Lab: Nightmares may help the brain prepare for frightening situations in real life – Metro Newspaper UK

ITS a terrifying thought but having nightmares could help us prepare for potentially frightening situations.

Theres a huge amount science still doesnt know about dreaming and its not even clear if everyone does it. We all experience rapid eye movement (REM) the stage of sleep when dreams occur.

But whether those who claim they never dream really dont, or do dream but simply dont remember it after waking, isnt clear.

Nor is the mechanism by which dreams are formed in the brain entirely understood, never mind why it happens.

However, many neuroscientists have long believed that bad dreams allow us to safely act out potentially dangerous situations before they occur in real life.

And the new findings from a study at the University of Geneva and University Hospitals Geneva, and the US University of Wisconsin, seem to add weight to that theory.

The researchers asked 18 volunteers to wear EEG headsets while they slept and then woke them multiple times during the night to ask them a series of questions about whether theyd been dreaming, and if that dream involved fear.

They then compared the volunteers answers with their mapped brain activity during sleep and discovered that during scary dreams, two areas of the subjects brains were particularly active: the insula and the cingulate cortex.

During the day, the insula is involved in identifying and evaluating emotional responses, while the cingulate cortex is responsible for preparing the bodys physical reaction to perceived threats the famous fight or flight response.

In the second part of the study, 89 participants kept a dream diary for a week, and were shown a series of distressing images while lying in an MRI scanner.

The images triggered less of a response in the two brain regions studied, and in the amygdala the brains fear centre in subjects who reported having a lot of frightening dreams than patients who reported few or none.

Patients who had more bad dreams showed more activity in the medial prefrontal cortex, a region of the brain thats known to dampen down the fear response.

Lead researcher Lampros Perogamvros said: Dreams may be considered as real training for our future reactions, and may potentially prepare us to face real-life dangers.

ITS about 40,000 years since the Neanderthal disappeared about the same time since modern humans started expanding out of Africa towards Europe and the Middle East.

Because those dates match up so well, its always been assumed the latter caused the former, but a study suggests the Neanderthals may have become extinct for reasons that were nothing to do with the arrival of homo sapiens.

A team at Eindhoven University of Technology in the Netherlands produced computer models to simulate the effects of various factors on Neanderthal populations of different sizes from 50 to 5,000 based on data gleaned from studies of modern hunter-gatherer populations worldwide.

Factors modelled included inbreeding, fluctuations in birth and death rates, changes in the ratio of the sexes and Allee effects a phenomenon first identified in the 1950s whereby, in a shrinking population, the average health and fitness of each individual tends to decline over time.

The researchers found that Allee effects alone could explain the extinction of any population numbering less than 1,000 individuals, while inbreeding plus Allee effects could easily account for the entire Neanderthal species decline over a 10,000-year period, without modern humans arrival having any effect at all.

The papers lead author Krist Vaesen said: Did Neanderthals disappear because of us? No, this study suggests. The species demise might have been due merely to a stroke of bad demographic luck.

The true picture, say the researchers, is probably a more complex amalgam of the two mechanisms. For instance, conflict with incoming humans may have caused an acceleration of Allee effects within the population, as well as simply reducing its size.

FLIGHT feathers are masterpieces of evolution: helping penguins swim, eagles soar and hummingbirds hover.

Now scientists have shed light on how feathers developed and helped birds spread across the world.

Weve always wondered how birds can fly in so many different ways and we found the difference in flight styles is largely due to the characteristics of their flight feathers, said Cheng-Ming Chuong, lead researcher of a global team led by the University of Southern California. Experts in stem cells, molecular biology, anatomy, physics and bio-imaging studied bird species of different styles including ostriches, sparrows, eagles, ducks, penguins and hummingbirds.

Feathers found in 100million-year-old amber had barbs, which could overlap each other but could not become a tight flat plane for flying. Feather shafts gradually became stronger yet more lightweight, leading to stiffer feathers and sturdier wings.

80 Per cent The proportion of school-going children aged 11 to 17 who get less than one hour of physical activity a day, according to the World Health Organization

4 BPM The average heart rate of a diving blue whale, as measured by researchers at Stanford University

HIBERNATING animals ability to pile on the pounds before the winter and wake up months later as fit as ever has led researchers to an intriguing link with obesity. After comparing the genomes of four animals a squirrel, a bat, a lemur and a Madagascan tenrec scientists at the University of Utah believe they have evolved ways to turn off areas that control genes linked to obesity.

A NEW technique that turns brewery waste into carbon, which can be used as barbecue charcoal, has been developed at Queens University Belfast. The UK currently imports liquid carbon from the Middle East and pellets from the US, but the new method may reduce the need to do so. If successful, it could lower carbon emissions by reusing 3.4million tons of waste grain produced by brewers each year, researchers say.

Many animals will choose where they stand to maximise camouflage. The common baron caterpillar has a stripe that looks like the central rib of the mango leaves it eats so natural selection has clearly favoured caterpillars that line themselves up with the rib. But it seems unlikely individual caterpillars know why they do this; its simply programmed into their genes. This is true of all invertebrates and most fish, reptiles and amphibians, but some more intelligent species do show some awareness. Japanese quail, for instance, lay eggs with patterns that vary widely from one bird to another. A 2013 study at Abertay University in Dundee found quail who laid darker eggs were more likely to select darker nesting sites, and vice versa.

The Adams apple is the notch at the top of the thyroid cartilage one of nine cartilages in the protective skeleton around the larynx (voice box). Men and women both have them, but they tend to be larger and more visible in men because their thyroid cartilage grows more during puberty, enlarging the larynx and deepening the voice. The Adams apple itself serves no particular purpose and can be reduced in size without changing the nature of the voice in gender reassignment surgery, for example.

Based on stories featured in BBC Science Focus magazine. Head to sciencefocus.com/metro for the latest science news and a special subscription offer for Metro readers

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Lab: Nightmares may help the brain prepare for frightening situations in real life - Metro Newspaper UK