Relief for Children’s Migraine Headaches

The findings suggest to Dr. Hershey, “It’s not so much what we do but how we do it. We offer options: ‘Do headaches bother you enough to take a preventive medication every day?’ We give patients the choice, and the expectation of a response drives a clinically positive result.

“We can use that expectation clinically, telling patients they don’t have to be on medication very long. When the frequency of headaches declines to two or three times a month and the headaches go away in an hour, they can stop preventive medication and use an acute therapy to treat the headache when it occurs.”

Based on the results of the CHAMP trial, Dr. Christina L. Szperka, pediatric neurologist and director of the pediatric headache program at Children’s Hospital of Philadelphia, suggests that clinicians first try a nutraceutical like magnesium or riboflavin (vitamin B2) to reduce headache frequency, along with lifestyle measures like staying well hydrated, eating regular meals, not skipping breakfast, getting enough sleep and getting some exercise.

She told NeurologyLive: “If the act of taking something like a pill every day and believing it is likely to help you and is part of what triggers the body’s response to heal itself, then we feel like it makes sense to think about using something that’s pretty harmless to start the process. If they don’t respond to those nutraceuticals, then that’s when we bring in the other prescription medications.”

Dr. Amy Gelfand, director of the child and adolescent headache program at the University of California, San Francisco, has found that taking melatonin along with riboflavin can also help to reduce the frequency of migraine attacks. Melatonin is the body’s natural sleep-inducing hormone and is available in pharmacies without a prescription.

“Too often kids and families are told nothing can be done about migraine,” Dr. Gelfand said. “That’s the wrong message. The kids who are being treated are doing really well.”

One often overlooked contributor to attacks of migraine is stress. Dr. Szperka told me, “Stress is a huge factor in migraine. Kids have told us, ‘If I’m worried about something, that’s when I have my headache.’ Kids today are under so much pressure to do well in school and in sports if they want to get into a good college. They push themselves and suffer. Sometimes the best suggestion to them is to ease up academically.”


How to Avoid Being Fleeced When Using a Credit Card Overseas

“It is a complete scam,” said Alexander Bachuwa, a frequent traveler and consumer lawyer who practices in New York, lives in Puerto Rico and writes the Points of Life travel blog. He advises using a currency app on your phone to estimate charges instead.

Just say no to conversions. Always pay in the local currency for the lowest cost to you.

Check your receipt for unauthorized conversions

Often, you don’t get a chance to say no, despite Visa and Mastercard rules that say consumers must be offered a choice if a merchant does currency conversion.

The giveaway that you’ve been hit is when the charge slip lists an amount in your home currency with microscopic print that claims you gave consent.

In India, this maneuver is common at higher-end hotels, where a bill can easily run $1,000 and an extra 5 percent fee is $50.

When the J.W. Marriott in Kolkata initially charged a May stay in dollars despite my request to pay in rupees, a manager explained that the hotel’s systems were set up to automatically add the markup and do the conversion. To run the charge in rupees without the markup, she had to reprocess the payment on a special machine. (Marriott declined to comment, as did Hyatt, another chain where I have seen such automatic conversion frequently occur.)

Banks, which share the extra fees with merchants, appear to be complicit in this fee extraction. When a currency markup suddenly appeared last month on a charge slip from my Mumbai car service, the finance manager said that his Indian bank, Axis, had upgraded his swipe machines, added the fees without his knowledge and was keeping the money.

Axis, which was also the bank for the City Palace in Udaipur, said it offers merchants two types of swipe machines, including one that automatically adds a fee and converts the charge to the customer’s home currency. With that machine, if the customer insists on paying in rupees, the clerk has to go through a convoluted process to redo the transaction.


That Perplexing Red Meat Controversy: 5 Things to Know

Dietary guidelines from groups as diverse as the Department of Agriculture to the World Health Organization urge all of us to eat less red meat — much less.

But the authors of four new studies, published on Wednesday in the Annals of Internal Medicine, report there is no compelling evidence that reducing consumption of red or processed meats will be beneficial to an individual.

