Higher Altitude Protects Teens from Concussions

The human brain is a vulnerable thing, perched in its peanut shell on top of our walking, stumbling bodies. Humans who enjoy collision-heavy pastimes—say, tackle sports—put their brains in particular danger. And when it comes to concussions, young people are at even more risk than adults. Yet kids who play at at higher altitudes seem to be safer than their peers. The reason, hidden somewhere in the brain's squishy dynamics, might help protect kids and adults who are smashing into each other everywhere.

You don't have to travel to Denver's Mile High stadium for your body to start responding to altitude. "Relatively small changes in altitude can have significant changes upon the physiology of the body," say Gregory Myer and David Smith, both in the sports medicine department at Cincinnati Children's Hospital Medical Center. (The coauthors responded to my email jointly.)

At just 600 feet above sea level, the authors point out, oxygen in the atmosphere has already dropped from 21 percent to 20 percent. Your body notices this slight change and adjusts. One measure it takes, upon noticing there's less oxygen available than usual, is to send a little more blood to your brain. "This leads to a slight filling up of the brain space," Myer and Smith say. Your brain ends up squeezed just a tad more tightly into your head.

Wherever you are, if you get suddenly knocked on the head, your brain will ricochet around inside your skull's fluids. In actual scientific terms, it "sloshes." The delicate brain squishes and twists, and hosts of neurons fire all at once. You may black out. Afterward, you might have memory loss, confusion, nausea, dizziness, and other symptoms that can last for days or months. The looser, stretchier blood vessels in the brains of people under age 20 may explain why they're at even greater risk.

Concussions might be prevented if the skull could keep the brain from sloshing by holding onto it a little tighter—as it does at higher altitudes. To find out whether this works, Myer, Smith and their colleagues used data from the National High School Sports-Related Injury Surveillance System. Run by the University of Colorado, Denver, this study collects data on injuries from high schools across the country.

The authors looked at nearly 6,000 concussions from about 500 schools. The concussed kids were athletes in all kinds of sports, at schools ranging from sea level to 6,900 feet. When the researchers divided student athletes into those living above and below the median altitude—which was 600 feet—they saw a significant difference in concussions. Across all sports, kids at higher altitudes had a 31 percent lower risk of concussion. Among football players only, the results were essentially the same: a 30 percent lower risk at higher altitude.

It's an intriguing difference. As sports organizations and the public learn more about chronic traumatic encephalopathy (CTE) and the long-term risks for athletes with head injuries, the quest to prevent concussions is growing more urgent. High schoolers, though, don't travel to play like professional athletes do. Could some of their lower risk have to do with changes in their bodies that happen over a lifetime of living at a certain altitude? "Visiting altitude will begin creating a tighter fit the minute you arrive," Myer and Smith say. However, adjustment happens over the long term too. "Everyone is likely different in how quickly they respond [to altitude] and how protection occurs for them," the authors say. "This is why we are working to evaluate technologies that can give this same protection whether you are in Denver or Miami." They'll be looking next at adults and professional athletes to try to find answers.

One hint comes from an earlier study David Smith performed on rats. While wearing a collar that slightly squeezed their jugular veins, the rats were hit hard on the head. The collar seemed to make rats less vulnerable to concussion, apparently because more blood was in their heads, squeezing their brains more tightly and preventing sloshing. This all sounds pretty unpleasant for the rats, but Myer and Smith insist that "the technologies we are studying are no more risky than yawning or even the act of lying down."

Animals like woodpeckers and head-ramming sheep manage to protect their brains from damage, the researchers point out. So why can't we? Of course, in our case the head ramming is in the name of fun. But there might be ways to safeguard our brains, like these animals do, from the inside out.


Image: Rocky Mountain High School in Colorado, by Paul L. Dineen (via Wikimedia Commons)

David W. Smith, Gregory D. Myer, Dustin W. Currie, R. Dawn Comstock, Joseph F. Clark, & Julian E. Bailes (2013). Altitude Modulates Concussion Incidence: Implications for Optimizing Brain Compliance to Prevent Brain Injury in Athletes. Orthopaedic Journal of Sports Medicine DOI: 10.1177/2325967113511588

What Left-Handed Ultimate Fighters Tell Us (or Not) About Evolution

Don't despair, left-handers who have just smeared the ink across your paper yet again. You have a true purpose in life, some scientists say—and it's walloping other people in the head. A flying elbow drop would work too. Researchers recently pored over video of hundreds of UFC fights to test the idea that lefties evolved with an edge in hand-to-hand combat.

Various other animals show a preference for one paw, or one swimming direction, over the other. But humans are notable for almost always preferring the right side. Only about 10 or 12 percent of us are lefties. Is this because there's a cost to being a left-handed human (aside from the ink thing)? Lefties are smaller in stature, and there's some evidence that they don't live as long. If these effects really add up to a raw evolutionary deal, perhaps the reason there are any lefties is that there's some advantage too.

Enter the so-called fighting hypothesis, which says that lefties have persisted at low numbers because they have the element of surprise in a fight.

In order for this theory to make sense, you have to imagine that sometime after our ancestors came down from the trees but before they built weapons, punching each other became very important to their survival. And that despite our squishy outer coverings, valuable dextrous hands, and vulnerable heads, we are a species built for combat. It's a speculative theory. A recent review paper about the fighting hypothesis—which shared an author with the current paper—called evidence for the idea "not particularly strong."

Nevertheless, a group of researchers in the Netherlands chose to explore the theory using mixed martial arts fighters. The UFC "seemed like a very interesting arena to test this hypothesis," says lead author Thomas Pollet, "pun intended." Pollet is a psychologist at VU University Amsterdam. Since the UFC is "a fierce fighting sport hardly constrained by rules," the authors write, it might be a good representation of humans scrapping in an ancestral state.

Pollet studies handedness but didn't have a particular interest in the Ultimate Fighting Championship when he began the study. To get perspective from a fan, I wrote to my friend Ryan, who happens to love watching MMA fighting. He's also a lefty. "A left-handed fighter will lead with their right foot, jab with their right, and cross with their left," Ryan explained. This is all unexpected to an opponent who mainly fights righties. "The speedy jab will come from the opposite side, and the lefty fighter will naturally circle the ring in the opposite direction as well."

Studying recordings of 210 UFC fights, Pollet found that lefties were significantly more common than in the general population. More than 20 percent of the 246 fighters were left-handed. (You can tell by checking their feet; the back leg corresponds to the dominant hand. "UFC fighters only rarely switch between stances within or between fights unless their lead leg is...severely injured," the authors write.)

