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Tuesday
May062014

Your Brain Channel Has Launched! 

Hi everyone! Just wanted to let you know that I've launched a new science video channel on YouTube called Your Brain Channel. We'll be featuring brief "News You Can Use" video segments on a range of science-related topics. Please check out the first couple of entries on the green tea-memory connection and testing the sleep debt theory. Plenty more videos to come, so check back often. Thanks! 

 

Thursday
May012014

The Connection Between Playing Video Games and a Thicker Brain

For all the negative news about the alleged downsides of playing video games, it’s always surprising to come across research that shows a potentially huge upside. A new study fills the bill by showing that heavy video game play is associated with greater “cortical thickness” – a neuroscience term meaning greater density in specific brain areas.

Researchers studied the brains of 152 adolescents, both male and female, who averaged about 12.6 hours of video gaming a week. As one might guess, the males, on average, played more than the females, but all of the participants spent a significant amount of time with a gaming console. The research team wanted to know if more time spent gaming correlated with differences in participants’ brains.

What they found is that the brains of adolescents that spent the most time playing video games showed greater cortical thickness in two brain areas: the left dorsolateral prefrontal cortex (DLPFC) and the left frontal eye field (FEF).

The prefrontal cortex is often referred to as our brain’s command and control center. It’s where higher order thinking takes place, like decision-making and self-control.  Previous research has shown that the DLPFC plays a big part in how we process complex decisions, particularly those that involve weighing options that include achieving short-term objectives with long-term implications. It’s also where we make use of our brain’s working memory resources – the information we keep “top of mind” for quick access when making a decision.

The FEF is a brain area central to how we process visual-motor information and make judgments about how to handle external stimuli. It’s also important in decision-making because it allows us to efficiently figure out what sort of reaction best suits what’s happening around us. The term “hand-eye coordination” is part of this process.

Together, the DLPFC and FEF are crucial players in our brain’s executive decision-making system. Greater “thickness” in these brain areas (in other words, more connections between brain cells) indicates a greater ability to juggle multiple variables, whether those variables have immediate or long-term implications, or both.

While this study doesn’t quite show that playing hours of videos games each week causes these brain areas to grow thicker, the correlation is strong – strong enough to consider the possibility that gaming is sort of like weight lifting for the brain.

And that, even more than the video game connection, is what makes this study really interesting. It suggests that the popular terms “brain training” and "brain fitness" are more than marketing ploys to sell specialized software. If it’s true that playing video games is not unlike exercise that beefs up our brain’s decision-making brawn, then it logically follows that we can not only perceptually, but physically improve our brains with practices designed for the purpose. Future research will continue exploring precisely that possibility.

The study was published in the online journal PLoS ONE.

You can find David DiSalvo on Twitter @neuronarrative and at his website, The Daily Brain. His latest book is Brain Changer: How Harnessing Your Brain’s Power To Adapt Can Change Your Life.

Monday
Apr282014

Can Chocolate In A Pill Boost Heart Health?

We've been hearing about the alleged health benefits of eating dark chocolate for the last decade or so, including lower blood pressure and improved cholesterol levels. Those claims are about to be put to an exhaustive test in a study of 18,000 adults in Boston and Seattle. But instead of eating chocolate bars every day, the study participants will take capsules containing concentrated amounts of the bio-active chemicals in cocoa beans, known as cocoa flavanols.

If study results are consistent with previous studies showing health benefits of eating cocoa flavanols, it will be a semi-sweet outcome for chocolate lovers. Generally, the higher the level of cocoa, the less sweet the chocolate -- though even chocolate with 72% cocoa contains in the neighborhood of 240 calories per serving, including 10 grams of sugar and 18 grams of fat.

The study participants will theoretically get all of the good stuff without the extra calories from fat and sugar.  Each participant will take two flavorless capsules a day containing 750 milligrams of cocoa flavanols (or dummy pills for those in the control group) for four years. Over that time, participants' heart health will be monitored to determine if the mega dose of cocoa does what previous, smaller studies indicate. To ingest the same amount of cocoa flavanols as the study participants would require eating almost five bars of dark chocolate a day.

Cocoa is thought to benefit heart health by acting as a vasodilator, meaning it triggers relaxation of muscle cells within blood vessel walls. Relaxed blood vessels naturally widen, resulting in greater blood flow and decreased blood pressure.

The latest research is being funded by Mars Inc., makers of M&Ms and other candies, and the National Heart, Lung and Blood InstituteMars co-sponsoring the study will raise red flags with critics, but it’s worth noting that the company has funded cocoa flavanol research since the 1990s, and much of what we know about the possible benefits of cocoa has emerged from Mars-supported studies.

You can find David DiSalvo on Twitter @neuronarrative and at his website, The Daily Brain. His latest book is Brain Changer: How Harnessing Your Brain’s Power To Adapt Can Change Your Life.

Sunday
Apr062014

How A Tiny Bit Of Procrastination Can Help You Make Better Decisions

Decision-making is what you might call “practical science.” Findings on how we make decisions have direct applicability to life outside the psychology lab, and in recent years there’s been quite a lot said about this most commonplace, yet complicated, feats of mind. A new study adds to the discussion by suggesting that a wee bit of procrastination can make us better decision-makers.

Researchers from the Columbia University Medical Center wanted to know if they could improve decision accuracy by inserting just a smidgen more time between peoples’ observation of a problem and their decision on how to respond.

The research team conducted two experiments to test this hypothesis. First, they asked study participants to make a judgment about the direction of a cluster of rapidly moving dark dots on a computer monitor. As the dots (called the “target dots” in the study) traveled across the screen, participants had to determine if the overall movement was right or left. At the same time, another set of brighter colored dots (the “distractor dots”) emerged on the screen to obscure the movement of the first set. Participants were asked to make their decisions as quickly as possible.

