How does memory work?

To remember something your brain goes through the following process:

First your brain consciously registers the memory, a process called encoding. The reason most people don’t remember a name straight away is because you haven’t encoded the name – perhaps because you weren’t paying full attention. Next, the brain must consolidate the memory, followed by the last step which is called retrieval.

The best way to improve your memory is to keep remembering the same thing, over and over again. This strengthens the neural pathway to the memory. There are other things you can do to improve your memory; get a regular sleep pattern, eat a balanced diet and exercise often.

This video is one of a series developed by researchers in Trinity College Dublin in a bid to allay fears about memory loss, promote brain health and tackle the stigma associated with dementia. You can watch the films (and others) here: http://freedemliving.com

Will we ever … cryopreserve our organs?

Imagine if doctors could dip into freezers and take their pick of kidneys, livers or hearts for life-saving operations. Here’s why it’s so hard to achieve.

Should you ever need a new kidney, a replacement heart or another vital organ, you won’t exactly be spoilt for choice. That’s because when it comes to healthy human organs for life-saving transplants, there is a vast chasm between supply and demand.

In the United States alone, 26,517 organs were transplanted in 2013, yet over 120,000 patients are stuck on the waiting list. Quite simply, there are not enough donations to go around. To make matters worse, even the organs that are made available sometimes go to waste because they don’t have much of a shelf life once they’ve been removed from a donor. At the moment the best we can do is to preserve them in a special solution just above 0C for a day or two, which doesn’t leave much time to find well-matched patients to receive them.

But there is a possible answer. If scientists could find a way to deep-freeze organs and bring them back without incurring damage, we could potentially bank them for weeks or months. The same could be done for lab-engineered organs, if we can create them. With that in mind, the Organ Preservation Alliance, a charity incubated by Singularity University Labs at Nasa’s Research Park in California, is planning a $1m prize to incentivise breakthroughs. So could we see a time when transplant surgeons can dip into freezers, and take their pick of kidneys, livers or hearts to carry out life-saving operations?

Scientists have been successfully freezing, or cryopreserving, small collections of human cells for 40 years. They preserve eggs and embryos by flooding cells with solutions of so-called cryoprotectant compounds – which prevent the formation of ice crystals that can rip cells apart, and also guard against lethal shrinkage. Unfortunately, they hit major hurdles when trying to scale this process up, as the architecture within more complex tissues and organs is much more vulnerable to ice-crystal-related damage.

Nevertheless, a small cadre of researchers has not given up, warming to the challenge in part by taking cues from nature. Antarctic icefish, for example, survive in waters as cold as -2C thanks to antifreeze proteins (AFPs), which lower the freezing point of their bodily fluids and bind to ice crystals to stop them spreading. Researchers have used solutions containing icefish AFPs to preserve rat hearts for up to 24 hours at a few degrees below zero. Any colder, however, and icefish AFPs backfire: they force budding ice crystals to form sharp spikes that pierce cell membranes. Another anti-freeze compound, recently discovered in an Alaskan beetle that can tolerate -60C, might prove more useful.

But anti-freeze ingredients alone won’t do the job. That’s because freezing also wrecks cells by affecting the flow of fluids into and out of them. Ice first forms in the spaces between cells, reducing the volume of liquid and increasing the concentration of dissolved salts and other ions. Water rushes from cells out to compensate, causing them to shrivel and die.

For eggs and embryos that’s where cryoprotectant compounds such as glycerol come in handy: they not only displace water to prevent ice formation within cells, but also help to prevent cell shrinkage and death. The problem is these compounds can’t work the same magic in organs. For one, cells in tissue are much more susceptible to ice penetration. And even if cells are protected, ice crystals forming in the spaces between cells shred the extracellular structures that hold the organ together and facilitate its function.

Glass act

One way to overcome the dangers of ice formation is to stop it from happening in the first place. That’s why some scientists are betting on a technique called vitrification, in which tissues are cooled in such a way that they’re transformed into an ice-free glass. The approach is already used by some fertility clinics, and it has produced some of the most encouraging results to date in terms of preserving complex tissues.

In 2000, for example, Mike Taylor and colleagues at Cell and Tissue Systems in Charleston, South Carolina, vitrified 5cm-long segments of rabbit vein, which falls somewhere between cells and organs in terms of complexity, and demonstrated that they retain most of their function after warming. Two years later, Greg Fahy and colleagues at 21st-Century Medicine, a California-based cryopreservation research company, made a significant breakthrough: they vitrified a rabbit kidney, keeping it below the glass transition temperature of -122C for 10 minutes, before thawing and transplanting it into a rabbit that lived for 48 days before it was killed for examination.