To look for a left-handed advantage, Pollet analyzed all the fights between a lefty and a righty. The results were an exact tie. A computer simulation in which the fighters' handedness was randomized led to the same conclusion: left-handers had no advantage over righties.

This alone might not disprove the fighting hypothesis. That's because the UFC represents the cream of the lawless-brawling crop. "A fighter must go through a minor league promotion in their home town before making it to the big stage," Ryan told me. On their way to the professional level, left-handed fighters might have an advantage, which would explain why there are so many of them in the UFC. But once they become more common—and face more opponents who are experienced at fighting lefties—their edge might disappear.

"I think it is a very attractive hypothesis," Pollet says. The advantage of being left-handed in a fight may depend on how many other lefties are around, but "testing frequency dependence can be hard," he says. He's hoping to compare results in the UFC to other competitions that include more amateurs.

Currently, Pollet and his colleagues are working on a meta-analysis of lefties in different sports. In tennis, for example, being left-handed can give players a boost. (My friend Ryan, who just happens to also play tennis, said that being a lefty gave him "a great advantage growing up." A lefty cross-court forehand shot, he explained, forces your right-handed opponent to return the ball with a weaker backhand.)

In addition to the UFC, left-handedness is especially common among badminton players, cricketers, and recent U.S. presidents. Maybe lefties can look to those areas to find their evolutionary reason for being. If they still feel existential angst, they can always go out and punch someone.


Image: by Krajten (via Wikimedia Commons)

Thomas V. Pollet, Gert Stulp, & Ton G.G. Groothuis (2013). Born to win? Testing the fighting hypothesis in realistic fights: left-handedness in the Ultimate Fighting Championship. Animal Behaviour DOI: 10.1016/j.anbehav.2013.07.026

Thanks to Ryan Sponseller for his thoughtful comments on handedness and punching dudes.

Baseball Players Make Worse and Worse Decisions as the Season Goes On

If their goal were to frustrate fans, they couldn't plan it any better. Major-league baseball players reach a low point in their decision making in September, just in time for playoffs. Across all teams, batters swing at more and more pitches they shouldn't as the season goes on.

They may just need a nap.

"Consistently getting too little sleep—even if it's just [by] one hour a night—can lead to a state of chronic sleep deprivation that can compromise performance," says Vanderbilt University neurologist Scott Kutscher. "Specifically, things like judgment and reaction time."

Judgment and reaction time are just what a baseball player needs when a ball is hurtling toward his body at 90 miles an hour: he has to decide whether to swing, then react quickly enough to actually get it done. And sleep deprivation is familiar to pro ball players, who have a packed schedule and frequently travel back and forth across the country.

To see whether baseball players suffer the effects of sleep loss as the season drags on (or skips along for six non-tedious months, depending on your inclinations), Kutscher and his colleagues looked at data from 2011 back to 2006, after the MLB cracked down on steroid use. For each team, they tracked how often players swung at pitches outside the strike zone.

Over the course of the season, the researchers saw a steady increase in how many out-of-the-strike-zone pitches players swung at. These badly judged swings went up by about six-tenths of a percent each month.

Then Kutscher and his colleagues tested that model on the data from the 2012 season. When the numbers from all the MLB teams were pooled together, the model was a tight fit. Out of 30 teams, 24 were swinging at more balls in September than in April. Kutscher presented the findings at a recent conference on sleep.

Other factors aside from sleepiness may be at work. Pitchers might be throwing better curveballs as the months pass, for example. But Kutscher says pitchers threw pretty much the same ratio of balls and strikes throughout the season; if they were improving a lot, you'd expect to see them throwing more strikes. (Not to mention that batters, too, are practicing and honing their skills during the season.)

Since the researchers looked at whole teams rather than individuals, it's also possible that a change in the roster during the season—say, the addition of less experienced players who are called up from the minors—has an effect. Kutscher doesn't think this could account for all the deterioration he witnessed, though.

"I am hesitant to argue that fatigue is 100% of the story," Kutscher says. "But we have findings that are consistent with what we know about fatigue and chronic sleep loss."

Pro ball players, and other athletes, might see their performance improve if they could avoid sleep deprivation. So stop shouting at that guy on your screen who just struck out—he needs to go home and get some rest.


Image: Ed Gaillard (via Flickr)

The Shambulance: Deer Antlers Are Not Unicorn Horns

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. The chief navigational officer of the Shambulance today is Steven Swoap.

This Superbowl season saw a star linebacker forcefully denying that he'd ever sprayed juice made from ground-up deer antlers into his mouth. The player was Ray Lewis, and using deer antler spray would have seemingly violated the National Football League's ban on performance-enhancing drugs. Like the horn of a unicorn, this product is alleged to heal and strengthen its users. Also like the unicorn horn, it's probably not something the NFL needs to worry about.

Bottles of deer antler spray—also called deer antler velvet or IGF-1 spray—are legal and easy to purchase for $20 to $50. Though no one's checking what's actually inside the bottles, makers claim their products come from antlers that are harmlessly sawed off of male deer each spring, or from the soft skin covering these new antlers. A few times a day, you spritz the solution into your mouth and swallow it.

The suggestion is that deer antler spray will make your own muscles or bones regrow as rapidly as a deer's antlers. Some products make other claims that are variously expansive, including weight loss, better endurance, a boosted immune system, and higher sex drive. Fueling all these promises is a hormone called IGF-1 (short for insulin-like growth factor). Like medieval "unicorn horns" that were really the tusks of narwhals, IGF-1 is less glamorous in reality than in legend.

It's true that deer antlers "grow like crazy," says Steven Swoap, a physiologist at Williams College. "There are not many examples where a tissue grows faster than an antler. Except for maybe some pumpkins."

We humans are naturally curious about tapping into that growing power. And IGF-1 is certainly involved in growth. In humans as well as deer, it's mostly manufactured by the liver. We make more of it during growth spurts, Swoap says. Producing too much IGF-1 is linked to certain cancers—growth that can't be stopped.

"Does IGF-1 cause antler growth? It is possible," Swoap says. "A more likely candidate is testosterone." Female deer, which also make IGF-1, don't grow antlers; male deer have extra testosterone in their bodies during the antler-growing season. "There are likely many factors involved," Swoap says.

Whatever ingredient gives deer antlers their seemingly magical growing power, we aren't likely to capture much of it by grinding up the antlers themselves. "The antler is not a hormone producing factory," Swoap says. Antler growth is triggered by hormones sent from elsewhere in the body, such as the liver, thyroid, or testes. ("You would be much better off making a spray out of the testes of deer," Swoap suggests. "Or you could perhaps get the IGF-1 from the liver, where it is made, and have a liver milkshake with your deer nut spray.")

