Archive for the ‘Neuroscience’ Category

Brain, artwork

Even if we cannot consciously see a person’s face, our brain is able to make a snap decision about how trustworthy they are.

According to a new study published in the Journal of Neuroscience, the brain immediately determines how trustworthy a face is before it’s fully perceived, which supports the fact that we make very fast judgments about people.

Researchers at Dartmouth College and New York University showed a group of participants photos of real people’s faces, as well as computer-generated faces that were meant to look either trustworthy or untrustworthy. It’s been shown in the past that people generally think that faces with high inner eyebrows and prominent cheekbones are more trustworthy, and the opposite features are untrustworthy, which the researchers were able to confirm.

In a second part of their experiment, the researchers showed a separate group of participants the same images but for only about 30 milliseconds while they were in a brain scanner. They then did something called “backward masking,” which consists of showing a participant an irrelevant image or “mask” immediately after quickly showing them a face. The procedure makes the brain incapable of processing the face.

Even though the patients were not able to process the faces, their brains did. The researchers focused on activity in the amygdala, a part of the brain responsible for social and emotional behavior, and found that specific areas of the amygdala were activated based on judgments of trustworthiness or non-trustworthiness. This, the researchers conclude, is evidence that our brains make judgments of people before we even process who they are or what they look like.

Thanks to Pete Cuomo for bringing this to the attention of the It’s Interesting community.

http://time.com/?xid=newsletter-brief#3083667/brain-trustworthiness/

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ONE moment you’re conscious, the next you’re not. For the first time, researchers have switched off consciousness by electrically stimulating a single brain area.

Scientists have been probing individual regions of the brain for over a century, exploring their function by zapping them with electricity and temporarily putting them out of action. Despite this, they have never been able to turn off consciousness – until now.

Although only tested in one person, the discovery suggests that a single area – the claustrum – might be integral to combining disparate brain activity into a seamless package of thoughts, sensations and emotions. It takes us a step closer to answering a problem that has confounded scientists and philosophers for millennia – namely how our conscious awareness arises.

Many theories abound but most agree that consciousness has to involve the integration of activity from several brain networks, allowing us to perceive our surroundings as one single unifying experience rather than isolated sensory perceptions.

One proponent of this idea was Francis Crick, a pioneering neuroscientist who earlier in his career had identified the structure of DNA. Just days before he died in July 2004, Crick was working on a paper that suggested our consciousness needs something akin to an orchestra conductor to bind all of our different external and internal perceptions together.

With his colleague Christof Koch, at the Allen Institute for Brain Science in Seattle, he hypothesised that this conductor would need to rapidly integrate information across distinct regions of the brain and bind together information arriving at different times. For example, information about the smell and colour of a rose, its name, and a memory of its relevance, can be bound into one conscious experience of being handed a rose on Valentine’s day.

The pair suggested that the claustrum – a thin, sheet-like structure that lies hidden deep inside the brain – is perfectly suited to this job (Philosophical Transactions of The Royal Society B, doi.org/djjw5m).

It now looks as if Crick and Koch were on to something. In a study published last week, Mohamad Koubeissi at the George Washington University in Washington DC and his colleagues describe how they managed to switch a woman’s consciousness off and on by stimulating her claustrum. The woman has epilepsy so the team were using deep brain electrodes to record signals from different brain regions to work out where her seizures originate. One electrode was positioned next to the claustrum, an area that had never been stimulated before.

When the team zapped the area with high frequency electrical impulses, the woman lost consciousness. She stopped reading and stared blankly into space, she didn’t respond to auditory or visual commands and her breathing slowed. As soon as the stimulation stopped, she immediately regained consciousness with no memory of the event. The same thing happened every time the area was stimulated during two days of experiments (Epilepsy and Behavior, doi.org/tgn).
To confirm that they were affecting the woman’s consciousness rather than just her ability to speak or move, the team asked her to repeat the word “house” or snap her fingers before the stimulation began. If the stimulation was disrupting a brain region responsible for movement or language she would have stopped moving or talking almost immediately. Instead, she gradually spoke more quietly or moved less and less until she drifted into unconsciousness. Since there was no sign of epileptic brain activity during or after the stimulation, the team is sure that it wasn’t a side effect of a seizure.

