How Children Learn to Recognize Faces

Babies get better at distinguishing faces in their own racial groups, less good with other groups, Dr. Gaither said. “Most research argues that this other-race effect comes online between 3 and 6 months of life, but it’s linked to exposure,” she said. Her own research has shown that biracial infants, growing up with exposure to both Asian and white faces, are faster at scanning faces by 3 months than children growing up with only one such group.

Other research has suggested that by school age, children’s ability to recognize and remember faces of those in other racial groups is associated with their understanding of race. For children growing up with varied exposure to varied faces, she said, such as transracially adopted children in diverse neighborhoods, “they’re better at recognizing faces within racial out-groups.”

Dr. Gaither said this topic can take on political overtones around Halloween, with heightened sensitivities about cultural appropriation. It may raise special questions this year, she said, thanks to the popularity of “Black Panther” and the question of how children can dress as a hero from another group without offending the members of that group by anything that would suggest appropriation or something as overtly offensive as blackface.

So thinking about recognizing and altering faces tells us a lot about how we perceive others — and ourselves. On Halloween, Dr. Lee said, a child might fail to recognize a somewhat familiar adult who has on makeup or a false beard, “but adult neighbors will recognize me, they can see through makeup, see through my beard, they know the structure of my face, that’s Kang, that’s not someone else.”

Face perception definitely has a genetic component, Dr. Lee said, though exposure is also critical; children who don’t see well during their first two years of life — who have congenital cataracts, for example, which are later removed — may not be able to recover the ability later in life.

There is a wide range of normal abilities in recognizing faces, and training is of somewhat limited value, Dr. Lee said (there is also a disorder — prosopagnosia, or “face-blindness — in which people cannot recognize faces, sometimes even of those they know well).

So go ahead, take the Cambridge Face Memory Test, and find out how you do. I’m not going to tell you how I did, lest I undermine whatever tenuous authority I may have to write about this subject (I do think I might have done better if there had been some female and nonwhite faces on the test — but maybe I’m just kidding myself).

And if you have a small child or cross paths with some on Halloween, remember that in their eyes, the transformation of familiar people by masks and makeup may seem pretty tricky — even if there are treats involved.


Urban Planning Guru Says Driverless Cars Won’t Fix Congestion

MOUNTAIN VIEW, Calif. — Peter Calthorpe thinks Silicon Valley has it all wrong. He rejects the ideas of tech industry visionaries who say personal autonomous vehicles will soon be the solution to urban problems like traffic congestion.

Mr. Calthorpe is a Berkeley-based urban planner who is one of the creators of New Urbanism, which promotes mixed-use, walkable neighborhoods. His designs emphasize the proximity of housing, shopping and public space.

He is not opposed to autonomous vehicles. Mr. Calthorpe’s quarrel is with the idea that the widespread adoption of personally owned self-driving cars will solve transportation problems. In fact, he worries it will lead to more urban congestion and suburban sprawl.

“One thing is certain: Zero- or single-occupant vehicles,” even ones that can drive themselves, “are a bad thing,” he and the transportation planner Jerry Walters wrote in an article last year in Urban Land, an urban planning journal. “They cause congestion, eat up energy, exacerbate sprawl and emit more carbon per passenger-mile.”

Mr. Calthorpe believes that in trying to solve a very hard technical problem, Silicon Valley is ignoring an easier application for autonomous technology that has the potential to quickly change mass transit and help solve the Valley’s housing crisis. It starts with backing away from solo car trips.

A popular claim by the advocates of self-driving cars is that not only will they be safer than human-driven cars, but they will lead to fewer cars, faster commutes and a radical rethinking of cities where finding a place to park is no longer a priority.

But Mr. Calthorpe, citing a range of transportation studies, has simulated through computer models the impact of self-driving vehicles in urban settings. He argues that if they are used the way today’s vehicles are — carrying a single individual in most cases — they will lead to more congestion.

“The key distinction is the number of people per vehicle,” said Mr. Walters, a principal at Fehr & Peers, a transportation consultancy in Walnut Creek. “Without pretty radically increasing the number of people per vehicle, autonomous systems will increase total miles traveled.”

When it is easier to travel in a city in self-driving cars, Mr. Calthorpe said, everyone will want to do so. And when self-driving vehicles are more affordable — which could take years to happen — people who currently rely on public transit while running their errands will instead send their cars to pick up the groceries and the dry cleaning, adding significantly to what Mr. Walters and other urban planners call “total vehicle miles.”

This year, Mr. Calthorpe challenged Silicon Valley to take another look at its housing and transportation problem in a proposal in which he asked: “Can one street solve the San Francisco Bay Area housing crisis?”

In addition to his planning consultancy, Mr. Calthorpe has created Urban Footprint, a company that offers a software design tool for planners, architects and environmental analysts who want to model different kinds of development in urban and regional settings.

He used his software to show that by changing just commercial zoning to permit higher density along El Camino Real — the 45-mile boulevard that stretches through the heart of Silicon Valley from San Francisco to San Jose — it would be possible add more than a quarter-million housing units.

