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Keeping up the pressure: New neural mechanism is found to regulate the chronic stress response -- ScienceDaily

The newly discovered nerve cells express a receptor, CRFR1, on their outer walls, which enables them to take in the message of the CRF neurotransmitter. The scientists' experiments showed that, in mice, the cortisol actually increases the number of CRFR1 receptors on these nerve cells, suggesting a positive feedback loop that could be self-renewing, rather than abating.

How the brain maintains useful memories -- ScienceDaily

there are specific groups of neurons in the medial prefrontal cortex (mPFC) of a rat's brain -- the region most associated with long-term memory. These neurons develop codes to help store relevant, general information from multiple experiences while, over time, losing the more irrelevant, minor details unique to each experience. The findings provide new insight into how the brain collects and stores useful knowledge about the world that can be adapted and applied to new experiences. "Memories of recent experiences are rich in incidental detail but, with time, the brain is thought to extract important information that is common across various past experiences," says Kaori Takehara-Nishiuchi, senior author and Associate Professor of Psychology at the University of Toronto. "We predicted that groups of neurons in the mPFC build representations of this information over the period when long-term memory consolidation is known to take place, and that this information has a larger representation in the brain than the smaller details."

Whatever you think, you don’t necessarily know your own mind

Carruthers makes a powerful case for an interpretive view of self-knowledge, set out in his book The Opacity of Mind (2011). The case starts with the claim that humans (and other primates) have a dedicated mental subsystem for understanding other people’s minds, which swiftly and unconsciously generates beliefs about what others think and feel, based on observations of their behaviour. (Evidence for such a ‘mindreading’ system comes from a variety of sources, including the rapidity with which infants develop an understanding of people around them.) Carruthers argues that this same system is responsible for our knowledge of our own minds. Humans did not develop a second, inward-looking mindreading system (an inner sense); rather, they gained self-knowledge by directing the outward-looking system upon themselves. And because the system is outward-looking, it has access only to sensory inputs and must draw its conclusions from them alone. (Since it has direct access to sensory states, our knowledge of what we are experiencing is not interpretative.)

Why the lights don't dim when we blink: Blinking prompts eye muscles to keep our vision in line -- ScienceDaily

"Our eye muscles are quite sluggish and imprecise, so the brain needs to constantly adapt its motor signals to make sure our eyes are pointing where they're supposed to," Maus said. "Our findings suggest that the brain gauges the difference in what we see before and after a blink, and commands the eye muscles to make the needed corrections." From a big-picture perspective, if we didn't possess this powerful oculomotor mechanism, particularly when blinking, our surroundings would appear shadowy, erratic and jittery, researchers said. "We perceive coherence and not transient blindness because the brain connects the dots for us," said study co-author David Whitney, a psychology professor at UC Berkeley. "Our brains do a lot of prediction to compensate for how we move around in the world," said co-author Patrick Cavanagh, a professor of psychological and brain sciences at Dartmouth College. "It's like a steadicam of the mind." A dozen healthy young adults participated in what Maus jokingly called "the most boring experiment ever." Study participants sat in a dark room for long periods staring at a dot on a screen while infrared cameras tracked their eye movements and eye blinks in real time. Every time they blinked, the dot was moved one centimeter to the right. While participants failed to notice the subtle shift, the brain's oculomotor system registered the movement and learned to reposition the line of vision squarely on the dot. After 30 or so blink-synchronized dot movements, participants' eyes adjusted during each blink and shifted automatically to the spot where they predicted the dot to be. "Even though participants did not consciously register that the dot had moved, their brains did, and adjusted with the corrective eye movement," Maus said. "These findings add to our understanding of how the brain constantly adapts to changes, commanding our muscles to correct for errors in our bodies' own hardware."

