Testing, not studying, makes for strong long-term memories

Blogging on Peer-Reviewed ResearchIt’s a familiar scene – the wee hours of the morning are ticking away and your head is bent over a stack of notes, desperately trying to cram as much knowledge into your head before the test in the morning.

Exam roomBecause of the way our education system works, this process of hard studying has become almost synonymous with the act of learning, and the inevitable tests and exams that bookend this ordeal merely assess how much information has stuck.

But a new study reveals that the tests themselves do more good for our ability to learn that the many hours before them spent relentlessly poring over notes and textbook. The act of repeatedly retrieving and using learned information drives memories into long-term storage, while repetitive revision produced almost no benefits.

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Third cousin couples have the most children and grandchildren

Blogging on Peer-Reviewed ResearchMarriage between closely related cousins is a heavy taboo in many cultures and its critics often cite the higher risk of genetic diseases associated with inbreeding. That risk is certainly apparent for very close relatives, but a new study from Iceland shows that very distant relatives don’t have it easy either. In the long run, they have just as few children and grandchildren as closely related ones.

Shuffling the genetic deck

Indian marriageSex chromosomes aside, every person has two copies of each gene, one inherited from their father and one by their mother. Not every gene will be in correct working order, but there’s a good chance that a faulty copy will be offset by a functional one from the other parent.

However, if two parents are closely related, there’s a higher-than-average chance that they will already share some of the same genes and a similarly increased chance that their child will receive two defective copies. That can be very bad news indeed and in cases where important genes are affected, the results can include miscarriage, birth defects or early death.

Sex, then, is a shuffling of their genetic deck and theoretically the more closely related the partners are, the greater the chance that their child will be dealt a dud hand. And yet, some studies have found that some closely related couples actually do better than distant relatives in terms of the number of children they manage to raise. This trend is certainly unexpected and the big question is whether it is the result of biology or money.

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Averaging photos creates infallible face recognition tool

Blogging on Peer-Reviewed ResearchCompare a photo of yourself all cleaned up for a night out with another one first thing the next morning, and you’ll begin to appreciate the problems that people working on face recognition software encounter.

DiazWhile some unfeasibly lucky people look great from all angles, most of us have to contend with a lottery of lighting conditions, odd angles, stupid expressions, stupider poses and the ravages of age. Faced with this unavoidable variability, it’s no wonder that automatic software flounder when tasked with comparing images to stock photos, like those in passports.

Now, Rob Jenkins and Mike Burton from the University of Glasgow have beaten the problem by creating a face recognition system that, so far, has proved to be 100% accurate. This level of accuracy is unheard of in the technological world. It is matched only by that most sophisticated of computers – the human brain – and indeed, it’s the brain that provided Jenkins and Burton with the inspiration for their method.

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Newborn babies have a preference for the way living things move

Blogging on Peer-Reviewed ResearchFrom an animal’s point of view, the most important things in the world around it are arguably other animals. They provide mates, food, danger and companionship, so as an animal gazes upon its surroundings, it pays for it to be able to accurately discern the movements of other animals. Humans are no exception and new research shows that we are so attuned to biological motion that babies just two days old are drawn to extremely simple abstract animations of walking animals.

Running animal Animals move with a restrained fluidity that makes them stand out from inanimate objects. Compared to a speeding train or a falling pencil, animals show far greater flexibility of movement but most are nonetheless constrained by some form of rigid skeleton. That gives our visual system something to latch on to.

In 1973, Swedish scientist Gunnar Johansson demonstrated this to great effect by showing that a few points of light placed at the joints of a moving animal to simulate its gait. When we see these sparse animations, we see them for what they represent almost instantaneously.

Don’t believe me? Just look at this human walker from Nikolaus Troje’s BioMotion Lab website. With just fifteen white dots, you can not only simulate a walking adult, but you can also tell if it’s male or female, happy or sad, nervous or relaxed. Movement is the key to the illusion – any single static frame merely looks like a random collection of unconnected dots. But once they start to move in time, the brain performs an amazing feat of processing that extract the image of a human from the random dots.

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Time doesn’t actually slow down in a crisis

Blogging on Peer-Reviewed ResearchIn The Matrix, when an agent first shoots at Neo, his perception of time slows down, allowing him to see and avoid oncoming bullets. In the real world, almost all of us have experienced moments of crisis when time seems to slow to a crawl, be it a crashing car, an incoming fist, or a falling valuable.

