Posts Tagged ‘ fear ’

5 Ways to Fight the Blues…with Science!

So you’re stuck in that mid-week slump…the weekend lies on the other side of a scorching desert of work, and you have no canteen because you gave up water for Lent (in this metaphor, “water” refers to alcohol…just to be clear).

YAY SCIENCE!

But fear not! Neuroscience knows how to cheer you up! Nope, this isn’t another post about sex or drugs…though those are coming soon. This one’s about five things science says you can do right now – with your mind – to chase your cranky mood away.

1.Take a look around
Research shows that people who focus on the world around them, instead of on their own thoughts, are much more likely to resist a relapse into depression. This is easy to do – just find something interesting (or beautiful) to look at, and think about that for a few seconds…you’ll be surprised how quickly your worries fade.

2. Do some mental math
Scientists say doing a little simple arithmetic – adding up the digits of your phone number, for example – reroutes mental resources from worry to logic. Don’t worry; your emotions will still be there when you’re done…but they’re less likely to hog the spotlight if you don’t give them center stage.

3. Get out and about
Lots of studies show that physical activity raises levels of endorphins – the body’s own “feel-good” chemicals – and helps improve your mood throughout the day. You don’t have to run a marathon; even a quick walk around the block will get your blood pumping and help clear your mind.

4. Find some excitement
Some very interesting studies have found that courage – a willingness to face some of your fears – feeds on itself; in other words, the more adventurous your behavior is, the fewer things your brain considers threatening. In a way, it’s a “fake it ’til ya make it” situation…but instead of trying to be someone you’re not, you’re becoming more comfortable with the person you are.

5. Remember, it’s not always a bad thing
It sometimes helps to remember that stress is a natural phenomenon…as natural as digestion or sleep. Though stress (or sadness, or worry) can sometimes get out of hand, our bodies have evolved these responses to help us, and there’s nothing “wrong” with you just because you’re feeling annoyed or down in the dumps today. Instead of trying to make the feeling go away, sometimes the best thing to do is acknowledge it, and think about what’s triggering it. You might surprise yourself with an insight.

So, those tips are pretty simple, right? Try some of ‘em out, and let me know which ones worked best for you. After all, that’s why scientists study this stuff – to help us all understand more about what our minds are up to.

Stress Intervention

Scientists have discovered a way to shut down the brain’s “stress process” before it gets going, says a new study.

Stress, or just a very acute case of the munchies? It's hard to say.

By blocking the brain’s ability to manufacture certain chemicals called neurosteroids, researchers have managed to temporarily cut off a biological process crucial for stressful behavior – and for many stressful feelings as well.

Animals from amphibians all the way up to humans produce a hormone called corticosterone in their adrenal glands. Corticosterone levels become elevated under stress, and this hormone is a major ingredient in a number of stress-related biological processes, from feelings of nervousness to aggressive behavior.

Corticosterone does most of its direct work within a brain pathway known as the hypothalamic-pituitary-adrenal axis (also called the HPA or HTPA axis). To be honest, the word “pathway” is a bit of an oversimplification – the HPA is actually a whole set of neurochemical feedback circuits involved in regulating digestion, immune response, and mood, among other things.

The HPA’s activity is mostly regulated by a neurotransmitter chemical called gamma-Aminobutyric acid (GABA to its friends). GABA is typically an inhibitory neurotransmitter, which means it prevents electrochemical signals from being passed beyond a certain point. It often works closely with a neurosteroid called tetrahydrodeoxycorticosterone (THDOC), which helps its inhibitory effects spread even more widely throughout the HPA.

But when we come under stress, everything changes: the adrenal glands start cranking out extra-large doses of THDOC and sending them up into the HPA. And here’s where things get weird – those conditions trigger a certain electrochemical shift that causes GABA and THDOC to activate the HPA rather than inhibit it.

As the Journal of Neuroscience reports, the discovery of that neurochemical mechanism is the first half of a two-part breakthrough made Jamie Maguire‘s team at Tufts University:

We have identified a novel mechanism regulating the body’s response to stress by determining that neurosteroids are required to mount the physiological response to stress.

But how did they discover this mechanism, you ask? Well, since the team suspected that neurosteroidogenesis - the production of neurosteroids like THDOC – was a crucial component in stress-related HPA activation, they got a bright idea: they wondered if a drug that blocked neurosteroidogenesis might be able to stop the brain’s stress response before it could even get into gear.

As it turned out, they were right – they cut off the THDOC rush by administering a drug called finasteride – which you might’ve heard of under the brand name Propecia. Yep, the baldness drug:

Blocking neurosteroidogenesis with finasteride is sufficient to block the stress-induced elevations in corticosterone and prevent stress-induced anxiety-like behaviors in mice.