CBT creates lasting changes in connectivity, drugs do not

In the original study, participants underwent fMRI imaging to assess the brain’s response to images of faces expressing different emotions, before and after six months of CBT. Participants were already taking medication when they took part in the study, and so were compared to a group receiving medication only. The group receiving medication only did not show any increases in connectivity, suggesting that the effects on brain connections could be attributed to the CBT. For the new study, the health of 15 of the 22 participants who received CBT was tracked for eight years through their medical records. They were also sent a questionnaire at the end of this period to assess their level of recovery and wellbeing. The results show that increases in connectivity between several brain regions – most importantly the amygdala (the brain’s threat centre) and the frontal lobes (which are involved in thinking and reasoning) – are associated with long-term recovery from psychosis. This is the first time that changes in the brain associated with CBT have been shown to be associated with long-term recovery in people with psychosis.

Nicotine Normalizes Brain Activity Deficits That Are Key to Schizophrenia – Neuroscience News

“Basically the nicotine is compensating for a genetically determined impairment,” says Stitzel. “No one has ever shown that before.” The international team of scientists set out to explore the underlying causes of “hypofrontality” — a reduction of neuronal firing in the prefrontal cortex of the brain. Hypofrontality is believed to be the root cause of many of the signature cognitive problems experienced by schizophrenics, including trouble paying attention, remembering things, making decisions and understanding verbal explanations.

Talking therapy changes the brain's wiring, study reveals for first time -- ScienceDaily

CBT -- a specific type of talking therapy -- involves people changing the way they think about and respond to their thoughts and experiences. For individuals experiencing psychotic symptoms, common in schizophrenia and a number of other psychiatric disorders, the therapy involves learning to think differently about unusual experiences, such as distressing beliefs that others are out to get them. CBT also involves developing strategies to reduce distress and improve wellbeing. The findings, published in the journal Translational Psychiatry, follow the same researchers' previous work which showed that people with psychosis who received CBT displayed strengthened connections between key regions of the brain involved in processing social threat accurately. The new results show for the first time that these changes continue to have an impact years later on people's long-term recovery.

How each generation gets the drugs it deserves | Aeon Essays

‘This is a big shift from the old model,’ says Cowles. ‘It used to be: “I am Henry. I am ill in some way. A pill can help me get back to being Henry, and then I’m off it.” Whereas now: “I am only Henry when I’m on my meds.” Between 1980, 2000, and now, the proportion of people on that kind of maintenance pill with no end in sight is just going to keep going up and up.’

How each generation gets the drugs it deserves | Aeon Essays

But, Cowles argues, one might just as easily say that ‘these drugs were created with various sub-populations in mind and they end up making available a new kind of housewife or a new kind of working woman, who is medicated in order to enable this kind of lifestyle’. In short, Cowles says: ‘The very image of the depressed housewife emerges only as a result of the possibility of medicating that.’

Your brain suppresses perception of heartbeat, for your own good

It did not take long for Roy to get over his initial surprise at his discovery. “You don’t want your internal sensations to interfere with your external ones. It’s in your interest to be aware of what’s outside you. Since our heart was already beating while our brain was still forming, we’ve been exposed to it since the very start of our existence. So it’s not surprising that the brain acts to suppress it and make it less apparent.” Is feeling one’s heartbeat realted to anxiety? Awareness of one’s heartbeat is known to be correlated with a number of psychological problems, including anxiety disorders. Patients typically perceive their heart rate more clearly than most people. “But someone who does not suffer from this type of disorder can also be aware of their heartbeat,” said Roy. “This can happen at times of intense excitement or fear, for example.”

Gambling addiction triggers the same brain areas as drug and alcohol cravings: Gambling addiction activates the same brain pathways as drug and alcohol cravings, suggests new research -- ScienceDaily

Gambling addiction activates the same brain pathways as drug and alcohol cravings, suggests new research.