“It was the first time a vital organ has been cryopreserved and transplanted with life support afterwards,” says Fahy. “It was proof that this is a realistic proposition.” But the kidney didn’t function as well as a healthy version, largely because one particular part, the medulla, was slower to soak up the cryoprotectant solution, which meant that some ice formed there during thawing. “Even though we had tremendous encouragement, we also knew we needed to do a better job,” Fahy adds.

“That’s the nearest we’ve come,” says Taylor, adding a note of caution. “That was over 10 years ago, and if the technique was sufficiently robust then there should have been follow-up studies and reports substantiating the finding, which there has not been.” Further progress has been slow, in part, Fahy says, because a chemical that was key part of his method went out of production. Nevertheless, his group has made up the ground and taken a step further: at the annual meeting for the Society of Cryobiology in 2013, Fahy presented a method that allows them to more quickly load the medulla with cryoprotectants.

Despite Fahy’s optimism, it’s clear that when it comes to preserving large organs, vitrification poses some formidable challenges. For a start, you need high concentrations of cryoprotectants – at least five times higher than in conventional slow cooling – which can poison the cells and tissues they’re supposed to protect. The problem gets worse with larger tissues because it takes longer to load the compounds, meaning slower cooling times and more opportunity for toxic exposure. In addition, if cooling is too rapid, or it reaches temperatures that are too low, cracks can appear.

The exceedingly delicate warming process presents more hurdles. If the vitrified specimen is not heated quickly or evenly enough, glassiness gives way to crystallisation – a process known as devitrification – and, again, cracking can occur. “[This] is a challenge we’ve not yet met,” says John Bischof, a cryobiologist and engineer at the University of Minnesota. “The limiting factor is how quickly and uniformly we can thaw it.” And that’s because warming is usually done from the outside in.

Last year, Bischof and graduate student Michael Etheridge proposed a way around the problem: add magnetic nanoparticles to the cryoprotectant solution. The idea is that the particles disperse through the tissue and, once excited by magnetic fields, heat the whole thing evenly and rapidly. The duo is currently working with Taylor and his colleagues to test the method on rabbit arteries

Ice in action

For the most part, advances in the field have arrived by trial and error: testing combinations of solutions and freezing/thawing methods. But researchers have also begun to take advantage of new technologies to get a closer look at how ice behaves in cells and tissues. If you understand the processes in detail, the hope is that you can design new and more effective approaches to control them.

The last 12 months has seen significant advances in this area. Taylor, working with Yoed Rabin, a mechanical engineer at Carnegie Mellon University in Pittsburgh, introduced a new device that enables high-resolution full-colour thermal imaging in large-volume tissues. Meanwhile,Jens Karlsson at Villanova University in Pennsylvania has recently captured ultra-slow-motion microscopic video footage of ice penetrating tiny pockets between two close-knit cells and then triggering crystallisation within them.

Insights from these methods could bring new ideas about how to manipulate the freezing process, says Karlsson, who is trying to figure out ways to cryopreserve tissues by carefully controlling the freezing and thawing process, rather than via vitrification. One possibility is to genetically engineer cells to coax them to make cell-cell junctions capable of withstanding cryopreservation. The next task would be to find a way to direct the formation of extracellular ice so that it doesn’t affect an organs’ function.

Karlsson is also eager to use computer simulations of the freezing process to efficiently test millions of possible protocols. “We need these sorts of tools to accelerate progress,” says Karlsson, who likens the task to “trying to get to the moon with a fraction of the funding that went into that endeavour”.

Even with limited resources, the field has demonstrated that ice-free cryopreservation is practical for small tissues such as a segment of blood vessel. “The remaining barrier, and it’s significant one,” says Taylor, “is scaling it up to a human organ.” For Karlsson, who suspects that such efforts “may hit a brick wall” before vitrification will ever work for human organs, freezing – or what he calls ice-assisted – approaches represent an equally, if not more, viable route to success.

But there is one final sobering thought. “No cryopreservation technique ever offers 100% survival of the component cells,” says Taylor. “In many applications this can be tolerated but for a single organ this may be a significant amount of injury to repair post-storage or transplantation.” Ultimately, that means no matter how well cryopreserved specimens are, they are likely to be sub-standard compared with freshly procured organs.