A furious backlash is already unfolding. Here are five takeaways from the debate.

Nutrition studies often do not meet the most rigorous scientific standards.

The majority of nutrition studies are observational — in the case of red meat, they asked if meat-eaters were less healthy, and if those who ate more were also less healthy than those who ate less.

But it’s extremely difficult to know what someone is eating; many study participants struggle to remember and accurately report their diets. And meat-eaters may differ from those who don’t eat meat, or eat less, in a variety of ways that also influence health.

Researchers try to correct for those variations, but the statistical analyses are difficult and, many experts say, not particularly reliable in a system as complex as human nutrition.

Even in the best of circumstances, observational studies do not prove cause and effect; they only suggest correlations. But policymakers often rely on this data when devising guidelines.

The studies sometimes do turn up small health benefits from eating less meat.

Here are some of the outcomes cited by the authors of the new research: If people were to reduce meat consumption by three servings a week, there might be one to six fewer heart attacks per 1,000 people. But there would be no effect on deaths resulting from heart disease or any cause over all.

For cancer, the group reports that decreasing meat consumption by three servings a week might result in seven fewer cancer deaths per 1,000 people. But there would be no effect on the risk of getting breast, colorectal, esophageal, gastric, pancreatic or prostate cancer.

But what does that mean for you personally?

Frank Hu, professor and chair of the nutrition department at the Harvard T.H. Chan School of Public Health, wrote in an email:

“These risk reductions are not small from a public health point of view and could save hundreds and thousands of lives in the U.S., because of the high prevalence of people consuming diets high in red and processed meats. Few dietary or lifestyle changes or even a drug could have multiple health benefits on major causes of deaths.”

But Dr. Dennis Bier of Baylor said the studies of meat consumption are so flawed that it is naïve to assume these risk reductions are caused by eating less meat.

“The rules of scientific proof are the same for physics as for nutrition,” he said in a telephone interview. But unlike experiments in physics, where investigators can control variables and determine causality, in nutrition “you can’t conduct the experiment.”

Major medical organizations are sticking to their dietary recommendations.

The American Cancer Society and the American Heart Association, among others, immediately released statements reiterating their advice to eat less red meat for better health.

We’re all going to have to live with some uncertainty about what to eat.

“The guidelines are based on papers that presumably say there is evidence for what they say. And there isn’t. That’s the history of nutrition,” said Dr. Bier.

Dr. David Allison, dean of the Indiana University School of Public Health — Bloomington, said there is a difference “between evidence for drawing a scientific conclusion, and making or recommending an action.”

“The standards of evidence for the former are scientific matters and should not depend on extra scientific considerations” he added. “The standards of evidence for the latter are matters of personal judgment or in some cases legislation.”

His advice: “People should be aware of the uncertainty and make their decisions based on that awareness.”


Brain Stimulation Shows Promise in Treating Severe Depression

For more than a decade, doctors have been using brain-stimulating implants to treat severe depression in people who do not benefit from medication, talk therapy or electroshock sessions. The treatment is controversial — any psychosurgery is, given its checkered history — and the results have been mixed. Two major trials testing stimulating implant for depression were halted because of disappointing results, and the approach is not approved by federal health regulators.

Now, a team of psychiatric researchers has published the first long-term results, reporting Friday on patients who had stimulating electrodes implanted as long ago as eight years. The individuals have generally fared well, maintaining their initial improvements. The study, appearing in the American Journal of Psychiatry, was small, with just 28 subjects. Even still, experts said the findings were likely to extend interest in a field that has struggled.

“The most impressive thing here is the sustained response,” Dr. Darin Dougherty, director of neurotherapeutics at Massachusetts General Hospital, said. “You do not see that for anything in this severe depression. The fact that they had this many people doing well for that long, that’s a big deal.”

The implant treatment is known as deep brain stimulation, or D.B.S., and doctors have performed it for decades to help people control the tremors of Parkinson’s disease. In treating depression, surgeons thread an electrode into an area of the brain that sits beneath the crown of the head and is known to be especially active in people with severe depression. Running electrical current into that region, known as Brodmann Area 25, effectively shuts down its activity, resulting in relief of depression symptoms in many patients. The electrode is connected to a battery that is embedded in the chest. The procedure involves a single surgery; the implant provides continuous current from then on.