Time doesn’t actually slow down in a crisisNow, a trio of scientists has shown that this effect is an illusion. When danger looms, we don’t actually experience events in slow motion. Instead, our brains just remember time moving more slowly after the event has passed.

Chess Stetson, Matthew Fiesta and David Eagleman demonstrated the illusion by putting a group of volunteers through 150 terrifying feet of free-fall. They wanted to see if the fearful plummet allowed them to successfully complete a task that was only possible if time actually moved more slowly to their eyes.

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Subliminal flag shifts political views and voting choices

Blogging on Peer-Reviewed ResearchSubliminal flag shifts political views and voting choicesFor all the millions that are poured into electoral campaigns, a voter’s choice can be influenced by the subtlest of signals. Israeli scientists have found that even subliminal exposure to national flags can shift a person’s political views and even who they vote for. They managed to affect the attitudes of volunteers to the Israeli-Palestine conflict by showing them the Israeli flag for just 16 thousandths of a second, barely long enough for the image to consciously register.

These results are stunning – even for people right in the middle of the one of the modern age’s most deep-rooted conflicts, the subconscious sight of a flag drew their sympathies towards the political centre.

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Songbirds need so-called “human language gene” to learn new tunes

Blogging on Peer-Reviewed ResearchThe nasal screech of Chris Tucker sound worlds apart from the song of a nightingale but both human speech and birdsong actually have a lot in common. Both infants and chicks learn their respective tongues by imitating others. They pick up new material most easily during specific periods of time as they grow up, they need practice to improve and they pick up local dialects. And as infants unite words to form sentences, so do songbirds learn to combine separate riffs into a full song. Songbirds need so-called “human language gene” to learn new tunes

Because of these similarities, songbirds make a good model for inquisitive neuroscientists looking to understand the intricacies of human speech. Zebra finches are a particularly enlightening species and they have just shown Sebastian Haesler that the so-called human ‘language gene’ FOXP2 also controls an songbird’s ability to pick up new material.

FOXP2 has a long and sordid history of fascinating science and shoddy science writing. It has been consistently mislabelled as “the language gene” and after the discovery that the human and chimp versions differed by just two small changes, it was also held responsible for the evolution of human language. Even though these claims are far-fetched (for reasons I’ll delve into later), there is no doubt that faults in FOXP2 can spell disaster for a person’s ability to speak.

Mutated versions cause a speech impairment called developmental verbal dyspraxia (DVD), where people are unable to coordinate the positions of their jaws, lips, tongues and faces, even though their minds and relevant muscles are in reasonable working order. They’re like an orchestra that plays a cacophony despite having a decent conductor and tuned instruments.

Brain scans of people with DVD have revealed abnormalities in the basal ganglia, an group of neurons at the heart of the brain with several connections to other areas. Normal people show strong activation of FOXP2 here and fascinatingly, so do songbirds. Haesler reasoned that studying the role of this gene in birds could tell him more about its human counterpart.

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Brain of the beholder – the neuroscience of beauty in sculpture

Blogging on Peer-Reviewed ResearchIs beauty simply in the eye of the beholder, or do all the beholders’ brains have something in common? Is there an objective side to beauty? Plato certainly seemed to think so. His view was that beauty was an inherent property that all beautiful objects possess, irrespective of whether someone likes it or not.

Brain of the beholder – the neuroscience of beauty in sculptureTo him, beauty in the world stemmed from an ideal version of Beauty that real objects can only aspire to. A biologist might instead suggest that the objective side of beauty stems from built-in predispositions for certain features, colours, shapes or proportions.

The opposing view is that art is a fully subjective enterprise and our preferences are shaped by our values and experiences. The real answer is likely to lie somewhere in the middle – after all, art students learn basic common skills such as proportion, perspective and symmetry before embarking on their own stylistic journeys.

Artists, critics and gallery visitors can argue about this question all they like, but some clearer answers have now emerged from three researchers in Italy, arguably the home of the some of the world’s most beautiful art. Cinzia Di Dio, Emiliano Macaluso and Giacomo Rizzolatti from the University of Parma have brought the tools of the modern neuroscientist into the debate.

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Delay not deviance: brains of children with ADHD mature later than others

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Attention-deficit hyperactivity disorder is the most common developmental disorder in children, affecting anywhere between 3-5% of the world’s school-going population. As the name suggests, kids with ADHD are hyperactive and easily distracted; they are also forgetful and find it difficult to control their own impulses.

brains of children with ADHD mature later than others

While some evidence has suggested that ADHD brains develop in fundamentally different ways to typical ones, other results have argued that they are just the result of a delay in the normal timetable for development.

