By Karin Jegalian

In Amanda Woodward's lab, set up like small theaters, researchers track how long babies watch various behaviors and use eye trackers to reveal exactly what a baby is watching. The experiments yield insights into human development and provide practical insights on how babies learn— not through technologies like videos but by interacting with the world.

Why Study Babies?

“They’re an interesting population because they’re close to just what nature brings,” says Amanda Woodward, professor of psychology, who studies cognitive development in infants as young as 3 months old. Infant researchers maintain that looking at behavior before experience, language or even the ability to walk have shaped the mind helps reveal what it means to be a human being.

Infant researchers want to understand how experience interacts with our innate biology to understand normal development and also to put the study of developmental disorders—such as autism, language disorders and motor disorders—on sounder footing. For example, says Jeffrey Lidz, an associate professor of linguistics who studies language acquisition, “If you can’t understand how unimpaired kids learn language, you will never understand what can go wrong in the process.”

Studying Inarticulate People

Infant research takes patience.One way researchers try to infer the thoughts of babies, who may barely be able to control their heads let alone answer questions, is by measuring what they look at and for how long. While infant researchers’ waiting rooms are typically brightly decorated, their test labs tend to look like sparse theater spaces. Dark, or at least plain, surroundings keep the focus on just a few key elements. With parent and baby seated, a toy and a hand may peek out from behind a drape. A camera discreetly videotapes the baby’s face; an undergraduate researcher in another room taps out where the baby is looking—now the toy, now the hand— in fraction-of-second increments.

Researchers test what catches babies’ interest. Woodward,who studies how babies view people, gathers data from watching large numbers of babies and pools the data to infer what interests babies in general. She has found that as early as 3 months, babies distinguish people from inanimate objects. For example, after a baby repeatedly sees a hand reaching for one of two toys, 6-month-old or even 3-month-old babies suddenly perk up when a hand grabs a new toy, more than if the hand reaches for the same toy in a new position.

“In almost every experiment, incidental changes in how a hand moves are uninteresting, but changes in goals are riveting,” explains Woodward. If a mechanical claw performs the same behavior, babies look at new movements and new “goals”with equal interest. Apparently,babies care about the intentions of people but not of mechanical devices.

Language acquisition researchers, like Lidz and Rochelle Newman, associate professor of hearing and speech sciences, also use visual preference experiments.

They find, for example, that babies will look longer when a sound matches what they’re seeing, whether a moving mouth or an oscillating pattern of sound waves. Language acquisition researchers also use a method called head-turn preference, in which lights flash in front of and then on either side of a baby in coordination with particular sounds.

The researchers can measure what babies like to listen to. Lidz studies how babies learn linguistic concepts to explore humans’ innate sense of grammar. “The way we see what’s innate is by seeing how we learn,” he says. For example, babies seem to have an inborn sense of how words are grouped into meaningful phrases. Also, babies learn the meanings of words from context. He found, for instance, that 16-month-old babies understand the meaning of the invented word “blicket” differently when one says,“He’s tapping the blicket,” or “He’s tapping with the blicket.”

Newman, who studies speech perception in people ranging in age from 4 months to adulthood, has tested babies’ ability to hear words through noise. She has found that infants less than a year old are sensitive to background noise and not able to hear their name if the surrounding noise is as high as it is, say, in the average daycare. She has also found that babies are attuned to specifics. “Babies are surprisingly sensitive to irrelevancies,” she says, such as pitch, tone or whether a word is spoken by a man or woman. It takes time for them to distinguish important differences in language from those irrelevancies. Being exposed to the same words in a breadth of ways—as babies who spend part of their time in daycare might be— gives babies a chance to sort out which variations matter. Newman has been tracking a relatively small group of children from 7 months into their early school years to test what skills early on predict language skills later.

Take these baby steps to nurture your baby Courtesy of Maryland professors who work with infants and toddlers.

Expose babies to a variety of speakers so they learn general rules for language and what’s irrelevant.

Make sure babies aren’t exposed to loud background noise all the time—they can’t hear individual words as clearly when there’s too much interference.

Remove clutter to help babies move around easily.

Allow babies to play with many toys (even something as simple as pulling a cloth to move a toy on top) to provide insight into how the world works.

Like Newman, Jane Clark, professor and chair of kinesiology, follows relatively small groups of babies as they grow. Clark studies posture control, or how babies systematically learn to balance the segments of their body—from the head to the trunk to the legs—to sit up, stand up and then walk. She uses virtual reality experiments to tease out the links among the four senses that tell us where our bodies are: our eyes, our sense of touch, the vestibular system in our inner ears that gives us a sense of balance, and the proprioreceptors in our joints and muscles that give us a sense of how our limbs are positioned. By seeing how babies respond to divergent inputs through these senses, Clark studies how these senses are fused.

In her testing lab, light displays on the walls can give babies an artificial sense of motion. Similarly, a moving touch bar may give another, possibly conflicting, indication of motion. Infants sit or stand on a platform that tracks their center of gravity, and sensors attached to babies’ heads, shoulders and lower backs track subtle body movements.

By looking at motor skills in babies, before the skills become routine, Clark studies how the brain gains mastery over the body. “My research is focused on how the brain connects to the muscles to do the things we do almost automatically,” she says. “The mapping of the environment to the brain to the muscles is very complicated.”

The Payoff of Studying Babies

Babies can shed light on the core abilities of our species. Among these are walking, talking and being attuned to other people. Studies also prove when babies learn particular skills and what constitutes normal variation. In motor development,we know that whether babies walk at 9 months or 18 months does not predict their motor skills and development later. In language acquisition, it’s not yet clear what early skills may or may not be a harbinger of later skills, a question Newman is addressing.

Studying infants also gives clues to those trying to raise them on how to promote their development, or at least not get in the way. For example, Clark suggests that “vestibular stimulation” — rocking babies of 3 or 4 months back and forth while they are standing on our thighs — can promote their sense of physicalmastery. By making sure babies’ spaces aren’t too cluttered, we can encourage their exploration and give them “a sense of efficacy.” Excessive background noise can impede language development,but exposing babies to a variety of speakers can encourage it, Newman’s research suggests.

Whatever it is that babies need, they certainly don’t seem to need instructional technology. Simply interacting with the world fills theirminds. “Babies are developmental machines,” says Woodward. “They are built to actively create the learning experiences that they need.” TERP

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