes in its intensity. Four times per second -- once every 250 milliseconds -- the spotlight dims and the house lights come up. Instead of focusing on the action "onstage," your brain takes in everything else around you, say the scientists. Their work appears as a set of back-to-back papers in in the Aug. 22 issue of Neuron; one paper focuses on human research subjects, the other on macaque monkeys. "The question is: How can something that varies in time support our seemingly continuous perception of the world?" said Berkeley's Randolph Helfrich, first author on the human-focused paper. "There are only two options: Is the data wrong, or is our understanding of our perception biased? Our research shows that it's the latter. Our brains fuse our perceptions into a coherent movie -- we don't experience the gaps."

How Shift Work Disrupts Metabolism - Neuroscience News

They found that, following the night shift schedule, 24-hour rhythms in metabolites related to the digestive system had shifted by a full 12 hours, even though the master biological clock in participants’ brains had only moved by about 2 hours. Biological clocks in digestive organs “No one knew that biological clocks in people’s digestive organs are so profoundly and quickly changed by shift work schedules, even though the brain’s master clock barely adapts to such schedules,” said co-senior author Hans Van Dongen, director of the WSU Sleep and Performance Research Center and a professor in the Elson S. Floyd College of Medicine. “As a result, some biological signals in shift workers’ bodies are saying it’s day while other signals are saying it’s night, which causes disruption of metabolism.”

Pando, the Trembling Giant – Richfield, Utah - Atlas Obscura

Spanning 107 acres and weighing 6,615 tons, Pando was once thought to be the world’s largest organism (now usurped by thousand-acre fungal mats in Oregon), and is almost certainly the most massive. In terms of other superlatives, the more optimistic estimates of Pando’s age have it as over one million years old, which would easily make it one of the world’s oldest living organisms.

Absence epilepsy: When the brain is like 'an orchestra without a conductor' -- ScienceDaily

"Normally the human brain, like an orchestra, is playing beautiful music and every player can understand what the others are playing. We thought that when a seizure started, the 'orchestra of neurons' would play extremely loud and intense music. And when the seizure ended, the neurons would go back to playing monotonous music," Maheshwari said. "Instead, we found that during an absence seizure the volume of the music went down and the 'musicians' were playing music without coordinating with others. Most of them were not playing at all, as if the conductor was not there anymore. When the seizure ended, it was like the conductor had returned and organized the musicians to play harmoniously again."

Waves Move Across the Human Brain to Support Memory - Neuroscience News

“We also found that these traveling waves moved more reliably when subjects performed well while performing a working memory task,” says Joshua Jacobs, assistant professor of biomedical engineering and senior author of the paper. “This indicates that traveling waves are significant for memory and cognition–our findings show that these oscillations are an important mechanism for large-scale coordination in the human brain.”

Neurons ripple while brains rest to lock in memories: How quiet minds encode spatial maps while 'introspecting' -- ScienceDaily

"Animals encode a memory of an environment as they run around," said Kemere, an assistant professor of electrical and computer engineering who specializes in neuroscience. "They form a spatial map as individual neurons are activated in different places. When they're awake in our experiments, they're probably doing that exploration process 40 to 60 percent of the time. "But for the other 40 percent, they're scratching themselves, or they're eating, or they're sort of snoozing," he said. "They're not asleep, but they're paused; I like to call it introspecting." Those periods of introspection provided the critical data for the study that inverted the usual process of matching brain activity to movement while the animals were active. The primary data was gathered over the course of many experiments under the direction of Diba, an associate professor and leader of the Neural Circuits and Memory Lab at Michigan Medicine. As the animals explored either back-and-forth tracks or maze-like environments, electrodes in their brains sensed sharp wave-associated bursts of neural activity called population burst events (PBEs). In these events, between 50,000 and 100,000 neurons all fire within 100 milliseconds and send ripples throughout the brain that are not yet fully understood.

The role of touch in regulating inter-partner physiological coupling during empathy for pain | Scientific Reports

The results indicate that the partner touch increased interpersonal respiration coupling under both pain and no-pain conditions and increased heart rate coupling under pain conditions. In addition, physiological coupling was diminished by pain in the absence of the partner’s touch. Critically, we found that high partner’s empathy and high levels of analgesia enhanced coupling during the partner’s touch.

Association of Depressive Symptoms and Heart Rate Variability in Vietnam War–Era Twins: A Longitudinal Twin Difference Study | Cardiology | JAMA Psychiatry | JAMA Network

The association between depression and autonomic dysregulation, indexed by HRV, is bidirectional, with stronger evidence suggesting that autonomic function affects depression risk rather than vice versa. The opposite causal pathway from depression to lower HRV is mostly driven by antidepressant use. These findings highlight an important role of autonomic nervous system in the risk of depression and contribute new understanding of the mechanisms underlying the comorbidity of depression and cardiovascular disease.

