TV, video games, or Internet: Which activity makes teenagers fat?

Maggie Koerth-Baker at 8:02 am • •

I talk a lot about the importance of context in understanding science. The results of one, single research paper do not tell you everything you need to know on a given subject. Instead, you have to look at how those results fit into the big picture. How do they compare to the results of other studies on the same subject? Have the results been independently verified? How do the specific experiments being done influence what you can and cannot say about the results? What questions aren't answered by the study, and what new questions does it bring up?

You should be thinking about that every time you see anybody talk about the results of a single, new study. Without context, you get situations like this one, described by Travis Saunders on the Obesity Panacea blog:

Earlier this year my friend and colleague Valerie Carson published an interesting paper examining the health impact of various types of sedentary behaviour in a sample of 2500 children and adolescents. They created a clustered risk score (CRS) which took into account a child’s waist circumference, blood pressure, cholesterol, and inflammation, and then examined whether it was associated with 3 different measures of sedentary behaviour – accelerometry (an objective measure of movement), self-reported TV watching, and self-reported computer use.

Here is what they found (emphasis mine): For types of sedentary behavior, high TV use, but not high computer use, was a predictor of high CRS after adjustment for MVPA and other confounders. Here is what the Daily Mail had to say: Watching TV most damaging pastime for inactive children, increasing risk of heart disease.

Last month, our group in Ottawa published another paper (led by Dr Gary Goldfield) looking at different types of sedentary behaviour and heart disease risk factors in a cohort of overweight and obese teens (in contrast, the earlier study was on a sample of nationally representative youth). Interestingly, we found that neither TV time nor computer time was associated with increased risk in this group - in our dataset it was video games that were by far the most important sedentary behaviour.

Why is this a problem? Put yourself in the shoes of someone who just read the Daily Mail article, and who now believes that TV viewing is the single most damaging sedentary behaviour for kids to engage in. What reaction are you going to have when you read a similar article about our new study, suggesting that TV viewing and computer use aren’t important at all, but that video games are actually “the most damaging activity an inactive child can indulge in”?

As the source of this problem, Saunders rightly calls out journalists for pushing every individual study as a "GROUNDBREAKING NEW FINDING". It is, unfortunately, rare to find TV and newspaper coverage that treats new studies in context, rather than as the final word. But to that, I'd add university PR people. The sad truth is, with newspaper layoffs, many of the people writing about science aren't specialists. They cover city council one day, school board the next, and a new research finding after that. The press releases they get (and I know, because I get those press releases, too) push GROUNDBREAKING NEW FINDINGS not research that fits into a larger context. It's the journalists job to know better. But it's also the university's job to not manipulate journalists.

Scientists: How do ethics and culture shape your work?

Maggie Koerth-Baker at 9:20 am • •

Recoding Innovation is a National Science Foundation-funded documentary that's basically about the anthropology of science and engineering.

If you're a scientist or an engineer, you can participate. How does your culture, values, and beliefs make your work happen? The idea here is that ethics aren't something that hold science back. Instead, applying ethics helps scientists and engineers be innovative. It's a cool idea, and I'm looking forward to watching the finished documentary. The video above includes a short example of the kind of stories the editors are looking for.

Submit your story by January 1.

Video Link

The trouble with lab mice

Maggie Koerth-Baker at 3:53 pm • •

You've probably seen this caveat pretty often: Just because a study that uses mice as subjects produces a specific result, doesn't mean you'd get the same result using human subjects. Mice are handy research animals, but they aren't perfect analogues to humans. A mouse study is a stepping stone towards better evidence. It is something we do because there are potentially useful ideas that we should not try out on humans first. But mouse studies should not count as incontrovertible proof of anything.

Usually, when that caveat comes up, the person giving it is talking about fundamental differences between mouse biology and human biology. For instance, a mouse might only need one copy of a genetic factor to grow normally. Meanwhile, a human needs to have both copies or risk altered sexual development.

But there are other problems with mice, problems that have more to do with how we select, breed, and raise mouse models. In a fascinating three-part series on Slate.com, Daniel Engber looks at how we undermine the usefulness of our own lab mice, and the risks we take when we do so.

If you put a rat on a limited feeding schedule—depriving it of food every other day—and then blocked off one of its cerebral arteries to induce a stroke, its brain damage would be greatly reduced. The same held for mice that had been engineered to develop something like Parkinson's disease: Take away their food, and their brains stayed healthier.