The Valley’s housing crisis can be explained in data that shows that since 2010, the region has added 11 jobs for every new home built; the median home price has reached $934,000; and rents have gone up 60 percent since 2012. One of the consequences of the growing imbalance between housing and jobs is the increasing traffic and congestion, according to an Urban Footprint report.

To avoid congestion, the plan requires efficient mass transit. Mr. Calthorpe has proposed an alternative — autonomous rapid transit, or ART — using fleets of self-driving vans in reserved lanes on main arteries like El Camino Real. Those lanes would allow the vehicles to travel faster and require a lower level of autonomous technology. And the vans could travel separately or be connected together.

A recent study that Urban Footprint did in collaboration with Fehr & Peers determined that an autonomous rapid transit system, which could be built today, would be twice as fast as a conventional bus and cost a little more than half as much to operate.

Mr. Calthorpe’s plan is an evolution of the concept of “transit-oriented development” he pioneered while teaching at the University of California, Berkeley, in the late 1980s. It focuses on designing urban communities that encourage people to live near transit services and decrease their dependence on driving.

The idea has attracted the attention of public transit activists in Southern California.

“Autonomous rapid transit’s greater capacity combined with lower cost could really be the stimulus for the housing development,” said Denny Zane, executive director of Move LA, a group that has built broad community support for funding improvements in transportation. “We need to integrate autonomous technologies in a setting that will enhance transit use.”

Mr. Zane said the ART technology would dovetail nicely with a planning idea called Grand Boulevards, which has been funded by two ballot propositions in the Los Angeles region and has until now been focused on a human-driven system known as bus rapid transit.

Most recent Silicon Valley start-ups have focused on personal vehicles rather than mass transit. But in July, Waymo, the self-driving car unit of Google’s parent company, Alphabet, announced a partnership with Valley Metro in the Phoenix region to develop a transportation system that would look very much like Mr. Calthorpe’s ART concept.

To gain broad acceptance for his idea, however, Mr. Calthorpe needs to convince city officials like Lenny Siegel, the mayor of Mountain View, where Google is based.

Mr. Siegel is a veteran community activist whose focus is on the imbalance between jobs and housing and the impact of the long commutes made by people who work in the city. He also has expressed concerns about anything that will affect the flow of conventional automobile traffic.

Mountain View is trying to plan for a future that will require moving as many as 40,000 people back and forth each day from the CalTrain railroad corridor that runs between San Francisco and San Jose to workplaces like Google. Currently, city planners envision an autonomous system like the one that Mr. Calthorpe envisions, but on an elevated track.

Mr. Calthorpe insists that planners need to take bold steps and argues that rethinking major boulevards like El Camino by filling in with denser housing and adding a more efficient autonomous transit system is the best place to start.

“You have to redesign the street itself,” he said. “You need to add autonomous transit, and you need to get rid of parallel parking and put in bikeways and better sidewalks.”


Smart-Home Devices to Make Your Holidays Easier

All the holiday planning, coordinating, decorating and entertaining can sap some of the enjoyment out of a season that should be full of cheer. Although people may not immediately associate the holidays with technology, in many ways smart-home devices can take a bit of the stress and worry out of the season by doing some of the more mundane (and necessary) work for you.

The best smart-home devices install easily, work dependably and make tasks that you need or want to do easier. Here are a few ways in which smart-home devices can make your holidays brighter.

Holiday light control

If the holidays mean filling your home inside and out with miles of string lights, blinking icicles, inflatable yard decorations and glowing roof ornaments that are visible from space, you know the pain of crawling around on your knees every evening to plug them all in. Wirecutter tested dozens of smart plugs that you can program to turn on automatically based on the time of day, or set to follow a custom schedule.

ImageThe iClever IC-BS06 is safe for outdoor use and has a pair of independently controlled outlets.CreditRachel Cericola/Wirecutter

Wirecutter recommends the Belkin Wemo Mini for indoor use. For outdoor use, we like the iClever IC-BS06, which has two independently controlled outlets — so you can control, say, a string of yard lights separately from an inflatable snowman. If you link these smart plugs to a smart assistant like an Amazon Echo or Google Home speaker, you can turn the cheer on and off with a simple voice command. That’s a lot easier than squeezing behind a prickly tree every night.

Besides controlling the holiday lights, you can swap out your regular bulbs with smart bulbs and change the whole look of a room by changing the lights’ colors. The smart bulbs Wirecutter likes, including Philips Hue and LIFX bulbs, can create custom scenes in different colors to light up walls or illuminate your décor to match a holiday or mood. As with smart plugs, you can control these bulbs with Alexa or Google Assistant.

Doorbell cameras

The holiday season means two things are likely to show up on your doorstep: visitors and packages. A doorbell camera like the Ring system can help you make sure you’re not surprised by either. Wirecutter reviewed all the latest doorbell cameras and especially liked models that allow you to view and chat with porch visitors through a smartphone app — whether you’re on the other side of the door or the other side of the world. Doorbell cameras can also alert you when a package is dropped off, so you can run to the door to pick it up, call a neighbor if you’re not home, or, in a worst-case scenario, identify the thief who ran off with it. In fact, just the sight of a doorbell camera on a front porch may deter such package thefts.