In other words, the researchers found that finasteride does more than just control stress – it blocks the chemical cascade that causes stress-related feelings and behavior. As far as they can tell, it prevents animals from experiencing stress at all - at least temporarily.

This has the potential to develop into a far more powerful treatment than benzodiazepines like Xanax and Ativan, which work by helping GABA inhibit more activity than it normally would. By contrast, a finasteride-like drug would make it almost impossible to feel stressed, even if you tried – meaning this drug might also be used to treat diseases like epilepsy and major depression, which have been linked to excessive activation of the HPA.

Right now, Maguire’s team is focused on isolating more of the exact neural connections that play roles in disorders like these. That means it may be a few years before this “wonder drug” becomes available. In the meantime, I wouldn’t recommend swallowing handfuls of Propecia when you’re feeling stressed – the drug needs to be applied in a pretty targeted way to make this work, which means a major part of pharmaceutical development will be the creation of an effective chemical delivery system.

Even so, it’s exciting to think that before long, depression and anxiety may be as easy to prevent as, say, polio and malaria are today. The thought’s enough to get my hormones pumping, anyway.


Psychopathic Anatomy

The brains of psychopaths have a significant physical difference from those of non-psychopaths, says a new study.

Inside the mind of a psychopath. (I was expecting it to be...scarier...somehow.)

In a psychopath’s brain, white matter (connective neural tissue) links between the ventromedial prefrontal cortex (vmPFC) and amygdala are unusually weak. This means a major brain area involved in anticipating risk (the vmPFC) is only weakly connected with an area crucial for processing fear and sadness.

Though the word “psychopath” gets thrown around a lot, it doesn’t necessarily refer to a maniacal killer. It’s simply a term used to characterize personality disorders in which a person has difficulty linking their actions with feelings like empathy, regret, and guilt.

Because many psychopathic individuals learn to mask their difficulty experiencing these linkages, they often don’t get the therapies they need – so many do, in fact, end up committing crimes; or at least making life tough for their friends and family. Even as we get better at understanding the symptoms of psychopathy, though, the causes have remained somewhat poorly understood.

But now, as the Journal of Neuroscience reports, a team of researchers from several institutions have joined forces to study the neuroanatomy of psychopathic prisoners in detail.

The University of Wisconsin’s Joseph Newman has spent years studying and working with psychopathic prisoners in the Wisconsin state correctional system. Newman teamed up with Kent Kiehl, a psychologist from the University of New Mexico, who brought a mobile fMRI scanner to a Wisconsin prison and took detailed scans of 20 psychopathic prisoners’ brains. The team also took diffusion MRI scans, which are useful for precisely mapping tiny anatomical structures deep within the brain.

When the team compared this data against equivalent scans of 20 non-psychopathic prisoners’ brains, they found that psychopathic prisoners’ brains showed some significant structural abnormalities:

Using diffusion tensor imaging, we show that psychopathy is associated with reduced structural integrity in the right uncinate fasciculus, the primary white matter connection between vmPFC and anterior temporal lobe.

In short, the white matter connecting the vmPFC to the amygdala isn’t particularly sturdy in psychopaths’ brains. This abnormality is also related to some major functional differences:

Using functional magnetic resonance imaging, we show that psychopathy is associated with reduced functional connectivity between vmPFC and amygdala as well as between vmPFC and medial parietal cortex.

In other words (as you might expect) the lack of healthy white matter connectivity means the vmPFC doesn’t communicate with the amygdala very well in psychopaths’ brains.

This study provides some of the first clear data on just what it is, in specific anatomical and physiological terms, that makes the brain of a psychopath different from yours or mine.

While these discoveries don’t let these prisoners off the hook for the crimes they committed, the data does provide encouragement that more targeted therapies could help prepare psychopathic individuals to lead healthy lives in the outside world. It also reminds us that “the criminal mind” may be as much a medical concern as it is a moral one.

And that, I think, is good news both for psychopathic individuals and for the rest of us.

Chemical Parasites

A certain brain parasite actually turns off people’s feelings of fear by increasing levels of the neurotransmitter chemical dopamine, says a new study.

T. gondii, gettin' ready to blow your %@&#$ mind.

Toxoplasma gondii, a parasitic protozoan (a kind of single-celled organism), mostly likes to live in the brains of cats - but it also infects birds, mice, and about 10 to 20 percent of people in the U.S. and U.K. This might sound like science fiction, but plenty of microbiologists will assure you it’s very real.