Runners' brains may be more connected, research shows | EurekAlert! Science News

University of Arizona researchers compared brain scans of young adult cross country runners to young adults who don't engage in regular physical activity. The runners, overall, showed greater functional connectivity -- or connections between distinct brain regions -- within several areas of the brain, including the frontal cortex, which is important for cognitive functions such as planning, decision-making and the ability to switch attention between tasks.

Manipulating brain activity to boost confidence | EurekAlert! Science News

"Surprisingly, by continuously pairing the occurrence of the highly confident state with a reward - a small amount of money - in real-time, we were able to do just that: when participants had to rate their confidence in the perceptual task at the end of the training, their were consistently more confident". Dr. Hakwan Lau, Associate Professor in the UCLA Psychology Department, was the senior author on the study and an expert in confidence and metacognition: "Crucially, in this study confidence was measured quantitatively via rigorous psychophysics, making sure the effects were not just a change of mood or simple reporting strategy. Such changes in confidence took place even though the participants performed the relevant task at the same performance level".

How hearing loss can change the way nerve cells are wired -- ScienceDaily

In mice whose ears were blocked, cells in the auditory nerve started to use their supplies of neurotransmitter more freely. They depleted their reserves of these chemicals rapidly each time a new auditory signal came in, and they decreased the amount of space within the cells that housed sac-like structures called vesicles -- biological storage tanks where neurotransmitter chemicals are kept. "When it's quiet, the demands on the auditory nerve cells are not as great," Xu-Friedman says. "So it makes sense that you would see these changes: You no longer need as much neurotransmitter, so why invest in a lot of storage? If you're not that active, you don't need a big gas tank. And you're not as afraid to use up what you have. This is one plausible explanation for what we observed." The changes in cellular structure and behavior were the opposite of what Xu-Friedman team's saw in a previous study that placed mice in a consistently noisy environment. In that project -- faced with an unusually high level of noise -- the mice's auditory nerve cells started to economize their resources, conserving supplies of neurotransmitter while increasing the storage capacity for the chemicals. "It looks like these effects are two sides of the same coin, and they might be the first hints of a general rule that nerve cells regulate their connections based on how active they are," Xu-Friedman says.

How physical exercise aids in stroke recovery: Engaging in voluntary physical exercise helps protects the brain it from the damaging effects of a stroke, shown in mice -- ScienceDaily

In order to do this, Kalogeraki and her co-authors used a standard test to assess the brain's 'plasticity' -- its ability to change the way it activates in response to an experience. When the visual input of one eye is compromised for a couple of days, then the part of the brain that processes visual information gets preferentially activated by the other, open eye. The brain's ability to change eye dominance (called ocular dominance plasticity) is age-related, being most pronounced in juvenile animals and completely absent in older mice that have been raised without any stimulation. As well as confirming existing knowledge about the anti-aging effects of voluntary physical exercise -- older mice that exercised retained the ability to change eye dominance in comparison to those that didn't -- the study also revealed some exciting new findings. Those mice that had free-access to a running wheel were able to maintain ocular dominance plasticity after suffering a stroke, compared to those that didn't. "We found that mice with free access to a running wheel throughout their life preserved a more juvenile brain into adulthood and were able to prevent the negative effects of a stroke," reveals Kalogeraki. That was not all -- in addition, the researchers observed that exercise could even be used therapeutically after suffering a stroke. "We also found that mice with no previous access to a running wheel showed an equally positive recovery if voluntary exercise started after a stroke had occurred," adds Dr. Justyna Pielecka-Fortuna, co-author of the study.

