17.2: Brain Development

Learning Objectives

1. Describe major structural and functional changes in the brain during middle childhood.
2. Explain the role of myelination and synaptic pruning in improving processing speed, memory, and cognitive efficiency.
3. Discuss how neurological development during middle childhood supports executive function, attention, and learning.
4. Identify how repeated experiences and learning shape brain architecture during this stage of development.

Typical Brain Development

The brain undergoes significant maturation during middle childhood, laying the foundation for advancements in thinking, learning, behavior, and emotional regulation. While the brain reaches approximately 90–95% of its adult size by around age 7, structural and functional development continues well into adolescence (Giedd et al., 1999). Between the ages of 10 and 12, the frontal lobes undergo significant development, which supports the growth of executive functions (van der Molen, 2000).

Processes and Changes in Brain Activity

One of the most important processes taking place in the school-aged brain is myelination. Myelination is the formation of a fatty sheath (myelin) around the axons of neurons. This sheath acts like insulation on electrical wires, allowing signals to be transmitted more rapidly and efficiently between different parts of the brain and nervous system. As myelination increases, children's reaction times improve, their thoughts become more organized, and they can process information more quickly and accurately. From ages 6 to 12, the nerve cells in the association areas of the brain—which are regions where sensory, motor, and intellectual functions are integrated—become nearly fully myelinated (Swaiman, 1978). This process supports the development of more complex cognitive tasks and smoother coordination between different types of input, such as understanding both verbal instructions and visual cues simultaneously.

The hippocampus, which plays a key role in memory consolidation—transferring information from short-term memory to long-term storage—also undergoes further myelination during this period. This development contributes to noticeable improvements in memory functioning, allowing children to retain, recall, and apply learned material more effectively (Rolls, 2000).

At the same time, the brain is continuing to undergo synaptic pruning from early childhood. This helps increase the brain's efficiency and tailor it to the child’s unique experiences and learning environment (Kolb & Gibb, 2011). This is one reason repeated practice and exposure are so crucial during this developmental period—each learning experience helps shape and refine the brain's architecture.

Figure \(\PageIndex{1}\): The human brain. Image by _DJ_ is licensed under CC BY-SA 2.0.

Research also shows that learning something new doesn’t just create an immediate effect; instead, learning can change the chemical pathways in the brain for hours or even days afterward. Neurons continue to fire and reorganize themselves following new experiences, which enhances long-term learning and adaptive thinking (Draganski et al., 2004). These processes occur mostly in the posterior regions of the brain during middle childhood, particularly in the parietal and occipital lobes, which are involved in spatial awareness/processing and attention. Activity in these regions supports learning in all academic areas across the curriculum.

As the prefrontal cortex matures, children also develop improved attention span and emotional regulation. These brain changes allow children to begin thinking more logically and systematically. They can engage in more effective problem-solving and begin to consider multiple perspectives. This increased cognitive flexibility also enables them to handle more responsibility in school and social settings.

References, Contributors and Attributions

Draganski, B., Gaser, C., Busch, V., Schuierer, G., Bogdahn, U., & May, A. (2004). Changes in grey matter induced by training. Nature, 427(6972), 311–312. https://doi.org/10.1038/nature02135

Giedd, J. N., Blumenthal, J., Jeffries, N. O., Castellanos, F. X., Liu, H., Zijdenbos, A., ... & Rapoport, J. L. (1999). Brain development during childhood and adolescence: a longitudinal MRI study. Nature Neuroscience, 2(10), 861–863. https://doi.org/10.1038/13158

Kolb, B., & Gibb, R. (2011). Brain plasticity and behaviour in the developing brain. Journal of the Canadian Academy of Child and Adolescent Psychiatry, 20(4), 265–276.

Rolls, E. T. (2000). Memory systems in the brain. Annual Review of Psychology, 51, 599–630. https://doi.org/10.1146/annurev.psych.51.1.599

Swaiman, K. F. (1978). Brain development in the middle childhood years. Journal of School Health, 48(5), 289–292.

van der Molen, M. W. (2000). Developmental changes in inhibitory processing: Evidence from psychophysiological measures. Biological Psychology, 38(1), 39–59. https://doi.org/10.1016/s0301-0511(00)00057-0