In fact, T. gondii isn’t the only parasite that controls its hosts’ behavior – a fungus called Ophiocordyceps unilateralis makes infected ants climb to the highest point they can find, sprout fungal spore pods from their heads, then stay there and starve to death; at which point the spores are unleashed to recruit more ants for the fungus’s zombie army. Other microbes force spiders to weave cocoons for them, or make roaches lay immobile while larvae grow inside their bodies, then chew their way out. Um, yeah, so… nature is pretty frickin’ hardcore.

Anyway, back to the parasite at hand. Throughout the past few years, a University of Leeds microbiologist named Glenn McConkey has worked at the forefront of T. gondii research – in 2009, his team made the astonishing discovery that the microbe’s genome encodes instructions for producing dopamine: in essence, this bug is living cocaine, and it’s bending the minds of millions of people at this very moment.

And now, as the journal PLoS ONE reports, McConkey’s team has made a breakthrough that is, if anything, even more incredible: once the parasite has taken up residence in a brain, it triggers the production and release of dopamine at a much greater level than normal, causing infected animals (including people) to engage in impulsive, compulsive and/or fearless behavior:

In this study, infection of mammalian dopaminergic cells with T. gondii enhanced the levels of K+-induced release of dopamine several-fold, with a direct correlation between the number of infected cells and the quantity of dopamine released … Based on these analyses, T. gondii orchestrates a significant increase in dopamine metabolism in neural cells.

In short, by changing the electrochemical properties of dopaminergic neurons (those that deal with dopamine transmission and reception), T. gondii basically causes its host’s brain to shout “I’m awesome!” ceaselessly at top volume. You can imagine the havoc this wreaks.

If the host is, say, a mouse or a bird, impulsive and fearless behavior will typically get it gobbled up by a predator, which allows the parasite to move into a new host and spawn a new generation. But if the host happens to be a human being – well, there’s no telling what might happen. For one thing, studies have found a strong link between T. gondii infection and schizophrenia.

Thanks to Science, though, there’s hope – McConkey’s team is optimistic that these new results will help doctors diagnose T. gondii infections more quickly and accurately, and perhaps use dopamine antagonists – drugs that block dopaminergic activity – to fight some of the psychotic symptoms these crazy little guys cause.

So, I guess one big question remains: why the hell isn’t this story making front-page news? Your guess is as good as mine. Kinda spooky, isn’t it?

The Sound of Fear

A certain inaudible sound frequency may directly trigger feelings of “creepiness” and physical symptoms of fear, one scientist says.

Don't look now, but I think I see a g-g-g-gh-gh-sound wave!

A sound frequency of around 19hz – just below the range of human hearing – has been detected in several “haunted” places, including a laboratory where staff had reported inexplicable feelings of panic, and and a pub cellar where many people have claimed to see ghosts.

Though no peer-reviewed studies have examined this phenomenon yet, I think it’s still intriguing enough to be worth talking about – and after all, it is that special time of year. So huddle up close, and let me tell you a tale – the tale of… The Frequency of Fear!

Back in the 1980s, an engineer named Vic Tandy began hearing strange stories from his otherwise-scientifically minded coworkers: whenever they spent time working in a certain laboratory, they’d experience inexplicable feelings of unease, and glimpses of ghostly apparitions.

At first, Tandy chalked these reports up to stress, or to the irritating wheeze of life-support machines that permeated the building. But one foreboding night, as Tandy toiled alone in the lab, he suddenly broke into a cold sweat, and felt the hairs on his neck stand up. He was overcome with the feeling that he was being watched. From the corner of his eye, he glimpsed a sinister gray form moving toward him – but when he turned to face it, it vanished. Tandy fled the lab for the safety of his home, his keen scientific mind churning, asking what could have triggered this bizarre episode.

The next day, Tandy happened to catch sight of a clue: in the lab, he noticed that a foil blade clamped in a vice was vibrating at a rapid rate. Fetching his trusty frequency meter, he discovered that the sound wave behind these vibrations was bouncing off the walls of the lab, and that its peak intensity was focused in the room’s center. Its frequency was 19hz – slightly below the minimum human-audible frequency of 20hz, but easy for a human body to feel as a subtle vibration.

Tandy began to delve into ancient forbidden texts (OK, actually he started reading biology papers) and learned that frequencies near this range can cause animals to behave nervously, hyperventilate, stumble dizzily, and even have trouble seeing clearly.

It’s likely that these animals’ sensitivity to these vibrations evolved as an early-warning system for earthquakes, tsunamis and related disasters, and may explain why animals flee the sites of these disasters en masse long before humans suspect anything’s the matter.

