What you need to know about children's brain development

Have you ever had an opportunity to share 20 minutes of information about a baby's brain development with a group of parents or policy makers and wondered how to select the most significant points to convey? Over the past eight years, we have, and we want to share with you what we've come up with.

Brain research is complicated, but its message is simple: babies are born learning and what they learn is up to us. New research on infant brain development shows that a child's experiences in the first three years of life have a distinct impact on her later development and learning. Here's why.

All babies are born with one organ that is not fully formed—the brain. Three-quarters of a child's brain develops after birth. Neuroscientists once thought that brain development was mostly influenced by genetics. Now there is evidence that a baby's environment determines how the neural pathways are connected.

Children's brains develop at an incredible rate in the first five years of life. A newborn's brain is only about one-quarter the size of an adult's. It grows to about 80 percent of adult size by three years of age and 90 percent by age five. Every baby is born with 100 billion neurons, or brain cells, mostly unconnected. The connections between neurons, called synapses, are created by the sensory experiences in a baby's physical and emotional environment. Hearing, seeing, touching, smelling, and tasting (especially tasting books!) stimulate the growth of these neural connections. This neural connection often is referred to as "getting wired."

Brain development is the continuous process of wiring and rewiring these connections. New experiences establish new connections. When a pathway is used frequently, the brain recognizes its importance and covers it with a myelin sheath to protect it. Messages are then sent more efficiently.

A baby's brain has the amazing capacity to adapt to the environment in which she is placed, influencing not only the number of connections but also the way these connections are wired. Her experiences will likely determine how she will express and control emotions, get along with others, and view learning. This ability to develop and change in response to the environment is called the brain's "neuroplasticity." Neuroplasticity makes it possible for a child's brain to compensate for some kinds of damage that might occur and makes it possible for us to continue learning all through our lives.

Dr. Bruce D. Perry of Baylor College of Medicine in Houston has researched the effects of neglect and trauma on a baby's brain. He found that children who receive little attention from adults or little opportunity to explore their world have 20 to 30 percent smaller brains than most children their age. And prolonged exposure to stress, abuse, or trauma also alters the way the brain functions. High levels of the hormones cortisol and adrenaline are released in response to stress. These children are then "stuck in high alert," continually reading facial expressions and situations for threats, which in effect will organize their brains differently. This leads to children who respond inappropriately to benign stimuli and makes it harder to develop secure relationships.

Research on the impact of early attachments confirms that warm, responsive caregiving is essential to healthy brain development and building secure attachments. These loving interactions lay the foundation for learning.

But there are no tricks to making baby smarter. This new information about how the brain develops confirms what we have known about child development. All children need good prenatal care, loving attachments to adults, freedom to explore their environment, and age-appropriate stimulation to prepare them for learning throughout life.

The brain is especially receptive to stimulation in the area of language acquisition during the first three years. Research shows that young children who have been talked to and read to by their adult caregivers exhibit language skills that far exceed those of children who received little verbal stimulation. Language is the foundation of cognitive development, so we tell parents that talking, singing, and reading to their baby is the best way to build a healthy, efficient brain.