If installing a doorbell camera seems like too much work, a Wi-Fi outdoor security camera can provide many of the same benefits, including recording suspicious activity. But these cameras don’t come with doorbells, so they aren’t as good for interacting with visitors.

Smart fire protection

According to the National Fire Protection Association, the top three days for home candle fires are Christmas, New Year’s Eve and New Year’s Day, and fires that begin in a Christmas tree are more likely to result in death than other home fires. A smart smoke alarm alerts you to a small problem before it becomes a big one. And unlike a standard smoke alarm, a smart one can alert you even when you’re not home, so you can call for help. If you have a Nest smart thermostat and a Nest security camera, the Nest Protect alarm can automatically turn off your HVAC system to prevent the spread of smoke and start recording video if it senses smoke so that you can see what the problem is.

ImageThe Apple HomePod offers clever design and good sound quality.
CreditJon Chase/WirecutterSmart assistance

In addition to helping you turn out the lights as described above, a smart speaker like the Amazon Echo or Google Home can help with an assortment of holiday-related tasks. The Lenovo Smart Display and Google Home Hub are pros at finding recipes, and they can even play videos to demonstrate how to cook them. Amazon’s Alexa can create multiple shopping lists (gift lists, party lists, housecleaning do-to lists); schedule reminders (pick up cousin Eddie at the train station); track an airline flight; and alert you that a package has been delivered (from Amazon, of course). Both smart assistants can even help you order last-minute gifts.

Despite the abundance of smart skills, playing music is still the most popular use of smart speakers. The Echo, the Google Home and Apple’s HomePod can each fill your home with music for your holiday party, and you can set up all three systems for multiroom music. That means you can perfectly synchronize all your holiday tunes from room to room — or when you tire of the holly-jolly, switch to something Arctic-cool — using just your voice, without ever touching your phone.


Flat Out: Rejecting Breast Reconstruction

In the recently published memoir “Flat: Reclaiming My Body From Breast Cancer,” Catherine Guthrie tells the story of grievous medical mistakes that she managed to record without sugarcoating their consequences or flailing against the injustice of it all. A women’s health reporter, Ms. Guthrie approached the cancer experience guided and guarded by her previous investigations. She nevertheless found herself stunned by the retrograde assumptions and defective practices of the physicians she consulted.

Eight years ago, I learned about Ms. Guthrie’s traumas when we met at a reception. She was a freelance journalist in her 30s and I was a professor of English in my 60s, but we instantly bonded. We were both living in Indiana and reeling from calamities related to our cancer treatments. Now, her landmark book persuades me that breast cancer care must be improved.

As “Flat” explains, all of the doctors Ms. Guthrie met assumed that she would want breast reconstruction after a mastectomy. One describes “how he would carve apart the largest muscle in my back, and, with one end of the muscle connected to its blood supply, tunnel the loose end (the flap) through my body and under my arm until it reached the empty socket on my chest where my breast had been.” Wouldn’t that weaken her back, she worried.

“Most women want to look normal in clothes,” the doctor informed her. But she knew that reconstruction could involve multiple surgeries that frequently result in major complications. Also, reconstructed breasts, which can “look normal in clothes,” may not feel much of anything.

To the queer ear of Catherine Guthrie, the doctor’s word “normal” rings a warning bell. Being queer means “pushing against cultural assumptions” of the norm. She worried less about appearance and more about preserving upper body strength. Balance was important, too, because of childhood scoliosis; she did not want to be lopsided. By conserving her back muscles, going flat would allow her to continue doing her favorite yoga postures: head and arm stands.

With its subtle analyses of the complexities of decision-making for breast cancer patients, “Flat” does not proselytize for any “proper” choice. Instead, it explores how challenging treatment alternatives remain. However, the book does implicitly argue that these judgments must be patient-driven. Ms. Guthrie counters her physicians’ objectionable suppositions about femininity while encountering the terrible wrongs they inflict.

The most shocking was made by an eminent surgeon. He removed both of her breasts without excising the cancerous lump. Hello? It is hard to wrap one’s mind around such a catastrophe, but Ms. Guthrie’s narrative embeds it in a succession of medical mishaps that serve as a warning: caveat emptor. Needless to say, a reoperation was necessary as well as an apology.

Buyers or patients must be wary even about seemingly minor procedures. After a dermatologist slices what looks like a mole off Ms. Guthrie’s flat chest, it turns out to be not a mole and not a recurrence but a second primary breast cancer tumor. The dermatologist also erred … in this case by possibly releasing cancer cells into Ms. Guthrie’s body. The growth should have been removed with wider margins by a cancer surgeon.

ImageWithout judging those who choose reconstruction, Ms. Guthrie encourages women to do “whatever makes them feel good, not what makes other people comfortable.” CreditKayana Szymczak for The New York Times

Has Ms. Guthrie lost faith in medicine, I wondered on turning the last page. “No,” she told me, although she does have “a heightened awareness of the fallibility of doctors and the limits of medical science.”