But Mattson wasn't so quick to prescribe his stern feeding schedule to the crowd in Atlanta. He had faith in his research on diet and the brain but was beginning to realize that it suffered from a major complication. It might well be the case that a mouse can be starved into good health—that a deprived and skinny brain is more robust than one that's well-fed. But there was another way to look at the data. Maybe it's not that limiting a mouse's food intake makes it healthy, he thought; it could be that not limiting a mouse's food makes it sick. Mattson's control animals—the rodents that were supposed to yield a normal response to stroke and Parkinson's—might have been overweight, and that would mean his baseline data were skewed.

Part 1: The unhealthy lives of industrialized lab mice
Part 2: The trouble with focusing so much research on one single mouse species
Part 3: Why the naked mole rat (and the Burmese python) can help

Faster-than-light neutrino update: What's going on behind the scenes?

Maggie Koerth-Baker at 12:02 pm • •

The publication process for a research paper about physics works a little differently than other subjects. That's because of arXiv. Funded by Cornell University, this site posts research papers, before they're formally published in a scientific journal. Unlike most scientific journals, which charge big fees for subscriptions or even to view a single paper, arXiv is free and open to the public. You can read everything published there—more than 700,000 papers about physics, math, computer science, and more. The other big difference: arXiv isn't peer reviewed. At least, not ahead of time.

A lot of the time, when you read a newspaper article about a new study in one of those fields, the study hasn't actually yet been published in a peer-reviewed journal. It's just been posted to arXiv, which sort of becomes a crowd-sourced peer review peer review of its own. Especially for headline-grabbing research making big, bold claims.

That's the background you need to understand what's going on right now with the study that claimed to find neutrinos traveling faster than the speed of light. That announcement was made in an arXiv paper. Putting those results on arXiv was as much a way of saying, "Woah, we just found something crazy, please tell us if you see something we've done wrong," as it was a formal declaration of scientific discovery.

Since that paper was published in September, there have been more than 80 follow-up papers, also published on arXiv, offering criticism of the original research or proposing theoretical explanations of how that seemingly crazy finding could fit into physics as we know it. And all of this is happening before anybody has gone through the peer-review publishing process.

That's why it's not terribly weird that you're now hearing all sorts of criticism of the original FTL neutrino findings. That's what was supposed to happen. It's also not terribly weird that the original researchers have announced that they're going to re-do the experiment themselves, taking into account some of the big criticisms brought up on arXiv. The BBC explains what will be done differently this time:

Read the rest

How do we know that the moon isn't cheese? —

Sean Carrol explains why there are some ideas science doesn't have to test in order to know that they're ridiculous. (Via Bora Zivkovic.) — Maggie •

Space dust: Your tax dollars at work

Maggie Koerth-Baker at 9:07 am • •

Your tax dollars build bridges. They pay the salaries of teachers and firefighters. Tax dollars help put people through college, provide a safety net for the elderly and the disabled, and pay for fighter jets and nuclear bombs.

You may not agree all those ways your tax dollars are spent, but they are all, at least, fairly tangible. When it's time for re-election, your senator can point to a roads project, a school, a saintly grandmother, or a missile silo. Through these projects, Americans are being educated, cared for, and protected.

But it's hard to make that clear cost/benefit analysis for basic scientific research. At least, not on a timetable that matches up with election cycles.

Basic research is often weird, and it's often boring. It's the years spent mapping the neurons of zebra fish, so that future scientists can have a more detailed biological model to work with. It's the chemical analysis that has to happen, so that two decades from now somebody else can discover a new cancer-fighting drug. Basic research is about curiosity, and knowledge for knowledge's sake. By it's very nature, basic research relies on public funding. But by it's very nature, it's hard to explain how the public benefits from the basic research we fund.

Attila Kovacs is one of the scientists who put your tax dollars to work. An astrophysicist at the University of Minnesota, he specializes in the study of space dust. That is, yes, dust. In space. It's the sort of thing that would be very easy to mock. (Imagine Bill O'Reilly making a joke about lemon-scent space Pledge.) But Kovacs says space dust matters more than you think. And he makes a good case for why it's important to spend tax dollars on funny-sounding science.

Read the rest

Meet Science: How clinical trials work

Maggie Koerth-Baker at 8:45 am • •

Did you know that, with a properly conducted series of clinical trials, it can take upwards of 20 years before a medical discovery makes it from the lab to the hospital?

Judy Stone, an infectious disease specialist who does clinical research, has a guest post on the Scientific American blog network today, explaining the basics of clinical trials—where they came from, and how they can go wrong.

She's going to be publishing a series of posts on this topic, and is looking for input on what you want to know about clinical trials. Disclaimer: As a clinical researcher, Stone has a goal here. She'd like to see more people volunteering for clinical research, and part of what she's interested in is the gaps in knowledge that make people wary of participating, or leave them unaware that they can participate. Your input would be helpful.

