Infant Brain Development

The Brain begins to develop rapidly immediately after birth and has reached 80% of its size by age 3 and 90% by age 5 (Gross, 2008).  The brain generates and migrates the neurons during the prenatal period, while after birth that have reached the region of the brain where they will specialize (Gross, 2008).  The spinal cord and brain stem which control the basic processes of life such as respiration, reflexes, sleep, etc. are well developed by birth (Gross, 2008).  Neurons interconnect with other neurons to create synapses by axons and dendrites forming together (Gross, 2008).  Axons carry information away from the cell they work with and dendrites carry the messages to that cell (Gross, 2008). 

Synaptogenesis occurs rapidly in the sensorimotor cortex, thalamus, brainstem and cerebellum prior to the infant reaching five weeks of life (Gross, 2008).  At the three month marker, most of the synaptogenesis activity is associated with the visual cortex (Gross, 2008).  Different regions increase activity at different time frames.   After the first year, pruning begins and decreased production of neural activity, varying according to the age and brain region (Gross, 2008).   The limbic system and cerebral cortex, which is needed for higher learning tasks, develop at a much slower rate (Gross, 2008).  Research indicates that two million synapse are produced every second during the active periods of the cerebral cortex (Gross, 2008). 

Learning is dependent upon experiences.  Experience activates neurons to fire and repeating the experience causes the neural networks formed to strengthen (Gross, 2008).  Environmental influences, however, can have a negative impact on brain development.  Early physical and psychological stress has been found to delay the development or hinder growth in the hypothalamus and brainstem (Gross, 2008).   Researchers using MRI techniques have found that severely neglected and abused children have a smaller head and decreased brain mass (Gross, 2008).  Another study using MRI technique found that the greater the abuse the smaller the brain volume (Gross, 2008).  Studies of abused and neglected children in early childhood have detected delays in cognition, emotional factors, social skills, and physical development (Gross, 2008). 

Valerie Poling

References:

Gross, D. (2008). Physical Growth Health and Nutrition. In D. Gross, Infancy: Development from Birth to Age 3 (pp. 141-152). Pearson Education, Inc: Allyn and Bacon.

So, knowing this, what do we do?  How do we reduce the Shaken Babies?  Improve the experiences and expectant learning opportunities?  Prevent influences that negatively impact the development...?  share!