In the early and mid-2000s, Dr. Helen Mayberg, a neurologist then at the University of Toronto, discovered the importance of Area 25 and was involved in the first experimental trials of D.B.S. treatments to target it, though her work isolating Area 25 extends well back into the 1990s.

In the new analysis, Dr. Mayberg, now at the Icahn School of Medicine at Mount Sinai, and Dr. Andrea Crowell of Emory University led a consortium of researchers from several institutions who evaluated the mental health and history of 28 people who had received D.B.S. for depression at Emory. About a third experienced full remission of symptoms in the months after surgery, and half reported measurable, noticeable reduction in their distress. They were doing just as well years later, the report found.

“The bottom line is that if you get better, you stay better,” Dr. Mayberg, a professor of neurology, neurosurgery, psychiatry, and neuroscience, said. “You don’t lose the effects over time. You wear the device like a pacemaker, and you stay well.”

Of the 28 subjects, 14 completed at least eight years of follow-up appointments, and 11 completed at least four years. Three patients had the implant removed, although they had been doing well with it, the report found. Most of the patients were on antidepressant drugs when they had the surgery, and they continued on the medications.

The researchers found no adverse effects related to the performance of the device. Seven subjects had received a diagnosis of bipolar depression, a severe distress that alternates with periods of high-energy mania. There was concern that deep-brain stimulation might prompt manic episodes in those individuals. That did not happen, the authors reported.

The most common complications came from underlying mental disorders and the surgical procedure itself. Over the years of follow-up, there were five suicide attempts in three subjects — a lower-than-average rate for people with this kind of severe depression, although the numbers were too small to be conclusive. In addition, there were 19 adverse events during the surgical procedures, including failure of the device and infection. That rate is roughly typical of D.B.S. surgery for movement disorders like Parkinson’s.

Several of the participants had surgery more than once, as the implant’s battery power faded over time, reducing the effect on mood. The technology has since improved and the devices are now rechargeable wirelessly, Dr. Mayberg said; the surgical techniques also have been refined in recent years. Dr. Mayberg retains a share of the intellectual property patent on the treatment approach.

The new report notwithstanding, gaining federal approval of deep-brain stimulation for depression will require time, money and commitment, as well as more evidence. In the mid-2010s, two device makers, Medtronic and St. Jude Medical, ran FDA-approved trials of D.B.S. for depression. Both trials were halted early, within the first six months, because the results were underwhelming.

In a recent review of the evidence to date, which included case reports, small samples and the larger trials, a team led by Dr. Steve Kisely of the University of Queensland in Australia, concluded that “D.B.S. may show promise for treatment-resistant depression but remains an experimental treatment until further data are available.”

Dr. Dougherty said, “The most important thing this report can do is encourage device manufacturers to re-trial these interventions. We can think whatever we want; there’s no way we get FDA approval without good trials.”


Intensive Care: What Makes a ‘Good’ Parent?

The experts who study parenting are interested in how we spend those moments. “If you really look in time diary data, on average parents are not spending hours a day doing these kinds of developmentally stimulating things with their kids,” said Ariel Kalil, a professor at the Harris School of Public Policy Studies at the University of Chicago, and the first author on an influential study of parent time use which showed that differences across the socioeconomic spectrum have increased over time.

Rebecca Ryan, a professor of psychology at Georgetown, who was a co-author on that study, said that with children 3 to 5 years old, college-educated mothers spent on average 14 minutes a day in teaching activities, whereas mothers with a high school degree or less spend about five minutes a day. So the individual amounts are relatively small, but when you multiply those differences out across the endless (or all-too-short) days of child rearing, they can be profound.

“Whatever the myth of hyperparenting is, there is basically no parent who spends two hours a day reading or doing puzzles,” Dr. Kalil said. “The average amount of time parents spend a day is between 20 and 30 minutes.”