By Daniel Cossins

Source: http://www.bbc.com/future/story/20140224-can-we-ever-freeze-our-organs

‘Biggest observed meteorite impact’ hits the Moon

‘Biggest observed meteorite impact’ hits Moon

 

The impact appeared as a bright white flash on 11 September 2013

Scientists say they have observed a record-breaking impact on the Moon.

Spanish astronomers spotted a meteorite with a mass of about half a tonne crashing into the lunar surface last September.

They say the collision would have generated a flash of light so bright that it would have been visible from Earth.

The event is reported in the Monthly Notices of the Royal Astronomical Society.

“This is the largest, brightest impact we have ever observed on the Moon,” said Prof Jose Madiedo, of the University of Huelva in south-western Spain.

“The impact we detected lasted over eight seconds” – Prof Jose MadiedoUniversity of Huelva

The explosive strike was spotted by the Moon Impacts Detection and Analysis System (Midas) of telescopes in southern Spain on 11 September at 20:07 GMT.

“Usually lunar impacts have a very short duration – just a fraction of a second. But the impact we detected lasted over eight seconds. It was almost as bright as the Pole Star, which makes it the brightest impact event that we have recorded from Earth,” said Prof Madiedo.

The researchers say a lump of rock weighing about 400kg (900lb) and travelling at 61,000km/h (38,000mph) slammed into the surface of the Moon.

They believe the dense mass, which had a width of 0.6-1.4m (2-4.6ft), hit with energy equivalent to about 15 tonnes of TNT.

This is about three times more explosive than another lunar impact spotted by Nasa last March. That space rock weighed about 40kg and was about 0.3-0.4m wide.

Scarred Moon

The team believes the impact has left behind a 40m-wide crater.

“That’s the estimation we have made according to current impact models. We expect that soon Nasa could observe the crater and confirm our prediction,” said Prof Madiedo.

It would be one of many scars on the lunar surface.

Unlike Earth, the Moon has no atmosphere to shield it from meteorite collisions, and its surface shows a record of every strike.

The researchers believe that impacts from rocks of about 1m in diameter could be far more common than was previously thought – both on the Moon and on Earth.

However, most rocks of this size would burn up as they entered the Earth’s atmosphere, appearing as a fireball in the sky.

For meteorites to make more of an impact here, they need to be larger.

For example, the asteroid that exploded over Chelyabinsk in Russia on 15 February 2013 was estimated to be about 19m wide.

It hit the atmosphere with energy estimated to be equivalent to 500,000 tonnes of TNT, sending a shockwave twice around the globe. It caused widespread damage and injured more than 1,000 people.

By Rebecca Morelle

Source: http://www.bbc.co.uk/news/science-envir

Body bacteria: Can your gut bugs make you smarter?

The bacteria in our guts can influence the working of the mind, says Frank Swain. So could they be upgraded to enhance brainpower?

I have some startling news: you are not human. At least, by some counts. While you are indeed made up of billions of human cells working in remarkable concert, these are easily outnumbered by the bacterial cells that live on and in you – your microbiome. There are ten of them for every one of your own cells, and they add an extra two kilograms (4.4lbs) to your body.

Far from being freeloading passengers, many of these microbes actively help digest food and prevent infection. And now evidence is emerging that these tiny organisms may also have a profound impact on the brain too. They are a living augmentation of your body – and like any enhancement, this means they could, in principle, be upgraded. So, could you hack your microbiome to make yourself healthier, happier, and smarter too?

According to John Cryan, this isn’t as far-fetched as it sounds. As a professor of anatomy and neuroscience at University College Cork, he specialises in the relationship between the brain and the gut. One of his early experiments showed the diversity of bacteria living in the gut was greatly diminished in mice suffering from early life stress. This finding inspired him to investigate the connection between the microbiome and the brain.

The bacterial microbiota in the gut helps normal brain development, says Cryan. “If you don’t have microbiota you have major changes in brain structure and function, and then also in behaviour.” In a pioneering study, a Japanese research team showed that mice raised without any gut bacteria had an exaggerated physical response to stress, releasing more hormone than mice that had a full complement of bacteria. However, this effect could be reduced in bacteria-free mice by repopulating their gut withBifidobacterium infantis, one of the major symbiotic bacteria found in the gut. Cryan’s team built on this finding, showing that this effect could be reproduced even in healthy mice. “We took healthy mice and fed themLactobacillus [another common gut bacteria), and we showed that these animals had a reduced stress response and reduced anxiety-related behaviours.”

