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Tag: neuroscience
Liberal Or Conservative? Brain’s ‘Disgust’ Reaction Holds The Answer

Liberal Or Conservative? Brain’s ‘Disgust’ Reaction Holds The Answer

By Amina Khan, Los Angeles Times (MCT)

Think your political beliefs arise from logic and reason? Think again. A team of scientists who studied the brains of liberal, moderate and conservative people found that they could tell who leaned left and who leaned right based on how their brains responded to disgusting pictures.

The findings, published in Current Biology, show that the brains of liberals and conservatives may indeed by wired differently — and shed light on the biological factors at play in political beliefs.

Biology and politics have long been seen by many researchers as two very separate realms. Some argue that biology is irrelevant to political questions, or that the links between the two are murky or oversimplified.

“Despite growing evidence from various fields, including genetics, cognitive neuroscience and psychology, many political scientists remain skeptical of research connecting biological factors with political ideology,” the study authors wrote.

But many of the same subjects at issue in certain political ideologies — attitudes toward sex, family, education and personal autonomy, for example — have an emotional component as much as a logic-based one. And some research has indicated that political leanings can be inherited (much in the same way that height can inherited but modified, affected by a number of factors from nutrition to the environment).

To probe this controversial question, a team led by Virginia Tech scientists called upon 83 volunteers who took a test to determine what their political leanings were. Then, while sitting in the fMRI machine, they looked at 80 different images — 20 each of disgusting, threatening, pleasant or neutral images. The researchers watched how the participants’ brains reacted to each of those images while in the machine. Later, they were asked to rate how disgusting, pleasant or threatening each image was.

When shown a disgusting image — particularly one of a mutilated animal body — the conservatives’ brains reacted more strongly, and in different ways, compared with the liberals’ brains.

“Although our results suggest that disgusting pictures evoke very different emotional processing in conservatives and liberals,” the authors wrote, “it will take a range of targeted studies in the future to tease apart the separate contribution of each brain circuit.”

The difference between the two groups was stark in spite of the fact that, oddly enough, these neural responses didn’t match the conscious ratings that participants gave those pictures.

Other images, whether threatening or pleasant or neutral, didn’t show the same link, but it’s possible that pictures of threats don’t register the same way a real threat would, the authors pointed out.

“People tend to think that their political views are purely cognitive (i.e., rational),” the study authors wrote. “However, our results further support the notion that emotional processes are tightly coupled to complex and high-dimensional human belief systems, and such emotional processes might play a much larger role than we currently believe, possibly outside our awareness of its influence.”

Certainly politics is more than a few (possibly subconscious) emotional reactions; life history and experience also affect political beliefs, the study authors wrote. But it does raise some questions about whether partisans will need to develop new strategies to reach across the political aisle.

“Would the recognition that those with different political beliefs from our own also exhibit different disgust responses from our own help us or hinder us in our ability to embrace them as co-equals in democratic governance?” the researchers wrote. “Future work will be necessary to answer these important questions.”

AFP Photo

Is Autism Like A Magic Show That Won’t End

Is Autism Like A Magic Show That Won’t End

By Geoffrey Mohan, Los Angeles Times

The brain is a biological machine that makes predictions. But what happens when a wrench is thrown in the works, and jams up the ability to foresee the trajectory of a moving object, or what happens after a frown?

Researchers at the Massachusetts Institute of Technology believe such a wrench lies at the core of autism, a disorder with widely disparate symptoms that strike with varied intensity.
Social and language deficits, repetitive behavior, hypersensitivity to stimuli and other symptoms may be manifestations of an impaired ability to predict the behavior of the outside world, according to an analysis published online Monday in the journal Proceedings of the National Academy of Sciences.

An impairment in the ability to place stimuli in context with what came before and after them leaves people with autism struggling with a seemingly capricious world that makes excruciating demands on their attention, according to the report.

“We sometimes affectionately call this the magical world theory of autism,” said MIT neuroscientist Pawan Sinha, lead author of the study. “The hallmark of a magical performance is the surprise, the unpredictability of the outcome. … Although for a brief period of time, a magic show might be pleasurable, if one is constantly immersed in that kind of a magical world, one can begin to get overwhelmed.”

Those who follow developments in the field of autism research can be forgiven if they sometimes think scientists are grasping at different parts of an elephant in a pitch-dark room. Studies often isolate the oddities of certain brain regions or genes, focus on isolated symptoms or examine niches of the disorder.

About 1 in 68 children have been diagnosed with autism spectrum disorder, according to the Centers for Disease Control and Prevention.