And the biggest difference is between parents who don’t do any of those developmentally stimulating activities and parents who do something, she said, which is why the focus of parenting programs and interventions should be to get parents to put in some minutes — not hours — on a regular basis. “What I believe is that what really matters is regular steady habits of modest investment,” she said.

And yes, the parents in the zero-minutes-a-day group are disproportionately low-income and less well educated, though there are certainly plenty of low-income families where lots of reading and talking and involvement goes on. For those at zero, “to shift the needle on moving them closer to what middle class or rich parents do does not mean asking them to read an hour a night,” Dr. Kalil said. “It means reducing the number of days when nothing happens.”

Dr. Kalil directs the center for human potential and public policy, where she studies low-income families. “We’ve interviewed thousands of low-income parents in Chicago,” she said. “They know reading is important, they have books in their house, but for a variety of reasons, because life in low-income circumstances is more stressful and more unpredictable, low-income families have a harder time following through on these aspirations.”

By working with text message reminders, she said, parents can set goals for what they want to do with their children. In another study, these behavioral tools more than doubled the amount of time parents spent engaging with their children.


What to Know When Choosing Cremation

Here are some questions and answers about cremation:

What does the price of a cremation include?

A basic cremation — called “direct” cremation by funeral homes — generally includes pickup and transportation of the body, filing necessary paperwork, the actual cremation and the return of the ashes to the family, said Joshua Slocum, executive director with the Funeral Consumers Alliance, a nonprofit advocacy group.

Some funeral homes have their own cremation equipment, but others use outside contractors. If an outside provider is used, Mr. Slocum said, consumers should be careful to review the fees to be sure they are not charged twice for similar services.

Rates vary by location, he said, but a reasonable rate for a direct cremation is $800 to $1,200.

Don’t be pressured to buy a coffin. There’s no need for one if someone is being cremated, AARP advises.

The Federal Trade Commission says that no state or local law requires the use of a coffin for cremation and that the funeral home must inform you that alternative containers — such as those made of unfinished wood or even cardboard — are available.

Must I hold a memorial service before or after a cremation?

No. Add-ons like visiting hours or a memorial service are entirely up to you. “You can do everything, or nothing, before the cremation,” Mr. Slocum said. Families sometimes organize their own informal memorial gatherings after the cremation without involving a funeral home.

Are cremation prices available online?

The federal Funeral Rule requires funeral homes to provide prices for all services, including cremation, upon request by telephone or in person. But the rule, which took effect in 1984, doesn’t address online pricing. Consumer advocates are pushing for the rule to be updated to require funeral homes to post their price lists online.

The F.T.C., which enforces the rule, was scheduled to review it this year, but whether that will happen is unclear. Earlier this year, the commission said that the 10-year review period it uses was not mandatory, and the commission could change timelines if it chooses.

A commission spokesman didn’t respond to a request for an update on the review’s status.

One state, California, requires funeral homes with websites to include pricing information online, or to list services and note that prices are available upon request.


In the Pancreas, Common Fungi May Drive Cancer

By now, you’ve probably heard that your body is teeming with bacteria. Some 100 trillion of them live on your skin, in your mouth and in the coils of your intestines. Some protect against infections and help you digest food, while others can make you seriously ill.

Fungi, viruses and protozoa call your body their home, too. Your fungal residents are less numerous than your bacteria by orders of magnitude, but as researchers are learning, these overlooked organisms play an important physiological role — and when their numbers get out of whack, they can modify your immune system and even influence the development of cancer.

A new study, published Wednesday in the journal Nature, found that fungi can make their way deep into the pancreas, which sits behind your stomach and secretes digestive enzymes into your small intestine. In mice and human patients with pancreatic cancer, the fungi proliferate 3,000-fold compared to healthy tissue — and one fungus in particular may make pancreatic tumors grow bigger.

Researchers were surprised by the presence of fungi in the typical pancreas and immense increase in their numbers in disease. “The pancreas was considered a sterile organ until a couple years ago,” said Dr. George Miller, a surgical oncologist at the New York University School of Medicine who led the study.

