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Structure of brain networks is not fixed - Neuroscience News

“You can think of the brain like an organization where employees work together to make the whole system run,” said Iraji. “For a long time, we thought brain networks were like departments or offices, where the same people were doing the same job every day. But it turns out that they may be more like coworking spaces, where people move in and out and there are different jobs being performed at any given time.” Ignoring these spatial and functional variations could result in an incorrect and incomplete understanding of the brain, Iraji added. “Let’s say we measure functional connectivity between two regions at different times, and we see some variability,” he said. “One view is to say that the strength of connectivity associated with specific task changes over time. But what if that region is responsible for different tasks at different times? Maybe there are different people in these two offices on different days, so that’s why we’re seeing the difference in communication.”

Multiple brain regions moderate and link depressive mood and pain -- ScienceDaily

"We were very surprised about the expansive roles of these regions," said Zeidan. "Brain regions involved in facilitating pain were also associated with lower pain and depression. Brain regions involved in regulating pain where also associated with increasing depression. Perhaps it's not surprising after seeing the results. Why shouldn't specific aspects of the brain perform multiple roles?"

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

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

Why visual stimulation may work in fight against Alzheimer's: Mouse study - Neuroscience News

Tsai’s original study on the effects of flickering light showed that visual stimulation at a frequency of 40 hertz (cycles per second) induces brain waves known as gamma oscillations in the visual cortex. These brain waves are believed to contribute to normal brain functions such as attention and memory, and previous studies have suggested that they are impaired in Alzheimer’s patients. Tsai and her colleagues later found that combining the flickering light with sound stimuli — 40-hertz tones — reduced plaques even further and also had farther-reaching effects, extending to the hippocampus and parts of the prefrontal cortex. The researchers have also found cognitive benefits from both the light- and sound-induced gamma oscillations. In their new study, the researchers wanted to delve deeper into how these beneficial effects arise. They focused on two different strains of mice that are genetically programmed to develop Alzheimer’s symptoms. One, known as Tau P301S, has a mutated version of the Tau protein, which forms neurofibrillary tangles like those seen in Alzheimer’s patients. The other, known as CK-p25, can be induced to produce a protein called p25, which causes severe neurodegeneration. Both of these models show much greater neuron loss than the model they used for the original light flickering study, Tsai says. The researchers found that visual stimulation, given one hour a day for three to six weeks, had dramatic effects on neuron degeneration. They started the treatments shortly before degeneration would have been expected to begin, in both types of Alzheimer’s models. After three weeks of treatment, Tau P301S mice showed no neuronal degeneration, while the untreated Tau P301S mice had lost 15 to 20 percent of their neurons. Neurodegeneration was also prevented in the CK-p25 mice, which were treated for six weeks.

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

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

Mathematical framework explores how the brain keeps a beat - Neuroscience News

Using neurobiological principles, the researchers built a mathematical model of a group of neurons that can cooperate to learn a musical beat from a rhythmic stimulus and keep the beat after the stimulus stops. The model demonstrates how a network of neurons could act as a “neuronal metronome” by accurately estimating time intervals between beats within tens of millisecond accuracy. This metronome relies on rhythmic brain activity patterns known as gamma oscillations to keep track of time.

Newborn babies have inbuilt ability to pick out words -- ScienceDaily

The researchers discovered two mechanisms in three-day-old infants, which give them the skills to pick out words in a stream of sounds. The first mechanism is known as prosody, the melody of language, allow us to recognise when a word starts and stops. The second is called the statistics of language, which describes how we compute the frequency of when sounds in a word come together. The discovery provides a key insight into a first step to learning language.

Brains of people with schizophrenia-related disorders aren't all the same: New study supports the use of a data-driven approach to identify novel biomarkers -- ScienceDaily

"We know that, on average, people with schizophrenia have more social impairment than people in the general population," says senior author Dr. Aristotle Voineskos in the Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health (CAMH) in Toronto. "But we needed to take an agnostic approach and let the data tell us what the brain-behavioural profiles of our study participants looked like. It turned out that the relationship between brain function and social behaviour had nothing to do with conventional diagnostic categories in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders)." Most brain research in the mental health field compares a disease group to a non-disease or "healthy" group to search for biomarkers, a biological measure of mental health symptoms. This search for biomarkers has been elusive. This multi-site research study -- which included 179 participants recruited at CAMH in Toronto, Zucker Hillside Hospital in New York and the Maryland Psychiatric Research Center in Baltimore -- calls that paradigm into question because people with the same mental illness may not show the same biological patterns. The study, which involved participants completing a facial imitation task while undergoing functional MRI brain scans, found three "activation profiles," says first author Dr. Colin Hawco, also of CAMH. These can be described as typical, over-activated and de-activated profiles.

