How the Brain Develops : Part 2

by Child Welfare Information Gateway

(Page 2 of 2)

Sensitive Periods

Researchers believe that during these years there may be "sensitive periods" for development of certain capabilities. Because synapses are being formed at such an intense pace during this time, the opportunities for learning are almost limitless. But as the process of pruning synapses starts to increase, especially after age 3, these opportunities begin to decrease. If certain synapses and neuronal pathways are not repeatedly activated, they may be discarded, and the capabilities they promised may be diminished. For example, all infants have the capacity, indeed the genetic predisposition, to form strong attachments to their primary caregivers. But if a child's caregivers are unresponsive or threatening, and the attachment process is disrupted, the child's ability to form any healthy relationships during his or her life may be impaired.

Although the first few years may be the "prime time" for learning, children and adults can learn later in life, but it is more difficult. This is especially true if a young child was deprived of certain stimulation, which resulted in the pruning of synapses and the loss of neuronal pathways. Helgeson offers the analogy of a country that has a dense network of branching streets; a traveler can go anywhere he wants, even unfamiliar places, by following the roads. If there are few roads, the traveler can still go places, but he has to travel "cross-country" and break new ground. It is doable, but much harder. As children progress through each developmental stage, they will learn and master each step more easily if their brains have built an efficient network of pathways.

Malnutrition

Malnutrition, both before and during the first few years after birth, has been shown to result in stunted brain growth and slower passage of electrical signals in the brain. These effects on the brain are linked to cognitive, social, and behavioral deficits with possible long-term consequences.

For example, iron deficiency (the most common form of malnutrition in the United States) can result in cognitive and motor delays, anxiety, depression, social problems, and problems with attention. Protein deficiency can result in motor and cognitive delays and impulsive behavior. The social and behavioral impairments may be more difficult to "repair" than the cognitive impairments, even if the nutritional problems are corrected.

While research has shown that the brain is more malleable in the first few years than at any other time in life, researchers disagree on how flexible or rigid the sensitive periods are. But they do agree that the experiences of the first few years form the foundation for children's future functioning. "While experiences may alter and change the functioning of an adult, experience literally provides the organizing framework for an infant and child".

Memories

The "organizing framework" for children's development is based on the creation of "memories." When repeated experiences strengthen a neuronal pathway, the pathway becomes "sensitized," and, at some point, it becomes a memory. Memories are an indelible impression of the world; they are the way in which the brain stores information for easy retrieval.

There are different types of memories, such as motor, cognitive, and emotional memories. Memories help us to navigate our world without having to really think about it. Children learn to put one foot in front of the other to walk. They learn words to express themselves. And they learn that a smile usually brings a smile in return. At some point, they no longer have to think much about these processes-their brains manage these experiences with little effort because the memories that have been created allow for a smooth, efficient flow of information.

The creation of memories is part of our adaptation to our environment. Our brains attempt to understand the world around us and fashion our interactions with that world in a way that promotes our survival and, hopefully, our growth. But if the early environment is abusive or neglectful, our brains will create memories of these experiences that may adversely color our view of the world throughout our life.

About the Author

www.childwelfare.gov
Formerly the National Clearinghouse on Child Abuse and Neglect Information and the National Adoption Information Clearinghouse, Child Welfare Information Gateway provides access to information and resources to help protect children and strengthen families. A service of the Children's Bureau, Administration for Children and Families, U.S. Department of Health and Human Services.