12/23/2022
The organization of a child’s brain is affected by early experiences.
Why would the brain create more synapses than it needs, only to discard the extras?
The answer lies in the interplay of genetic and environmental factors in brain development.
The early stages of development are strongly affected by genetic factors; for example, genes direct newly formed neurons to their correct locations in the brain and play a role in how they interact.
However, although they arrange the basic wiring of the brain, genes do not design the brain completely.
Instead, genes allow the brain to fine-tune itself according to the input it receives from the environment.
A child’s senses report to the brain about her environment and experiences, and this input stimulates neural activity. Speech sounds, for example, stimulate activity in language-related brain regions. If the amount of input increases (if more speech is heard) synapses between neurons in that area will be activated more often.
Repeated use strengthens a synapse. Synapses that are rarely used remain weak and are more likely to be eliminated in the pruning process.
Synapse strength contributes to the connectivity and efficiency of the networks that support learning, memory, and other cognitive abilities.
Therefore, a child’s experiences not only determine what information enters her brain, but also influence how her brain processes information.
Genes provide a blueprint for the brain, but a child’s environment and experiences carry out the construction.
The excess of synapses produced by a child’s brain in the first three years makes the brain especially responsive to external input.
During this period, the brain can “capture” experience more efficiently than it will be able to later, when the pruning of synapses is underway.
The brain’s ability to shape itself – called plasticity – lets humans adapt more readily and more quickly than we could if genes alone determined our wiring.
The process of blooming and pruning, far from being wasteful, is actually an efficient way for the brain to achieve optimal development.
Read more: http://www.urbanchildinstitute.org/why-0-3/baby-and-brain