 

When this bacteria was fed to mice it reduced stress and anxiety (Science Photo Library)

 

But why should bacteria in the gut affect the brain? There are several different ways that messages can be sent from one organ to the other. It can be hormones or immune cells via the bloodstream, or by impulses along the vagus nerve, which stretches from the brain to intertwine closely with the gut. Through these pathways, actions in one produce effects in the other.

So how might you go about altering your microbiome to do a spot of brain-hacking? Cryan’s team works on several fronts, investigating the potential to manage stress, pain, obesity and cognition through the gut. “We have unpublished data showing that probiotics can enhance learning in animal models,” he tells me. His team tested the effects of two strains of bacteria, finding that one improved cognition in mice. His team is now embarking on human trials, to see if healthy volunteers can have their cognitive abilities enhanced or modulated by tweaking the gut microbiome.

Another method of adjusting the bacterial profile of your gut is to undergo a transplant that involves taking faecal material from a donor’s intestine – often a close relative – and implanting into a recipient via enema infusion. This unorthodox treatment has been shown to successfully treat infections caused by pathogenic bacteria colonising the gut.

Brain boost

Thankfully, Cryan has a far more appetising method on offer.  “Diet is perhaps the biggest factor in shaping the composition of the microbiome,” he says. A study by University College Cork researchers published in Nature in 2012 followed 200 elderly people over the course of two years, as they transitioned into different environments such as nursing homes. The researchers found that their subjects’ health – frailty, cognition, and immune system – all correlated with their microbiome. From bacterial population alone, researchers could tell if a patient was a long-stay patient in a nursing home, or short-stay, or living in the general community. These changes were a direct reflection of their diet in these different environments. “A diverse diet gives you a diverse microbiome that gives you a better health outcome,” says Cryan.

Beyond a healthy and varied diet, though, it still remains to be discovered whether certain food combinations could alter the microbiome to produce a cognitive boost. In fact, Cryan recommends that claims from probiotic supplements of brain-boosting ought to be taken with a pinch of salt for now. “Unless the studies have been done, one can assume they’re not going to have any effect on mental health,” he says. Still, he’s optimistic about the future. “The field right now is evolving very strongly and quickly. There’s a lot of important research to be done. It’s still early days.”

Hacking the brain often conjures up ideas of electrical hardware such as implants and trans-cranial stimulators. But it might be the case that a simple change in diet can shift your brain up a gear. The transhumanists and body hackers who believe that technology is the sole way to improve human ability would do well to pay as much attention to the living augmentation that already resides in their gut.

Depression speeds up ageing

Depression can make us physically older by speeding up the ageing process in our cells, according to a study.

Lab tests showed cells looked biologically older in people who were severely depressed or who had been in the past.

These visible differences in a measure of cell ageing called telomere length couldn’t be explained by other factors, such as whether a person smoked.

The findings, in more than 2,000 people, appear in Molecular Psychiatry.

Experts already know that people with major depression are at increased risk of age-related diseases such as cancer, diabetes, obesity and heart disease.

This might be partly down to unhealthy lifestyle behaviours such as alcohol use and physical inactivity.

But scientists suspect depression takes its own toll on our cells.

Telomere shortening

To investigate, Josine Verhoeven from the VU University Medical Centre in the Netherlands, along with colleagues from the US, recruited 2,407 people to take part in the study.

More than one third of the volunteers were currently depressed, a third had experienced major depression in the past and the rest had never been depressed.

The volunteers were asked to give a blood sample for the researchers to analyse in the lab for signs of cellular ageing.

The researchers were looking for changes in structures deep inside cells called telomeres.

Telomeres cap the end of our chromosomes which house our DNA. Their job is to stop any unwanted loss of this vital genetic code. As cells divide, the telomeres get shorter and shorter. Measuring their length is a way of assessing cellular ageing.

People who were or had been depressed had much shorter telomeres than those who had never experienced depression. This difference was apparent even after lifestyle differences, such as heavy drinking and smoking, were taken into account.

Furthermore, the most severely and chronically depressed patients had the shortest telomeres.