Even if a useful quantity of IGF-1 made it out of the antlers and into the spray, the molecule would have a hard time completing its journey into the hopeful athlete's body. Swoap says IGF-1 is a hefty protein that's unlikely to slip into your bloodstream through the soft tissues under your tongue. And once swallowed, it would break down in your digestive tract.

Swoap compares IGF-1 to another famous protein hormone: insulin. "For years, we had to inject it, and it is only recent technological advances that allowed us to deliver it subcutaneously," he says. "To say that the technology is replicated in a bottled spray is ridiculous."

Mitch Ross, the owner of the company that claimed Ray Lewis used its deer spray to recover from an injury, calls his products "technologies that are light years ahead of what people can understand." In other words, even if we can't explain the science, we should accept that deer antler extract helps people.

Except that it doesn't.

Researchers have given oral deer antler supplements to various groups of people, compared them with placebos, and looked for any effect. Men who took deer antler supplements during a strength training program showed no change in hormone levels (including IGF-1) and no difference in aerobic endurance. Rowers also showed no change in hormone levels and no difference in strength or endurance. (As for those other claims, a study in middle-aged men found no increase in sexual function.) A review paper last year concluded there is no convincing evidence that deer antler extract is useful to athletes.

It seems we haven't yet lopped anything special off the heads of those deer. Ray Lewis and (because even athletes who compete at a walk apparently want performance boosters) golfer Vijay Singh are busy defending their reputations against deer antler spray. Yet the product wouldn't have given them any extra powers except a placebo spritz of confidence. Professional sports organizations have plenty of real beasts to chase down in the world of banned substances, but this one is only a mythical creature.


Image: skipnclick (Flickr)

Fishing Yanks the Best Parents from the (Gene) Pool

A fishing rod and reel aren't just gear for human recreation: they're the tools of evolution. The difference between fish we pull out of lakes or commercial fisheries by their lips and those we leave behind can drive change in entire fish populations. And that change may be for the worse. In at least some species, the fittest fish are the ones that end up on our hooks.

The largemouth bass (Micropterus salmoides) lives all over the United States and is a popular target of recreational anglers. You wouldn't guess it from the bug eyes and mailbox mouth, but M. salmoides males are also doting dads. For several days after the female lays her eggs and before they hatch, the male stays close to the nest. He fans the eggs with his tail and chases off any other creatures who come looking for a snack.

The more aggressively a male largemouth bass attacks intruders near his nest, the more of his offspring are likely to survive. But when fending off threats, a bass doesn't necessarily notice the difference between a hungry fish and a dangling lure. So the fish that guard their nests most aggressively might also be the most likely to bite into a fishhook.

David Sutter, a PhD student at the University of Illinois at Urbana-Champaign, and other researchers used specially bred largemouth bass in artificial ponds to investigate this question. Their fish had been bred into two lines: one that's especially likely to attack a fishhook, and one that's especially unlikely.

(Vulnerability to being caught on a rod and line is heritable, Sutter explains—a kind of personality trait for fish. Largemouth bass were first bred this way starting in the late 1970s. Researchers kept the bass in a reservoir where any fish that got caught were marked and rereleased. Eventually researchers drained the reservoir, revealing some fish with multiple marks and others that had never been caught. These extremes were separated into new ponds where the experiment was repeated. After a few generations of this, the researchers had created one line of fish that was consistently catchable and a second line that was consistently hard to catch.)

Sutter and his colleagues put the two kinds of male bigmouth bass together in a pond, along with ordinary females. Once the fish had spawned, snorkelers visited their nests to count their eggs. By spying on the fish remotely, researchers could observe how attentive the fish dads were to their nests—and how aggressive they were to "intruders," which in this case were hookless fishing lures.

The fish bred for catchability, as expected, attacked the fishing lures more often than other fish. In addition to chasing these imaginary predators away from their eggs, they also spent more time hanging out near the nest and fanning their eggs with their tails. By comparison, the fish bred to ignore fishhooks spent more time away from the nest and didn't bother chasing away intruding lures. Overall, as the authors report in PNAS, the easiest-to-catch largemouth bass are also the best dads.

Hooking one of these fish from a body of water obviously removes him—and his good-dad DNA—from that population's gene pool. It also dooms any eggs he was guarding, which carry those same genes, to become food for roving predators.

There's another way fishing fouls up the next generation of fish. The researchers found that females spent more of their eggs on aggressive males, especially large ones. Apparently the female fish can tell which males will guard a nest well. When these sexy bass are removed from a pond, they leave behind more eggs (and more potential young) than a smaller and less aggressive male would.

All this means that humans can drive the evolution of a whole fish population. Thanks to our fishing lines, male largemouth bass (or species with similar behaviors) can become less aggressive, less capable as parents, and less attractive to females. And, of course, less catchable by us. The authors suspect these changes are already happening in popular angling spots, though it hasn't been studied yet.

Sutter says fisheries might be able to prevent the problem by leaving largemouth bass alone during their spawning season. "It would probably be best to allow fish to successfully reproduce and minimize disturbances," he says—by disturbances he means fishhooks—"especially in areas where fish only have limited opportunities to reproduce." Otherwise, the only fish that are left alive may be the deadbeats.


David A. H. Sutter, Cory D. Suski, David P. Philipp, Thomas Klefoth, David H. Wahl, Petra Kersten, Steven J. Cooke, & Robert Arlinghaus (2012). Recreational fishing selectively captures individuals with the highest fitness potential PNAS : 10.1073/pnas.1212536109

Image: (Not a largemouth bass) by Blake Facey (Flickr)

The Shambulance: Copying Roger Clemens Won't Help You Lose Holiday Pounds

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. With me at the wheel of the Shambulance are Steven Swoap and Daniel Lynch.

The injections he'd been receiving in the buttocks during his major-league baseball career, pitcher Roger Clemens explained to a jury this summer, were not steroids. They were perfectly legal and innocent shots of vitamin B12. The jury acquitted him, lifting the weight of a felony perjury charge from his shoulders. You, too, can use B12 to put some spring back into your step—at least, if you believe the companies that market the injections for weight loss, energy, and general well-being. In reality, this is not a performance enhancer.

B12 is a quirky vitamin that you can't get from plants. It's manufactured by bacteria that provide their services to some animals by living in their guts. Humans mainly get B12 from meat, eggs, and dairy. Of course, this means vegan humans have to find the vitamin elsewhere, such as in fortified breakfast cereals or Flintstones chewables. (They might also ingest B12 from soil bacteria on vegetables that haven't been washed well.)