How does she feel now about her decision to go flat? “I am as strong, mobile and flexible today as when I was diagnosed,” she said. The ease of lying on her stomach in bed, on a yoga mat or at the beach “is priceless.” Noting “similarities between the flat movement and the queer movement,” Ms. Guthrie pointed out that some post-op patients are urged to conceal themselves, as if their condition were shameful: “The panic of being ‘seen’ or ‘outed’ is real.”

Without judging those who use prostheses, she encourages women to do “whatever makes them feel good, not what makes other people comfortable.” For Ms. Guthrie, “flat visibility is about refusing to buy into the narrative that women without breasts are disfigured.” The number of women who decide against reconstruction remains steady: 1 in 4 double mastectomy patients and 1 in 2 single mastectomy patients. But the notion that women who go flat must hide their bodies has become “antiquated.”

What improvements in care does Catherine Guthrie hope to witness? “I would like to see breast and plastic surgeons offer women the option to go flat as readily as they offer them the choice of reconstruction, with no bias or judgment or pressure.” She also believes that rural women should be getting the state-of-the-art attention urban women receive. During her treatment she moved to Boston, where she was surprised to discover that physical therapy was built into recovery plans. Among the approximately 1.5 million women who have gone through radiation for breast cancer, she wonders, “how many live with reduced mobility?” After radiation in Bloomington, Ms. Guthrie had not been offered physical therapy, although in her car she found it difficult to reach back and grab the seatbelt.

Still, the pleasures of small-town life permeate “Flat”: the gratifications of owning a house, of planting and weeding a garden, and of a community of friends who attend a “Boobapalooza,” a send-off party before surgery for which Catherine Guthrie’s partner, Mary, furnished “boob-shaped candles, boob lollipops and balloons that inflated into a buxom twosome” as well as “a pair of pink, plastic windup boobs with red, mouse-sized feet.”

Spoiler alert!

Not a mawkish misery memoir, “Flat” records how a youthful couple tackles and transcends the daunting challenges of disease and treatment. Reader, they marry.

Susan Gubar, who has been dealing with ovarian cancer since 2008, is distinguished emerita professor of English at Indiana University.


How to Respond When the Market Turns

The long bull market in the United States has looked fragile lately. In our quarterly report on investing, we offer insights, analysis and some humor that may help you deal with it all.

ImageCreditCreditTim CookJeff Sommer

Many investors received a nasty reminder in early October: that they could lose a lot of money in a very short time.

Stocks fell for six consecutive days, reversing the gains of a third quarter that had been remarkable chiefly for its lack of stress. That October shock may have been just a blip in a long bull market, but it pointed out that American stocks clearly can’t rise forever. What is a long-term investor to do?

Our quarterly survey contains some lessons and suggestions. Prospecting for stocks in other countries is favored by some strategists now. Buffering stocks with bonds — and taking advantage of the higher interest rates available in shorter-term securities — is widely recommended. Of course, staying calm and sticking to a plan — as many index fund investors do — is always in fashion.

In a new book and interview, the investor Howard Marks explains why most people can’t beat the market. And if you’re worried about climate change — and want your portfolio to reflect your concerns — we’ve got some ideas for you.

For entertainment, try John Schwartz’s essay on the profit-making possibilities in mind-altering drugs, which he, personally, doesn’t use. But, he says, “Some people might benefit. Shouldn’t it be our humanitarian goal to make money off them?”

U.S. Stocks Became Expensive. Are Other Countries’ Stocks Better Bets?

The extended bull market has made stocks fairly expensive in the United States. For investors capable of handling the stress, neglected foreign markets may offer better prospects, according to some — though by no means, all — strategists.

Read more » These Funds Aim to Power Their Returns With Clean Energy

Renewable energy funds can’t shutter a coal plant tomorrow, if that’s your goal, but they can pair profits with a commitment to a green economy.

Read more » Finding a Fortune in the Market for Bliss

Somebody is going to get rich from legal, psychoactive drugs linked to blockchain technology, our columnist says. Why not him?

Read more » Income Investors Finally Have a Chance to Cash In

A decade after the financial crisis, multiple Federal Reserve rate increases are at last making it possible to earn a decent yield with little risk.

Read more » Index Fund Investors’ Simpler Approach May Enrich Returns

Fund investors often earn less than they could because emotions get in the way. People who use index funds seem to make fewer and better choices.

Read more » Big Bets Are Great, When They’re Right

Focused investing can be risky, but growth stocks and high-conviction bets helped propel three mutual funds to outsize gains in the third quarter.

Read more » Energy Partnerships Rebound as U.S. Oil and Gas Output Rise

After a deep decline for funds that invest in energy infrastructure partnerships, it could be time for a turnaround.

Read more » Advice on Dealing With the Market, if You Are Already a Pro

Want to risk trying to outsmart other investors? Start by understanding where we are in the market cycle, a Wall Street veteran says in a new book.

Read more » Why You May Be Your Own Worst Enemy as an Investor

A successful professional investor says most people aren’t able to beat the market. So, he advises: Understand your limitations and act accordingly.

