Science Notes 2009

What's On My Baby's Mind?

More than it can tell us, child psychologists say. Emmanuel Romero visits the babies of an infant psychology lab and asks how we can peer into their minds. Illustrated by Krista Anandakuttan.

Illustration: Krista Anandakuttan

(Writer's note: To abide by confidentiality policies, the names of all research subjects and their family members have been changed.)

Behind closed curtains, Lenny braces for a battery of laboratory tests. Cameras spy his every move, and a special tracking device records each darting motion of his eyeballs. He watches pulsating images on a TV monitor as two female researchers calibrate their instruments. But the stimulation is too intense for Lenny, who cries out to stop the trial. When the researchers open the curtains, Lenny smiles and, unexpectedly, starts flirting with them. He kicks up the charm, oozing charisma with his nearly bald head and mischievous smile. The researchers giggle, powerless to his spell.

Lenny's mother, Amber, rolls her eyes. Her 15-month-old son is a bona fide ham.

It's all in a day's work in the lab of developmental psychologist Su-hua Wang at UC Santa Cruz. Her team deals with a steady stream of babies to piece together the puzzle of how infant minds process the world around them.

“How do children learn? That's one of the central questions we psychologists try to answer,” Wang says of her field. Its roots tap deeply into the philosophy of Plato and Aristotle, who questioned how much of human knowledge is innate, and how much is learned. Today, Wang and her colleagues have extended that search for answers to the little ones among us.

Beyond academia, developmental psychology's findings can enhance the bonds between parents and their babies.

“The more you feel you understand somebody else—including your own kid—the stronger the attachment you can form and the deeper the appreciation you have,” says Thomas Schilling, a behavioral scientist at Fitchburg State College in Massachusetts.

The challenge in figuring out what babies are thinking is that babies can't verbalize their thoughts, Wang says. Over the last half-century, this barrier has forced psychologists to get creative and open their own windows into the minds of infants.

Setting off “a revolution”

Wang's fascination with infants began when she was an undergraduate at National Taiwan University during the early 1990s. At that time, scholars in the field argued passionately over the intellectual abilities of babies. The debate challenged more than 20 years of dogma from renowned developmental theorist Jean Piaget. Piaget believed children younger than 2 had little capacity to understand the physical world. However, psychologist Renée Baillargeon of the University of Illinois, a former mentor of Wang's, believed Piaget's tests required too much of his infant subjects.

Piaget focused on the links between the motor skills and senses of his subjects. For example, to test whether a baby grasped the concept of “object permanence”—the fact that an object still exists even when it's not visible—Piaget placed something in front of a baby, then hid it. To succeed, the baby would have to search for the object and reach for it. Most of Piaget's subjects failed.

But if a baby didn't reach for the object, the baby still might have known it was hidden, Wang says. Babies don't have full control of their arms until about 5 months of age, she says. Piaget's tests may have demanded more than a baby's physical capabilities.

To refine Piaget's methods, Baillargeon helped develop the psychology lab technique known as the “violation of expectation” paradigm. In this technique, researchers put on rudimentary magic shows for infants. From behind a stage curtain, researchers manipulate objects on a small puppeteer's stage. This method helps psychologists gauge a baby's knowledge by measuring the amount of time they stare at each event in the show. Here's the idea: Babies tend to stare longer at an event that contradicts what they would normally expect.


Photo: Courtesy of Su-hua Wang, UC Santa Cruz
Can a baby tell the difference between these two pictures? If she spends more time staring at the mustard, it could mean she has an idea of where a mustard bottle belongs.

“If you're walking on campus, and it's cold outside, and you see someone wearing shorts, you will tend to look at that person a little longer,” Wang says. “Adults still have this tendency. Babies, too—they have this systematic tendency to stare at things longer when it violates their expectations.”

“This 'violation of expectation' paradigm set off a revolution in infant studies,” Schilling says. The technique has since become the standard of infant labs around the world, including Wang's.