Dr Verhoeven and colleagues speculate that shortened telomeres are a consequence of the body’s reaction to the distress depression causes.

“This large-scale study provides convincing evidence that depression is associated with several years of biological ageing, especially among those with the most severe and chronic symptoms,” they say.

But it is unclear whether this ageing process is harmful and if it can be reversed.

UK expert Dr Anna Phillips, of the University of Birmingham, has researched the effects of stress on telomere length.

She says telomere length does not consistently predict other key outcomes such as death risk.

Further, it is likely that only a major depressive disorder, not experience of or even a lifetime of mild-to-moderate depressive symptoms, relates to telomere length, she said.

Source: http://www.bbc.co.uk/news/health-24897247

Test ‘predicts’ teen depression risk

A tool for predicting the risk of clinical depression in teenage boys has been developed by researchers.

Looking for high levels of the stress hormone cortisol and reports of feeling miserable, lonely or unloved could find those at greatest risk.

Researchers at the University of Cambridge want to develop a way of screening for depression in the same way as heart problems can be predicted.

However, their method was far less useful in girls.

Teenage years and early adulthood are a critical time for mental health – 75% of disorders develop before the age of 24.

But there is no way to accurately say who will or will not develop depression.

Risky combination

Now researchers say they have taken the “first step” towards a screening tool.

Tests on 1,858 teenagers, reported in Proceedings of the National Academy of Sciences, combined hormone levels and mood questionnaires to assess risk.

They showed that having both high cortisol levels and depressive mood symptoms posed a higher risk of depression than either factor alone and presented a risk of clinical depression 14 times that of those with low cortisol and no depressive symptoms.

Around one in six boys was in the high-risk category and half of them were diagnosed with clinical depression during the three years of study.

One of the researchers, Prof Ian Goodyer, said: “Depression is a terrible illness that will affect as many as 10 million people in the UK at some point in their lives.

“Through our research, we now have a very real way of identifying those teenage boys most likely to develop clinical depression.

“This will help us strategically target preventions and interventions at these individuals and hopefully help reduce their risk of serious episodes of depression, and their consequences, in adult life.”

‘Many contributory factors’

Women are twice as likely as men to develop depression during their lifetimes, but the test was little help in determining risk.

One theory is that women naturally have higher cortisol levels, which affects their risk.

However, the test is not yet ready for clinical use.

Dr John Williams, from the Wellcome Trust, which funded the study, said: “Progress in identifying biological markers for depression has been frustratingly slow, but now we finally have a biomarker for clinical depression.”

Sam Challis, from mental health charity Mind, said: “This study claims there is a biomarker linked to depression, but it’s important to bear in mind that many factors play a part in depression, such as life events, genetic factors, side effects of medication and diet.

“However, this research could help identify those who may need extra support.

Source: http://www.bbc.co.uk/news/health-26224812

Dog and Human Brain Link Revealed

Devoted dog owners often claim that their pets understand them. A new study suggests they could be right.

By placing dogs in an MRI scanner, researchers from Hungary found that the canine brain reacts to voices in the same way that the human brain does.

Emotionally charged sounds, such as crying or laughter, also prompted similar responses, perhaps explaining why dogs are attuned to human emotions.

The work is published in the journal Current Biology.

Lead author Attila Andics, from the Hungarian Academy of Science’s Eotvos Lorand University in Budapest, said: “We think dogs and humans have a very similar mechanism to process emotional information.”

Eleven pet dogs took part in the study; training them took some time.

“We used positive reinforcement strategies – lots of praise,” said Dr Andics.

“There were 12 sessions of preparatory training, then seven sessions in the scanner room, then these dogs were able to lie motionless for as long as eight minutes. Once they were trained, they were so happy, I wouldn’t have believed it if I didn’t see it.”

The canine brain reacted to voices in the same way that the human brain does

For comparison, the team looked at the brains of 22 human volunteers in the same MRI scanners.

The scientists played the people and pooches 200 different sounds, ranging from environmental noises, such as car sounds and whistles, to human sounds (but not words) and dog vocalisations.

“It is the first time we have seen this in a non-primate” – Attila AndicsEotvos, Lorand University

The researchers found that a similar region – the temporal pole, which is the most anterior part of the temporal lobe – was activated when both the animals and people heard human voices.

“We do know there are voice areas in humans, areas that respond more strongly to human sounds that any other types of sounds,” Dr Andics explained.