"Healthy individuals have a six-year supply of B12 stored in their liver," says Daniel Lynch, a biochemist at Williams College. So even a temporary shortage in your diet shouldn't harm you. Long-term vegans, though, can become deficient in B12. Some older adults and gastric-bypass patients who can't absorb enough B12 from their food need to get it from an outside source. And patients who suffer from a disorder called (oddly) "pernicious anemia" need B12 supplements.

B12 deficiency causes weakness and fatigue, and an injection of the vitamin reverses those symptoms. This has apparently led some people to conclude that healthy, non-deficient folks will also get stronger and more energetic by taking B12. Why settle for normal functioning when you could be a vitamin-powered superhuman?

"[Weekly] vitamin B12 injections are intended to crank up the metabolism and boost energy levels to increase daily activity and help weight loss even when the body is at rest," says one Chicago weight-loss center.  An "anti-aging" clinic asserts that "B12 injections are...an effective means of boosting the body's metabolism for those looking to lose weight."

You'll start by shedding weight in the wallet region: a 3-month course of shots from that office will relieve you of nearly $500.

It's true that vitamin B12 is involved in metabolism. However, according to the National Institutes of Health, "Vitamin B12 supplementation appears to have no beneficial effect on performance in the absence of a nutritional deficit."

In other words? "Basically, for any healthy person this is a sham," Lynch says. "Any excess B12 is peed out anyway."

Non-human animals store B12 in the liver, just as humans do. "So you could get the same effect of the injection by munching on liver," says Steven Swoap, a physiologist who's also at Williams College. "This is how they 'cured' vitamin B12 deficiency a hundred years ago."

If you still feel a craving for B12 but don't care for liver sandwiches, you can buy bottles of B12 pills—and they'll run you about five cents a tablet. "It begs the question as to why anyone would stick a needle in themselves when you can buy this stuff as a pill at the local drugstore," Swoap says. Maybe we can find a Hall-of-Fame-nominated baseball player to explain it.

Image: Craig Strachan (Flickr)

Your Sharkskin Speedo Makes Sharks Scoff

"Inspired by the sleek, hydrodynamic properties of sharkskin," Speedo claims, its Fastskin FSII swimwear mimics the texture of a shark to reduce drag and make you faster. But the material might work better if you wore it inside-out. And a closer look at the shark itself reveals engineering features that put our technology to shame.

Calling the suit--or the shark--"sleek" is a little misleading. A shark's skin is covered in miniature teeth called denticles (in case you thought sharks weren't toothy enough). The denticles themselves have ridges that run parallel to the line of the shark's body. To see what these tiny ridged teeth are or aren't doing, researchers at Harvard assembled some robotic sharkskin sandwiches.

Johannes Oeffner and George V. Lauder tested fresh pieces of skin from two kinds of sharks, the porbeagle and shortfin mako; a ribbed silicone material; and Speedo's Fastskin FSII fabric. They glued pairs of sharkskin pieces together sandwich-style to make flat rectangles of skin. With the silicone and Speedo pieces, they made both normal and inside-out sandwiches (with the textured surface on the inside).

These rectangles of skin, rubber, or swimsuit were tested with a kind of robotic swimming machine. The device dangles a rectangle of material in a current of water, waving it back and forth like an undulating 2D fish. Outside the water tank, the device floats on something "rather like an expensive air hockey table," George Lauder explains. This lets the robot propel itself: It may outswim the current, fall behind, or keep up like a person on a treadmill. It also lets the researchers see just how fast each material can swim on its own.

The sharkskin rectangles propelled themselves through the water significantly more quickly when they were intact than when they had their denticles scraped off, suggesting that the little teeth do aid in swimming speed. The rectangles made of ribbed silicone also swam faster when they were right-side-out than smooth-side-out.

But the Speedo Fastskin sandwiches were not so fast. They actually propelled themselves more quickly through the water when they were turned inside-out. That highly engineered fabric surface made the robot swim "quite a bit slower," Lauder says.

When viewed at a microscopic level, it's pretty clear why the Speedo performed differently from the real sharkskin.

Each of the shark's denticles (left) has three pronounced ridges. The imitation of this ridged pattern is presumably what helped the ribbed silicone rectangles swim faster, even though the sharkskin as a whole doesn't really have a ridged pattern. The Speedo fabric (right) doesn't have pronounced ridges at all, but does have occasional grooves--you can see these as the darker stripes in the material. 

When it comes to lessening drag, it seems Speedo's sharkskin impression is a bust. But the shark is only getting started. Those tiny teeth have another speed-enhancing trick besides reducing drag: They actually increase thrust, helping to propel the shark forward through the water.

Oeffner and Lauder discovered this by tracking the flow of water around their flapping robot. What they saw was a vortex--a little whirlpool of water--forming near the leading edge of the flapping sharkskin. "Insects and birds form these on their wings in flight," Lauder says. Comparing the intact sharkskin to the skin that had its denticles sanded off, the researchers saw that the toothed skin enhanced this vortex and held it closer. The low-pressure vortex helps to suck the sharkskin forward through the water.

(To make sure the flapping of the sharkskin wasn't too exaggerated compared to the motion of a real shark swimming, the researchers observed live sharks called spiny dogfish. These sharks had been trained to swim steadily in a flow tank, like a human in one of those Endless Pools. The sharkskin sandwiches, according to their measurements, did curve back and forth comparably to a real shark.)

Even though the Speedo Fastskin FSII material didn't show any signs of inherent fastness (and seemed to actually increase drag, compared to when it was turned smooth-side-out), that doesn't discount the Speedo swimsuit as a whole. Fastskin suits compress an athlete's body, making it more streamlined. Panels of material squeeze the body into a shape that's, according to the company, more efficient for swimming. And the newest designs, which use a different fabric than the one tested here, even come with a corresponding Fastkin swim cap "designed using global head scanning data."

There's one more crucial ingredient to the Speedo: psychology. "Comfort allows focus and inspires confidence," the company's website says. "And with confidence comes peak performance." 

The mental game may be just as important to athletes as the physical one. And when it comes to confidence, a swimsuit that's marketed to make you feel like a top predator can't hurt. (The sharks themselves, one assumes, don't need any such ego boost.)

Oeffner, J., & Lauder, G. (2012). The hydrodynamic function of shark skin and two biomimetic applications Journal of Experimental Biology, 215 (5), 785-795 DOI: 10.1242/jeb.063040


Photo: Shortfin mako shark jidanchaomian/Flickr; swimsuit www.speedousa.com; ESEM images Oeffner and Lauder.