But recent research from Dr. Miller’s lab and others had indicated that some microorganisms, such as bacteria, could sneak past a muscle called the sphincter of Oddi, which separates the pancreas from the rest of the gut. Perhaps fungi could also colonize the pancreas the same way.

To find out, Dr. Miller and his team fed mice a species of brewer’s yeast labeled with a green fluorescent protein. The fluorescent marker revealed that the yeast had indeed moved from the digestive tract to the pancreas in a matter of minutes.

In mice, the types of fungi that ended up in the pancreas were usually very different from those that remained in the gut. Ascomycota and Basidiomycota were the only varieties of fungi that colonized pancreatic tissue.

One particular fungus was the most abundant in the pancreas: a genus of Basidiomycota called Malassezia, which is typically found on the skin and scalp of animals and humans, and can cause skin irritation and dandruff. A few studies have also linked the yeast to inflammatory bowel diseases, but the new finding is the first to link it to cancer.

The results show that Malassezia was not only abundant in mice that got pancreatic tumors, it was also present in extremely high numbers in samples from pancreatic cancer patients, said Dr. Berk Aykut, a postdoctoral researcher in Dr. Miller’s lab.

Administering an antifungal drug got rid of the fungi in mice and kept tumors from developing. And when the treated mice again received the yeast, their tumors started growing once more — an indication, Dr. Aykut said, that the fungal cells were driving the tumors’ growth. Infecting a control group of mice with different fungi did not accelerate their cancer.

There is increasing scientific consensus that the factors in a tumor’s “microenvironment” are just as important as the genetic factors driving its growth.

“We have to move from thinking about tumor cells alone to thinking of the whole neighborhood that the tumor lives in,” said Dr. Brian Wolpin, a gastrointestinal cancer researcher at the Dana-Farber Cancer Institute in Boston.

The surrounding healthy tissue, immune cells, collagen and other fibers holding the tumor, as well as the blood vessels feeding it all help support or prevent the growth of the cancer.

Microbes are one more factor to consider in the alphabet soup of factors affecting cancer proliferation. The fungal population in the pancreas may be a good biomarker for who’s at risk for developing cancer, as well as a potential target for future treatments.

“This is an enormous opportunity for intervention and prevention, which is something we don’t really have for pancreatic cancer,” said Dr. Christine Iacobuzio-Donahue, a pancreatic cancer researcher at Memorial Sloan Kettering in New York.

Nearly 57,000 people will be diagnosed with pancreatic cancer in the United States this year, but their prognosis will be poor. Three-fourths die within a year of diagnosis, and only about 1 in 10 live longer than five years.

“That’s because we don’t have any screening or methods of early detection for pancreatic cancer,” said Lynne Elmore, director of the translational cancer research program at the American Cancer Society.

By the time the cancer is diagnosed, surgery alone isn’t enough. Standard chemotherapies are very limited, and there aren’t any great targeted therapies, Dr. Elmore said.

The new study also sheds light on how fungi in the pancreas may drive the growth of tumors. The fungi activate an immune system protein called mannose-binding lectin, which then triggers a cascade of signals known to cause inflammation. When the researchers compromised the ability of the lectin protein to do its job, the cancer stopped progressing and the mice survived for longer.

But the interaction between microbes and their hosts is extremely complex, Dr. Miller said, and further experiments will be needed before the new findings can be applied in treating cancer patients. Microbial populations can change in response to a person’s age, diet, use of antibiotics or antifungal drugs and other factors.

“This is intriguing and exciting research,” said Dr. Ami Bhatt, who studies microbes at Stanford University. “But it’s probably too soon to add broad spectrum antifungals, many of which have lots of side effects, to cancer treatment regimens, even in experimental settings.”


What Whales and Dolphins Left Behind for Life in the Ocean

When the land-dwelling ancestors of today’s whales and dolphins slipped into the seas long ago, they gained many things, including flippers, the ability to hold their breath for long periods of time and thick, tough skin. Along the way they also discarded many traits that were no longer relevant or useful.