“The location (of the activity) in the dog brain is very similar to where we found it in the human brain. The fact that we found these areas exist at all in the dog brain at all is a surprise – it is the first time we have seen this in a non-primate.”

The team used a variety of techniques to train the dogs

Emotional sounds, such as crying and laughter also had a similar pattern of activity, with an area near the primary auditory cortex lighting up in dogs and humans.

Likewise, emotionally charged dog vocalisations – such as whimpering or angry barking – also caused a similar reaction in all volunteers,

Dr Andics said: “We know very well that dogs are very good at tuning into the feelings of their owners, and we know a good dog owner can detect emotional changes in his dog – but we now begin to understand why this can be.”

However, while the dogs responded to the human voice, their reactions were far stronger when it came to canine sounds.

“It would be interesting to see the animal’s response to words rather than just sounds” – Prof Sophie ScottUCL

They also seemed less able to distinguish between environmental sounds and vocal noises compared with humans.

About half of the whole auditory cortex lit up in dogs when listening to these noises, compared with 3% of the same area in humans.

Commenting on the research, Prof Sophie Scott, from the Institute of Cognitive Neuroscience at University College London, said: “Finding something like this in a primate brain isn’t too surprising – but it is quite something to demonstrate it in dogs.

“Dogs are a very interesting animal to look at – we have selected for a lot of traits in dogs that have made them very amenable to humans. Some studies have show they understand a lot of words and they understand intentionality – pointing.”

But she added: “It would be interesting to see the animal’s response to words rather than just sounds. When we cry and laugh, they are much more like animal calls and this might be causing this response.

“A step further would be if they had gone in and shown sensitivity to words in the language their owners speech.”

Secret To Thinking Like A Genius

Albert Einstein famously said: “Imagination is more important than knowledge.” They’re both important, says physicist and Nobel Prize recipient Frank Wilczek, but knowledge without imagination is barren. Take his subject of theoretical physics. As Wilczek says a lot of what you do is to try to understand Mother Nature’s mind and her sense of beauty to see how the laws of physics could be more beautiful.

Not many people truly appreciate what happened in physics in the last part of the 20th Century. We understood at a level whose profundity would be difficult to exaggerate what matter is. We really have the equations for the different fundamental building blocks of matter – the different particles have mathematical characterisations that are precise and elegant. They have no secrets, in principle we have the equations.

The bad news, however, is we are not so good at solving them. There are still gaps in fundamental understanding, we have very good equations or practical purposes, but they are kind of lop-sided; they are beautiful but not quite as beautiful as they should be given they are close to God’s last word in some sense. We’re trying to think of better ways to solve the equations, which takes a lot of imagination because they describe an unfamiliar world – it’s a very small world and things behave differently in it. The only way to get experience is to play around with the equations and imagine how they might behave in different circumstances, it’s more like imaginative play than anything else.

The laws we have discovered, especially in the quantum world are so strange you have to play with them in your mind. Usually what you envision is wrong, but its mind expanding and every once in a while you see something that may be right. Sometimes it even is right.

The questions we are now able to ask are so compelling, so extraordinary. What is most of the Universe made of? Are the laws of physics ultimately unified? What was the Big Bang like? You just say them and they have such grandeur. The more you learn about the equations, the more you learn about physics, the more you learn how beautiful it is. That’s the real value, it’s an ornament to the human mind.

Source: http://www.bbc.com/future/story/20131127-secret-to-thinking-like-a-genius

Why Everyone Must Understand Science

Science is undoubtedly humanity’s greatest achievement, says AC Grayling, Master of the New College of the Humanities. People have to wake up to the fact that they have to be part of the story in thinking about science, and thinking about the meaning of science as it applies to our world.

People feel excluded by science and debates about science, they use laptops, they fly in planes, use appliances in the home and they don’t know what’s behind this technology. That is a problem, as it turns people into the slaves of our technology. The less people know the more they are likely to be manipulated or influenced by people who may not have their best interests at heart.

People are aware that there are lots of problems with the environment and the climate. If people knew more about the science behind this, they more likely they would be to press governments that are involved in policy decisions.

We have to start this at school. Our traditional way of teaching science is that the people who are learning it will go on to be scientists. For many people, that’s not the way to go. People could get a good understanding of science, without the need to have technical expertise. Universities tend to be very over-specialised very early on. Educated people should be challenged to have knowledge across the humanities and sciences. And in society there needs to be more interchange between people at the coal-face of science and the people on the street.