Koubeissi thinks that the results do indeed suggest that the claustrum plays a vital role in triggering conscious experience. “I would liken it to a car,” he says. “A car on the road has many parts that facilitate its movement – the gas, the transmission, the engine – but there’s only one spot where you turn the key and it all switches on and works together. So while consciousness is a complicated process created via many structures and networks – we may have found the key.”

Counter-intuitively, Koubeissi’s team found that the woman’s loss of consciousness was associated with increased synchrony of electrical activity, or brainwaves, in the frontal and parietal regions of the brain that participate in conscious awareness. Although different areas of the brain are thought to synchronise activity to bind different aspects of an experience together, too much synchronisation seems to be bad. The brain can’t distinguish one aspect from another, stopping a cohesive experience emerging.

Since similar brainwaves occur during an epileptic seizure, Koubeissi’s team now plans to investigate whether lower frequency stimulation of the claustrum could jolt them back to normal. It may even be worth trying for people in a minimally conscious state, he says. “Perhaps we could try to stimulate this region in an attempt to push them out of this state.”

Anil Seth, who studies consciousness at the University of Sussex, UK, warns that we have to be cautious when interpreting behaviour from a single case study. The woman was missing part of her hippocampus, which was removed to treat her epilepsy, so she doesn’t represent a “normal” brain, he says.

However, he points out that the interesting thing about this study is that the person was still awake. “Normally when we look at conscious states we are looking at awake versus sleep, or coma versus vegetative state, or anaesthesia.” Most of these involve changes of wakefulness as well as consciousness but not this time, says Seth. “So even though it’s a single case study, it’s potentially quite informative about what’s happening when you selectively modulate consciousness alone.”

“Francis would have been pleased as punch,” says Koch, who was told by Crick’s wife that on his deathbed, Crick was hallucinating an argument with Koch about the claustrum and its connection to consciousness.

“Ultimately, if we know how consciousness is created and which parts of the brain are involved then we can understand who has it and who doesn’t,” says Koch. “Do robots have it? Do fetuses? Does a cat or dog or worm? This study is incredibly intriguing but it is one brick in a large edifice of consciousness that we’re trying to build.”

http://www.newscientist.com/article/mg22329762.700-consciousness-onoff-switch-discovered-deep-in-brain.html?full=true#.U7n7sI1dVC8

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

brain

The many documented cases of strange delusions and neurological syndromes can offer a window into how bizarre the brain can be.

It may seem that hallucinations are random images that appear to some individuals, or that delusions are thoughts that arise without purpose. However, in some cases, a specific brain pathway may create a particular image or delusion, and different people may experience the same hallucination.

In recent decades, with advances in brain science, researchers have started to unravel the causes of some of these conditions, while others have remained a mystery.

Here is a look at seven odd hallucinations, which show that anything is possible when the brain takes a break from reality.

1. Alice-in-Wonderland syndrome
This neurological syndrome is characterized by bizarre, distorted perceptions of time and space, similar to what Alice experienced in Lewis Carroll’s “Alice’s Adventures in Wonderland.”

Patients with Alice-in-Wonderland syndrome describe seeing objects or parts of their bodies as smaller or bigger than their actual sizes, or in an altered shape. These individuals may also perceive time differently.

The rare syndrome seems to be caused by some viral infections, epilepsy, migraine headaches and brain tumors. Studies have also suggested that abnormal activity in parts of the visual cortex that handle information about the shape and size of objects might cause the hallucinations.