The new analysis does not offer new data – it instead surveyed developments in the field and tried to unite them under one over-arching hypothesis. It is likely to draw the attention of neuroscientists in large part because it was led by Richard Held, an emeritus MIT professor who has researched the brain for a half century. (His 92nd birthday is Friday.)

“This paper is deliberately a theory-heavy paper,” said Sinha. “We wanted to take a broader look at many pieces of experimental evidence that have already been collected by many different labs and see whether there were some commonalities, some way to explain the very diverse collection of results.”

The MIT researchers believe that impaired prediction often leads to anxiety, which can lead to many of the behaviors that have come to be associated with autism spectrum disorder.
For example, many people with autism are hypersensitive to sensory stimuli, even though studies show their senses are no more acute than those of others. Some can’t wear tight clothing because they find it irritating.

The authors suggest that people on the autism spectrum don’t habituate well to outside stimuli. While typical brains “get used to” touch, sounds and sights, and can prioritize them, the autistic brain is unable to do so and is constantly aroused.

That hypersensitivity is at the heart of another attempt to unify the symptoms of autism, known at the “intense world theory.” It holds that hyper-reactive brain circuits can become autonomous and follow their own development path. This could explain many extremes in relatively narrow areas, such as near-photographic memory as well as acute sensation, emotion and attention, according to the theory outlined by Swiss researchers Kamila and Henry Markram.

The theory, however, “leaves open what is causing the intensity of the world,” said Sinha. “We are saying that the world perhaps is appearing hyper-intense because it appears unpredictable,” he said.

Under the predictive impairment hypothesis, social difficulties could stem from an inability to place behaviors in context, such as what usually comes before or after a smile, a cry or a shout.

In addition, people with autism often fill their lives with routines, and some even resort to repetitive or self-stimulating behaviors, which “almost seem to be an attempt to impose order on a seemingly chaotic world,” Sinha noted.

The report suggested several general ways to test the hypothesis, and highlighted brain regions related to prediction that also are implicated in autism, such as the cerebellum, basal ganglia and anterior cingulate cortex.

“This theory is intuitive; it makes sense,” said University of California, Los Angeles neuroscientist Dr. Carlos Portera-Cailliau, who was not involved in the analysis. “It’s very exciting that people are thinking about autism beyond experiments like I do in the lab.”

Nonetheless, the hypothesis does not address “the underlying defect in the brain” that impairs prediction, Portera-Cailliau said. “I think that’s where more work needs to be done — what are the experiments that can be done to test this theory and prove it right or wrong?”

Photo via Wikicommons

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Researchers Aim To Build Database Of Brain Health

Researchers Aim To Build Database Of Brain Health

By Lisa M. Krieger, San Jose Mercury News

SAN JOSE, Calif. — Quick: Find the fruit! Feed the fish! List a sequence of steps, in reverse!

Your online test results aren’t pass-fail. You aren’t graded. But your scores give valuable snapshots of your mental flexibility and memory, contributing to what researchers at the University of California, San Francisco, hope will someday be a vast archive of information about brain health — and the first neuroscience project to use the Internet on such a scale to advance research.

By volunteering — repeatedly over time — participants join a pool of research subjects in the new Brain Health Registry, opened Tuesday, for studies on brain diseases such as Alzheimer’s and Parkinson’s, as well as depression, post-traumatic stress disorder and other neurological ailments.

You won’t learn your own scores; that disclosure could influence your future performance or trigger unwarranted “freak outs,” said UCSF’s Dr. Michael Weiner, founder of the registry and lead investigator of the Alzheimer’s disease Neuroimaging Initiative, the world’s largest observational study of the disease.

Rather, you will help speed up research by helping cut the time and cost of conducting clinical trials.

“To accelerate research, studies have to be done more quickly, and efficiently,” said Weiner.

One-third of the cost of running trial studies is patient recruitment — and many trials fail, or are delayed, due to problems getting enough of the right volunteers.

The traditional approach to finding participants is low-tech, such as posting notices on bulletin boards or buying ads in newspapers. And it’s time-consuming to determine if someone is even eligible to volunteer, then document that person’s family and personal medical history. Think clipboards, and pens and paper.

Frustrated by how much effort would be required to launch a giant San Francisco Bay Area-based study in Alzheimer’s prevention, “a light bulb went off in my mind,” said Weiner.

“Why not use the Internet as a way to enroll in trials,” he said, “where volunteers take a few minutes to take some online neuropsychological test to measure brain performance?”

Hundreds of other researchers could share this pooled and updated database of patient information — with participants’ identities removed — saving the time and expense of new recruitment with every new clinical trial.

“The large pool of data gathered by this registry can help the broader brain research community,” said Maria Carrillo, vice president of medical and scientific relations for the Alzheimer’s Association. “It’s paving the way or better treatment options for others,” she said.

