https://developingchild.harvard.edu/resources/inbrief-science-of-ecd/
During the first year of life, the brain develops in regions associated with vision, hearing and language, as well as in higher cognitive function. Within the first year, the neural connections for the sensory pathways and language peak and start to decrease. This indicates fine tuning of the neural connections that are important in those areas are mostly completed. For higher cognitive function, neural connections peak up until year 4/5, followed by the fine tuning of certain pathways that continue on until later teen years.
4 years old:
- During the first few years after being born, our brains develop the areas that are responsible for controlling our most basic functions such as the somatosensory and somatomotor cortices.
- At 4 years old, sensation and vision have been fully developed.
6 years old:
- Language is in the early stages of development
- The prefrontal cortex is still very immature. Abstract thinking, and reasoning have yet to develop. This is a reason why young children can not process a large amount of information at once. Children will also throw temper tantrums due to the immaturity of their prefrontal cortex.
9 Years old:
- Children develop their fine motor skills such as being able to write neater and use scissors with proficiency when creating crafts. This is because the Basal Ganglia is developing. Their basic motor skills have already developed at the age of 4.
- Their parietal lobes are also beginning to develop which means that their math and geometry skills will develop.
11 years old:
- Reasoning and judgement are immature at this stage since the prefrontal cortex is not fully developed.
- The limbic system, emotional control centre, is increasing its development. This development of the limbic system and the immature prefrontal cortex explains why teens take dangerous risks with little emotional control due to the lack of reasoning and judgement capabilities.
- The parietal lobe is continuing its development. With this development, the logical thinking skills of a human is starting to mature.
15 years old:
- After 2 years old, neural pathways that are not needed start to die. This process of ‘Pruning’ allows our brains to become more efficient by only keeping the needed pathways. By 15 years of age, our brains have specialized due to the efficient pathways developed.
18 years old:
- The prefrontal cortex is much more matured. Abstract thought, reasoning, and self-control become possible.
21 years old:
- The brain is mostly mature. There is still room for maturation shown by the green areas in the prefrontal cortex. More emotional and decision-making skills will continue to develop in the next few years.
Source:
Dr. Paul Thomson, and Dr. Jay Giedd. "The Child's Developing Brain." The New York Times. September 15, 2008. Accessed June 05, 2018. https://archive.nytimes.com/www.nytimes.com/interactive/2008/09/15/health/20080915-brain-development.html.