Why Super Bowl Advertisers Want a Close Game

While Americans gather around the nachos today to find out whether the Patriots beat the Giants and how much clothing Danica Patrick wears in her GoDaddy spot, advertisers will have their fingers crossed that their commercial makes a good impression. They've paid millions of dollars for each 30-second ad. That's because they assume this piece of TV real estate is the most valuable there is. But they should be crossing their fingers for a close game--with their ad aired at the very end.

A theory called excitation transfer says that your excitement from one event can overflow into the next thing that happens. So researchers from the University of Oregon decided to find out whether a hotly contested sports game makes the ads that interrupt it more exciting too. They also wanted to know if it mattered where in the game an ad was shown. And finally, did the commercial itself have to be exciting for the effect to work?

Colleen Bee and Robert Madrigal gathered 112 undergrads and 4 TV ads. In earlier testing, people had rated these ads as especially suspenseful or especially not suspenseful. (To prove it, the authors describe each ad in their paper. A suspenseful Nike ad: "International football (soccer) commercial featuring international players against monsters/demons in a dramatic match for the survival of football." An un-suspenseful ad: "Two women playing golf illustrating the frustrations and subsequent solution to bladder control issues." I'd argue that bladder control issues are pretty suspenseful, but apparently that urgency didn't carry over to the commercial.)

In small groups, subjects watched footage of basketball games involving their college team. The footage was edited into four different mini-games (each consisting of two four-minute halves). Subjects saw a close game that the home team lost; a close game the home team won; a win where their team had a wide lead the whole time; or a loss in which their team was always well behind.

Subjects also saw two ads at "halftime," and the other two after the game was over, making note of their reactions to each ad. The order of the four ads was shuffled between the different groups of subjects. From all this, the researchers found three things that make viewers see ads more positively:

A nail-biter
When they watched suspenseful games--that is, games where the score was close throughout--viewers reported having a more powerful emotional response to an ad. They also reported feeling more positive about the ad and the brand itself.

But wait, there's more! This effect was only found when there was also...


A conclusion
The ads that drew the best response from viewers were the ones shown immediately after the end of a suspenseful game. Not in the middle of the game; not a couple ad slots after the game ended; but right after the clock ticked down.

This fits with the theory that residual excitement about an event can spill over into the next event. It's interesting, though, that excitement during the middle of a game doesn't have the same effect. Maybe anxiety over the outcome takes away from people's positive feelings about the ads they're seeing.

Finally, the researchers found that it was necessary to have...


Added suspense
The ad itself must also be suspenseful for the effect to appear. No matter how exciting a sporting event is, that bladder control golf game is just not going to get anyone revved up. But suspenseful ads (like the Nike spot with the demonic soccer players) can get a boost by appearing at the very end of an exciting game.

Since subjects were watching their home basketball team compete, the researchers expected the outcome of the game to be important too. But in this case, they were surprised. Win or lose, the results were the same. Suspenseful ads immediately following a suspenseful game got the best response from viewers, whether or not their team won.

The outcomes of these basketball games, though, had been decided long before viewers saw the footage. Subjects might have felt more suspense--and been more swayed by a win or loss--if the games were taking place in real time. Additionally, the authors point out that pausing after every commercial to rank your emotional responses isn't exactly the normal way of watching TV. Viewers who aren't being forced to stop and reflect on their feelings might not have the same perception of ads as these subjects did.

This study doesn't address how someone's positive feelings about an advertisement might translate into recognizing a brand in the future, or buying that brand's products. That's, of course, the bottom line for advertisers. But it stands to reason that your positive feelings about a TV ad could become positive feelings the next time you see that brand--maybe on a store shelf.

The Super Bowl, too, is a special case. Some people look forward to the ads more than the game itself, and advertisers are pulling out all the stops. But if today's game is a close one--and if it's immediately followed by an exciting ad--we'll see whether critics are swayed to put that ad on their top-10 lists Monday morning.



Colleen C. Bee, & Robert Madrigal (2012). It's not whether you win or lose, it's how the game is played: The influence of suspenseful sports programming on advertising Journal of Advertising, 41 (1)


Image: Screenshot from Bud Light "Replay" commercial, my favorite.

Chimps Prefer the 2-Point Conversion

If non-human great apes were coaching more football games, you could expect to see fewer extra points being kicked. We risk-averse humans usually prefer kicking an easy extra point after a touchdown, rather than attempting a more difficult 2-point conversion. But chimps and other great apes, after considering their odds, usually opt for the greater risk and the bigger reward.

By "reward," I mean banana.

Researchers at the Max Planck Institute in Germany tested a group of chimpanzees, bonobos, gorillas and orangutans on their risk-taking strategies using chunks of banana. They wanted to know whether the apes' likelihood to go hunting for banana pieces hidden under cups, rather than taking a smaller banana piece already in front of them, depended on the "expected value" of their choices. Expected value is simply an item's worth, multiplied by your odds of getting it. If a 2-point conversion attempt is successful exactly half the time, then its expected value is 1 point.

The 22 apes each sat through a series of experiments involving banana bits in cups. On one side of a table, they saw a small piece of banana placed under a yellow cup. Next to that was a row of blue cups,  anywhere from one to four of them. Under one of the blue cups was a larger piece of banana.

The apes knew the larger piece of banana was hidden under one of the blue cups, but unless there was only one blue cup, they didn't know exactly where the banana was. (They understood the setup because there was also a series of trials in which the apes watched the banana being placed under one of the blue cups.) In each trial, an ape could point to just one cup and get the reward--if there was any--underneath.

The yellow cup was a guaranteed small reward. The blue cups were a gamble. And the size of the gamble (in other words, its expected value) depended on how many blue cups were on the table. It also depended on the difference in size between the two banana chunks. The "safe" piece of banana in the yellow cup ranged from one-sixth to two-thirds the size of the large piece.

The researchers found that the apes' decisions did correlate to the expected value of their options. Overall, as the expected value of picking a blue cup increased--there were fewer blue cups on the table, or the safe piece of banana was small and untempting--apes opted more often to try a blue cup. When the expected value of the gamble was lower--because there were a lot of blue cups to choose between, or the safe banana piece was large to begin with--they were more likely to stick with the yellow cup.

Adjusting choices based on the expected value of each option is similar to how humans would decide. But the apes were less human-like in their general propensity for risk. Even at the lowest possible expected values, apes chose to gamble on a blue cup more than 50% of the time.

In other words, apes acted more like humans playing the lottery than humans kicking an extra point after a touchdown. These apes, of course, didn't have their coaching jobs on the line. They might have just enjoyed playing the cup game. And in a human football game, there are plenty of situations in which a kicked extra point is better than going for 2--even though its expected value, with a success rate of about 50%, is the same.