Babies also express surprise during the experiments by laughing, crying, smiling, or showing other emotions. But because reactions vary among babies, staring time is recorded as the only official measure of violation of expectation.

Do researchers check if the babies soil themselves? “No, that has never happened,” Wang says with a laugh.

Foraging for babies

Wang's experiments need test subjects, but they face an ongoing challenge: “Santa Cruz is a small town,” Wang says. To forage for babies, lab members visit new-parent support groups, stop by lactation education groups at hospitals, post fliers at public libraries, and browse the newspaper for birth announcements. No child is turned away for being too young. Wang accepts younger babies right away, then tells parents to return when their child is eligible. She also asks parents to bring their babies back for future studies that require older subjects, if they wish.

Amber and her husband run their own real estate brokerage from home. They agreed to participate after receiving a phone call from Wang's lab.

“It seems like a good thing to learn about,” says Amber, who volunteered Lenny for several experiments. “Being parents, we knew probably not a lot of parents were willing to [participate] because they're busy and they're running around. So we figured, we have the time, and it seems like good research. Why not?”

As Lenny demonstrated, Wang needs as many babies as possible. Some simply don't cooperate. Babies who become bored, fussy, or missed a much-needed nap make unusable test subjects. Either they reschedule or Wang has to throw out their data.

“Of 100 babies we test, about 20 babies won't be able to provide us useful data,” Wang says. Parents can also ruin an experiment by reflexively trying to keep their babies attentive.

Wang happily adapts on the fly. “Babies are very limited in giving verbal feedback,” she says. “So the way they communicate their feelings is by crying or being fussy, and we respect that. That's why we end our study early when we see babies being overly upset.”

Wang made her own data contributions by volunteering her two-year-old son when he was a little baby. “When I play with him, I think it really helps me to look at [play] from his perspective,” Wang says.

It's. . . showtime!

Just inside the entrance to Wang's lab stands a baby-changing table, dressed with pastel bedding. Nearby, there's a preschool-sized desk and toy chest. The toy corner is complete with children's books, coloring markers, and disinfectant wipes for scrubbing toys. (The occupational hazard of kiddie germs is on display: A research assistant frequently swipes at the tissue box to blow her nose.) Smiling jungle animals line the walls, marching up to the high-tech setup that reminds visitors this is a major university lab.

Wang's research assistants helm a computer center, which monitors their recording equipment and handles data entry. The experiments take place on two separate, back-to-back puppet-show stages, which take up half the lab. One stage houses a television. In front of the TV is an eye-tracking device, which locks onto its subjects' gaze. It uses infrared light to follow what the babies are watching.

About an hour after Lenny and Amber leave this stage, Jerrald and his mother visit the lab. Wang's assistants seat them at the other stage.

Photo: Emmanuel Romero

Researchers at the UC Santa Cruz infant psychology lab set the stage for a show. An assistant spies on the baby through a peephole in the side curtain.

Backstage, one assistant dons a white canvas cloak, which blends most of her body behind the white curtain. Her arms are free to razzle-dazzle during the stage show. She takes animal figurines and drops them into different containers. Jerrald sees several rounds of the same show: animal stands beside empty container; arm drops animal into container; animal stands inside container; arm removes animal from container.

It's not exactly Macbeth, or even Barney and Friends, but several short rounds of this show should do the trick: The babies get used to it, to the point where they're no longer interested in watching. They know what to expect. This technique, called “habituation,” was an early precursor for Baillargeon's violation of expectation.

While the hidden researcher habituates Jerrald to the animals in the container, two more students stand by and record his staring time during each round. One watches Jerrald through a hidden camera, and the other watches him through a peephole on the stage door. Once they agree Jerrald is properly habituated to the show (that is, he's bored), the real experiment can begin: Will he stare longer after seeing an animal placed behind a container rather than inside it? Wang thinks her experiment will provide clues to the spatial reasoning of infants.

Unfortunately, forty rounds of animal drops have bored Jerrald to tears. He cannot continue.