In fact, as scientists reported in a study published Wednesday in Science Advances, the loss of some genes in the common ancestor of whales and dolphins allowed them to shed features that would have been liabilities beneath the waves, which may have contributed to the survival of future generations.

As more species’ genomes are sequenced, researchers can begin to pick out which genes are shared among groups of organisms. Presumably, these genes were also found in the group’s last common ancestor.

A team led by Michael Hiller, a geneticist at the Max Planck Institute of Molecular Cell Biology and Genetics and an author of the new paper, used this technique with modern cetaceans, the group that includes whales, dolphins and porpoises. Then they compared that set of genes to those of the cetaceans’ nearest relatives, the hippo family, and pinpointed 85 genes that were switched off or inactivated in the cetaceans’ ancestor during its move to the aquatic life.

These genes were involved in a wide variety of processes, such as blood clotting, sleep and hair growth. Although some of the genes had been flagged before, others had not been identified. (Dr. Hiller and colleagues had previously found that genes necessary for the development of hair had been lost in cetaceans, which perhaps reduced drag as the animals swam through the water.)

“Many of the things we found were at least for me quite unexpected,” said Dr. Hiller.

For instance, one of the lost genes produces an enzyme involved in DNA repair. Because whales and dolphins go without fresh oxygen for long periods of time, their DNA is often damaged and must be mended. But this particular repair enzyme does messy work, introducing errors even as it fixes. Other, less mistake-prone enzymes are still found in cetaceans; this led the researchers to conclude that the gene for the messy enzyme may have been discarded because, in a living situation with frequent DNA repair, it did more harm than good.

Other lost genes were involved in blood coagulation. You might think that jettisoning such genes might seem a risky evolutionary gambit, but when cetaceans dive, their blood vessels narrow and nitrogen bubbles in their blood make clots more likely to form. Getting rid of clotting genes may have been a healthy move in the long run.

Four genes related to melatonin, a sleep hormone, were also lost. In most creatures, melatonin production rises as the body prepares for sleep. But cetaceans do not sleep the way most mammals do. Instead, half the brain slumbers while the other half monitors the nearby environment. Living underwater, “you cannot really have extended periods of sleep where the body is largely inactive,” said Dr. Hiller. Under those circumstances, he added, melatonin may have been counterproductive.

In general, Dr. Hiller said, the rule of thumb in evolution is that genes that are not actively being used tend to disappear or be inactivated. But the new study suggests that the same process can purge the genome of genes that would make a new way of living too dangerous, extra baggage that emerging species — which became today’s whales, porpoises, dolphins — were better off without.


What Omnivores Get Wrong About Vegetarian Cooking

I needed to push more flavor into everything.

For meat eaters, the natural umami in meat and fish is satiating; even if the roasted potatoes alongside are plain and the salad dressing is basic, the savoriness brings satisfaction. Without that to lean on, everything on the plate wants to be thoroughly and thoughtfully seasoned, including basics like grains and beans.

“Just using enough salt will get you halfway there,” said Raquel Pelzel, the author of “Umami Bomb” (Workman, 2019), a new book of vegetarian recipes built around umami-rich ingredients: cooked tomatoes, mushrooms and Parmesan cheese. Then, she said, build elements like sweetness, heat, acid and smoke. (Smoked paprika is vegan sorcery, used in everything that I once flavored with bacon. I picked up a new trick for the spice from “Sababa,” a new cookbook of Israel-inspired food: the author, Adeena Sussman, recommends stirring it in the end of cooking, to preserve its bright taste.)

Marinate everything that can be marinated, garnish everything that can be garnished (preferably with crunchy things like nuts and croutons) and season your cooking liquids (when you’re pressed for time, throw in a vegetable bouillon cube).

I was avoiding meat and dairy substitutes for no good reason.

Growing up among hippies made me perpetually suspicious of anything offered as a healthier substitute for something good. The fact is that there are many products on the market that are delicious on their own terms, and more and more foods that are doing a good job of pretending to be meat and dairy. Go out and try them. Thanks to the recipes in “I Can Cook Vegan,” a new book from the chef Isa Chandra Moskowitz, coconut oil is my new best friend.