Tick tock: Study links body clock to mood disorders | AFP.com

or the new study, an international team led by University of Glasgow psychologist Laura Lyall analysed data -- taken from the UK Biobank, one of the most complete long-term health surveys ever done -- on 91,105 people aged 37 to 73. The volunteers wore accelerometers that measured patterns of rest and activity and had this record compared to their mental history, also taken from the UK Biobank. Individuals with a history of disrupting their body's natural rhythm -- working night shifts, for example, or suffering repeated jetlag -- also tended to have a higher lifetime risk of mood disorders, feelings of unhappiness, and cognitive problems, the researchers found.

Brain Activity Alternates While Stepping - Neuroscience News

The researchers found that activity in the 20-30 Hz (beta) range alternated between the left and right STN when the opposite foot touched the ground and the other foot was to be raised. The introduction of a metronome synchronized to the cartoon steps improved participants’ accuracy and enhanced their STN beta activity accordingly.

Seniors stick to fitness routines when they work out together -- ScienceDaily

Over the 24-week period, participants who worked out with people their own age attended an average of 9.5 more classes than counterparts in the mixed-age group. Participants in the mixed-age group averaged 24.3 classes. Participants in the same-age, mixed-gender group averaged 33.8 classes, and participants in the same-age, same-gender group averaged 30.7 classes.

Brain Waves Synchronize at Live Music Performances - Neuroscience News

“When the brain waves were synchronized in this live condition, they synchronized around the rate at which people tend to feel the beat. We call this ‘the delta band.’ This seemed to be the highest in the live condition.” This indicates greater enjoyment of music in the presence of a live performance, as well as greater enjoyment when experienced as part of a group.

A neuroscientist who studies decision-making reveals the most important choice you can make | World Economic Forum

His neuroscience research has found that when two people are in each other's company, their brain waves will begin to look nearly identical. One study of moviegoers, for instance, found the most engaging trailers all produced similar patterns in people's brains. "The more we study engagement, we see time and again that just being next to certain people actually aligns your brain with them," based on their mannerisms, the smell of the room, the noise level, and many other factors, Cerf said. "This means the people you hang out with actually have an impact on your engagement with reality beyond what you can explain. And one of the effects is you become alike."

A heavy working memory load may sink brainwave 'synch' -- ScienceDaily

They suggest that the "coupling," or synchrony, of brain waves among three key regions breaks down in specific ways when visual working memory load becomes too much to handle. "When you reach capacity there is a loss of feedback coupling," said senior author Earl Miller, Picower Professor of Neuroscience at MIT's Picower Institute for Learning and Memory. That loss of synchrony means the regions can no longer communicate with each other to sustain working memory.

Attention deficit disorders could stem from impaired brain coordination: Researchers uncover link absent between brain regions in attention deficit hyperactivity disorder, schizophrenia -- ScienceDaily

When the researchers attached probes to the mice to measure brain activity, they found mice without ErbB4 had brain regions that were acting independently, rather than together in synchrony. In particular, the researchers studied the prefrontal cortex -- normally associated with decision-making -- and the hippocampus -- a region that supports memory. These two regions coordinate for a variety of brain tasks, including memory and attention. "We found top-down attention, previously thought to be controlled by the prefrontal cortex, also involves the hippocampus in a manner where the two regions are highly synchronized when attention is high," says Mei. "Our findings give importance to synchrony between the prefrontal cortex and hippocampus in top-down attention and open up the possibility that attention deficit disorders, like ADHD, might involve impairments in the synchrony between these two regions." According to the new study, ErbB4 coordinates a cascade of brain signals that "bridge" the two regions. ErbB4 itself encodes a receptor found on the surface of brain cells. The study found that when a protein (neuregulin-1) attaches to the ErbB4 receptor, it triggers a chain reaction that ultimately determines neurotransmitter levels in the prefrontal cortex and hippocampus. Without ErbB4, neurotransmitter levels go awry. The researchers discovered mice lacking ErbB4 have low levels of a particular neurotransmitter -- GABA, or gamma-aminobutyric acid -- in their brain. Low GABA levels can lead to impaired top-down attention in the prefrontal cortex, and impairs how the prefrontal cortex can efficiently coordinate with the hippocampus. The researchers concluded that ErbB4 helps link the two brain regions to maintain attention.