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Do Certain Sounds Enrage You? Neurologists May Know Why

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If the sound of a co-worker repeatedly clicking his pen can send you into a flaming furor, take heart: You’re not being hypersensitive, and you’re not alone. Neurologists in the UK have spotted physical differences in the brains of people with this sound-related rage, although whether these differences are the cause or the result of the disorder remains to be seen. The scientists published their findings in the journal Current Biology.

The technical term for that noise-triggered irritation and rage is misophonia (“hatred of sound”). People who have it experience uncontrollable and intense negative emotions after hearing certain repetitive noises like chewing, lip-smacking, pen-clicking, and foot-tapping.

It’s a relatively new concept within the medical community, although people have been complaining of symptoms for a long time. To those who’ve never experienced misophonia, it may sound silly or made-up—which is what many doctors have concluded. Others have categorized it as a form of anxiety or obsessive-compulsive disorder.

The authors of the current paper wondered if the problem might not be psychological but neurological. They recruited 20 British adults with misophonia and 22 without, and gave them all questionnaires to gauge their responses to various noises. Then they put each participant inside MRI and fMRI machines and played them all sorts of noises, including the benign (a kettle whistling, rain), the universally unpleasant (a baby crying, someone screaming), and common misophonia triggers (breathing, chewing).

As the researchers suspected, the results for the two groups looked very different. People with misophonia had more myelin, or insulation, around the gray matter in their prefrontal cortex. They also showed abnormal connections between this cortex and the anterior insular cortex, which is involved in processing information and emotions.

Hearing the trigger noises caused a spike in activity in both cortices for people with misophonia. For people without it, activity only increased in the prefrontal cortex. The trigger sounds also provoked a clear stress response in people with misophonia. Their heart rates increased and they began sweating.

Lead researcher Sukhbinder Kumar is a neuroscientist at Newcastle University and University College London. He says his team’s research should reassure people with misophonia and validate the condition’s existence to their doctors.

“Patients with misophonia had strikingly similar clinical features, and yet the syndrome is not recognized in any of the current clinical diagnostic schemes,” he said in a statement. “This study demonstrates the critical brain changes as further evidence to convince a skeptical medical community that this is a genuine disorder."

It also suggests a possible way of treating the condition. “My hope is to identify the brain signature of the trigger sounds,” Kumar said. “Those signatures can be used for treatment such as for neuro-feedback, for example, where people can self-regulate their reactions by looking at what kind of brain activity is being produced."

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Researchers Say You’re Exercising More Than You Think
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They say a journey of a thousand miles starts with a single step. If the thought of a thousand-mile journey makes you tired, we've got some great news for you: You've probably already completed one.* A new study published in the journal Health Psychology [PDF] finds that people underestimate the amount of exercise they're getting—and that this underestimation could be harmful.

Psychologists at Stanford University pulled data on 61,141 American adults from two huge studies conducted in the 1990s and the early 2000s: the National Health Interview Survey and the National Health and Nutrition Examination Survey. Participants answered questionnaires about their lifestyles, health, and exercise habits, and some wore accelerometers to track their movement. Everybody was asked one key question: "Would you say that you are physically more active, less active, or about as active as other persons your age?"

The researchers then tapped into the National Death Index through 2011 to find out which of the participants were still alive 10 to 20 years later.

Combining these three studies yielded two interesting facts. First, that many participants believed themselves to be less active than they actually were. Second, and more surprisingly, they found that people who rated themselves as "less active" were more likely to die—even when their actual activity rates told a different story. The reverse was also true: People who overestimated their exercise had lower mortality rates.

There are many reasons this could be the case. Depression and other mental illnesses can certainly influence both our self-perception and our overall health. The researchers attempted to control for this variable by checking participants' stress levels and asking if they'd seen a mental health professional in the last year. But not everybody who needs help can get it, and many people could have slipped through the cracks.

Paper authors Octavia Zahrt and Alia Crum have a different hypothesis. They say our beliefs about exercise could actually affect our risk of death. "Placebo effects are very robust in medicine," Crum said in a statement. "It is only logical to expect that they would play a role in shaping the benefits of behavioral health as well."

The data suggest that our ideas about exercise and exercise itself are two very different things. If all your friends are marathoners and mountain climbers, you might feel like a sloth—even if you regularly spend your lunch hour in yoga class.

Crum and Zahrt say we could all benefit from relaxing our definition of "exercise."

"Many people think that the only healthy physical activity is vigorous exercise in a gym or on a track," Zahrt told Mental Floss in an email. "They underestimate the importance of just walking to the store, taking the stairs, cleaning the house, or carrying the kids."
 
*The average American takes about 5000 steps per day, or roughly 2.5 miles. At that pace, it would take just a little over a year to walk 1000 miles.

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Medicine
Scientists Are Working on a Way to Treat Eye Floaters With Lasers
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Even people with 20/20 eyesight should be familiar with this scenario: You're enjoying a clear view when a faint doodle shape drifts into your peripheral vision like an organism under a microscope. Floaters affect almost everyone, but there's currently no medically accepted, non-invasive way to treat them. Two doctors with Ophthalmic Consultants of Boston are working to change that. As IFLScience reports, the team believes that lasers may be the solution to bothersome eye squiggles.

As Chirag Shah and Jeffrey Heier write in their study in the journal JAMA Ophthalmology, lasers can be used to safely combat the underlying causes of floaters. Also known as muscae volitantes, Latin for “hovering flies,” the condition comes from physical debris leaking into your eyeball. The front of your eyes is filled with a liquid called vitreous humor, and when drops of that gelatinous substance break off from the whole, the bits cast shadows on your retinas that look like gray blobs. Because floaters literally float inside your eyes, trying to focus on one is almost impossible.

These spots aren't typically a problem for young people, but as you get older your vitreous humor becomes more watery, which increases the chance of it slipping out and clouding your vision. Retinal detachment and retinal tears are also rare but serious causes of symptomatic floaters.

Shah and Heier tested a new method of pinpointing and eliminating floaters with a YAG laser (a type of laser often used in cataract surgery) on 36 patients. An additional 16 test subjects were treated with a sham laser as a placebo. They found that 54 percent of the treated participants saw their floaters decrease over six months, compared to just 9 percent of the control group. So far, the procedure appears be safe and free of side effects, but researchers noted that more follow-up time is needed to determine if those results are long-term.

At the moment, people with symptomatic floaters can choose between surgery or living with the ailment for the rest of their lives. YAG laser treatment may one day offer a safe and easy alternative, but the researchers say they will need to expand the size of future studies before the treatment is ready to go public.

[h/t IFLScience]

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