MRI technique shows unique signatures of concussion in rugby players -- ScienceDaily

The authors point out that there is growing evidence of persistent changes in the brain that last well beyond clinical recovery and clearance to return to play. This study confirmed those findings showing clear brain changes in both structure and function that persisted six-months after injury. They also showed that these persistent brain changes related to concussion history, even in healthy athletes. "We were able to show evidence of prior concussion history through this method," said Menon who is also a scientist at Robarts Research Institute and the director of the Western Centre for Functional and Metabolic Mapping. "This component correlates directly with the number of previous concussions that an athlete has had. This hasn't been shown before."

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


Babies kicking in the womb are creating a map of their bodies -- ScienceDaily

The findings suggest that fetal kicks in the late stages of pregnancy -- the third trimester -- help to grow areas of the brain that deal with sensory input, and are how the baby develops a sense of their own body. The fast brainwaves evoked by the movement disappear by the time babies are a few weeks old. "Spontaneous movement and consequent feedback from the environment during the early developmental period are known to be necessary for proper brain mapping in animals such as rats. Here we showed that this may be true in humans too," explained study author Dr Lorenzo Fabrizi (UCL Neuroscience, Physiology & Pharmacology). Kimberley Whitehead (UCL Neuroscience, Physiology & Pharmacology) said: "We think the findings have implications for providing the optimal hospital environment for infants born early, so that they receive appropriate sensory input. For example, it is already routine for infants to be 'nested' in their cots -- this allows them to 'feel' a surface when their limbs kick, as if they were still inside the womb.

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


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

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

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

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

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

Andreasen’s background outside neuroscience might have helped her perceive the value lurking in the rest state, where her peers saw only trouble. As a professor of Renaissance literature, she published a scholarly appraisal of John Donne’s “conservative revolutionary” poetics. After switching fields in her 30s, she eventually began exploring the mystery of creativity through the lens of brain imaging. “Although neither a Freudian nor a psychoanalyst, I knew enough about human mental activity to quickly perceive what a foolish ‘control task’ rest was,” she would later write. “Most investigators made the convenient assumption that the brain would be blank or neutral during ‘rest.’ From introspection I knew that my own brain is often at its most active when I stretch out on a bed or sofa and close my eyes.”

Sometimes noise is the signal

“What happened is that we began putting people in scanners that can measure their brain activity,” Buckner recalls now, “and Mother Nature shouted back at us.” When people were told to sit and do nothing, the PET scans showed a distinct surge of mental energy in some regions. The resting state turned out to be more active than the active state. The odd blast of activity during the resting state would be observed in dozens of other studies using a similar control structure during this period. To this first generation of scientists using PET scans, the active rest state was viewed, in Buckner’s words, as “a confound, as troublesome.” A confound is an errant variable that prevents a scientist from doing a proper control study. It’s noise, mere interference getting in the way of the signal that science is looking for. Buckner and his colleagues noted the strange activity in a paper submitted in 1993, but almost as an afterthought, or an apology.

Could consciousness all come down to the way things vibrate?


Traumatic brain injuries can lead to long-term neurological and psychiatric disorders -- ScienceDaily


New target of alcohol in the brain -- ScienceDaily

"The KCNK13 channel is absolutely required for alcohol to stimulate the release of dopamine by these neurons," said Mark Brodie, professor of physiology and biophysics in the UIC College of Medicine and lead author of the study. "Without the channel, alcohol can't stimulate the release of dopamine, and so drinking is likely less rewarding. We think that the KCNK13 channel presents an extremely exciting new target for drugs that could potentially help people with alcohol use disorder to stop drinking."

Brain cells called astrocytes have unexpected role in brain 'plasticity': Researchers show protein made by astrocytes enables the brain's maturation and regulates its flexibility -- ScienceDaily




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).

Great minds may think alike, but all minds look alike -- ScienceDaily

The (skeleton) structure of the brain is like a road map consisting of many narrow streets (i.e., weak links), and a small fraction of highways each containing thousands of lanes (i.e., very strong links). Such a diverse road map could either be a spontaneous outcome of a random brain activity, or alternatively could be directed by a meaningful learning activity, where the "highways" direct the information flow in the brain. "A byproduct of dendritic learning is the wide spectrum of link strengths. The dendritic learning enables us to offer an explanation for an additional universal phenomenon observed in all brains and indicates its important role," said Prof. Kanter, whose research team includes Herut Uzan, Shira Sardi, Amir Goldental and Roni Vardi. The underlying mechanism is a fast response of a neuron to its strong entry compared to a slow response to a weak one. "The mechanism is similar to a pool filled through a wide pipe or through a narrow one. The wide pipe fills the pool faster," explained the research team.

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."

Why Sitting May Be Bad for Your Brain - The New York Times

It was equally apparent when people broke up their sitting after two hours, although blood flow rose during the actual walking break. It soon sank again, the ultrasound probes showed, and was lower at the end of that session than at its start. But brain blood flow rose slightly when the four hours included frequent, two-minute walking breaks, the scientists found. Interestingly, none of these changes in brain blood flow were dictated by alterations in breathing and carbon dioxide levels, the scientists also determined. Carbon dioxide levels had remained steady before and after each session.