Details of information processing in the brain revealed: New research shows that, when focused, we process information continuously, rather in waves as previously thought -- ScienceDaily

Our brains oscillate at many different frequencies, explains Mathewson, and each frequency has a different role. "This study examined 12 hertz alpha oscillations, a mechanisms used to inhibit, or ignore, a certain stimulus thereby allowing us to focus on a particular time or space that we are experiencing, while ignoring others," says Mathewson. For example, if there is a repetitive stimulus in the world, such as the sound of someone's voice in a lecture theatre, the alpha waves lock onto the timing of that stimulus, and the brain becomes better at processing things that occur in time with that stimulus. The new findings show, surprisingly, that this happens more in places we are ignoring. "We are bombarded with so much information and stimulation that we can't possibly process it all at once. Whether it be commuting, engaging in our work, studying for a class, or working out, our brains select the useful information and ignore the rest, so that we can focus on a single or a few items in order to make appropriate responses in the world. This research helps explain how," says Mathewson.

Portions of the brain fall asleep and wake back up all the time, Stanford researchers find | EurekAlert! Science News

The team used what amounts to sets of very sensitive pins that can record activity from a column of neurons in the brain. In the past, people had known that individual neurons go through phases of being more or less active, but with this probe they saw for the first time that all the neurons in a given column cycled together between firing very rapidly then firing at a much slower rate, similar to coordinated cycles in sleep. "During an on state the neurons all start firing rapidly," said Kwabena Boahen, a professor of bioengineering and electrical engineering at Stanford and a senior author on the paper. "Then all of a sudden they just switch to a low firing rate. This on and off switching is happening all the time, as if the neurons are flipping a coin to decide if they are going to be on or off." Those cycles, which occur on the order of seconds or fractions of seconds, weren't as visible when awake because the wave doesn't propagate much beyond that column, unlike in sleep when the wave spreads across almost the entire brain and is easy to detect.

How Expressing Gratitude Might Change Your Brain

participants who’d completed the gratitude task months earlier not only reported feeling more gratefulness two weeks after the task than members of the control group, but also, months later, showed more gratitude-related brain activity in the scanner. The researchers described these “profound” and “long-lasting” neural effects as “particularly noteworthy,” and they highlighted that one of the main regions that showed this increased sensitivity — the “pregenual anterior cingulate,” which is known to be involved in predicting the effects of one’s own actions on other people — overlaps with a key brain region identified in the only previous study on the neurological footprint of gratitude.

This is your brain on God: Spiritual experiences activate brain reward circuits -- ScienceDaily

"When our study participants were instructed to think about a savior, about being with their families for eternity, about their heavenly rewards, their brains and bodies physically responded," says lead author Michael Ferguson, who carried out the study as a bioengineering graduate student at the University of Utah. Based on fMRI scans, the researchers found that powerful spiritual feelings were reproducibly associated with activation in the nucleus accumbens, a critical brain region for processing reward. Peak activity occurred about 1-3 seconds before participants pushed the button and was replicated in each of the four tasks. As participants were experiencing peak feelings, their hearts beat faster and their breathing deepened. In addition to the brain's reward circuits, the researchers found that spiritual feelings were associated with the medial prefrontal cortex, which is a complex brain region that is activated by tasks involving valuation, judgment and moral reasoning. Spiritual feelings also activated brain regions associated with focused attention.

Our 86 Billion Neurons: She Showed It | by Steven Mithen | The New York Review of Books

And then a surprise: the elephant brain had more neurons than the human brain, not just a few more but three times as many: 247 billion to our 86 billion. But 98 percent of these were located in the cerebellum at the back of the brain, leaving a mere 5.6 billion in the 2.8-kilogram cerebral cortex compared to the 16 billion in the 1.2-kilogram human cerebral cortex. What are all those neurons doing in the elephant cerebellum, ten times more than one would expect? Most likely controlling that other exceptional feature of the elephant, its 100-kilogram and highly sensory muscular trunk.

Cooking is the essential human act

Our 86 billion neurons need so much energy that if we shared a way of life with other primates we couldn’t possibly survive: there would be insufficient hours in the day to feed our hungry brain. It needs 500 calories a day to function, which is 25 percent of what our entire body requires. That sounds like a lot, but a single cupful of glucose can fuel the brain for an entire day, with just over a teaspoon being required per hour. Nevertheless, the brains of almost all other vertebrates are responsible for a mere 10 percent of their overall metabolic needs. We evolved and learned a clever trick in our evolutionary past in order to find the time to feed our neuron-packed brains: we began to cook our food. By so doing, more energy could be extracted from the same quantity of plant stuffs or meat than from eating them raw.

