Understanding Brain Development

The teenage brain is very different from the adult brain. In fact, our brains are only 80 percent developed by adolescence, says Dr. James Wheless, co-director of Le Bonheur Children's Neuroscience Institute. Our brains develop at different rates from birth to adulthood, and understanding typical brain development helps us comprehend why kids do and say the things they do. In connection with Brain Awareness Month, Wheless helped explain brain development.

First Few Years of Life

At birth the brain has 100 billion cells -- more than the number of stars in the Milky Way, says Wheless. By age 2, the brain has many connections as an adult brain, and by age 3, it has twice as many. The brain develops most rapidly between the ages of 2 and 3, so this is why it's important for parents and caregivers to stimulate their child's mind. Reading, singing and interacting with your child help strengthen these brain connections.

Childhood

From ages 5 to 12-14 in girls (and two years later for boys) gray matter increases in the brain. Gray matter are the brain cells that do the work, or serve as the "hard drive." After age 14 (or 16 in boys), white matter in the brain increases. White matter forms the cabling or connections in the brain -- similar to wires in a computer -- so various parts of the brain can connect and communicate to each other). In the past, the brain was thought to have matured by age 10 or 12, but that's not the case.

Adolescence

Teens have more neurons than their adult parents, which is why they can learn very complex material quickly. But the wiring or connections are not fully refined. This is why teens can make apparent poor decisions and differ in emotional response from adults. The prefrontal cortex, which has to do with judgment, organization and self-control, is the last part of the brain to develop.

Most importantly, as teens' brains develop, they can be easily influenced. Getting adequate sleep and not overloading the brain allow it to make better connections during this critical time period in adolescence. Also, because final connections are being made, the brain is more susceptible to toxins (e.g., alcohol) than the adult brain. Teenage brains can take days to weeks to recover from the effects of alcohol, so drinking on the weekend can affect their test performance the next Thursday -- something that would not occur in an adult.