But even outside of football games, humans are known by psychologists for being risk averse, especially when it comes to potential gains. We'd rather take a small guaranteed reward than a larger and riskier one. (For losses, though, we tend to feel the opposite way.)

When the researchers broke down their results by species, they found that while all four species were risk prone, bonobos were a little more conservative in their choices than chimps were. With only a small number of ape subjects, it's hard to draw any serious conclusions. But it's interesting to speculate about the differences between us and our two closest living relatives. Have chimps evolved to take more risks, always gambling on finding something better, because in the wild they must search for fresh fruit year-round? Can bonobos afford to be more conservative because their diet in the wild is more flexible? What factor in our past put risk-averse humans at an evolutionary advantage?

Next time your favorite football team takes an overly conservative extra point, don't blame the coach for his evolutionary history. You could always call up the owners, though, and suggest they hire a chimpanzee instead.









Photo: Flickr/Mat_the_W 


Haun, D., Nawroth, C., & Call, J. (2011). Great Apes' Risk-Taking Strategies in a Decision Making Task PLoS ONE, 6 (12) DOI: 10.1371/journal.pone.0028801

Lessons from Kobe on Life's 3-Pointers

You might expect NBA players to know when and where to take their shots. They get paid millions of dollars a year to work out, avoid hitting their heads on door frames, and put the ball in the basket. Yet even years of training can't overcome a basic human superstition about our own behaviors: We believe that whatever just happened is about to happen again. If we stopped trusting in streakiness, we might all score more points.

Tal Neiman and Yonatan Lowenstein, researchers in Israel with a mysterious interest in professional American basketball, scrutinized play-by-play accounts of games from the 2007-08 and 2008-09 seasons. Their analysis included 291 NBA players and 41 WNBA players (indicating a good grasp of Americans' proportional interest in women's sports).

Specifically, the researchers were interested in decisions players make after hitting, or missing, a 3-point shot. After a successful 3-pointer, what are the odds that a player's next attempt is another 3 (rather than a 2-pointer)? What about after a missed 3-point shot?

For both men and women, the success or failure of a 3-pointer had a major influence on what their next shot was. After sinking a 3-point shot, NBA players attempted a second one 41% of the time. But after missing a 3-pointer, only 30% of follow-up shots were 3's.

The numbers were remarkably similar for women: 41% of shots attempted right after a sunk 3-pointer were also 3's, but that number went down to 34% after a missed 3-point attempt.

Men and women were so similar in their behaviors, in fact, that the researchers could pool their data for further analysis. But there was at least one major outlier, politely referred to as "the Most Valuable Player (MVP) of the 2007-2008 season." Although he didn't name that player, we can hear the authors' implied "cough, KOBE, cough." A big believer in his own hot hands, Kobe Bryant followed more than half of his sunk 3-pointers with another 3-point attempt. But after missing a 3-pointer, he tried again only 14% of the time.

Kobe or not, basketball players are clearly more eager to take a second 3-point shot after they've sunk the first one. And they're even more likely to line up a 3-pointer after making two in a row. Intellectually or just instinctively, they believe this to be a good strategy. But there's bad news: it's not. 

Professional players are, in fact, slightly less likely to hit a second 3-point shot after hitting their first one than after missing it. The difference is just 6%, and it might be due to overconfidence or to better defense. But players make the situation worse by assuming they're on a streak. (A player's decisions might be justified if his team as a whole scored more points when he attempted a second 3-pointer, maybe through rebounding or general intimidation. But this was not the case. And 2-point shots were equally successful after making or missing a 3-point shot.)

The authors say this is an example of "reinforcement learning." Like a dog that sits on cue or a laboratory pigeon that pecks at the right button, getting an immediate reward tells us we should repeat our behavior. The basketball players in this study are "overgeneralizing": they ignore what they've learned about a shot's likelihood of success in general, and respond only to the emotional reward of their last sunk shot. And like a rat in a maze getting a tiny electrical shock, players who miss a shot respond to the pain of that most recent experience.

Overgeneralizing is obviously hard to overcome. We're wired to learn by experience, and that might be what leads us to trust in streaks. A success makes us feel like we'll succeed again; a failure suggests more failure. But if we could remember that every shot on net is a new one, we might all (even Kobe) make better decisions.

Image: Keith Allison/Wikimedia Commons


Neiman, T., & Loewenstein, Y. (2011). Reinforcement learning in professional basketball players Nature Communications, 2 DOI: 10.1038/ncomms1580

Why Don't Woodpeckers Get Concussions?

To help protect our big, fragile brains from trauma during sports, why not turn to another animal that voluntarily smashes its skull into solid objects? The woodpecker hammers its beak into tree trunks twelve thousand times a day at at fifteen miles an hour. In so doing, it drills out nests, finds tasty bugs, and does not (as far as one can tell) give itself brain damage. What's its secret?

Lizhen Wang at Beihang University in Beijing led a study to find out what makes the woodpecker so resilient. The team used Dendrocopus major, the great spotted woodpecker, which is common in China. For comparison, they also studied the Eurasian hoopoe,* a relative that pecks soft soil instead of wood.

With the birds caged, the researchers used high-speed cameras to record their pecking motions and sensors to measure the force with which the birds struck the metal cage or a piece of foam. They also took detailed scans of the birds' skulls, examining them at a microscopic level. After mechanically testing pieces of woodpecker skull and beak, the researchers used those results to create a computer model of a woodpecker head. Then they virtually smashed the model head into a tree trunk, tweaking different parameters and observing the effects.

"Simple reasoning would indicate that if woodpeckers got headaches, they would stop pecking," Wang writes. The researchers' interest was not just in preventing headaches, of course, but the disability and death that can accompany hard head whacks in humans. Sports organizations have started to recognize the danger of repeated concussions, especially concussions that follow close on the heels of earlier ones. In 2009, the NFL changed their rules about how soon concussed players can return to a game. But even without serious concussions, repeated blows to the head might lead to chronic traumatic encephalopathy (CTE), a degenerative disease of the brain that can cause dementia and personality changes. Athletes themselves are becoming wary of CTE, too. Former NFL player Dave Duerson illustrated that brutally earlier this year, when he committed suicide by shooting himself in the chest so that doctors could examine his brain for CTE. (They found it.)

Some of what Wang found in woodpeckers is of no immediate use to athletes. For example, some of the woodpecker's sturdiness comes from the hyoid bone, a nifty sling-shaped structure that extends from the top of the head through the skull to the nasal cavity. This bone (letter b below) only exists in woodpeckers. Additionally, the woodpecker's beak, with its uneven upper and lower parts, is calibrated to absorb much of the blow.