I was being snobbish about frozen vegetables.

Pulling off a weeknight vegetarian dinner with variety, like a sheet-pan dinner, a vegetable stew or a stir-fry, means having some parcooked vegetables on hand. New vegetarians are often advised to do a big vegetable shop once a week and prep everything at once. I did it, but was discouraged by the fact that at the end of all that labor, I still had to cook everything as the week went on.

Bhavna Patel, a home cook in Lake City, Fla., with a popular YouTube channel, grew up in Gujarat, India, where a majority of people are vegetarian or vegan. She has streamlined her family’s recipes, she said, and often relies on homemade frozen vegetables. If you are peeling and cutting them anyway, it’s just as easy to boil them in salted water and freeze them in resealable bags. Or, find a brand you like and buy them. The route to dinner is much faster. Pav bhaji, her go-to meal for her sons, is a vegetable curry served on toasted buttered buns.


What Rolls Like an Armadillo but Lives in the Sea?

Why did the chiton roll into a ball?

“To get to the other side,” said Julia Sigwart, an evolutionary biologist at Queens University Belfast in Northern Ireland.

About 500 million years ago, a couple species of now extinct trilobites became the first animals to roll themselves into a ball for protection. The trilobite’s living doppelgänger is the chiton. This marine mollusk’s plated shell drapes over a soft body and mucousy foot, giving it the appearance of a flattened piece of shrimp nigiri. But you’re more likely to find it clinging to a tidepool rock than awaiting chopsticks on a dinner plate.

Like trilobites, three-banded armadillos, pill bugs, hedgehogs and other animals, the chiton can roll itself into a ball. Many scientists had assumed this acrobatic maneuver, known as conglobation, defends the animals, most of which are smaller than an inch or two, against predators. But Dr. Sigwart, who studies chitons, never really bought that explanation: If a predator can swallow you whole, she reasoned, rolling into a tic-tac probably would not save you.

In a series of lab experiments, Dr. Sigwart showed that rolling into balls has more to do with helping chitons get to places where they can reattach after losing their footing. She hopes that these findings, published Wednesday in Biology Letters, add evidence to a novel argument: that chitons are capable of making decisions.

“People who think about chitons usually think about them as primitive animals with a simple nervous system and not much behavior,” Dr. Sigwart said. “So it’s an unexpected level of complexity compared to the textbook assumptions about these animals.”

Chitons do sometimes roll defensively, for instance, if they perceive a need to protect their soft bodies when poked. But usually they do not do much more than stick to habitable surfaces. And occasionally they move.

When they detach, they may curl into balls, which can help them fall and roll more safely to a new location.

The critical problem for chitons is that they are top-heavy, but not flexible enough to twist and have no appendages. So when they accidentally land on their backs, they cannot flip back. All they can do is arch and thrust out their foot. With luck, they will touch something they can push off to right themselves — or a place to stick and stay safe.

Their foot glue is so strong that if you were to lift a chiton off a rock too strongly, its body and shell would rip off, leaving the foot behind. And that makes the foot an important element of their defense against hungry predators, Dr. Sigwart said.

In each experimental trial, the researchers placed a chiton upside down in the middle of a test tank. Then, they added water from a tank with more chitons or a tank with an ocher sea star.

Chitons can detect this natural predator’s scent. The researchers found that the chitons exposed to it were three times less likely to spend time rolled up than those that were not. These threatened chitons opted to arch and reach. It’s an energy-intensive defense that can risk exposing its soft body, but it can also reward a chiton by helping it find a safe place to survive.

Dr. Sigwart thinks that at some level, chitons are capable of weighing risk and reward. Other work from her lab suggests greater complexity in the chiton’s nervous system and that chitons have a true brain.

More research will be needed to confirm that notion. But Dr. Sigwart is hoping for more appreciation of the chiton’s neural complexity.

“They have no head. They have this really weird body. They’re animals we find really difficult to relate to. But they’re still making decisions in the same way we do,” she said. “They’re not so unlike us after all.”