Making The Connection

The Brain Is `Wired' In Steps, Which Suggests There Are Optimal Times For Learning.

February 26, 1998|By Ronald Kotulak, Tribune Staff Writer.

Parents who think their children may be budding geniuses in math, language or music may get a helping hand from University of Chicago researchers who have found that the best time for learning these subjects may start earlier and last longer than previously thought.

The new research indicates that various parts of the brain are "wired" at different times after birth, making it possible to more precisely chose the optimal windows for learning different skills.

An infant, for example, can recognize music it heard during fetal development. Newborns can do simple math long before they can speak, and foreign languages are more easily learned in preschool or elementary school than in high school.

The findings, reported in the Journal of Comparative Neurology, confirm earlier discoveries of the importance of the first three years in brain development, but they go much further. They show that wiring of the brain--the explosive burst of synaptic connections between brain cells after birth--appears to extend well into adolescence, when reasoning and other higher functions mature.

"We have always suspected that there may be a difference in the ways children learn at different ages, but until we did this study we didn't know for sure that those differences reflected the development of synapses," said Dr. Peter Huttenlocher, U. of C. professor in pediatrics. Arun Dabholkar, research technician in pediatrics, is co-author of the report.

Some parts of the brain, such as the visual cortex, are wired rapidly in the first year of life and need little coaxing other than exposure to people, objects and movement to develop.

The auditory cortex, which processes sound, explodes with new connections after birth and maintains this high level of activity until about age l2. Many experts now believe this is the best time for learning music and foreign languages.

"I can usually tell when somebody came to this country," Huttenlocher said. "If you come after the age of 15 or 16, you will learn English with an accent. Before that you can learn a foreign language accent-free."

The prefrontal cortex, which is involved in processing higher thoughts and motivation, undergoes an initial growth spurt after birth, but it does not appear to be fully developed until early adolescence, he said. This may be the best time to teach such things as calculus.

By showing that synaptic growth occurs in phases, researchers may be able to delineate the times for optimal learning of different skills, Huttenlocher said.

"This is a good beginning," said Carla Shatz, a neuroscientist at the University of California, Berkeley. "It points an arrow toward trying to learn what those different areas of the brain are doing at different times. The next step is to ask when we should be teaching certain skills."

Huttenlocher's research in the '70s and '80s revealed that most of the brain is built after birth. These findings, along with many other lines of research, have uncovered the role that appropriate early mental stimulation plays in helping the developing brain reach its potential. Some of the most important types of stimulation include talking to an infant from birth and reading to the child thereafter.

But there is concern that some parents may overdo mental stimulation in the misguided belief that they can turn their newborns into "super brains" by exposing them to flash cards and other types of activity.

"There has been a great deal of emphasis lately on the importance of early learning," Huttenlocher said. "That is important, but we need to realize what children are able to learn and not cram them with information they are not ready to handle."

There is also concern that the new information is sometimes misinterpreted to mean that if a child has not learned appropriate mental skills by the age of 3, it may be too late to improve brain function.

"We need to appreciate what adolescents can learn," Huttenlocher said. "They are able to perform higher-level thinking that is beyond most younger children."

Bruce McEwen, a Rockefeller University neuroscientist, said that research on how the brain learns shows it is capable of building and renewing synaptic connections throughout life.

The great explosion of synapses after birth enables the brain to learn how to make itself work from the experiences it encounters. Later, in adulthood and throughout life, the brain constructs new synapses in response to learning.

"If a kid lacks advantages early on, does that mean he's doomed for the rest of his life? No. The new findings tell us that we shouldn't give up on people who haven't had all the right advantages," McEwen said.

Synapses are the telephone lines that enable brain cells to communicate. Trillions are formed during the first two years of life. They are overproduced, it is believed, to guarantee that enough are available to form neural networks for vision, speech, thinking, emotions and other mental capacities.