Tag: Brain

Blind Fish In Dark Caves Shed Light On The Evolution Of Sleep

Out of the approximately 3 billion letters of DNA that make up your genome, there are about a 100 letters that neither of your parents possess.

These are your own personal mutations. The machinery that copies DNA into new cells is very reliable, but it is not perfect. It makes errors at a rate equivalent to making a single typo for every 100 books filled with text.

The sperm and egg cells that fused to form you carried a few such mutations, and therefore so do you.

Changes to DNA are more likely to be disruptive than beneficial, simply because it is easier for changes to mess things up than to improve them.

This mutational burden is something that all life forms have to bear. In the long run, individuals that carry harmful mutations will, on average, produce fewer offspring than their peers.




Over many generations, this means that the mutation will dwindle in frequency. This is how natural selection is constantly ‘weeding out’ disruptive mutations from our genomes.

There is a flip side to this argument, and it is the story of the blind cave fish. If a mutation disrupts a gene that is not being used, natural selection will have no restoring effect.

This is why fish that adapt to a lifestyle of darkness in a cave tend to lose their eyes. There is no longer any advantage to having eyes, and so the deleterious mutations that creep in are no longer being weeded out.

Think of it as the ‘use it or lose it’ school of evolution.

A world without light is quite an alien place. There are many examples of fish that live in completely dark caves.

Remarkably, if you compare these fish to their relatives that live in rivers or in the ocean, you find that the cavefish often undergo a similar set of changes. Their eyes do not fully develop, rendering them essentially blind.

They lose pigmentation in their skin, and their jaws and teeth tend to develop in particular ways.

This is an example of what is known as convergent evolution, where different organisms faced with similar ecological challenges also stumble upon similar evolutionary solutions.

The changes mentioned above are all about appearance, but what about changes in behavior? In particular, when animals sleep, they generally line up with the day and night cycle.

In the absence of any daylight, how do their sleep patterns evolve?

A recent paper by Erik Duboué and colleagues addressed this question by comparing 4 groups of fish of the same species Astyanax mexicanus.

Three of the populations (the Pachón, Tinaja, and Molino) were blind cavefish that inhabited different dark caves, whereas the fourth was a surface-dwelling fish.

The authors defined sleep for their fish to be a period of a minute or more when the fish were not moving. They checked that this definition met the usual criteria.

Sleeping fish were harder to wake up, and fish that were deprived of sleep compensated by sleeping more over the next 12 hours (these are both situations that any college student is familiar with).

The researchers also tracked the speeds of all the fish, and found that, while they were awake, the cavefish moved faster or just as fast as the surface fish.

This means that it’s not that the cavefish are constantly sleep deprived and in a lethargic, sleepy state. They are just as wakeful as the surface fish (if not more so), and genuinely need less sleep.

These three cavefish populations all evolved independently, and yet they have converged on remarkably similar sleep patterns.

To study the genetics of this phenomenon, the researchers cross-bred the surface fish with the cavefish. The cave dwellers and surface fish all belong to the same species, which means that they can have viable offspring.

They found that the mixed offspring (Pachón x surface and Tinaja x surface) had a reduced need for sleep that was indistinguishable from that of their cave-dwelling parent.

Thus sleep reduction is clearly a genetic trait, and it is a dominant trait (Dominant traits are present in the offspring if they are inherited from just one parent. A recessive trait, on the other hand, will only be present if it is inherited from both parents.)

Unlocking the secrets of sleep is inherently cool science, and it also has the potential to help people suffering from sleep disorders.

Who knows, it may even lead to the superpower of doing away with sleep altogether.

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Pass it on: Popular Science

Hug Hormone Oxytocin Boosts Bonding By Releasing Cannabis-Like Molecules

Whichever persona you prefer – the love molecule, cuddle chemical or hug hormone – oxytocin plays a big role in bonding.

Spraying monkeys with the stuff, for example, has been found to positively affect their social behavior, making them more communicative and promoting interaction with others.

Among many other things, weed also exerts similar effects on human behavior, but how exactly it does this has been hazy.

Now, a new study is offering us clues, and a link between these two very different substances.

It turns out that oxytocin might make social interactions more rewarding and pleasurable by stimulating our own cannabinoid system.

According to the research, it does this by triggering the release of another wonderfully nicknamed chemical, the “bliss molecule” anandamide, coined as such due to the fact that the brain receptors it activates lead to increased motivation and happiness.




This is the first time that this marijuana-like neurotransmitter has been shown to contribute to the reward of being social, and also offers us further insight into how oxytocin acts on the brain.