Humans can't very well insert stabilizing bones behind our faces or grow beaks that absorb an impact like the front of a car. But findings about the woodpecker's skull bones might be more useful. Compared to the hoopoe, the brain of the woodpecker is packed tightly in dense bone. The hoopoe's skull contains more spongy bone, an airy-looking material made of branches surrounding pockets of space. The woodpecker's spongy bone has less space inside it and looks compressed, like sheets of bone stacked on one another. The woodpecker skull is preferentially padded with this spongy bone at the forehead and the back of the skull.

If we can incorporate some of the woodpecker's evolved technology into future helmets, we may be able to better protect ourselves from the recreational activities that threaten our brains, from field sports to bicycle riding. We may be the more cerebral species, but the better-protected birdbrain could help keep us alive.

*Linguistic point of interest: "hoopoe" is from the Latin upapa, an imitation of the bird's call.


Images: Wang et al.


Wang, L., Cheung, J., Pu, F., Li, D., Zhang, M., & Fan, Y. (2011). Why Do Woodpeckers Resist Head Impact Injury: A Biomechanical Investigation PLoS ONE, 6 (10) DOI: 10.1371/journal.pone.0026490

Exercise and Your Immune System Revisited

It's not every day I get an email from someone in Taiwan about exercise, white blood cells, and menstruation. But in response to my post How Much Exercise Harms Your Immune System?, Guan-Da Syu from National Cheng Kung University Medical College dropped me a friendly note (if you can call an email with its own bibliography a "note") a few days ago. Syu is the lead author of the paper I'd discussed in that post, and he wanted to respond to some questions I raised.

The paper reported that after out-of-shape individuals engaged in sudden and intense exercise, their white blood cells died at an accelerated rate. An increase in reactive, oxygen-containing molecules seemed to be the culprit. But when those same people got consistent and moderate exercise--five days a week for 30 minutes--their white blood cells lived for longer. Furthermore, consistent exercise buffered the harmful effects of more strenuous exercise sessions on white blood cells.

I had asked whether we could be sure that shortening or increasing the life span of white blood cells (specifically, neutrophils) had a net negative or positive effect on individuals' immune systems. Might the body compensate somehow? Syu says that it's hard to quantify a person's immunity, but his findings fit with other research that linked extreme exercise with higher infection risk. Additionally, he says that after severe exercise, it takes about a half a day for the proportion of healthy white blood cells in the body to return to normal.

The consistent exercisers, Syu says, adapt to the oxidizing molecules, and begin to produce neutrophils that live for longer. I had asked whether prolonging the lifespan of short-lived cells might be a burden on the body somehow, but Syu points out that the number of neutrophils living in the body at one time remains the same throughout subjects' exercising or sedentary weeks. We don't have more white blood cells when we're in shape; we are able to produce fewer because they live for longer.

Finally, I'd pointed out that since the study only used male subjects, it's hard to generalize the results for woman, whose bodies don't necessarily react to exercise in the same way. Syu acknowledges that it's unknown how exercise affects women's white blood cells. But it's possible that the effect might depend on the time of the month. In a previous study, the same research group looked at women's platelets (the blood cells responsible for clotting). In the first half of the menstrual cycle, extreme exercise had a notable effect on platelet function. But in the second half of the cycle (from ovulation to menstruation), women's platelets didn't respond to severe exercise in any way.

So the effect of exercise on your immune system might depend on many factors: how hard you work out; how consistently you work out; whether you're a woman and what time of the month it is. It seems that consistent exercise protects your immune system, but going from zero to 60 when you start a workout routine is harmful. And women, for now, will remain a mystery.



Syu, G., Chen, H., & Jen, C. (2011). Severe Exercise and Exercise Training Exert Opposite Effects on Human Neutrophil Apoptosis via Altering the Redox Status PLoS ONE, 6 (9) DOI: 10.1371/journal.pone.0024385

How Much Exercise Harms Your Immune System?

I'm looking at you, marathoners and triathletes. While you're out there building superhuman endurance and making the rest of us feel bad, are you also beefing up your immune systems? Or does becoming an Ironwoman actually weaken your body's defenses?

It may depend on how you're exercising. Researchers in Taiwan compared two types of exercise, the names of which might reveal the researchers' own feelings toward hitting the gym: "Acute Severe Exercise" (ASE) and "Chronic Moderate Exercise" (CME). In medicine, "acute" is something that comes on quickly and is over soon, as opposed to a chronic illness. The flu, say, as opposed to mono.

The subjects were 13 males between the ages of 20 and 24. Though young and otherwise healthy, they weren't in shape; the subjects had been getting less than one hour a week of exercise for at least the past six months. At the beginning of the study, all 13 subjects underwent "acute" exercise, cycling at increasing levels of difficulty until they reached exhaustion.

Afterward, five subjects became controls. They were told to continue not exercising for the next four months. Twice during that period, they showed up for another bout of ASE, so researchers could make sure that their bodies and their exercise abilities were staying the same. Meanwhile, the other eight subjects began two months of "chronic" exercise. They worked out five days a week for 30 minutes. The moderate intensity of their workout was defined as a percentage of the work they'd been able to do during ASE. After two months, the exercisers were also instructed to stop exercising. They spent two more months getting no exercise at all. In each month of the study, they also did an ASE test so researchers could see how their bodies' response to severe exercise was changing.

Outwardly, the effect of consistent (excuse me, chronic) exercise on the bodies of formerly sedentary people was unsurprising. After two months of training, the CME subjects had lost weight, lowered their resting heart rates, and increased their endurance. Then they stopped exercising. After the two-month "detraining" period, subjects' weights and heart rates had returned to their original levels, though the work they could do in the ASE task was still elevated, showing a lasting effect on their fitness. The control subjects did their job well, staying the same during the four months.

But what the researchers were interested in was the inner changes in their subjects; namely, changes to white blood cells called neutrophils. These are key players in the immune system, responding to the site of infection in the body and attacking any invaders they find. Neutrophils are short-lived cells, committing cell suicide (called apoptosis) after only a few days in the bloodstream. If these white blood cells are too enthusiastic about offing themselves, it can weaken the immune system.

Neutrophil death may be linked to the abundance of oxygen-containing molecules that react with everything around them, harming structures inside the cell. Since extreme exercise can increase the amount of these harmful "reactive oxygen species" in the body's tissues, the researchers wanted to know how exercise affected neutrophils. They drew blood from their subjects periodically, both at rest and after their ASE trials, and removed the neutrophils for analysis.