Over the years, subsequent investigations have found that similar frequencies occur in other reputedly haunted spots, which seems to indicate that we humans may be sensitive to these frequencies as well.

If you ask me, though, the scariest part of this story is that as you read this, scientists with less noble purposes could potentially be developing devices to project these frequencies directly into a target’s body. Not to be paranoid here, but I’m not too keen on the idea of a fear ray. Just putting that out there.

On the whole, I think right now is a pretty awesome time to be alive – we’ve got mind-controlled computers, we’ll soon be able to record videos of our thoughts and dreams, and it won’t be long before we can see, hear and even touch virtual worlds. But we’ve also learned that magnetic stimulation can make people want to lie, that electrical stimulation can alter our decision-making processes, and that sound waves can make us feel pain and fear.

We’re on the brink of an unprecedented epoch in human history, when miracle-working may quite literally lie within any person’s grasp – but with that power also comes the potential to create truly unimaginable hells at the push of a button. All I can say is, I hope with all my might that our better nature wins out.

Because, I don’t know about you guys, but I can hardly wait to see what the future holds.

Facing Fear

New neuroscientific studies are shedding light on the allure of dark forests and eerie old houses…and cliff diving.

Sensational!

In psychology, this drive to explore the unusual is one manifestation of the behavior pattern known as “sensation-seeking” – the tendency to pursue intense, novel experiences out of curiosity, or just for the sheer joy of excitement.

Though the behavior of sensation-seekers has been thoroughly studied, the exact reasons for that behavior – and the neuroscience behind those reasons - are only now beginning to be unraveled. As a report in the journal Psychological Science explains, the brains of people who seek out thrills and mysteries actually behave differently from those of more cautious people.

Now, for me, this is about is about as awesome as life gets – my two great loves are weird mysteries and neuroscience, and I’ve spent most of my adult life exploring the the enigma of why the human mind is so fascinated by enigmas. But anyway, on to the data!

A group of researchers led by Dr. Jane Joseph at the University of Kentucky used fMRI to study subjects’ neurophysiological responses to various types of “strongly arousing” stimuli. They discovered that these stimuli activate different cerebral regions, depending on whether or not the subject was a  sensation-seeker:

Regardless of whether the pictures were pleasant (e.g., mild erotica) or unpleasant (e.g., a snake poised to strike), the high-sensation seekers showed early and strong activation in the insula [a cerebral area involved in what might be called "raw" emotions and sensations, such as excitement, pride, hunger, and lust]. In contrast, in the low-sensation seekers, insula activity barely rose above baseline levels.

The brains of these more conservative subjects responded with increased activity in the anterior cingulate cortex (ACC), an area involved in anticipation of errors and conflicts. What’s interesting is that ACCs of sensation-seekers eventually reached similar levels of activation, but took much longer to get there. It’s possible that their brains were responding first with sheer excitement, and only later considering the possibility of danger or failure:

“If you look at the data, you can see that the insula response in the lows starts to rise, just as in the highs, but then the anterior cingulate kicks in and almost seems to deflect the insula response in the low-sensation seekers,” Joseph said.

Sensation-seeking behavior can sometimes be linked with the personality trait known as novelty-seeking, which plays out as an impulsive tendency to explore new stimuli, even to the point of irresponsibility or personal harm. While a moderate amount of novelty-seeking can be evolutionarily beneficial – we might call it “bravery” in such cases – an excess is obviously dangerous.

Some studies suggest that novelty-seeking may be linked to a deficiency in midbrain D2 receptors, which process the “reward” and “motivation” chemical dopamine. Studies on another type of dopamine receptor seem to show an almost opposite effect: sensation-seeking may be linked with higher numbers of D4 dopamine receptors.

The exact mechanisms at work here are still uncertain: it may be that when it’s harder for someone to feel the joy of a thrill, they’ll go further than normal to get it; it’s also been suggested that D2 receptors act as “brakes” on dopamine release, so a deficiency of them would actually allow more dopamine to pump around.

Still, many of us who don’t qualify as real-life novelty-seekers still love to watch thrilling or scary movies now and then. In those cases, the ACC may actually be helping us enjoy the show:

Thrill-seekers may be able to use cognitive parts of the brains to recognize that the scary movie or ride isn’t really going to hurt them … They can put the brakes on the flight and avoidance response and experience the emotional salience of the fear.

The difference between cliff divers and horror fans, it seems, may be less a matter of taste, and more a matter of response threshold. In other words, the safer we feel, the more fun it is to be scared.

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