When an infant is born, her brain already has the approximately 100 million neurons that are present in a healthy adult brain. In the first year of life, those neurons grow and form connections at remarkable speed. In fact, by her first birthday, 75 percent of her brain's wiring will be completed.
Hearing
At birth, babies already possess an acute sense of hearing, an ability they develop in the uterus. Dr. Charles Nelson of the University of Minnesota's Institute of Child Development asserts that "full-term infants have the benefit of having heard their mother's voice for weeks preceding delivery." By monitoring the brain activity of 1-day-old newborns, Nelson found that they are capable of distinguishing their mother's voice from that of a stranger.
Vision and Movement
In the first few months of life, the anterior regions of the brain that control vision and movement grow at a decidedly faster pace than the prefrontal region that is responsible for abstract thought. Dr. John Gilmore of the University of North Carolina at Chapel Hill made this determination, and he also found that an infant's gray matter--the tissue in which most of the brain's neurons are found--grows by about 40 percent during this time.
Speech
From 6 to 12 months, brain activity in the temporal lobe of the left hemisphere increases. This region, known as the Broca's area, is responsible for speech. Patricia Kuhl of the University of Washington attributes this increased activity to practice and exposure to sound. Kuhl says that "babies form brain connections by listening to themselves and linking what they hear to what they did to cause the sounds. Eventually they will use this skill to mimic speakers in their environments."
Forming Attachments
In just days after birth, babies begin to form attachments with their caregivers. Sally Ozonoff of University of California at Davis' MIND Institute notes that healthy babies first form connections through eye contact. She says that babies "understand at a basic, perhaps hardwired level, that eyes are special - they look more at eyes than at other parts of the face." Between 4 and 8 months, babies respond to others with a social smile. This expression is different than earlier expressions of contentment in that it is provoked by the presence of a loved one.
Environmental Effects
If an infant is deprived of meaningful interaction and sensory input, her brain will be unable to develop properly. Jill Stamm of New Directions Institute for Infant Brain Development demonstrates this by comparing the brain scans of two toddlers, one of which had suffered sensory deprivation. The healthy toddler's neuroimage showed large yellow and orange areas, which is commensurate with healthy brain activity, while the neglected toddler's neuroimage was mostly black. Detroit Children's Hospital's Dr. Harry Chugani explains that if the baby is not exposed to necessary stimuli, "the brain areas that normally would be assigned to those functions would be reassigned to something else or might even become dormant."
References
- "US Fed News Service;" Newborn Brains Grow Vision and Movement Regions First; February 2007
- "Baby Talk;" What's Going On In Your Baby's Mind; Linda Henry; August 2001
- "Maryland Gazette;" Infant Mental Health Treatment Shows Promise For Helping Children With Autism: Associated Press; June 2007
- "Baby Talk;" Is It Love or Is It Gas?; Jenny Deam; December 2005
- "US Fed News Service;" Practice Builds Brain Connections for Babies Learning Language; July 2006
