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Domain: jneurosci.org
Stories and comments across the archive that link to jneurosci.org.
Stories · 10
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Could Electrically Stimulating Criminals' Brains Prevent Crime? (newatlas.com)
future guy shares a report from New Atlas: A new study by a team of international researchers from the University of Pennsylvania and Nanyang Technological University suggests that electrically stimulating the prefrontal cortex can reduce the desire to carry out violent antisocial acts by over 50 percent. The research, while undeniably compelling, raises a whole host of confronting ethical questions, not just over the feasibility of actually bringing this technology into our legal system, but whether we should?
The intriguing experiment took 81 healthy adults and split them into two groups. One group received transcranial direct-current stimulation (tDCS) on the dorsolateral prefrontal cortex for 20 minutes, while the other placebo group received just 30 seconds of current and then nothing for the remaining 19 minutes. Following the electrical stimulation all the participants were presented with two vignettes and asked to rate, from 0 to 10, how likely they would be to behave as the protagonist in the stories. One hypothetical scenario outlined a physical assault, while the other was about sexual assault. The results were fascinating, with participants receiving the tDCS reporting they would be between 47 and 70 percent less likely to carry out the violent acts compared to the blind placebo control. -
Breakthrough Study Reveals How LSD Dissolves a Person's Sense of Self (newatlas.com)
New submitter future guy shares a report from New Atlas: A fascinating study led by scientists at the University of Zurich has uncovered key insights into the mechanisms behind how our brain generates our sense of self. The researchers administered lysergic acid diethylamide (LSD) to several participants in order to home in on where in the brain our sense of self is activated and what happens when a powerful psychedelic drug interferes with that process. The study administered 24 subjects either LSD, LSD in combination with ketanserin, or a placebo. Ketanserin is a compound that is known to inhibit many of the effects of LSD by blocking the serotonin 2A receptor (5-HT2A receptor). Each subject lay in an MRI scanner while undergoing a series of social interaction simulations with a virtual avatar. As well as the brain imaging, the subjects' eye movements were monitored to track when they were or were not following the gaze of the virtual avatar.
The study demonstrated LSD-altered brain activity in several regions previously identified as fundamental for developing coherent self-representation during social interaction, including the posterior cingulate cortex, medial prefrontal cortex and the angular gyrus. Most importantly though was the observation that ketanserin normalized the effects of LSD to the point where the group influenced by ketanserin and LSD displayed similar results to those under the effect of the placebo. These results strongly suggest that the 5-HT2A receptor plays a fundamental role in the development of self-awareness, and differentiation between the self and others. The value of this research is two-fold. As well as simply increasing our knowledge of how the brain functions under the influence of psychedelic drugs, it is suggested that different psychiatric conditions could be treated by manipulating the 5-HT2A receptor pathways. The study has been published in the journal JNeurosci. -
Teens' Penchant For Risk-Taking May Help Them Learn Faster, Says Study (npr.org)
An anonymous reader quotes a report from NPR: The teenage brain has been characterized as a risk-taking machine, looking for quick rewards and thrills instead of acting responsibly. But these behaviors could actually make teens better than adults at certain kinds of learning. "In neuroscience, we tend to think that if healthy brains act in a certain way, there should be a reason for it," says Juliet Davidow, a postdoctoral researcher at Harvard University in the Affective Neuroscience and Development Lab and the lead author of the study, which was published Wednesday in the journal Neuron. But scientists and the public often focus on the negatives of teen behavior, so she and her colleagues set out to test the hypothesis that teenagers' drive for rewards, and the risk-taking that comes from it, exist for a reason. When it comes to what drives reward-seeking in teens, fingers have always been pointed at the striatum, a lobster-claw-shape structure in the brain. When something surprising and good happens -- say, you find $20 on the street -- your body produces the pleasure-related hormone dopamine, and the striatum responds. But the striatum isn't just involved in reward-seeking. It's also involved in learning from rewards, explains Daphna Shohamy, a cognitive neuroscientist at the Zuckerman Mind Brain Behavior Institute at Columbia University who worked on the study. She wanted to see if teenagers would be better at this type of learning than adults would. To test this, Shohamy and her colleagues used an fMRI scanner to watch brain activity in a group of adults and teenagers. They were looking at the striatum, but also in a different part of the brain called the hippocampus. The hippocampus (which looks like, and is named after, a seahorse) helps people remember things like dates and times: the who, what, when and where. As the adults and teens had their brains scanned, they played a game that rewarded players for guessing correctly. Between questions, participants saw random pictures of neutral objects. As expected, the reward-hungry teenagers figured out the game faster than the adults did. Surprisingly, the striatum was equally active in both teenagers and adults. But in teens, it also worked closely with their hippocampus. -