Read more »

Jeff Sommer writes Strategies, a column on markets, finance and the economy. He also edits business news. Previously, he was a national editor. At Newsday, he was the foreign editor and a correspondent in Asia and Eastern Europe. @jeffsommer • Facebook


A (Kafkaesque) Legal Battle Over the Author’s Papers Is at the Heart of ‘Kafka’s Last Trial’

The Case of a Literary Legacy
By Benjamin Balint
Illustrated. 279 pp. W.W. Norton & Company. $26.95.

Max Brod’s original sin — the linchpin that launched Kafka’s posthumous career and a thousand scholarly ones besides — has always possessed something of the uncanniness and mythic aura of Kafka’s fiction itself. In 1924, dying of tuberculosis and facing what surely seemed to him the ignominious end of his literary life, Kafka bequeathed to Brod — his closest ally and fellow Prague scribbler — a pair of notes instructing him to burn “unread and to the last page” everything he was leaving behind: manuscripts, diaries and letters. Brod defied the injunction and instead spent the rest of his own life tirelessly editing, compiling and promoting Kafka’s work, building him up into the sainted laureate of alienated modernity he remains for many readers today.

Brod, in fact, twice saved Kafka’s writing from destruction, first from the self-immolating flames of his dying testament, and, later, from the bonfires of Nazi barbarism (which claimed Kafka’s three sisters), when, in 1939, he escaped by train from Prague to Palestine, clutching a briefcase full of Kafka’s papers. Brod, who died in 1968, left his collection to his secretary, Esther Hoffe, with the apparent intention that she ultimately deposit it in a public library or archive. Instead, Hoffe kept the papers vaulted away, sold what she could — most controversially, the manuscript of “The Trial” — and gave the rest to her two daughters. When she died, in 2007, the National Library of Israel contested the rights to Brod’s and Kafka’s archives, precipitating a succession of courtroom showdowns that pitted the institution against Esther’s daughter Eva and the German Literature Archive in Marbach, which had long hoped to acquire the papers. In 2016, the Israeli Supreme Court finally decided in favor of the National Library.


That Brod, the great custodian of Kafka’s legacy, managed to leave it in the hands of a gaggle of litigious would-be inheritors is no small irony, though a fitting one, given the nature of Kafka’s court-riddled work. This irony forms the basis of Benjamin Balint’s new book, “Kafka’s Last Trial: The Case of a Literary Legacy.” It is an unusual hybrid: part courtroom procedural, part double portrait of Kafka and Brod, part account of the postwar construction of Israeli and German national identity. As with his previous book, an admirably levelheaded history of Commentary magazine, Balint writes most naturally in the interrogative mode, preferring the probing of difficult questions to easy resolutions. A gifted cultural historian with a scholarly sensibility, he is perhaps less suited to the role of investigative reporter. The first third of his book cuts back and forth between the origins of Kafka’s career and friendship with Brod, and the unfolding Israeli custody battle. The latter material, dense with the names of lawyers and the convolutions of the proceedings, feels plodding at times. Balint never quite manages to illuminate the motivations behind Eva Hoffe’s increasingly desperate appeals to retain her inheritance, whether rooted in her desire to convert Kafka’s cultural capital into a financial asset or some deeper identification with her mother’s and Brod’s hidden aims. Whatever the case, one comes to tire of the courtroom rigmarole, longing to return to the roomier vistas of Kafka’s mind.


Even a 10-Minute Walk May Be Good for the Brain

Ten minutes of mild, almost languorous exercise can immediately alter how certain parts of the brain communicate and coordinate with one another and improve memory function, according to an encouraging new neurological study. The findings suggest that exercise does not need to be prolonged or intense to benefit the brain and that the effects can begin far more quickly than many of us might expect.

We already know that exercise can change our brains and minds. The evidence is extensive and growing.

Multiple studies with mice and rats have found that when the animals run on wheels or treadmills, they develop more new brain cells than if they remain sedentary. Many of the new cells are clustered in the hippocampus, a portion of the brain that is essential for memory creation and storage.

The active animals also perform better on tests of learning and memory.

Equivalent experiments examining brain tissue are not possible in people. But some past studies have shown that people who exercise regularly tend to have a larger, healthier hippocampus than those who do not, especially as they grow older. Even one bout of exercise, research suggests, can help most of us to focus and learn better than if we sit still.

But these studies usually have involved moderate or vigorous exercise, such as jogging or brisk walking and often for weeks or months at a time.

Whether a single, brief spurt of very easy exercise will produce desirable changes in the brain has remained unclear.

So for the new study, which was published in September in Proceedings of the National Academy of Sciences, scientists from the University of California, Irvine, and the University of Tsukuba in Japan turned to a group of healthy, young college students.

They recruited students in part because they are easy to come by on college campuses but also because bright, healthy, young men and women should have brains and memories that are functioning well.

For an experiment to produce improvements in their brain function, its effects would need to be potent.

The scientists invited 36 of the students to the lab and had them sit quietly on a stationary bicycle for 10 minutes or, on a separate visit, pedal the bicycle at a pace so gentle it barely raised their heart rates.

