How Kids Learn
Babies are quick studies-and parents are cramming them with Mozart and French lessons
Rather than preparing a child for a lifetime of high achievement, some researchers warn that overstimulation can actually impede learning. "If you try to teach infants with too much stimulation," says Arnold Sameroff, a psychologist at the University of Michigan, "it takes them much longer to learn than if you pace it out."
Consider the confusing world a baby sees: A bottle sits on a desk, and a picture hangs on a wall. Where does the desk stop and the bottle begin? How does the picture float? Can everything do that? A father prattles on about traffic. Which are the meaningful words in the stream of garble? At the dawn of this century, William James, a pioneering psychologist and philosopher, decided that infants were overwhelmed by the cacophony around them and were most interested in sleeping through it all. Today we know that a newborn brain is a complex computer that arrives with its wiring incomplete. An infant cannot focus his or her eyes more than a foot away, nor remember what happened five minutes ago. But baby's brain contains 100 billion neurons, which will sprout 1,000 trillion synapses before the child graduates from diapers. As these connections come online, the brain's many parts start to work in concert.
Early learning. The processing power inside that still-soft skull suggests that infants know a lot more than they are able to convey. But gathering hard scientific data on babies is not as easy as it might seem, because even the latest brain imaging technologies can't make out fine details, nor can they be used on babies: PET scans pose a radiation risk, and infants wriggle too much for an MRI. As a consequence, only a few researchers are investigating infant neural function. What they're finding is ample evidence that babies start on their journey of learning much earlier than traditionally thought. Charles Nelson, a neuroscientist at the University of Minnesota, measures the raw electrical signals emitted by the brain by attaching up to 128 electrodes on babies' scalps. He has discovered that even newborns produce distinctive brain waves showing they can distinguish their mothers' voices from another woman's, even while asleep.
Between 3 and 12 months, babies show an explosion in skills, which parallels big increases in the number of synaptic connections in their brains. The density of synapses in the visual system peaks at 3 months, allowing the development of depth perception. By 3 months, the cerebellum, which coordinates motor control, has matured enough for the baby to try to roll over. Meanwhile, the brain centers responsible for comprehending language have made enough connections to start functioning. Even before babies can say "dada," they seem to have the basic tools for learning syntax. To confirm this, Gary Marcus, a cognitive scientist at New York University, exposed 7-month-olds to an artificial language for two minutes. They heard sentences such as "la ta la" followed by a slight variation, like "la la ta." The infants discerned the difference and paid more attention to the sentences with changes.
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