Importantly, these findings could help us understand the mechanisms underlying certain social impairments, for example in those with autism, suggesting a possible avenue to explore for treatment.

Rewinding a little bit, endocannabinoids, like anandamide, are molecules our own body produces that act on the same system that cannabis does, binding to receptors on various cells throughout the body called the cannabinoid receptors.

Previous work has found that the endocannabinoid system is involved in regulating neuronal signaling from the nucleus accumbens (NAc), a brain region shown to be critical for the effects of oxytocin on social reward.

To scrutinize these links further, scientists from the University of California, Irvine looked at the brains of juvenile mice reared in groups that had been isolated from their peers for 24 hours, then either returned to the group or kept in isolation for a further three hours.

They found that social contact increased the release of anandamide in the NAc, whereas isolation had the opposite effect. The resulting cannabinoid receptor activation, they found, reinforced the rewards of social interaction.

Taking this one step further, the team wanted to see how oxytocin, known to reinforce both parental and social bonding, fits into this emerging story.

After stimulating oxytocin-producing cells in the brain, they noticed a subsequent boost in the mobilization of anandamide in the NAc.

But when they blocked oxytocin receptors with drugs, the same response was not observed.

Tying the results together, the team found that boosting anandamide levels by blocking its degradation with a drug promoted social reward, causing mice to spend more time interacting with others when compared to those given a placebo, which could have implications for those with social deficits, for example in autism.

We think that there is a disruption in cooperative oxytocin-anandamide signaling in autism,” lead researcher Daniele Piomelli told IFLScience. “

Animal models of autism have multiple disruptions in endocannabinoid signaling.

In these models, Piomelli said, increasing anandamide levels in the same way as before corrected social reward deficits.

This raises the possibility that similar effects could be achieved in humans, helping those with autism socialize more.

The study has been published in Proceedings of the National Academy of Sciences.

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Pass it on: New Scientist

People Smell Great! Human Sniffers Sensitive as Dogs’

As you read this, take a whiff. What smells do you detect? How do these smells affect how you feel?

It’s rare that people consciously take in the smells around them, but a new review argues that the human sense of smell is more powerful than it’s usually given credit for, and that it plays a bigger role in human health and behavior than many medical experts realize.

The fact is the sense of smell is just as good in humans as in other mammals, like rodents and dogs,” John McGann, a neuroscientist at Rutgers University-New Brunswick in New Jersey and the author of the new review, said in a statement.




People often think of dogs and rats as the superior sniffers in the animal kingdom, but humans also have an extremely keen sense of smell, McGann argued in the review, which was published last year, May 11 in the journal Science.

In fact, humans can discriminate among 1 trillion different odors, McGann wrote, far more than a commonly cited claim that people can detect only about 10,000 different smells. [10 Things That Make Humans Special]

By overlooking humans’ keen smelling abilities, medicine may be missing a key component of human health, McGann said. S

mell influences human behavior, from stirring up memories to attracting sexual partners to influencing mood to shaping taste, he said.

It’s no coincidence that the French word for smell, “sentir,” also means to feel; emotion and smell are often intricately linked.

It’s true that humans have relatively smaller olfactory organs and fewer odor-detecting genes compared with other animals. However, the power of the human brain more than makes up for this.

When a person smells something, odor molecules bind to receptors in the nose.

These receptors send information about the molecules to the human olfactory bulb in the brain, which then sends signals to other areas of the brain to help identify scents.

This is different from the way smell works in dogs, McGann said. Dogs have a “pump” in their noses that’s designed to take in chemicals in liquid form for identification, he said.

Because the smelling mechanisms are so different, it’s hard to compare humans to dogs, McGann said.

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Pass it on: New Scientist

How To Actually Keep New Year’s Resolutions, According To A Behavioral Scientist

If you plan on becoming a better person in 2015 by exercising more, eating less, or learning a new language, you’re going to need a whole lot more than just good intentions to get you there.

Here’s a little psychological experiment that just might help you stick to your goals.

So, in 2018 we’re all going to go to the gym more regularly, eat better, earn more, and read twice as many books, right?

Wrong – for the majority of us anyway. If you want a good indication for what you’ll be doing in 2018, your best bet is to look at what you did in 2017.

Studies have shown that good intentions alone will only prompt a change in behavior 20 to 30 percent of the time.




In the vast majority of cases, something a little more concrete is going to have to come into play if you want to make a meaningful change to your habits.

So, surprise, surprise, it takes a whole lot more effort to stick to your new year’s resolutions than just writing them down in a fancy list.