In technical terms, the exercise was performed at about 30 percent of each volunteer’s maximum heart rate. By comparison, brisk walking should raise someone’s heart rate to about 50 percent of his or her maximum.

So this exercise was very easy.

It also was short, lasting for only 10 minutes.

Immediately after each session of the sitting or slow pedaling, the students completed a computerized memory test during which they would see a brief picture of, for instance, a tree, followed by a variety of other images and then a new image of either the same tree or a similar one.

The students would press buttons to show whether they thought each image was new or the same as an earlier shot.

The test is difficult, since many of the images closely resemble one another. It requires rapid, deft shuffling through recent memories to decide whether a picture is new or known.

Next, the scientists had each student repeat this sequence — riding or sitting on the bike for 10 minutes and then completing memory testing — but the testing now took place inside an M.R.I. machine that scanned the young people’s brains while they responded to the images.

Then the researchers compared results.

The effects of the exercise, undemanding as it was, were clear. The young people were better at remembering images after they had ridden the bike, especially when the images most closely resembled one another.

In other words, the harder their memories had to strain, the better they performed after the exercise.

More unexpected, their brains also worked differently after they had ridden. The M.R.I. scans showed that portions of each student’s hippocampus lit up in synchronized fashion with parts of the brain associated with learning, indicating that these physically separate parts of the brain were better connected now than when the students had not first exercised.

And the greater the coordination between the disparate parts of the brain, the better the students performed on the memory test.

“It was exciting to see those effects occurring so quickly and after such light exercise,” says Michael Yassa, the director of the U.C. Irvine Center for the Neurobiology of Learning and Memory and senior co-author of the new study with Hideaki Soya of the University of Tsukuba.

The findings show that exercise can change people’s brains and minds right away, he says, without requiring weeks of working out. Even better, the exertion required can be so slight as to allow almost anyone, even those who are out of shape or possibly disabled, to complete the exercise.

How, at a molecular level, such gentle exercise affects the brain’s operations is still unknown, he says, although he and his colleagues suspect that changes in blood flow and hormone levels are probably involved.

They hope to explore those issues in future studies and also look at the impacts in younger and older people.

But already, the message is cheering.

“We are not talking about marathons,” he says. “It looks like people can improve their memories with a short walk or an easy session of something like yoga or tai chi.”


Just Embed a Phone Into This Editor’s Mind, Already

Tech We’re Using

Choire Sicha, who runs The New York Times’s Styles desk, has such a close relationship with his smartphone, he says, it may be time to “punch the circuitry into the back of our skull.”

ImageChoire Sicha, styles editor for The New York Times, says, “I use this phone more than I use any other device in my life.”CreditCreditJeenah Moon for The New York Times

How do New York Times journalists use technology in their jobs and in their personal lives? Choire Sicha, the editor of the Styles desk at The Times, which reports on everything from weddings and fashion to social change and self-care, discussed the tech he’s using.

What does your tech setup look like? And what do you do to make it look stylish?

Like 19 out of 20 Americans, according to the Pew Research Center, I have a mobile phone. Like those belonging to three out of four Americans, according to the same, mine is a janky hand-held device that I use for talking, playing games, reading, writing, taking photographs, keeping in touch with friends, checking weather, hate-reading, Netflixing, learning chords to 1980s songs from websites that probably give me weird viruses and creating expressions of my identity to display to strangers across the internet.

Why do we do that? I use this phone more than I use my office laptop. I use this phone more than I use any other device in my life, including my television. Sometimes instead of turning on the television I will just watch television on my phone. Don’t tell David Lynch!

ImageHe used a Google Pixel XL, but recently bought a Samsung Galaxy Note 9.CreditJeenah Moon for The New York Times

I also should stop calling it my phone, because I do not make phone calls on it, because phones are fairly useless as phones and mostly because the phones are infested with incessant spam calls that apparently, as with school shootings, food-borne illness incidents and the removal of registered voters from the rolls, we are incapable as a society of preventing in any way. Also, because I am on an Android phone (a Pixel XL), none of my friends will text with me, and it makes me sad. They love their beloved iMessage on their beloved, stupid iPhones. Companies don’t care about us, or at least not me. They care about themselves (and about not paying taxes in America, and I get that, truly, I have been there myself).

My phone does have a New York Fashion Week PopSocket on it, though, and I’m a real PopSocket convert! It makes reading in bed great again.

What’s so janky about your setup? What features or tools are on your wish list to make it better?

It’s agonizing and surreal that for this funny time-window in human society there is an annual New Phone Season. Each year we are besieged by very barely updated versions of existing phones that are larger and more expensive than ever, and usually just as fragile. As the New Phone Season approaches each year — it’s usually September to October, when Google, Samsung, Apple and others either bring out or announce their annual lines — one tries ever more desperately to time the death of one’s primary digital device to coincide with it.

