Brain Development

Summary:

Prenatal Period

The formation of neurons begins in the prenatal period. A few weeks after conception, the neurons begin dividing and migrating to their specific area of the brain. In this stage, the neurons will also begin myelination which is the forming of the myelin sheath around the axon of the neurons.

Newborn Period

At birth, the newborn brain has about 100 billion neurons and weights 2/3 to 3/4 pounds. The areas in charge of basic survival and reflexes are almost fully developed and the neurons controlling vision and hearing are quickly developing at this stage. The connections of neurons in the brain begin to rapidly develop in the newborn period.

Childhood

During early childhood the brain goes through rapid change. The brain forms and refines neuron networks through the processes of synaptogenesis, pruning, and myelination.

Synaptogenesis is the process of forming connections in the brain. This process, although it is biologically driven, is affected by experiences. During early childhood the brain will go through a process called synaptic overproduction which is when the brain forms more synapses than it will use. That’s when pruning comes into the picture. Pruning is the process that refines the synapses, which were created during synaptogenesis, based on experience. The connections that are used regularly are strengthened, and the connections that are not are pruned by the brain.

Adolescence

The brain of an adolescent reaches its adult weight at about fourteen.  Myelination in the frontal lobes enables the adolescent to become more capable of insight, judgment, inhibition, reasoning, and social conscience.  This front lobe development continues until age 25-30. The regions responsible for judgment, planning, assessing risks, and decision-making are the last areas to finish developing.

In this stage, the connections that are used regularly become stronger and more complex. Pruning also continues through adolescence. Also, new synapses form in response to new experiences.

Adulthood

In adulthood the brain is still changing but at a much slower rate than in childhood. The brain continues to develop connections but they are formed based only on specific experiences.

Keeping the mind active is important in order to prevent brain atrophy. Activities such as reading, crossword puzzles, talking to others, and maintaining relationships can help maintain healthy brain growth.

Analysis:

The fact that neurons form in the prenatal period and that the areas in charge of basic survival and reflexes are highly developed at birth shows that everyone starts with pretty much the same abilities. Synaptogenesis is also a biologically driven process. All of this is then shaped by experience. If an infant is not exposed to new information and experiences during early childhood, many of their synaptic connections will be lost. Early childhood is a critical period during a person’s life that can definitely affect that person’s intelligence levels later on. If the connections are used regularly and the brain is kept active these connections will become stronger and more complex which will lead to higher intelligence levels. Exposure to new experiences is important, not only during childhood, but all throughout that person’s life in order to keep the brain active.

Questions:

·         What could be the consequences of lack of exposure to experiences during early childhood?

·         What plays a bigger role, genes or exposure to experiences?

Link:

http://www.fcs.uga.edu/ext/bbb/brainTimeNewBorn.php

·         Brain development timeline. (2012). Retrieved from http://www.fcs.uga.edu/ext/bbb/brainTimeNewBorn.php