Brain development of a child

Conception to 2 weeks post conception (1st trimester)

Jun 17, 2005

The development of the brain begins in the first 8 weeks after fertilization. This stage of development involves the appearance of structural features of the brain during the embryonic period which continue to grow and develop for the rest of the pregnancy. Roughly 2 weeks after conception a layer of specialized cells in the embryo, the neural plate, begins to slowly fold over onto itself, eventually forming a tube-shaped structure.

4 weeks post conception (1st trimester)

Jul 17, 2005

At 4 weeks post conception, the tube gradually closes as the edges of the plate fuse together. The neural tube continues to change, eventually becoming the brain and spinal cord.
https://coverthree.com/blogs/research/kids-brain-development#:~:text=When%20a%20child%20is%20born,to%20half%20by%20age%20two
https://health.howstuffworks.com/pregnancy-and-parenting/pregnancy/conception/how-long-after-sex-does-conception-occur.htm

7 weeks post conception (1st trimester)

Sep 5, 2005

Then, 7 weeks after conception, the first neurons and synapses begin to develop in the spinal cord which allow the fetus to make its first movements that although cannot be felt, can be detected via ultrasound and MRI. Moreover, movement provides the brain with sensory input that prompts further development over the next weeks, like more coordinated movements.

2nd Trimester

Sep 17, 2005

At the start of the 2nd trimester gyri and sulci begin to appear on the brain’s surface which is basically complete by the end. The cerebral cortex is thickening, and complexity and synapse formation begins in the same area. Myelin, which allows for fast processing of information, begins to appear on the axons of some neurons which continue through adolescence.
https://neuroscientificallychallenged.com/posts/know-your-brain-cerebral-cortex

3rd trimester

Dec 17, 2005

The beginning of the 3rd trimester is crucial in transition as the cerebral cortex begins taking on jobs previously done by the more primitive brainstem. This includes reflexes like fetal breathing, responses to external stimuli becoming more regular, and it continues to develop for early learning.
https://www.facebook.com/Medicaspace.official/photos/a.1026003094251521/1690028354515655/?type=3
http://www.urbanchildinstitute.org

Birth

Mar 17, 2006

Newborns recognize and prefer human faces and discriminate expressions as well as their mother’s voice as a result of prenatal brain development. They have 100 billion neurons connected by 50 trillion synapses (neuron average 2,500 synaptic connections at birth), At this stage, cranial nerves are myelinated, and the cerebellum and prefrontal cortex continue making new neurons. The brain reaches 25% of adult size. Newborns have basic reflexes for survival such as sucking, startling, and grasping.

3 months

Jun 17, 2006

At 3 months, infants' recognition improves dramatically concuring with growth in the hippocampus (limbic structure related to recognition memory). Language circuits in the frontal and temporal lobes combine due to the language an infant hears. For example, a baby in an English-speaking home can differentiate sounds of a foreign language at 3 months but loses this ability at 12 months as the language they hear at home wired their brain for English.
https://iseg2017.web.unc.edu/
www.unicef.org

3-12 months

Mar 17, 2007

The brain’s language areas continue developing synapses and becoming more interconnected correlating with the child’s increase in language abilities. The cerebellum triples in size in relation to the rapid development of motor skills. As the visual areas of the cortex grow, the infant’s initially dim, limited sight changes to full binocular vision. Myelination proceeds from the posterior to the anterior of the brain and from the center to the sides. The brain reaches 50% of adult size at age 1.

1 years old to 2 years old

Mar 17, 2008

From age 1 to 2 synaptic density is reduced to half. Additionally, there is a significant increase in the rate of myelination which supports the brain in performing more complex tasks. For example, 2-year-olds can understand 2 step directions, talk, and walk. Also, higher-order cognitive abilities such as self-awareness develop as an infant is increasingly aware of their emotions and intentions leading them to desire more independence.
https://www.simplypsychology.org/critical-period.html