“He was so close,” Wang's assistants say with defeated smiles.

The “change blindness” phenomenon

Wang's latest completed study tested whether infants could notice physical changes to an object. The inability to detect these changes, a phenomenon known as “change blindness,” interests Wang because everyone can suffer from it, infants or adults.

“When you're driving, and the traffic light changes, you don't want to miss that,” Wang says.

To notice a visual change, you need two pieces of information: what you see before a change happens, and what you see afterward. For the change to register mentally, you must take the extra step of comparing both pieces of information. Wang wondered where our attention goes haywire. Do we not retain what we see before the change takes place, or are we unable to compare 'before' and 'after'? Wang's study in babies concludes it may be the latter.

Wang set up a simple show where babies compared the heights of three different cylinders: short, medium, and tall. During side-to-side comparisons of any two cylinders, the babies stared longer at whichever cylinder they had not seen previously. But as the experiment progressed, the babies had a hard time keeping track of what they had or had not already seen. Wang interprets this to mean that change blindness is a glitch of processing visual information as it comes in.

“Change blindness occurs when the person loses track of what's relevant,” Wang says. “It's not really about our memory. Our memory is good enough. It's about how we use the available memory.”

After finding that babies are just as prone to change blindness as adults are, Wang believes there is something about processing visual information that stays the same from infancy to adulthood.

Careful conclusions

Developmental psychology labs around the world use the violation of expectation technique. Is it reliable? Jeanne Shinskey, who runs her own infant lab at Royal Holloway, University of London, believes violation of expectation is useful for testing a baby's basic perception of changes in objects. However, she thinks it's risky to draw conclusions about the more complex capacity for reasoning.

“Because these methods were designed to study visual perception, I think you need to be careful about drawing higher level interpretations about cognitive abilities, like physical knowledge,” she says.

Schilling agrees, adding that violation of expectation experiments are difficult to replicate. Because the tests are so easy to manipulate, the results leave too much room for alternative explanations to a baby's staring time. For example, the baby simply might prefer looking at certain objects.

Schilling thinks other lab techniques are more reliable. One is operant conditioning, which actively engages a baby's capacity to learn. Schilling cites a 1980s study by Anthony DeCasper of the University of North Carolina, in which pregnant women read specific stories out loud toward the end of their third trimester. Three days after a baby was born, it listened to recordings of its mother reading different stories. If an infant sucked on the pacifier at a specific rate, the recorder would play the particular story the mother read in her final weeks of pregnancy. The study showed infants not only recognized the sound of the specific story, but also learned how to play the desired recording.

Despite their reservations, both Shinskey and Schilling praise Wang's meticulous approach to ruling out alternative explanations.

“Su-hua consistently acknowledges the challenges that others and I have made,” Schilling says. “She actually incorporates those challenges and alternative hypotheses in her research designs. Doing so not only makes her a first-rate scientist, but it also leads to more sophisticated and compelling theoretical interpretations.”

No added pressure for parents

If babies are smarter than Piaget led us to believe, should parents take extra steps to ensure their babies develop sharp brains?

“Unless you're shoving your baby in the closet for weeks on end, most kids turn out to be okay within reason,” Shinskey says. “Most parents are probably already doing the right kinds of things with their kids.”

“The value [of developmental psychology] is never on pushing babies to be smarter,” Wang adds. “We're trying to understand the nature of these infant minds without manipulating anything.”

The experiments may yield insights into how to create optimal learning environments for babies, Wang says, but using this knowledge to create concrete learning tools is still years away.

“These are just building blocks for people to understand better about the nature of learning in early childhood,” she says.

Using the change blindness study as an example, Wang says researchers have made no direct connection between change blindness and learning disabilities, such as attention deficit disorder. But for the future, Wang believes her study can bolster people's efforts to help children afflicted with the learning disability.

“Sometimes, in some sad cases, children never master their attention well,” Wang says. “Perhaps we'll be able to come up with ideas to help kids who already suffer from attention deficits.”