Image: Pills Phial, a Creative Commons Attribution Share-Alike (2.0) image from luca_volpi's photostream

Clinical trials seek to learn whether a drug (or device) works as expected—it’s unknown, until tested in people. That’s why early phase trials use only a few people, and more are added as experience is gained. Sometimes unexpected discoveries are made along the way. For example, Rogaine was discovered by an astute clinician researcher during a clinical trial studying high blood pressure. The drug, minoxidil, originally under study as an anti-hypertensive medication, was serendipitously found to have the unexpected side effect of stimulating hair growth, prompting a whole new line of products for baldness.

Similarly, Viagra was discovered by accident. Sildenafil, the generic form, was being studied as a treatment for angina, as it dilates blood vessels by blocking an enzyme, phosphodiesterase (PDE). While not very effective for angina, it was found to prolong erections, stimulating the whole “life-style drug” industry. Fortunately, PDE inhibitors are now being found useful for a host of important medical conditions, ranging from pulmonary hypertension to asthma and muscular dystrophy.

Of course, not all inadvertent discoveries have such rosy outcomes.

For example, Diethylstilbesterol (DES), a synthetic estrogen, was commonly prescribed in the US 1938-1971, to help prevent miscarriages. It was only after many years that DES was found to cause a rare type of vaginal cancer in daughters of exposed women. Later, other types of cancers showed up as well, in small numbers.

Via Aaron Rowe

Caffeine hallucinations: Why "Letters to the Editor" matter in science

Maggie Koerth-Baker at 6:50 am • •

Letters to the Editor are an interesting feature of peer-reviewed scientific journals. The function of this section varies from journal to journal, but, in general, this is where you'll find things like critiques of research published in previous issues, and short write-ups on findings that don't yet warrant their own big, formal research paper. Neuroscience blogger Vaughan Bell found a neat example of the latter in an old 1993 issue of the American Journal of Psychiatry.

Dr. Harold W. Koenigsberg and his colleagues were in the process of studying the causes of panic and anxiety disorders, in hopes of better understanding why some people are prone to panic attacks and others aren't. Part of that research involved determining whether you could have a panic attack while sleeping. They wanted to see whether a panic attack could still happen if the patient wasn't actively thinking about the causes of the panic attack, like they might when awake. Basically, Koenigsberg was trying to figure out how much of a panic attack was attributable to chemistry changes, and how much was related to cognitive processing.

Koenigsberg and company injected sleeping patients with caffeine, to produce the physical symptoms of panic. And that's when they noticed something odd. Two of the patients reported olfactory hallucinations—they smelled things that weren't there. Here's what Koenigsberg wrote in his Letter to the Editor:

Mr. A, a 38-year-old man with no personal or family history of psychiatric disorders, received an intravenous dose of 250 mg of caffeine, delivered as a bolus over a 60-second period during an episode of stage 3-4 sleep. Fourteen minutes after receiving the caffeine, he awakened and reported an “interesting smell or taste-more like a smell.”

Ms. B, a 34-year-old woman with a generalized anxiety disorder, awakened experiencing a smell like that of “plastic or burnt coffee” 3 minutes after receiving a 250 mg bolus of caffeine during a period of stage 3-4 sleep.

Previous research by other people had found that hallucinations like this could happen, but the hypothesis had been that the hallucinations were related to seizures. Koenigsberg's patients had no history of seizures, and they hadn't shown any signs of experiencing seizures when they had their hallucinations.

So Koenigsberg offered a new hypothesis: We know caffeine can work as a taste enhancer. So, maybe, the intravenous caffeine was either causing people to pick up smells and tastes that were normally undetectable, or the caffeine was prompting sensory systems to trick themselves, finding "smells" where none actually existed.

And this is why Letters to the Editor are so nifty. Koenigsberg later published on his panic attack study, but the biochemical function of caffeine on the human sensory system wasn't something he was much interested in. Letters to the Editor allowed him to share a weird finding, which might otherwise have been shoved into a drawer, never to be heard from again.

Instead of being lost, Koenigsberg's finding on caffeine-induced hallucinations went on to influence at least four other studies, including one on migraine hallucinations published last month.

Image: Caffeine fix, a Creative Commons Attribution (2.0)image from davemorris's photostream

Meet a paleontologist

Maggie Koerth-Baker at 11:33 am • •

What does a scientist do all day? The Smithsonian's Matthew Carrano explains his job as a paleontologist, what he hopes to discover, and why he made a career out of dinosaurs.