It’s also been suggested that Carroll himself experienced the condition during migraine headaches and used them as inspiration for writing the tale of Alice’s strange dream.

English psychiatrist John Todd first described the condition in an article published in the Canadian Medical Association Journal in 1955, and that’s why the condition is also called Todd’s syndrome. However, an earlier reference to the condition appears in a 1952 article by American neurologist Caro Lippman. The doctor describes a patient who reported feeling short and wide as she walked, and referenced “Alice’s Adventures in Wonderland” to explain her body image illusions.

2. Walking Corpse Syndrome
This delusion, also called Cotard’s Syndrome, is a rare mental illness in which patients believe they are dead, are dying or have lost their internal organs.

French neurologist Jules Cotard first described the condition in 1880, finding it in a woman who had depression and also symptoms of psychosis. The patient believed she didn’t have a brain or intestines, and didn’t need to eat. She died of starvation.

Other cases of Cotard’s syndrome have been reported in people with a range of psychiatric and neurological problems, including schizophrenia, traumatic brain injury and multiple sclerosis.

In a recent case report of Cotard’s syndrome, researchers described a previously healthy 73-year-old woman who went to the emergency room insisting that she was “going to die and going to hell.” Eventually, doctors found the patient had bleeding in her brain due to a stroke. After she received treatment in the hospital, her delusion resolved within a week, according to the report published in January 2014 in the journal of Neuropsychiatry.

3. Charles Bonnet syndrome
People who have lost their sight may develop Charles Bonnet syndrome, which involves having vivid, complex visual hallucinations of things that aren’t really there.

People with this syndrome usually hallucinate people’s faces, cartoons, colored patterns and objects. It is thought the condition occurs because the brain’s visual system is no longer receiving visual information from the eye or part of the retina, and begins making up its own images.

Charles Bonnet syndrome occurs in between 10 and 40% of older adults who have significant vision loss, according to studies.

4. Clinical lycanthropy
In this extremely rare psychiatric condition, patients believe they are turning into wolves or other animals. They may perceive their own bodies differently, and insist they are growing the fur, sharp teeth and claws of a wolf.

Cases have also been reported of people with delusional beliefs about turning into dogs, pigs, frogs and snakes.

The condition usually occurs in combination with another disorder, such as schizophrenia, bipolar disorder or severe depression, according to a review study published in the March issue of the journal History of Psychiatry in 2014.

5. Capgras delusion
Patients with Capgras delusion believe that an imposter has replaced a person they feel close to, such as a friend or spouse. The delusion has been reported in patients with schizophrenia, Alzheimer’s disease, advanced Parkinson’s disease, dementia and brain lesions.

One brain imaging study suggested the condition may involve reduced neural activity in the brain system that processes information about faces and emotional responses.

6. Othello syndrome
Named after Shakespeare’s character, Othello syndrome involves a paranoid belief that the sufferer’s partner is cheating. People with this condition experience strong obsessive thoughts and may show aggression and violence.

In one recent case report, doctors described a 46-year-old married man in the African country Burkina Faso who had a stroke, which left him unable to communicate and paralyzed in half of his body. The patient gradually recovered from his paralysis and speaking problems, but developed a persistent delusional jealousy and aggression toward his wife, accusing her of cheating with an unidentified man.

7. Ekbom’s syndrome
Patients with Ekbom’s syndrome, also known as delusional parasitosis or delusional infestations, strongly believe they are infested with parasites that are crawling under their skin. Patients report sensations of itching and being bitten, and sometimes, in an effort to get rid of the pathogens, they may hurt themselves, which can result in wounds and actual infections.

It’s unknown what causes these delusions, but studies have linked the condition with structural changes in the brain, and some patients have improved when treated with antipsychotic medications.

http://www.livescience.com/46477-oddest-hallucinations.html

By Jeannie Baumann

Many scientists now spend more time scrambling to raise money for their work than actually doing the research because of the erosion of NIH funding over the last decade, the president of a biomedical research university said during a June 18 congressional briefing.