Mr. Sicha uses his phone to scroll Twitter.CreditJeenah Moon for The New York TimesHe also uses his phone to watch Netflix (but not at work, he says).CreditJeenah Moon for The New York Times

My phone is ragged now. We barely made it. The screen is horribly burned in. It’s hot. When I plug it in, it begins to download and update things and everything freezes. It smells a little bad?

And now the decision time is here, and I’m unhappy.

The more I’m put in the position of deciding whether I will spend more than $1,000 on a “phone” (as the prime large-size offering from each of the three major companies ends up being more than two weeks’ take-home pay for a Whole Foods employee) or daringly branch out into the slightly less premier brands, the more I realize how awful it is that these disgusting, beeping, needy Tamagotchis are my most constant companion. I have a more active friendship and, to be honest, romantic life with my phone than I do with almost any humans. Can this be good for me? Am I an experiment?

At the very least I would like them to make digital devices that aren’t incredibly fragile and scratchable. Right now, until they just punch the circuitry into the back of our skull, like the way they murder cows, we have to carry these things around as if they were tiny flat glass babies.

Will I buy an iPhone? A Note 9? A Pixel 3? Will I buy a one-way ticket off this crazy thing and set myself free? Not as long as I have a job, I suppose. *Looks around office nervously*

In the end, as you can see in the pictures, I finally bought a Samsung Galaxy Note 9.

How has tech affected style?

The biggest trend around the world is that nearly every man now has a worn-in rectangle in the front pocket of his jeans. I also predict that hand-enlargement surgery for women will briefly become a trend until the time of the, you know, putting the phones into the skull bones. Then there are no more worries!

Mr. Sicha texted on his Samsung Galaxy Note 9 at the Times building in Manhattan.CreditJeenah Moon for The New York Times

The best part of how they’ll put the phone in our heads is that when the seawaters all rise, the phone will be the last part of us to get wet.

What other tech product are you currently obsessed with?

The majority of my tech use actually occurs while I sleep. I have a Wirecutter-endorsed Coway air filter, which may or may not be doing anything but I love it to death, and a small symphony of Dyson fans and Bose noise machines that create an envelope of air and sound all around me, as if Kate Bush were constantly twirling at high speed while I dream the night away.

This setup saves marriages and also soothes cats. If you sleep in silence next to someone, you are doing it wrong!

The tongue of this whooshing envelope, if you will, actually intrudes into my person in the form of a small plastic mandibular advancement device. It’s a kind of fancy mouth guard, and the technological arms race around sleep apnea is fascinating. For instance, while I was being fitted with this device — it gently juts the jaw forward, basically, allowing you to breathe while you sleep and not rush toward death as quickly — it was casually mentioned that if it didn’t fit handily, they could install little bumps on my teeth that would fit into slots in the device, locking it in overnight, in a real steampunk nightmare of medical intervention. It fit.

Does your lover or spouse report that your snoring is terrible? Do you feel exhausted in the morning? Do you feel like you have a cold all the time but you don’t? Do you wake up suddenly at night screaming in panic? No, wait, that last one’s normal.

The rest of you, visit an otorhinolaryngologist today!

A version of this article appears in print on , on Page B7 of the New York edition with the headline: Nurturing, While He Can, His Tiny Flat Glass Baby. Order Reprints | Today’s Paper | Subscribe


Is This ‘A Star is Born’ Pop Song Supposed to Be Bad or Glorious?

Reader, I have a question. Why do you look so good in those jeans?

Forgive me for being forward, but it’s been nearly two weeks since the release of the soundtrack for “A Star Is Born,” which means it’s been nearly two weeks since I’ve been unable to get the impolite lyrics from “Why Did You Do That?” out of my head. If you’ve seen the film, you may remember that’s the pop song that Ally (Lady Gaga) performs on “Saturday Night Live,” the one that convinces her rock-tinged paramour Jackson Maine (Bradley Cooper) that she has sold out.

As Ally wriggles around onstage and sings, “Why’d you come around me with an ass like that?” the audience may be bopping their heads, but Jackson is grimacing. I’ll admit that “Why Did You Do That?,” with all of its butt- and texting-related lyrics, can initially seem like a bit of a shock: It’s nothing like the rootsy music we’ve watched Jackson and Ally compose together, and it forgoes the timelessness of “Shallow” and its ilk in favor of what feels like pop disposability.

But if the song is so paper-thin, why can’t I stop singing it under my breath? And why has the internet been moved to slap “Why Did You Do That?” on top of videos of dancing robots and gyrating Pokemon? Is the song, with its xylophone intro and unpretentious pop charm, actually a stealth treasure?

[Read our review of “A Star Is Born.”]

To get to the bottom of this mystery, I rang up Diane Warren, a nine-time Oscar nominee and veteran songwriter who helped put lyrics to “Why Did You Do That?” with Lady Gaga. (The song’s track was conceived by Gaga, Warren, Mark Nilan Jr., Nick Monson and Paul Blair.) Here are excerpts from our conversation:

Diane, I heard “Why Did You Do That?” in a gay bar the other night. We need to discuss it.

It’s getting a life of its own! “Why’d you come around me with an ass like that?” I have to take guilty credit for that line. I remember when we were working on it, I said, “Can we say that?” And Gaga went, “Yeah, why not?”