And even more discouraging – research has shown that the better we feel about our new year’s resolutions and our ability to stick with them, the less likely we actually will.

But, as Stephen J. Meyer writes at Forbes, it’s not hopeless:

“I’d be a hardened pessimist if not for one thing – there’s a magic bullet that can bridge the gap between goal intentions and goal accomplishment.”

“It’s what behavioural psychologists call “implementation intentions.” Ugly phrase, I know. But it could be the difference between achieving your goals in 2015 and failing miserably.”

So what exactly is this “implementation intentions” concept?

Back in 2002, researchers in the UK gathered together a group of volunteers who had set themselves the goal of taking up regular exercising. The volunteers were split into three groups.

The first group, called the “motivational intervention group”, was given educational materials showing that exercise does amazing things for your cardio-vascular health.

The second group was asked to plan and write down their “implementation intentions”.

For example, exactly where, when, what, they were going to do for exercise, and how frequently, and for how long, each session.

The control group was left to their own with no help from the researchers.

Amazingly, 91 percent of Group 2, who actually thought about and wrote down all the details of their plan, ended up exercising.

According to Meyer, just 29 percent of the control group and 39 percent of the group who learned extensively about the benefits of exercise ended up actually doing it.

So implementation intentions are essentially about fooling ourselves into doing something – you consciously formulate a plan, and then unconsciously execute it.

Gollwitzer mentioned a study in which students were asked to write a paper during the Christmas break.

Of the group that wrote down their implementation intentions – when and where they intended to write their paper – two-thirds of them actually did it.

Exactly zero students who didn’t write their implementation intentions got around to writing the paper.

Apparently similar results can be seen in people trying to lose weight.

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Pass it on: Popular Science

Smartphone Addiction Can Lead To Chemical Imbalance In Brain

Smartphone and internet addiction can cause a chemical imbalance in the brain, especially in young people, according to new research released this week at the Radiological Society of North America.

As scientists continue to evaluate the physical and emotional effects of an increasingly screen-dependent population, researchers in South Korea found that teenagers addicted to their smartphones had increased levels of two types of neurotransmitters involved in a number of emotional and cognitive functions.




They included gamma aminobutyric acid, or GABA, which slows down brain signals and is involved in vision and motor control and helps regulate emotions including anxiety.

The second chemical is glutamate-glutamine (Glx) and is known to cause neurons to fire more rapidly.

The study evaluated 19 young people with an average age of 15, who were diagnosed with an internet or smartphone addiction, compared to 19 healthy-controls.

The addicted youth also reported higher instances of depression, anxiety, insomnia severity and impulsiveness, in comparison with the “healthy” controls.

Using a Magnetic Resonance Spectroscopy (MRS) brain scan, researchers found that the addicted youth had higher elevations of both GABA and Glx compared to the controls, although the researchers said more study is needed to understand the exact implications of the imbalance.

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Pass it on: New Scientist

The Adolescent Brain – What All Teens Need To Know

Adolescents have dynamic, open, hungry minds. They are creative, brave and curious. It has to be this way.

The only way to learn many of the skills they will need to be strong, healthy adults will be to stretch beyond what they’ve always known and to experiment with the world and their place in it.

The adolescent brain is wired to drive them through this transition, but there will be a few hairpin curves along the way. Skillful drivers are not born from straight roads.

There will be good days, great days and dreadful days.

Adolescence is something they have to do on their own. We can guide them, but we can’t do it for them.




This is their time for growth and learning, but there is something powerful we can do to help them along the way. We can give them the information they need to light their way forward.

Our teens are amazing. Their brains are on fire – powerful, creative, insightful. Here’s what they need to know.

  • Your brain is changing. But you have enormous capacity to influence those changes. You’re transitioning into adulthood. There’s no hurry to do this – you’ll have plenty of time. Your adult brain won’t be fully developed until you’re about 24. In the meantime, it’s your time to learn, experience and experiment with the world and your place in it.
  • Your brain is like a high-performance sports car but your brakes aren’t ready yet. Your brain will wire and strengthen from the back to the front. One of the first parts of the brain to develop is the amygdala, which is involved in instinctive, impulsive, emotional, aggressive reactions. It’s great for keeping you alive if there’s trouble, but not always great when it comes to making balanced decisions.
  • Hello hormones! (But your brain will take time to adjust.) You’ve probably heard a lot of people blaming hormones for the things adolescents do that aren’t so lovable. It’s not so much your hormones that cause trouble but the way your brain reacts to them.
  • Your brain is like an open window. Expose it to good and it will thrive. Expose it to bad and that window will slam shut.