We have to have a healthy scepticism, says Grayling, people can’t just shut their eyes to things that are important. We now have the technologies and the opportunities to go out there and capture imaginations and invite people to have a much better understanding of science.

Source: http://www.bbc.com/future/story/20130527-we-all-must-be-science-literate

Why our bodies jerk before we fall asleep

As we give up our bodies to sleep, sudden twitches escape our brains, causing our arms and legs to jerk. Some people are startled by them, others are embarrassed. Me, I am fascinated by these twitches, known ashypnic jerks. Nobody knows for sure what causes them, but to me they represent the side effects of a hidden battle for control in the brain that happens each night on the cusp between wakefulness and dreams.

Normally we are paralysed while we sleep. Even during the most vivid dreams our muscles stay relaxed and still, showing little sign of our internal excitement. Events in the outside world usually get ignored: not that I’d recommend doing this but experiments have shown that even if you sleep with your eyes taped open and someone flashes a light at you it is unlikely that it will affect your dreams.

But the door between the dreamer and the outside world is not completely closed. Two kinds of movements escape the dreaming brain, and they each have a different story to tell.

Brain battle

The most common movements we make while asleep are rapid eye-movements. When we dream, our eyes move according to what we are dreaming about. If, for example, we dream we are watching a game of tennis our eyes will move from left to right with each volley. These movements generated in the dream world escape from normal sleep paralysis and leak into the real world. Seeing a sleeping persons’ eyes move is the strongest sign that they are dreaming.

Hypnic jerks aren’t like this. They are most common in children, when our dreams are most simple and they do not reflect what is happening in the dream world – if you dream of riding a bike you do not move your legs in circles. Instead, hypnic jerks seem to be a sign that the motor system can still exert some control over the body as sleep paralysis begins to take over. Rather than having a single “sleep-wake” switch in the brain for controlling our sleep (i.e. ON at night, OFF during the day), we have two opposing systems balanced against each other that go through a daily dance, where each has to wrest control from the other.

Deep in the brain, below the cortex (the most evolved part of the human brain) lies one of them: a network of nerve cells called the reticular activating system. This is nestled among the parts of the brain that govern basic physiological processes, such as breathing. When the reticular activating system is in full force we feel alert and restless – that is, we are awake.

Opposing this system is the ventrolateral preoptic nucleus: ‘ventrolateral’ means it is on the underside and towards the edge in the brain, ‘preoptic’ means it is just before the point where the nerves from the eyes cross. We call it the VLPO. The VLPO drives sleepiness, and its location near the optic nerve is presumably so that it can collect information about the beginning and end of daylight hours, and so influence our sleep cycles.

As the mind gives in to its normal task of interpreting the external world, and starts to generate its own entertainment, the struggle between the reticular activating system and VLPO tilts in favour of the latter. Sleep paralysis sets in. What happens next is not fully clear, but it seems that part of the story is that the struggle for control of the motor system is not quite over yet. Few battles are won completely in a single moment. As sleep paralysis sets in remaining daytime energy kindles and bursts out in seemingly random movements. In other words, hypnic jerks are the last gasps of normal daytime motor control.

Some people report that hypnic jerks happen as they dream they are falling or tripping up. This is an example of the rare phenomenon known asdream incorporation, where something external, such as an alarm clock, is built into your dreams. When this does happen, it illustrates our mind’s amazing capacity to generate plausible stories. In dreams, the planning and foresight areas of the brain are suppressed, allowing the mind to react creatively to wherever it wanders – much like a jazz improviser responds to fellow musicians to inspire what they play.

As hypnic jerks escape during the struggle between wake and sleep, the mind is undergoing its own transition. In the waking world we must make sense of external events. In dreams the mind tries to make sense of its own activity, resulting in dreams. Whilst a veil is drawn over most of the external world as we fall asleep, hypnic jerks are obviously close enough to home – being movements of our own bodies – to attract the attention of sleeping consciousness. Along with the hallucinated night-time world they get incorporated into our dreams.

So there is a pleasing symmetry between the two kinds of movements we make when asleep. Rapid eye movements are the traces of dreams that can be seen in the waking world. Hypnic jerks seem to be the traces of waking life that intrude on the dream world.

Source: http://www.bbc.com/future/story/20120522-suffer-from-sleep-shudders