Children's Brain Development (Part 1 of 2) (Feb 10)

Children’s Experiences Shape Development of their Brains

By Eric Pakulak, Ph.D.; Jessica Fanning, Ph.D.; Scott Klein, Ph.D.; and Helen Neville, Ph.D.

We are researchers who study human brain and cognitive development, and the effects of different kinds of experiences on this development. Results from such research carry important implications for parents, educators and policymakers – anyone who cares for children.

The human brain controls every single aspect of human functioning: Everything we know, do and feel depends upon different and specific brain systems that develop at different times. Yet this all-important organ is surprisingly small, weighing only two to three pounds, and is very soft and fragile – it’s about the consistency of room temperature butter. Any hard knock to the head can lead to irreversible harm to the brain. For the most part, the cells in the brain do not regrow. Thus, it’s a very good idea for people of all ages to wear helmets when doing sports activities.

Unlike some other animals, the brain of a human infant is very immature and isn’t fully adult-like until 25 years after birth. This long period of development means there is a lot of time for children’s experiences to shape their brains, and this is exactly what research has found: In fact, we now know that the architecture of the brain is dependent on the experiences children have. This is called “neuroplasticity,” which refers to how “plastic” or changeable by experience the brain is. Different parts of the brain are more or less sensitive to the effects of experience at different times in development, with some parts of the brain maturing faster than other parts. But, as you might guess, young children’s brains are especially “plastic.” This is one reason why it is important to consider scientific evidence on brain development when making decisions about how to care for and educate children.

For example, research has shown that for a child to see well it is important not only to have healthy eyes, but also that the parts of the brain important for vision need to be tuned by early visual experience. Some common vision problems, like cataracts in a newborn’s eyes that blur vision, can be corrected. But research has shown that cataracts must be removed early, within six weeks of birth, for the brain and vision to be tuned properly. Because other parts of the brain are more “plastic” throughout life, other problems are correctable later. Research suggests that there are some warning signs that a child might need to see an eye doctor if:

·                    one eye drifts or aims in a different direction

·                    the child turns or tilts his/her head to see

·                    the child squints or closes one eye, particularly when reading

·                    the child complains of headaches or eye strain

·                    the child experiences double vision

The story is similar with hearing. The brain is also important for healthy hearing and needs to be trained to do this with positive early experiences with sounds. Research also suggests that good hearing in early childhood is important for the development of speech. This research suggests that loud, repetitive sounds in early childhood can lead to poor brain organization for hearing, which is why it’s a good idea to avoid activities that would expose your child to such sounds, like constant and loud TV, music and movie theaters. As with other parts of the brain, it is also possible to identify and improve problems with hearing. For example, in individuals who are deaf, cochlear implants can help improve both hearing and spoken language development. Again, as in the visual system, this improvement is better when the implant is received before about age.

Other brain systems are also more sensitive to experience early in life. For example, many of you know that when exposure to a language is delayed, people will speak that language with more of an accent and have poorer grammar. Scientists have documented how brain systems important for these aspects of language need to be tuned early, and that this is the case for both spoken languages like English and for signed languages like American Sign Language.

Another brain system that is sensitive to experience early in life is important for certain aspects of attention. Next month, in Part 2, we’ll discuss attention and its development and how, through our research, we have designed and implemented training programs for both children and their parents.