All new skills take time to master. It’s no different for our teens. In the meantime, they might wobble. A lot.

We are learning to see them in a different light – as soon-to-be adults who will be independent of us. We are learning to trust their capacity to cope, and to stand back and let them steady themselves.

They have it in them to be extraordinary. The more information they have, the more potential they have to find the most direct way there.

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Pass it on: New Scientist

A New Study Claims That Married Couples Are Less Likely To Get Dementia

Levels of social interaction could explain to the finding, experts have said, after the research showed that people who are single or widowed are more likely to develop the disease.

Experts conducted an analysis of 15 studies which held data on dementia and marital status involving more than 800,000 people from Europe, North and South America, and Asia.

Their study, published in the Journal of Neurology, Neurosurgery, and Psychiatry, concluded that lifelong singletons have a 42% elevated risk of dementia compared with married couples.

Those who have been widowed had a 20% increased risk compared with married people, they found. But no elevated risk was found among divorcees compared with those who were still married.




The researchers, led by experts from University College London, said that previous research has shown that married people may adopt healthier lifestyles.

They may also be more likely to be socially engaged than singletons.

Meanwhile, the effect observed in people who have been widowed could be due to stress that comes with bereavement, they added.

Another explanation could be that developing dementia could be related to other underlying cognitive or personality traits.

Commenting on the study, Dr Laura Phipps of Alzheimer’s Research UK, said: “There is compelling research showing married people generally live longer and enjoy better health, with many different factors likely to be contributing to that link.

The study was published as Alzheimer’s Research UK launched its Christmas campaign calling for more funds for dementia research.

The Santa Forgot campaign, backed by presenter Stephen Fry, aims to raise awareness of the condition as well as funds for studies examining the brain.

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Pass it on: New Scientist

Scientists Have Created Brain Implants That Could Boost Our Memory By Up To 30%


Scientists have developed a groundbreaking brain implant that can boost human memory.

In recent years, studies have shown that so-called ‘memory prostheses’ can be used to improve memory in rodents and primates, helping them to perform better on cognitive tasks.

Now, researchers have shown for the first time that the technique can enhance human memory, too, by mimicking processes that occur naturally in the brain.

The new study, presented at the Society of Neuroscience meeting in Washington DC this past weekend, found that stimulating a region in the brain responsible for learning and memory can improve performance on memory tasks by up to 30 percent.

Researchers recruited 20 volunteers who were undergoing epilepsy monitoring, in which they were fitted with electrodes targeting the brain’s hippocampus.




Subjects were first asked to participate in a training session, where they were given visual delayed-match-to-sample (DMS) tasks.

Each participant was shown images in a sample presentation, and later had to recall the images during a match phase up to 75 seconds later.

The researchers then modeled the neural recordings from the training session to pinpoint the regions likely activated during the task.

Then, in a second session, the researchers used the implant to stimulate the subjects’ brains with micro-electric shocks based on the model.

In the trials, the technique was found to improve performance by as much as 30 percent.

While prior research has shown similar methods to enhance memory in some mammals, the researchers say it’s the first time it’s been demonstrated in humans.

These studies have yielded a prosthetic system that restored DMS task-related memory in rodents and nonhuman primates, and is now extended to successful memory facilitation in humans,” the authors wrote in an abstract detailing their presentation.

The work has implications for the treatment of memory disorders, suggesting that stimulating the brain based on patterns in a healthy brain could help to improve function, according to New Scientist.

And, it could pave the way for memory-enhancing prosthetics.

Cognitive task performance on MIMO stimulated trials was compared with non-stimulated and random pattern stimulated trials,” according to the researchers.

MIMO stimulation resulted in a 15-25% improvement in DMS task performance in five patients, demonstrating successful implementation of a new neural prosthetic system for the restoration of damaged human memory.”

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Pass it on: New Scientist

Are Fidget Toys Legitimately Good For Your Brain?

Fidget” isn’t exactly a word with the most positive of connotations. For many of us, it recalls veiled childhood threats of “stop fidgeting or,” and then the promised removal of something we value more highly than fidgeting.

Type “stop” into Google’s search box and “stop fidget” is one of the first recommendations its autocomplete feature presents you with.

But fidgeting, like beloved 1990s TV properties, is making a comeback.

Last year, the creators of Fidget Cube a Kickstarter desk toy allowing users to click, roll, flip, glide, spin and assorted fidgety verbs set out to raise $15,000 to make their product a reality.

They wound up raking in $6,465,690 from 154,926 backers.

Fidget Cube has inevitably been followed by a number of other crowdfunding campaigns designed to appeal to the twitchy fingers of those who supported it.