When the first and second set of dots moved in generally the same direction, participants completed the task with near-perfect accuracy. When the second set of dots moved in a different direction than the first, the error rate significantly increased. Simple enough.

The second experiment was identical to the first, except this time participants were told to make their decisions when they heard a clicking sound. The researchers varied the clicks to be heard between 17 and 500 milliseconds after the participants began watching the dots – a timespan chosen to mimic real-life situations, such as driving, where events happen so quickly that time seems almost imperceptible.

The research team found that when participants’ decisions were delayed by about 120 milliseconds, their accuracy significantly improved.

"Manipulating how long the subject viewed the stimulus before responding allowed us to determine how quickly the brain is able to block out the distractors and focus on the target dots," said Jack Grinband, PhD, one of the study authors. "In this situation, it takes about 120 milliseconds to shift attention from one stimulus, the bright distractors, to the darker targets."

The researchers were careful to distinguish “delaying” from “prolonging” the decision process. There seems to be a sweet spot that allows the brain just enough time to filter out distractions and focus on the target. If there’s too little time, the brain tries to make a decision while it’s still processing through the distractions. If there’s too much time, the process can be derailed by more distractions.

If you’re wondering how anyone can actually do this with so little time to make a decision, the answer—suggested by this study—is practice. Just as the participants were cued by the clicks to make a decision, it would seem that we have to train ourselves to delay just long enough to filter distractions.

Said another way, doing nothing--for just a tiny amount of time--gives the brain an opportunity to process and execute. (In my book, Brain Changer, I refer to this as the "awareness wedge" because it's a consciously inserted "wedge" between the immediacy of whatever situation we're facing and our next action.)

This research also underscores just how dangerous it can be to add distractions to the mix—like using a phone while driving—when our brains already need a cushion of time to filter the normal array of distractions we experience all the time.

The study appears in the online journal PLoS One.

You can find David DiSalvo on Twitter @neuronarrative and at his website, The Daily Brain. His latest book is Brain Changer: How Harnessing Your Brain’s Power To Adapt Can Change Your Life.

Saturday
Mar152014

The Good and Bad News About Your Sleep Debt

Sleep, science tells us, is a lot like a bank account with a minimum balance penalty. You can short the account a few days a month as long as you replenish it with fresh funds before the penalty kicks in. This understanding, known colloquially as “paying off your sleep debt,” has held sway over sleep research for the last few decades, and has served as a comfortable context for popular media to discuss sleep with weary eyed readers and listeners.

The question is – just how scientifically valid is the sleep debt theory?

Recent research targeted this question by testing the theory across a few things that sleep, or the lack of it, is known to influence: attention, stress, daytime sleepiness, and low-grade inflammation. The first three are widely known for their linkage to sleep, while the last—inflammation—isn’t, but should be. Low-grade tissue inflammation has been increasingly linked to a range of unhealthiness, with heart disease high on the list.

Study participants were first evaluated in a sleep lab for four nights of eight-hour sleep to establish a baseline. This provided the researchers with a measurement of normal attention, stress, sleepiness and inflammation levels to measure against.

The participants then endured six nights of six-hour sleep (a decent average for someone working a demanding job and managing an active family and social life). They were then allowed three nights of 10-hour catch-up sleep. Throughout the study, participants’ health and ability to perform a series of tasks were evaluated.

Sleep debt theory predicts that the negative effects from the first six nights of minimal sleep would be largely reversed by the last three nights of catch-up sleep – but that’s not exactly what happened.

The analysis showed that the six nights of sleep deprivation had a negative effect on attention, daytime sleepiness, and inflammation as measured by blood levels of interleukin-6 (IL-6), a biomarker for tissue inflammation throughout the body — all as predicted. It did not, however, have an effect on levels of the stress hormone cortisol—the biomarker used to measure stress in the study—which remained essentially the same as baseline levels.

After three-nights of catch-up sleep, daytime sleepiness returned to baseline levels – score one for sleep debt theory. Levels of IL-6 also returned to baseline after catch-up – another score in the theory’s corner. Cortisol levels remained unchanged, but that’s not necessarily a plus for the theory (more on that in a moment).

Attention levels, which dropped significantly during the sleep-deprivation period, didn't return to baseline after the catch-up period. That’s an especially big strike against the theory since attention, perhaps more than any other measurement, directly affects performance. Along with many other draws on attention—like using a smart phone while trying to drive—minimal sleep isn’t just a hindrance, it’s dangerous, and this study tells us that sleeping heavy on the weekends won’t renew it.

Coming back to the stress hormone cortisol, the researchers point out that its level remaining relatively unchanged probably indicates that the participants were already sleep deprived before they started the study. Previous research has shown a strong connection between cortisol and sleep; the less sleep we get, the higher the level of the stress hormone circulating in our bodies, and that carries its own set of health dangers. This study doesn’t contradict that evidence, but also doesn’t tell us one way or the other if catch-up sleep decreases cortisol levels.

The takeaway from the study is that catch-up sleep helps us pay off some, but by no means all of our sleep debt. And given the results on impaired attention, another takeaway is that it’s best to keep your sleep-deprived nights to a minimum. Just because you slept in Saturday and Sunday doesn’t mean you’ll be sharp Monday morning.

You can find David DiSalvo on Twitter @neuronarrative and at his website, The Daily Brain. His latest book is Brain Changer: How Harnessing Your Brain’s Power To Adapt Can Change Your Life.