Wang and Shinskey are careful to point out the preliminary status of developmental psychology's findings. However, commercial enterprises have capitalized on parents' eagerness to raise juvenile geniuses, with litigious results.

In May 2006, the Campaign for a Commercial Free Childhood filed a complaint with the Federal Trade Commission against the Baby Einstein Company, a Disney-associated toy company specializing in educational toys and multimedia for children as young as one month. The Campaign asserted Baby Einstein's marketing claims deceived customers into thinking their videos had educational value for babies. Such claims clashed with research from the American Academy of Pediatrics. Children younger than two years of age should refrain from watching television because it detracts from much-needed time for parent-child interaction, the academy maintained.

In December 2007, the FTC concluded its investigation by refusing to enforce legal action against Baby Einstein, citing the need for more research. Even so, Baby Einstein changed its website to remove any claims of educational value.

“I worry about parents thinking that if they get these kinds of things for their kids, they can create smarter kids,” Shinskey says. “That could result in some unnecessary parental pressure for children to achieve.”

Baby Einstein declined to comment for this article. However, Baby Einstein's press office sent official product information, which included the following statement: “Baby Einstein products are not designed to make babies smarter. Rather, [they] are specifically designed to engage babies and provide parents with tools to help expose their little ones to the world around them in playful and engaging ways—inspiring a baby's natural curiosity.”

Surprises for the future

Since Piaget's time, technology has allowed psychologists to create more sophisticated techniques to peer into infant minds, Shinskey says. These include measuring brain waves, functional magnetic resonance imaging, and Wang's use of the eye tracker.

Wang is now conducting eight research projects in her infant lab, breaking down infant intellectual development into fine points of study. One study, nearing completion, aims to determine what three- to six-month-old babies are capable of learning when taught a “false rule” (for example, a tall object can be concealed with a short cover). Early results show that the younger babies are capable of learning these false rules whereas the older ones aren't, a finding that surprises Wang.

“Very young infants who don't have much experience with the physical world are willing to learn all kinds of rules, including the impossible ones,” Wang says. “However, by the age of 5 months, they grow skeptical to the rules that don't make sense to them.” She's curious to see to what extent babies are willing to apply the false rule across different scenarios, and examine whether hands-on experience helps infants select the “right” rule to learn.

Like any other parent, Amber would be thrilled if Lenny turned out to be a genius.

“It would be great if he came home with A's every day,” she says. Being smart would open all kinds of doors for Lenny's future. Amber already wants Lenny to go to college later in life.

Will Lenny be a big flirt there? “I think he's going to be a ladies' man,” Amber says. “He'll take after his dad.”

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Biographies

Emmanuel Romero

B.S. (biology, with honors) San Francisco State University
Internship: California Institute for Regenerative Medicine (state stem-cell institute), San Francisco

Writing about science makes me feel like Dick York from a famous episode of The Twilight Zone. We both flipped a coin that landed on neither heads nor tails.

Am I a scientist? A creative writer? I came close to an answer in my community theater in San Francisco. There, the two joined in unholy matrimony—I wrote a futuristic play about robotic boyfriends (translation: love slaves). People laughed, cried, and learned that isotopes are natural variations of the same element differing in atomic mass.

I'm now a writer, but I'll never stop being a scientist. I researched infectious blindness in Ethiopia, and I manufactured biochemical reagents. I worked at the cutting edge, but I'd rather educate people on how deeply that edge penetrates.

I also hope to become telepathic, just like Dick York.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Krista Anandakuttan

B.S. (ecology and evolutionary biology) UC Santa Cruz
Internship: Bishop Museum, Honolulu, HI

I am inspired by the patterns in nature, and the research that explores them. Every day I hope to see something familiar in a new way and to share that through my work. The small things mean so much: a decaying leaf, a sprouting tree, my own kids. . . . Since discovering that I'm a science illustrator, I haven't looked back. Visit my web site.

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