And now I can’t stop saying it.

It’s seeping into the consciousness!

I saw someone tweet that “Why Did You Do That?” is supposed to be a “bad” pop song, and you replied, “That was not the intention, actually.”

No, it’s not the intention. I would never purposefully sit down to write a bad song, although I guess I’ve done some without trying that turned out that way. This was a fun song, and I love fun pop songs. Not everything has to be serious all the time.

Was there any sort of directive about what this song was supposed to represent for Ally?

No, the directive was just to write a fun song, something that shows she’s becoming this pop artist.

Did you know that Bradley’s character, Jackson Maine, would later make fun of the lyrics?

It surprised me when I saw it! I was sitting next to my friend and I jabbed her in the arm and went, “That’s my line he’s quoting!” I love that her character defended her music. It doesn’t have to be what he thinks music should be — music can be everything. It can be a serious song, it can be a pop song, it can be a song about an ass.

ImageThe songwriter Diane Warren, a nine-time Oscar nominee.CreditRochelle Brodin

And is he any more authentic? The film points out that Jackson adopted his older brother’s voice to make it in rock. In many ways, his persona involves as much artifice as hers.

That’s true, when you look at it like that. Her character writes her own songs, and maybe that’s how she expresses herself. It doesn’t make her character less artistic than his character.

As someone who has worked with many pop stars as a songwriter, did Ally’s arc ring true to you?

I’ve seen stuff like that, where they try to push an artist — especially a female artist — into something they’re not, and then they rebel against it and try to discover what their true voice is. But by the way, maybe her true voice is being a pop star, you know? And that’s O.K., if that’s who you are.

It’s interesting how upset people can become about pop music.

I mean, you’re talking to the woman who wrote “Blame It on the Rain” for Milli Vanilli. I have nothing against a good pop song.

But a lot of people think it’s less important than a good rock song. They treat it like — —

A guilty pleasure, right? But it has its revenge because it sticks in your brain. And then you end up saying, “Why did you do that, do that, do that.”

How did you feel about the movie in general, once you saw it?

I thought it was really impressive. The thing is, when Gaga was talking about acting in it, some people I know were like, “She’s not gonna be great,” but I knew she would be. I’ve spent time with her, I know how hard she works: This is someone who works with a vocal coach for hours a day. She has that discipline, that work ethic that very few people have. She has it, and Beyoncé has it. They just go that extra mile. Good isn’t good enough, so when I knew she was serious about this, I knew she would be great — and she is.

Tell me about your song “I’ll Fight” for the documentary “RGB,” which is performed by Jennifer Hudson.

I feel like it’s the third song in a trilogy I’ve written, which started with “Til It Happens to You” from “The Hunting Ground” [performed by Gaga], and then last year I did “Stand Up for Something” from the movie “Marshall.” Now you have “I’ll Fight,” which is taking the next step. You’re standing up and announcing you’ll fight, and even though Ruth Bader Ginsburg is not loud, with her soft voice she defends us so much. We need her voice, and we need her more than ever right now.

“I’ll Fight” is the more conventional Oscar song, but I want to imagine an alternate reality where “Why Did You Do That?” is somehow an Oscar contender, too.

I don’t know about that, but stranger things have happened! Can you imagine a really serious performance of that song on the Oscar stage? They should do it as a ballad.


The Computer Chauffeur Is Creeping Closer

Still, A.I. is already quietly making driving safer. Beyond the applications now found in new cars, typically in conveniences like the speech-recognition feature of infotainment systems, are the subsystems that make up the packages of safety features common largely in luxury vehicles. Enhancements like night vision, automatic emergency braking and lane keeping all depend on processors that use sensors and computer instructions to warn drivers of danger or act to avoid collisions.

The term artificial intelligence, coined in the 1950s, is something of an unfortunate choice, at least in terms of the automobile. The intelligence within cars — that is, their ability to learn and to apply that knowledge — is far from artificial; it is hard-earned. It comes down to capable electronics, sensors and, especially, extensive training.

“Training is like teaching our kids to drive, with rules, absolutes and best practices,” Glen De Vos, chief technology officer at Aptiv, said in a telephone interview. “Some rules are embedded in the system — never out-drive the free space around the vehicle, obey road signs — but as you move up the spectrum toward accident avoidance, a predictive capacity is necessary.”

Aptiv, a spinoff from Delphi Automotive, an auto industry supplier, builds the data sets that a trained A.I. system depends on. Most of that data is accumulated on the road, acquired in videos to create the basic knowledge bank that computers draw on. In some cases, this work is done overseas to reduce costs, and suppliers can make use of basic image collections — known as a trained data set — obtained off the shelf from market-research organizations.

The key to making the images useful is adding detailed annotation — instructions that specify, “This is a tree, this is a garbage can” — for the object recognition function that is vital to preventing collisions. The work is tedious and until recently has been mainly a manual task, with up to 80 percent of the work devoted to classifying images and cleansing data, said Sachin Lulla, IBM’s automotive leader.