Mark Tessier-Lavigne said the 25 percent decline in the National Institutes of Health’s purchasing power has led to grants being funded at historically low rates, causing promising young scientists to leave the field altogether and threatening the future of the biomedical research workforce.

“The financial squeeze has triggered a crisis in the biomedical research enterprise,” according to Tessier-Lavigne, who is president of the Rockefeller University in New York and investigates how neural circuits in the brain form during embryonic development. “Renewing NIH funding is an essential investment, not just for our health, but also for our economy.”

Tessier-Lavigne was the main speaker at the Capitol Hill briefing, “Paying Dividends: How Federally Funded Biomedical Research Fuels the Pharmaceutical Industry in the U.S.,” which was organized by the Coalition for the Life Sciences and theCongressional Biomedical Research Caucus as part of the 2014 caucus briefing series.

The key point of Tessier-Lavigne’s presentation—that scientific opportunity has never been greater while federal funding for basic research is at a low—has been echoed, especially by NIH Director Francis S. Collins when testifying before lawmakers in both the House and the Senate.

“We live in a golden age of biological research, of disease research, and of drug discovery that’s been enabled by a revolution in the biosciences that’s occurred over the past 40 years, thanks to the development of very powerful technologies,” said Tessier-Lavigne, citing as examples recombinant DNA, gene sequencing, human genetics and imaging. “We can now tackle disease systematically and that is enabling systematic drug discovery.”

The research ecosystem requires early investment through NIH funding to academia to yield the treatments and cures from the pharmaceutical industry, Tessier-Lavigne said.

“There’s a division of labor,” he said. “Most of the scientific discovery that leads to the insights that are built upon are made in academia, in research labs, in research institutes, in universities supported by the NIH. At the other end of the spectrum, industry—mostly large pharmaceutical companies and large biotech companies—are responsible for making the drugs and taking them through human clinical trials.”

Tessier-Lavigne has worked at both ends of the spectrum, serving as chief scientific officer at biotechnology company Genentech before taking over at Rockefeller. He rejected the idea that drug companies could take on funding the basic research. The cost and time lines of drug discovery and development are already too great, he said.

“To make a drug, to get a drug approved there’s huge attritions,” he said. The process starts with targeting 24 projects, and scientists try to make drugs to fight them that yields on average about nine drug candidates that make it into clinical trials.

“But of those nine, only a single one will make it over the finish line as an approved drug,” he said.

That drug-making process takes an average of 13 years, including five years to make the drug candidates and eight years to get to clinical approval. Including failures, he estimated those costs at anywhere between $2 billion to $4 billion per drug.

“So companies that do this are already struggling to succeed just at this. There are no more resources to fund the ferment back here that leads to the identification of new knowledge. The companies can’t do it and they won’t do it,” he said.

“Couldn’t we just rely on other nations to generate the basic knowledge and then industry here could continue to do the translational work?” Tessier-Lavigne asked rhetorically.

“Well, that’s not how it works. Industry wants its R&D [research and development] sites to be located next to the sites of innovation. It’s as simple as that,” he said.

Over the past 30 years, Tessier-Lavigne said, there has been a “massive” transfer of industry from Europe to the U.S. because of the prominence of the U.S. biomedical enterprise.

“If we don’t maintain, sustain our investment in our basic biomedical enterprise, industry will pick up and move to the other sites,” he said, adding that countries like China are where these companies will move, taking jobs with them.
Rep. Jackie Speier (D-Calif.), co-chairman of the Congressional Biomedical Research Caucus, also mentioned that the U.S. may lose its position as the leader in R&D.