How internal circadian clocks in neurons encode external daily rhythms of excitability -- ScienceDaily

Molecular clocks in cells throughout the body control many physiologic changes in a 24-hour day/night circadian rhythm -- among them the timing of sleep and wakefulness. The master pacesetter for those clocks resides in a tiny part of the human brain, where about 42,000 nerve cells spontaneously and independently maintain a 24-hour cycle through rhythmic internal surges and falls of biochemical signals. But nerve cells communicate to each other via external electrical impulses. So how do those internal biochemical clock signals get turned into changes in external electrical firing activity, the activity that spreads the pacesetter timing in those 42,000 cells throughout the brain and the rest of the body? Researchers led by Karen Gamble, Ph.D., associate professor in the University of Alabama at Birmingham Department of Psychiatry and Behavioral Neurobiology, have identified a key mechanism linking the two in a paper published today in Nature Communications. It involves the activity of a kinase enzyme called GSK3 that changes the excitability -- a technical term for the likelihood of a nerve cell to fire an electrical impulse -- of those neurons. Identification of this role for GSK3 raises clinical interest because GSK3 is the target of lithium and other mood-stabilizing drugs used to treat bipolar disorder. Also, the sodium channels that were found to be regulated by GSK3 are the target of riluzole, a drug used to treat amyotropic lateral sclerosis, known as ALS or Lou Gehrig's disease, as well as anxiety disorders and depression.

I predict me

Instead of ‘I think therefore I am’ we can say: ‘I predict (myself) therefore I am.’ The specific experience of being you (or me) is nothing more than the brain’s best guess of the causes of self-related sensory signals.

The hard problem of consciousness is a distraction from the real one | Aeon Essays

Predictive processing can also help us understand unusual forms of visual experience, such as the hallucinations that can accompany psychosis or psychedelic trips. The basic idea is that hallucinations occur when the brain pays too little attention to incoming sensory signals, so that perception becomes unusually dominated by the brain’s prior expectations. Different sorts of hallucination – from simple geometric experiences of lines, patterns and textures to rich hallucinatory narratives full of objects and people – can be explained by the brain’s over-eagerness to confirm its predictions at different levels in the cortical hierarchy.

Consciousness is tied to 'entropy', say researchers - physicsworld.com

Key to this has been the study of synchronization – how the electrical activity of one set of neurons can oscillate in phase with that of another set. Synchronization in turn implies that those sets of neurons are physically tied to one another, just as oscillating physical systems, such as pendulums, become synchronized when they are connected together. The latest work stems from the observation that consciousness, or at least the proper functioning of brains, is associated not with high or even low degrees of synchronicity between neurons but by middling amounts. Jose Luis Perez Velazquez, a biochemist at the University of Toronto, and colleagues hypothesized that what is maximized during consciousness is not connectivity itself but the number of different ways that a certain degree of connectivity can be achieved.

Running triggers brain repair and extends life in mouse model - Medical News Today

The researchers allowed some of the mice the opportunity to run by installing a wheel into their cages. Surprisingly, the mice given the opportunity to run lived more than 12 months (a relatively normal lifespan for a mouse). On top of their extended lives, the running mice also put on more weight and achieved a better sense of balance, compared with their less active siblings. "We saw that the existing neurons became better insulated and more stable. This means that the unhealthy neurons worked better and the previously damaged circuits in the brain became stronger and more functional." Dr. Matías Alvarez-Saavedra, lead author However, these changes were reversed if the opportunity to exercise was taken away. Once the running wheel was removed, the symptoms returned, and their lives were once more cut short.