Chapter 1. Brain Development: Middle Childhood

Synopsis

Human Development Video Activity

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You must read each slide, and complete any questions on the slide, in sequence.

dendrite

Slender projections of the nerve cell body that receive electrical impulses from adjacent neurons.

dendrites

Slender projections of the nerve cell body that receive electrical impulses from adjacent neurons.

myelination

The growth of myelin on nerve cells. The myelin coating allows nerve impulses to travel faster.

neuron

A nerve cell that receives and communicates information throughout the body as part of the central nervous system.

neurons

A nerve cell that receives and communicates information throughout the body as part of the central nervous system.

prefrontal cortex

The part of the brain at the front of the frontal lobe just behind the forehead. It is responsible for executive functioning, such as decision-making, reasoning, planning, impulse control, and prioritizing tasks.

synapse

The microscopic gap across which the axon of a neuron can transfer an electrical impulse to the dendrites of an adjacent neuron.

synapses

The microscopic gap across which the axon of a neuron can transfer an electrical impulse to the dendrites of an adjacent neuron.

Brain Development: Middle Childhood

Author

S. Stavros Valenti, Hofstra University

Synopsis

4 children (two girls and two boys) aged 6 to 11 standing on the edge of a dock in their bathing suits.

In this activity, you will observe illustrations and animations of brain development during middle childhood (ages 6 through 11). The brain adds myelin to the connecting fibers of neurons while also the pruning of synaptic connections occurs. The activity ends with a discussion of the role of experience and the continued development of the prefrontal cortex.

REFERENCES

Kolb, B., & Whishaw, I. Q. (2001). An introduction to brain and behavior. New York: Worth Publishers.

Siegler, R., Deloache, J., & Eisenberg, N. (2006). How children develop. New York: Worth Publishers.

Important Changes in the Middle Childhood Brain

Around the world, children between the ages of 6 and 11 are given more learning opportunities, responsibilities, and independence. One reason for this is that children of this age are better at thinking, planning, and attending.

Children in middle childhood can think logically most of the time as long as the problems are not too abstract, and they can master almost any physical skill that they attempt to learn. They can sit still for a long span of time and focus their attention on a school lesson or a game played with peers. At this age, learning is mostly fun, and mastering skills is not nearly as frustrating as it often was during early childhood.

Why do these changes begin to occur in middle childhood around the world? Clearly, important brain changes are at work.

Slowing of Brain Growth

^{The head and brain enlarge, the sutures of the skull close, and the brain is 95 percent adult size by the age of 10.}

Sometime between the ages of 6 and 8, the brain grows more slowly in size limited by the closing of the gaps (sutures) between the separate skull parts. By age 10, the brain is 95 percent the size of an adult brain. The number of neurons changes very little between infancy and adulthood. The growth of the brain at this time in life is due to the addition of more dendrites on the neurons and the myelination of the neural fibers.

Play the animation and watch the enlargement of the brain and head during middle childhood.

Question 1.1

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Correct! It is the increase in the number of dendrites and in myelination that is responsible for brain growth during middle childhood.

Sorry. Correct! It is the increase in the number of dendrites and in myelination that is responsible for brain growth during middle childhood.

Brain Maturation in the Prefrontal Cortex

Although the brain grows slowly during middle childhood, important changes are occurring at the microscopic level. The brain continues to mature in two important ways: the addition of myelin to the connecting fibers of neurons and the remodeling (pruning) of synaptic connections. Both of these changes are most pronounced in the prefrontal cortex, the area of the brain most responsible for inhibiting impulsive behavior, putting the breaks on emotional outbursts, focusing attention, goal-setting, and planning.

Graph showing the change in synaptic density over time for both the prefrontal cortex and visual cortex. The synaptic density in the prefrontal cortex steadily climbs until about 4 years old and then makes a gradual decline into adolescence. There is a steep decline in synaptic density between adolescence and adulthood. The synaptic density in the visual cortex climbs steeply from birth until the first year of life. Then, the synaptic density makes a gradual decline from one year old into adulthood.

Synaptic connections in the prefrontal cortex are reduced and reorganized throughout middle childhood and into early adulthood. In comparison, the visual cortex shows less maturation during this period.

The Role of Experience

Fine-tuning of neural networks is, in part, a spontaneous maturational process, but the unique life experience of every child is a primary influence on how the brain develops. Synapses that are used frequently tend to be retained while those that are not are lost. All that a child experiences in play, when practicing a musical instrument, or learning the rules of a game lead to a faster, more honed brain. A more efficient brain makes possible the advances in language, thinking, and social behavior that characterize middle childhood.

Assessment: Check Your Understanding

Question 1.2

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Correct! Children ages 6 to 11 can sit still for a longer span of time, focus their attention, and master skills without getting nearly as frustrated as they would have during early childhood (age 2 to 6).

Sorry. Children ages 6 to 11 can sit still for a longer span of time, focus their attention, and master skills without getting nearly as frustrated as they would have during early childhood (age 2 to 6).

Assessment: Check Your Understanding

Question 1.3

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Correct! At age 10, the brain is 95 percent of its adult size.

Sorry. At age 10, the brain is 95 percent of its adult size.

Assessment: Check Your Understanding

Question 1.4

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Correct! From ages 6 to 11, the brain matures by continued myelination and pruning of synaptic connections.

Sorry. From ages 6 to 11, the brain matures by continued myelination and pruning of synaptic connections.

Assessment: Check Your Understanding

Question 1.5

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Maturation in the form of synaptic pruning, or remodeling, is a spontaneous process. In addition, the brain develops in large part due to the unique experience of each child because synapses that are used more frequently tend to be retained, and those that are not are lost.

Congratulations! You have completed this activity.Total Score: x out of x points (x%) You have received a provisional score for your essay answers, which have been submitted to your instructor.