“We still lead in terms of patents and overall research, but China is about to eat our lunch,” said Speier, whose district includes the Bay Area and Genentech’s headquarters. “In fact, China has just about eclipsed Japan now in terms of research and within the next 10 years, it is anticipated that they will indeed overcome us in terms of research and development. And that would indeed be a tragic set of circumstances.”
Action Plan

Tessier-Lavigne proposed an action plan that primarily involves gradually restoring NIH funding in absolute dollars to its 2003 level—the final year of a five-year doubling. Since the 2003 doubling, the NIH’s budget has remained flat at about $30 billion. Collins has said that his agency would have about a $40 billion annual budget if the NIH had continued to receive the steady, 3 percent increases it received from the 1970s onward.

Restoring funding to the 2003 levels would relieve the squeeze on existing programs so scientists can focus on their work as well as stimulate new initiatives to accelerate progress and open new areas of discovery, Tessier-Lavigne said.

At the same time, the academic sector has a responsibility to make sure it spends these dollars effectively while developing a pipeline of new talent. And all stakeholders—academia, the NIH, disease foundations and the private sector—must ensure research discoveries are effectively translated into new therapies and cures.

The next congressional briefing is scheduled for July 16 on the advances and potential of embryonic stem cell research, withLawrence Goldstein, director of the University of California, San Diego, Stem Cell Program.

Thanks to Pete Cuomo for bringing this to the attention of the It’s Interesting community.

They say laughter is the best medicine. But what if laughter is the disease?

For a 6-year-old girl in Bolivia who suffered from uncontrollable and inappropriate bouts of giggles, laughter was a symptom of a serious brain problem. But doctors initially diagnosed the child with “misbehavior.”

“She was considered spoiled, crazy — even devil-possessed,” Dr. José Liders Burgos Zuleta, ofAdvanced Medical Image Centre, in Bolivia, said in a statement.

But Burgos Zuleta discovered that the true cause of the girl’s laughing seizures, medically called gelastic seizures, was a brain tumor.

After the girl underwent a brain scan, the doctors discovered a hamartoma, a small, benign tumor that was pressing against her brain’s temporal lobe.The doctors surgically removed the tumor, and the girl is now healthy, the doctors said.

The girl stopped having the uncontrollable attacks of laughter and now only laughs normally, the doctors said.

Gelastic seizures are a form of epilepsy that is relatively rare, said Dr. Solomon Moshé, a pediatric neurologist at Albert Einstein College of Medicine in New York. The word comes from the Greek word for laughter, “gelos.”

“It’s not necessarily ‘hahaha’ laughing,” Moshé told Live Science. “There’s no happiness in this. Some of the kids may be very scared,” he added.

The seizures are most often caused by tumors in the hypothalamus, especially in kids, although they can also come from tumors in other parts of brain, Moshé said. Although laughter is the main symptom, patients may also have outbursts of crying.

These tumors can cause growth abnormalities if they affect the pituitary gland, he said.

The surgery to remove such brain tumors used to be difficult and dangerous, but a new surgical technique developed within the last 10 years allows doctors to remove them effectively without great risk, Moshé said.

The doctors who treated the girl said their report of her case could raise awareness of the strange condition, so doctors in Latin America can diagnose the true cause of some children’s “behavioral” problems, and refer them to a neurologist.

The case report was published June 16 in the journal ecancermedicalscience.

Thanks to Michael Moore for sharing this with the It’s Interesting community.

http://www.cbsnews.com/news/girls-uncontrollable-laughter-caused-by-brain-tumor/

by Amanda L. Chan

If you’ve ever gotten the death glare from your parent, child or S.O., you already know the results of this new study to be true.

New research in the journal Psychological Science shows that people are more likely to give in to an unfair demand when they are presented with a threatening facial expression.

For one of the experiments in the study, 870 people played a negotiation game, which involved deciding how to split $1 between two people. In each scenario, there was a “proposer,” who decided how the dollar would be split and a “responder.” However, before making the decision, the proposer was shown a video clip of the responder making either a neutral facial expression or an angry one. (Little did the study participants know, the responder was actually an actress who was instructed to portray a certain facial expression in each scenario).

