12/05/97

The Infant Brain: An Unwritten Symphony

The brain of a baby is still forming long after the child has left the womb--not merely growing bigger, as toes and livers and arms do, but forming the microscopic connections responsible for feeling, learning, and remembering.

--- "How to Build a Baby's Brain," by Sharon Begley, Newsweek, Spring, 1997.

Scientists are learning that the stimulation of experiences after birth, rather than something innate, determines the actual wiring of the human brain.  Peek-a-boo, play with blocks or beads, touch, early music lessons and thousands of other interactions strengthen synaptic connections (the wiring) and lead to permanent cognitive, motor, language, social and emotional learning patterns. 

The infant brain forms neural connections at an astounding rate.  In the second half of the first year of life, for example, the prefrontal cortex, which is the seat of planning and logic, forms synapses so fast that it consumes twice as much energy as an adult brain.  In the first months of life, the number of synapses increases about twenty-fold.

Research on language acquisition has shown how "neuroplastic" an infant's brain is, plasticity that diminishes with age as neural connections form and become more specialized.  The size of a toddler's vocabulary, for example, depends on the amount of language he hears from those who interact with him most.  A recent study found that 20 month old children of chatty mothers averaged 131 more words than children of less chatty ones.  By two years of age, the gap had more than doubled to 295 words.  (J. Huttenlocher, Univ. of Chicago). 

The effect holds true for the complexity of sentence structure as well. "Mothers who used complex sentences 40 percent of the time," says Huttenlocher, "had toddlers who did so 35 percent of the time; mothers who used such sentences in 20 percent of their utterances had children who did so 5 percent of the time." 

Only live language, not television, produced these boosts in vocabulary and sentence complexity.  "Language has to be used in relation to ongoing events, or it's just noise," Begley reports.  Add cuddling, smiling, singing and other loving behavior between parent and child and learning enhancement is even more pronounced.

The downside of the infant brain's great plasticity is its vulnerability to trauma.  Portions of the brain have been shown to be 20 to 30 percent smaller than normal in some abused children, and synaptic development is reduced.  Trauma can also scramble neurotransmitter signals, which causes children exposed to chronic and unpredictable stress to suffer deficits in their ability to learn. 

Knowledge about infant brain development has profound implications for the education of our children.  During the first three years of life the rate of brain development reaches its peak, yet we usually begin formal education at age 4 or 5, after huge amounts of learning have already taken place.  Ironically, the vast majority of our best educated mothers and fathers work outside the home and leave their infants and young children in the care of modestly educated, minimum wage earning adults, who may know little about optimum conditions for mental, social and emotional human development.  

Research suggests that our most highly motivated and loving infant educators, namely parents and early childhood specialists, should be interacting with and educating our young.  Makeshift arrangements, low wages and indifferent care (or worse) lead to abysmal developmental outcomes for many U.S. children.  A shift of resources is indicated, to increase salaries of the early childhood labor force, to support family-friendly, licensed childcare centers and to fund intensive parent education programs. 

Think of the newborn baby's brain as an unwritten symphony.    Little by little, through interaction with the human and physical environment, notes cluster into phrases, rhythms and harmony.  Whether each symphony makes music or noise depends on the richness and quality of those interactions, which only the most enlightened caregivers can provide.

Please send questions or comments to bbruno@snet.net.