They found that "acute severe exercise" did, in fact, accelerate neutrophil suicide. It also increased the amount of reactive, oxygen-containing molecules in the cells.

"Chronic moderate exercise," on the other hand, appeared to slow down the death of neutrophils. After two months of regular exercise, subjects' white blood cells were showing less oxidative stress and slower apoptosis. Even after subjects spent the following two months not exercising, the effect lingered.

In a final twist, the positive effects of consistent exercise seemed to counteract the harmful effects of extreme exercise. After the acute exercise task, subjects who'd been exercising regularly did not show the same damage to their neutrophils that they had at first. But after two sedentary months, the protective effect had begun to fade.

What does all this mean for the marathoner or the Ironwoman? Unfortunately, since the subjects were all men, the study says very little about women of any kind. But for the young, previously sedentary males involved, the study suggests that sudden, exhausting exercise accelerates the death of certain immune cells. Consistent and moderate exercise, on the other hand, prolongs these cells' lives. It also buffers the damaging effect of occasional extreme exercise. And when you stop exercising, the positive effects of your old routine linger, at least for a little while.

The researchers point to other studies that have shown a connection between sudden, extreme exercise and upper respiratory tract infections. In this study, we can't see the effect that various rates of neutrophil death had on subjects' immune systems as a whole. When neutrophil death was accelerated after acute exercise, were subjects truly more vulnerable to infection, or did the immune system compensate somehow for neutrophil loss? In subjects who got regular exercise and prolonged the lives of their neutrophils, was the immune system strengthened? Does keeping these short-lived cells alive for longer necessarily help prevent infection, or could it create a burden for the body?

Overall, the authors think the evidence is in favor of consistent and moderate exercise. For patients whose immune systems are impaired by HIV or chemotherapy, regular exercise might provide a boost. This study suggested that consistent exercise counteracts the negative effects of extreme exercise--at least some of the effects. But to stay on the safe side, the authors recommend that you avoid "acute severe exercise" like, well, the plague.


Syu, G., Chen, H., & Jen, C. (2011). Severe Exercise and Exercise Training Exert Opposite Effects on Human Neutrophil Apoptosis via Altering the Redox Status PLoS ONE, 6 (9) DOI: 10.1371/journal.pone.0024385

Goldilocks Would Never Use Banned Substances (a quiz)

It's time to find out how well you've been following the news! This week was a big one for both space and Spain.

1. Astronomers are pretty excited about a newly discovered planet called Gliese 851. The planet orbits its star in a so-called "Goldilocks zone," which means it is:

a. in close orbit to a small planet, a medium planet, and a large planet

b. just the right size for humans to be able to walk around comfortably--unlike a huge planet whose gravity would pin us down, or a tiny planet where we'd bounce around uselessly

c. just the right temperature for liquid water to exist

d. blond, with a propensity to sit in the wrong chair

2. Speaking of outer space, congress just passed a new NASA bill. Under President Obama's plan, the space organization will do all of the following EXCEPT:

a. return to the moon by 2020

b. fly to an asteroid and/or Mars

c. fund private spaceflight

d. retire the NASA shuttles for good

3. If you live in a mid-Atlantic state, you might be currently overrun by stink bugs. What makes these triangular brown fellows such formidable opponents?

a. They have a sulfurous odor that becomes overwhelming when they're in large groups.

b. They were introduced from Asia and have no natural predators here.

c. They have a fondness for biting people's ankles and fingers.

d. They are impervious to pesticides.

4. Spanish cyclist Alberto Contador, who's won the Tour de France three times, was suspended this week over a positive test for the banned substance clenbuterol. He insists the drug came from a contaminated steak. (Though if it's true that plastic residues were also found in his blood--suggesting a blood transfusion from a plastic bag--the steak excuse is not going to get him very far.) In addition to cheating cyclists, other users of clenbuterol include all of the following EXCEPT:

a. horses

b. asthmatics

c. farmed fish

d. Hollywood types trying to lose weight

e. cheating baseball players

5. A Spanish team took home the prize at the 2K BotPrize 2010 robotics competition this week (presumably without the help of banned substances). Contest judges played against both humans and robots in a video game, and tried to guess which avatars were which. The Spanish team had the most convincing robot, with a "humanness rating" (how often it was guessed to be human) of 31.8%. For comparison, the actual humans had humanness ratings ranging from:

a. 85-95%

b. 60-90%

c. 50-85%

d. 35-80%

Answers are in the comments.

The End of Football?

I hate to be a party pooper about the start of the football season--and it's not only bitterness about my second-drafted fantasy player dropping the ball four times in this week's game. It's just that it's hard to watch all these guys steamrolling each other, in light of Monday's news.

Owen Thomas was a junior on the football team at U. Penn. Last spring, after a sudden emotional breakdown, he killed himself. His parents let researchers at Boston University autopsy Owen's brain, and what they found was shocking: Owen was the youngest person ever with chronic traumatic encephalopathy (CTE), a deterioration of the brain that comes from repeated pummels to the head.

CTE was first described in boxers, back in the 1920s. It can only be diagnosed with an autopsy. The disease involves protein buildup in the brain, and can lead over time to memory loss, impulsivity, aggression, depression, and dementia.

More recently, researchers started to find CTE in the brains of retired NFL players who had died of dementia or drug overdoses. Before Owen Thomas, the youngest person ever diagnosed was Chris Henry, the 26-year-old Bengals player who died last year after he jumped or fell from a moving truck during a domestic dispute.

After denying the science for as long as possible (that is, until they were compared to the tobacco industry in a congressional hearing), the NFL finally changed its tune last year. They started funding CTE research and tightened rules about allowing players to return after concussions.

Not that people are necessarily following those rules: In their opening game this Sunday, two players were allowed to stay on the field after suffering concussions. The resulting criticism, at least, shows that the sports world is becoming more aware of the issue.

Neuropsychologist and invented-word enthusiast Adam Shunk thinks football is getting more dangerous: "I think the game is unsafer," he says. "Just look at the physicalness of football now." Neologisms aside, is there a way to reconcile obvious safety concerns with our national desire to see guys knock each other down? If research continues to show that years of tackles can lead to brain deterioration even in young people, what happens next? Will the NFL change the rules? Build fancier helmets? Disallow tackles for kids and teens, whose brains are still forming?

In the longer term, maybe a genetic test can be developed to predict who's most at risk for CTE. After all, repeat concussions clearly don't have the same effect on every player. Or maybe football as it's currently played will go the way of Joe Camel.

If anybody who knows more about football than I do (which is to say, anybody) has thoughts about how the game will change--or whether it will change at all--feel free to share!