Now, Philip Shaw, Judith Rapaport and others from the National Institute of Mental Health have found new evidence to support the second theory. When some parts of the brain stick to their normal timetable for development, while others lag behind, ADHD is the result.

The idea isn’t new; earlier studies have found that children with ADHD have similar brain activity to slightly younger children without the condition. Rapaport’s own group had previously found that the brain’s four lobes developed in very much the same way, regardless of whether children had ADHD or not.

But looking at the size of entire lobes is a blunt measure that, at best, provides a rough overview. To get an sharper picture, they used magnetic resonance imaging to measure the brains of 447 children of different ages, often at more than one point in time.

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Metabolic gene and breastfeeding unite to boost a child’s IQ

Blogging on Peer-Reviewed ResearchBreastfed babies have higher IQs if they have the ‘C’ version of the FADS2 gene.The nature-nurture debate is one of the most famous in biology, but its own nature has shifted substantially in recent years. We now know that genes and environment are not opposing agents that shape our lives separately, but partners walking hand-in-hand. More often than not, genes affect our bodies and behaviour by altering the ways in which we react to our environment.

Now, an international team of researchers have discovered a stark example of this gene-environment partnership. They found that breastfed children have higher IQ scores, but only if they have a certain version of a gene called FADS2.

The concept of IQ has been central to the nature-nurture debate for years, ever since studies in twins suggested that a large part of the variation in IQ scores could be explained through inherited genetic factors. Avshalom Caspi and Terrie Moffitt from King’s College London wanted to kill this tiresome debate finding a gene that affected IQ via the environment.

They chose to look at breastfeeding, as studies have mostly found that babies who drink their mothers’ milk have higher IQ scores, among other benefits. These higher scores persist into adulthood and across social classes. We also have a reasonable idea of how breastfeeding could affect brain development at a molecular level, and it involves fatty acids.

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Broken chains and faulty mirrors cause problems for autistic children

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Autistic children have sever social problemsYour brain has an amazing ability to predict the future. For example, if you see someone reach for a chocolate, you can guess that they’re likely to pick it up, put it in their mouths and eat it. Like most people, you have a talent for understanding the goal of an action while you see it being performed – in this case, you know that reaching for the chocolate is only a step towards eating it.

That may not sound very impressive, but as with many mental skills, it’s only apparent how complicated it is when you see people who can’t do it.

Autistic people, for example, find it incredibly difficult to relate to other people and this may, in part, be because they can’t understand the why of someone else’s actions. While a typical child would understand that a mother holding her hands out is readying for a hug, an autistic child might be baffled by the gesture.

Now, a new study by Luigi Cattaneo, Giacomo Rizzolatti and colleagues suggests that autistic people find it difficult to understand the purpose of an act because they cannot string together different actions into a coherent whole. And underlying this problem is a special group of nerve cells called mirror neurons.

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‘Brainbow’ paints individual neurons with different colours

Brainbow - psychedelic neuroscienceAt Harvard University, a group of creative scientists have turned the brains of mice into beautiful tangles of colour. By mixing together a palette of fluorescent proteins, they have painted individual neurons with up to 90 different colours. Their technique, dubbed ‘Brainbow’, gives them an unprecedented vision of how the brain’s cells are connected to each other.

Black-and-white to colour

The art of looking at neurons had much greyer beginnings. Over a century ago, a Spanish scientist called Santiago Ramón y Cajal, one of the founders of modern neuroscience, became the first person to get a clear look at the neural network that houses our thoughts. He found that neurons stood out among other cells when stained with a silver chromate salt.

These monochrome images told us what neurons were, but made it very difficult to work out how they joined up into a network. It would be like trying to make sense of London’s famous tube map if all the lines were coloured with the same dull grey. Nowadays, neuroscientists can ‘tag’ neurons with fluorescent proteins, but even these are available in only a few shades.

Enter Brainbow, the brain-child of Jean Livet, Jeff Lichtman and colleagues from Harvard. It uses combinations of just four basic fluorescent proteins – which glow in either red, orange, yellow or blue ­– to paint neurons with a vast range of hues. It works like a TV, which combines red, green and blue light to form the entire colour spectrum.

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