BRAIN BASICS SET BY AGE 1, EXPERTS SAY : SPOKEN LANGUAGE SAID TO BE CRUCIAL TO INTELLECTUAL DEVELOPMENT.

Byline: Sandra Blakeslee The New York Times

When a White House conference on early child development convenes today, one of the findings Hillary Rodham Clinton will hear from scientists is that the neurological foundations for rational thinking, problem solving and general reasoning appear to be largely established by age 1 - long before babies show any signs of knowing an abstraction from a pacifier.

Furthermore, new studies are showing that spoken language has an astonishing impact on an infant's brain development. In fact, some researchers say the number of words an infant hears each day is the single most important predictor of later intelligence, school success and social competence. There is one catch - the words have to come from an attentive, engaged human being. As far as anyone has been able to determine, radio and television do not work.

``We now know that neural connections are formed very early in life and that the infant's brain is literally waiting for experiences to determine how connections are made,'' said Dr. Patricia Kuhl, a neuroscientist at the University of Washington in Seattle and a key speaker at today's conference.

``We didn't realize until very recently how early this process begins,'' she said in a telephone interview. ``For example, infants have learned the sounds of their native language by the age of 6 months.''

This relatively new view of infant brain development, supported by many scientists, has obvious political and social implications.

It suggests that infants and babies need not only a loving, but talkative and articulate caretaker, and that a more verbal family will increase an infant's chances for success. It challenges some deeply held beliefs - that infants will thrive intellectually if they are simply given lots of love and that efforts to purposely influence the cognitive development of babies are harmful.

If the period from birth to age 3 is crucial, parents may assume a more critical role in a child's intellectual development than teachers, which is sure to provoke new debates about parental responsibility, said Dr. Irving Lazar, a professor of special education and resident scholar at the Center for Research in Human Development at Vanderbilt University in Nashville, Tenn. And it offers yet another reason to provide stimulating, high-quality day care for infants whose primary caretakers work, which is unavoidably expensive.

The idea that early experience shapes human potential is not new, said Dr. Harry Chugani, a pediatric neurologist at Wayne State University in Detroit and one of the scientists whose research has shed light on critical periods in child brain development.

What is new is the extent of the research in the field known as cognitive neuroscience and the resulting synthesis of findings on the influence of both nature and nurture. Before birth, it appears that genes predominantly direct how the brain establishes basic wiring patterns. Neurons grow and travel into distinct neighborhoods, waiting further instructions.

After birth, it seems that environmental factors predominate. A recent study found that mice exposed to an enriched environment have more brain cells than mice raised in less intellectually stimulating conditions. In humans, the inflowing stream of sights, sounds, noises, smells, touches - and most importantly, language and eye contact - literally makes the brain take shape. It is a radical and shocking concept.

Experience in the first year of life lays the basis for networks of neurons that enable us to be smart, creative and adaptable in all the years that follow, said Dr. Esther Thelen, a neurobiologist at Indiana University in Bloomington.

The brain is a self-organizing system whose many parts cooperate to produce coherent behavior, Thelen said. There is no master program pulling it together, but rather the parts self-organize.

``What we know about these systems is that they are very sensitive to initial conditions,'' she said. ``Where you are now depends on where you've been.''

The implication for infant development is clear. Given the explosive growth and self-organizing capacity of the brain in the first year of life, the experiences an infant has during this period are the conditions that set the stage for everything that follows.

In later life, what make us smart and creative and adaptable are networks of neurons that support our ability to use abstractions from one memory to help form new ideas and solve problems, said Dr. Charles Stevens, a neurobiologist at the Salk Institute in La Jolla. Smarter people may have a greater number of neural networks that are more intricately woven together, a process that starts in the first year.

The Growing Brain:

What Might Help Your Infant

Dr. William Staso, an expert in neurological development, suggests that different kinds of stimulation should be emphasized at different ages. At all stages, parental interaction and a conversational dialogue with the child are important. Here are some examples:

First month: A low level of stimulation reduces stress and increases the infant's wakefulness and alertness. The brain essentially shuts down the system when there is overstimulation from competing sources. When talking to an infant, for example, filter out distracting noises, like a radio.

Months 1 to 3: Light/dark contours, like high-contrast pictures or objects, foster development in neural networks that encode vision. The brain also starts to discriminate among acoustic patterns of language, like intonation, lilt and pitch. Speaking to the infant, especially in an animated voice, aids this process.

Months 3 to 5: The infant relies primarily on vision to acquire information about the world. Make available increasingly complex designs that correspond to real objects in the baby's environment; motion also attracts attention. A large-scale picture of a fork, moved across the field of vision, would offer more stimulation than just an actual fork.

Months 6 to 7: The infant becomes alert to relationships like cause and effect, the location of objects and the functions of objects. Demonstrate and talk about situations like how the turning of a doorknob leads to the opening of a door.

Months 7 to 8: The brain is oriented to make associations between sounds and some meaningful activity or object. For example, parents can deliberately emphasize in conversation that the sound of water running in the bathroom signals an impending bath, or that a doorbell means a visitor.

Months 9 to 12: Learning adds up to a new level of awareness of the environment and increased interest in exploration; sensory and motor skills coordinate in a more mature fashion. This is the time to let the child turn on a faucet or a light switch, under supervision.

Months 13 to 18: The brain establishes accelerated and more complex associations, especially if the toddler experiments directly with objects. A rich environment will help the toddler make such associations, understand sequences, differentiate between objects and reason about them.

The New York Times

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