One was a fidget pen called Think Ink, which combines a titanium pen exterior with a number of tactile elements for distracted fingers to play with. It made more than quadruple its funding target.

I made this for my daughter,” co-founder Kent Lyon said.

She had just started a new job, which she nervous about, and started noticing that she was fidgeting a whole lot. Whether it was clicking her pen or playing with her hair, she found that she couldn’t stop doing something with her hands.” Lyon gave Think Ink the subtitle “Fidget to focus.

But is this really a thing — or is the idea that a distracting toy can actually help us just a pseudoscientific marketing ploy?

It’s tempting to bust out the klaxons at the breaking news that a fidget toy purveyor thinks fidget toys increase productivity.

However, it just may be correct.

Research has shown that even small repetitive activities can increase the levels of neurotransmitters in the brain in a way that increases our ability to focus and pay attention.

Even if the fidget you are carrying out involves minimal concentration fidgeting with a pen, chewing gum, or doodling on a piece of paper this type of multitasking can positively impact the outcome of a particular task.

This is especially noticeable when dealing with children with ADHD, as Purdue University professor Sydney Zentall has noted in her work.

According to Zentall, while failure to stay on task can reduce work speed and production, there is no evidence that most “distractions” increase errors among children with ADHD.

Surprisingly, she said, these kind of fidget distractions “may actually help the child perform in the classroom, especially when tasks are long and tedious.

That is, off-task looking may provide ‘doses’ of environmental stimulation that the child needs.

There is even evidence that fidgeting can have a positive impact on people’s physical health.

Examinations regarding the physical benefits of fidgeting are relatively few and far between, but a 2008 study tracked daily movements for a group of slim and overweight women, and discovered that the slimmer group tended to fidget more.

If the obese women adopted the activity patterns of the lean women,” the authors of the study noted, they might burn an extra 300 calories per day.

Sure, you’re never going to match a five-mile run by playing with your Fidget Cube, but the findings suggest that every little bit helps.

Ultimately, we’re still still a long way from the makers of fidget-focused desk toys being able to make explicit medical claims for their devices — but it seems that there is real scientific evidence to suggest that fidgeting has an important role to play in our lives.

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Pass it on: New Scientist

Why Are We Still Using Electroconvulsive Therapy?

The idea of treating a psychiatric illness by passing a jolt of electricity through the brain was one of the most controversial in 20th Century medicine.

So why are we still using a procedure described by its critics as barbaric and ineffective?

Sixty-four-year-old John Wattie says his breakdown in the late 1990s was triggered by the collapse of his marriage and stress at work.

We had a nice house and a nice lifestyle, but it was all just crumbling away. My depression was starting to overwhelm me. I lost control, I became violent,” he explains.

John likens the feeling to being in a hole, a hole he could not get out of despite courses of pills and talking therapies.




But now, he says, all of that has changed thanks to what is one of the least understood treatments in psychiatry – electroconvulsive therapy (ECT).

“Before ECT I was the walking dead. I had no interest in life, I just wanted to disappear. After ECT I felt like there was a way out of it. I felt dramatically better.

The use of electricity to treat mental illness started out as an experiment. In the 1930s psychiatrists noticed some heavily distressed patients would suddenly improve after an epileptic fit.

Passing a strong electric current through the brain could trigger a similar seizure and – they hoped – a similar response.

By the 1960s it was being widely used to treat a variety of conditions, notably severe depression.

But as the old mental asylums closed down and aggressive physical interventions like lobotomies fell out of favour, so too did electroshock treatment, as ECT was previously known.

The infamous ECT scene in One Flew Over the Cuckoo’s Nest cemented the idea in the public’s mind of a brutal treatment, although by the time the film was released in 1975 it was very rarely given without a general anaesthetic.

Perhaps more significantly, new anti-depressant drugs introduced in the 1970-80s gave doctors new ways to treat long-term mental illness.

But for a group of the most severely depressed patients, ECT has remained one of the last options on the table when other therapies have failed.

Annually in the UK around 4,000 patients, of which John is one, still undergo ECT.

It’s not intuitive that causing seizures can be good for depression but it’s long been determined that ECT is effective,” says Professor Ian Reid at the University of Aberdeen, who heads up the team treating John.

In the 75 years since ECT was first used scientists have argued about why and how it might work. The latest theories build on the idea of hyperconnectivity.

This new concept in psychiatry suggests parts of the brain can start to transmit signals in a dysfunctional way, overloading the system and leading to conditions from depression to autism.

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Pass it on: Popular Science