In addition to viewing the facial expressions of the responder, the proposer received a written demand from the responder for either half of the amount (considered a “fair” request), or 70 percent of the amount (an “unfair” request). If the responder didn’t accept the proposer’s deal, neither party would get the money.

Researchers found an association between the offer made by the proposer and the facial expression of the responder. If the responder made an angry face and requested the 70 percent, the proposer was more likely to give the 70 percent.

Meanwhile, if the responder made an angry face and only requested the 50-50 split, this didn’t seem to affect how much the proposer offered, likely because the request was already deemed fair. (Something to consider: Because a woman actor was used for the experiment and female and male anger can be perceived differently, the results of the study apply only in the context of a woman’s angry facial expressions being able to influence giving into an unfair demand.)

http://www.huffingtonpost.com/2014/06/09/look-angry-facial-expression-demand_n_5473238.html

By Tanya Lewis

Just as humans lament not pursuing a lover or bemoan having eaten that extra slice of chocolate cake, rats may experience feelings of regret, too, new research suggests.

When rats were given the option of visiting rooms that contained different foods, and they skipped a good deal for a worse one, they glanced back at the former room, rushed through eating the snack and were more likely to tolerate longer wait times for what they considered the more desirable food , researchers found.

Furthermore, the rats’ brain activity represented the missed opportunity, suggesting the animals were, in fact, experiencing regret over their choice.

“The rat is representing the counterfactual — the ‘what might have been,'” David Redish, a neuroscientist at the University of Minnesota in Minneapolis, and senior author of the study detailed today (June 8) in the journal Nature Neuroscience.

No other studies have shown convincingly that any animal besides humans experience regret, though some studies hinted it was possible, the researchers said.

How do you define regret? You can’t exactly ask a rat if it feels regret, but even if you could, it wouldn’t be proof, just as it can be difficult to tell if a human feels regret just by asking them.

It’s important to distinguish between regret and disappointment, Redish told Live Science. Regret occurs when you make a mistake, but recognize there’s an alternate action you could have taken that would have resulted in a better outcome, he said. Disappointment happens when “the world’s just not as good as you hoped, but it’s not necessarily your fault,” he said.

To test whether rats could feel regret, Redish and his graduate student Adam Steiner designed a kind of “restaurant row” for the animals — a circular enclosure with pathways leading off it to “restaurants” with different kinds of food, which were dispensed after some delay.

As a rat passed each pathway, it heard a tone that told the animal how long it would have to wait for the food (like being told the wait time at a restaurant). Each rat had its own favorite food, such as banana or chocolate, and would wait longer to get it, Redish said. Each rat was given an hour to explore the enclosure, during which it could only move in one direction between restaurants.

If the rat passed up a good deal — for instance, bypassing a food it liked in favor of a shorter wait time — and encountered a worse deal at the next restaurant, it would glance backward at the one it passed up. Not only that, the rat rushed through eating its chosen food, much like a regretful human would, and was more likely to take a “worse deal” in the future, the researchers said.

But the rats’ behavior was only part of the story. The researchers also made electrical recordings of the rats’ brains during the task, from neurons in the orbitofrontal cortex, the part of the brain that is active in human brain scans when people feel regret. Decoding these signals allowed the researchers to “read the rat’s mind,” Redish said.

Surprisingly, when the rats were looking back at the restaurant they ultimately passed up, their brains showed a representation of entering that restaurant — not of the food they missed. The findings suggest the animals were expressing regret over their actions, rather than just disappointment, the researchers said.

If rats can feel regret, what about other animals? Redish speculates that any mammal might be capable of the feeling, because they have many of the same brain structures as rats and humans.

“Regret is something we think of as very human and very cognitive,” Redish said, but “we’re seeing that the rats are much more cognitive than we thought.”

http://www.livescience.com/46184-rats-experience-regret.html