The initial focus will be on the San Francisco Bay Area, and the goal is to recruit 100,000 people by the end of 2017. Nearly 2,000 people have already signed up during the registry’s test phase.

Volunteer Jackie Boberg of Saratoga, Calif., called the fast-paced tests “a little nerve-racking,” but enjoyed the challenge.

“I want to help any scientific efforts,” said Boberg, 62, an artist recently retired from high-tech sales and marketing at Adobe Systems Inc. “I am watching a lot of my friends help with their parents and relatives who are suffering from Alzheimer’s or other dementia, and see the toll it is takes the entire family. I feel like it is just the tip of the iceberg, as aging Baby Boomers come along.”

She cares less about her personal results than broader population-based findings.

“It is not about me. It is more about being able to contribute,” she said. “Anything I can do to help with science moving forward.”

Volunteers provide a brief personal overview — such as family history of dementia and health status — and take online neuropsychological tests designed by companies Lumosity and Cogstate to evaluate memory, attention and response times.

Later tests will reveal information about how volunteers’ brains are changing as they age.

“We’re seeking people with all kinds of problems — or are completely normal — to build this database,” said Weiner.

“It will open up the research world,” he said.

AFP Photo

 

Autism ‘Patchwork’ Begins During Pregnancy

Autism ‘Patchwork’ Begins During Pregnancy

By Kerry Sheridan

Washington (AFP) — The brains of children with autism contain a built-in patchwork of defects, suggesting that the developmental disorder begins while they are growing in the womb, said a U.S. study.

Researchers described their findings in the New England Journal of Medicine as “direct evidence” of a prenatal origin for autism, which affects as many as one in 88 children in the United States and has no known cure.

“Building a baby’s brain during pregnancy involves creating a cortex that contains six layers,” said co-author Eric Courchesne, professor of neurosciences and director of the Autism Center of Excellence at University of California, San Diego.

“We discovered focal patches of disrupted development of these cortical layers in the majority of children with autism.”

For the study, researchers dissected brain tissue from 11 children, aged two to 15, who had been diagnosed with autism spectrum disorder (ASD) and who had died, most of them by drowning.

Looking for a specific set of 25 genes that had “robust, consistent, and specific expression patterns in the cortex,” they compared them to brain samples from 11 children without autism, said the study.

Researchers found that 91 percent of the autistic brains were lacking — or showed an unusual pattern — of the expected genetic markers in several layers of the cortex.

The signs of disorganization were found in patches across the different layers of the frontal and temporal lobes of the brain, the parts that are responsible for social function, communication, emotions, and language.

“The most surprising finding was the similar early developmental pathology across nearly all of the autistic brains, especially given the diversity of symptoms in patients with autism, as well as the extremely complex genetics behind the disorder,” said co-author Ed Lein of the Allen Institute for Brain Science in Seattle.

Researchers said they still don’t understand why these changes come about in some children, apparently leading to autism, but not in others.

The patchwork nature of the defects does, however, provide a clue as to why autism can affect people in various degrees, from severe to mild disabilities.

It also may explain why some children respond to intensive therapy and become better communicators when identified early, since the brain may be able to rewire some connections to overcome the areas that are not working.

“While autism is generally considered a developmental brain disorder, research has not identified a consistent or causative lesion,” said Thomas Insel, director of National Institute for Mental Health, which funded the study.

“If this new report of disorganized architecture in the brains of some children with autism is replicated, we can presume this reflects a process occurring long before birth.”

The same research team had previously found that the brains of children with autism were heavier than other children’s, and that they had more neurons in the prefrontal cortex.

The brains sampled for this study “represented nearly the entirety of tissue suitable for study at the Brain and Tissue Bank for Developmental Disorders at the National Institute of Child Health and Human Development and the Harvard Brain Tissue Resource Center,” said the article.

Still, the fact that only 11 were studied means that more research is necessary, said Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children’s Medical Center of New York.

“This study would have been stronger if they had a larger sample and included a group of children who had neurologic deficits but not autism,” said Adesman, who was not involved with the research.

He nevertheless described the team’s techniques for identifying microscopic brain abnormalities as “extremely sophisticated.”

While some of the physical brain changes in autism were already known to science, the latest research provides a more detailed look at how this happens.

“This study is particularly important as it points to the potential role of several genes involved in the specification of distinct cortical layers during early brain development,” said Patrick Hof, vice-chair of the Fishberg Department of Neuroscience, Friedman Brain Institute, and Seaver Autism Center at the Icahn School of Medicine at Mount Sinai.

Research like this “can provide us with crucial clues to develop novel therapeutic strategies toward a cure,” he said.

©afp.com/Jean-Philippe Ksiazek