Weak Electrical Field Found To Carry Information Around the Brain (eurekalert.org)
Zothecula writes: In a development that could lead to improved understanding of memory formation and epilepsy, scientists have discovered a new way information may be traveling throughout the brain. The team has identified slow-moving brainwaves it says could be carried only by the brain's gentle electrical field (abstract), a mechanism previously thought to be incapable of spreading neural signals altogether. "Although the electrical field is of low amplitude, the field excites and activates immediate neighbors, which, in turn, excite and activate immediate neighbors, and so on across the brain at a rate of about 0.1 meter per second." -
Music Training's Cognitive Benefits Could Help "At-Risk" Students
AthanasiusKircher writes In recent years, emphasis on standardized testing and basic skills has forced many schools to cut back on things like arts and extracurricular activities. A study out this week from Northwestern University hints that schools may be hurting "at-risk" kids even more by cutting such programs. Just two years of music lessons were shown to have significant effects on brain activity and language processing which the researchers argue could help close achievement gaps between at-risk students and more affluent students. Aside from better brain response to language observed in the lab, practical effects of the interventions were readily apparent: 'Leaders at Harmony Project approached the researchers after the non-profit observed that their students were performing much better than other public school students in the area. Since 2008, over 90 percent of high school seniors who participated in Harmony Project's free music lessons went on to college, even though the high school dropout rates in the surrounding Los Angeles areas can reach up to 50 percent.' Note that this is only one of several ongoing studies showing significant cognitive benefits for music training among at-risk students; an article last year from The Atlantic gives a more detailed summary of related research. -
Electric 'Thinking Cap' Controls Learning Speed
An anonymous reader writes "Vanderbilt researchers say they've shown it's possible to selectively manipulate our ability to learn by applying a mild electrical current to the brain. Using an elastic headband that secured two electrodes conducted by saline-soaked sponges to the cheek and the crown of the head, the researchers applied 20 minutes of transcranial direct current stimulation (tDCS) to each subject. Depending on the direction of the current, subjects either learned more quickly, slower, or in the case of a sham current, with no change at all. The [paywalled] study appears in the current issue of the Journal of Neuroscience." -
Sleep Found To Replenish a Type of Brain Cell
New submitter wrackspurt writes "Sleep deprivation has long been thought to be prevalent in the industrialized world. A new study (abstract) explains one very good reason why at least seven hours of sleep a night is necessary. Quoting the BBC: 'Sleep ramps up the production of cells that go on to make an insulating material known as myelin which protects our brain's circuitry. ... The increase was most marked during the type of sleep that is associated with dreaming - REM or rapid eye movement sleep — and was driven by genes. In contrast, the genes involved in cell death and stress responses were turned on when the mice were forced to stay awake.'" -
Goodbye, IQ Tests: Brain Imaging Predicts Intelligence Levels
An anonymous reader writes "Research from Washington University in St. Louis has identified variations in brain scans that they believe identify portions of the brain that are responsible for intelligence (abstract). As suspected (and as explained by cartoons) brain size does play a small role; they said that brain size accounts for 6.7 percent of variance in intelligence. Recent research has placed the brain's prefrontal cortex, a region just behind the forehead, as providing for 5 percent of the variation in intelligence between people. The research from Washington University targets the left prefrontal cortex, and the strength of neural connections that it has to the rest of the brain. They think these differences account for 10 percent of differences in intelligence among people. The study is the first to connect those differences to intelligence in people." -
Easily Distracted People May Have 'Too Much Brain'
fysdt writes with this excerpt from New Scientist: "Those who are easily distracted from the task in hand may have 'too much brain.' So says Ryota Kanai and his colleagues at University College London, who found larger than average volumes of grey matter in certain brain regions in those whose attention is readily diverted. To investigate distractibility, the team compared the brains of easy and difficult-to-distract individuals. [Abstract] They assessed each person's distractibility by quizzing them about how often they fail to notice road signs, or go into a supermarket and become sidetracked to the point that they forget what they came in to buy. The most distractible individuals received the highest score." -
Better Brain Wiring Linked To Family Genes
Third Position sends this excerpt from PhysOrg: "How well our brain functions is largely based on our family's genetic makeup, according to a University of Melbourne led study. The study ... provides the first evidence of a genetic effect on how 'cost-efficient' our brain network wiring is, shedding light on some of the brain's make up (abstract). Lead author Dr. Alex Fornito from the Neuropsychiatry Centre at the University of Melbourne said the findings have important implications for understanding why some people are better able to perform certain tasks than others and the genetic basis of mental illnesses and some neurological diseases."