the fetus develops nerve fibers allowing it to feel pain before it has developed the nerve fibers to suppress pain (Human, 2004). There is evidence that the fetus can respond to sound at four months. Eye movements and startle responses have been recorded from 16 to 32 weeks in the fetus. There is also evidence that the fetus can display a selective preference for different types of music at four to five months, and can recognize sounds after birth that it heard while in utero. Babies learn to recognize their motherÆs voice while in utero. A fetus at 16 weeks can also respond to light, and in late pregnancy some light filters through the uterine wall, eliciting a reaction in the fetus. In late pregnancy, the fetus has been seen to exhibit waking, calm sleeping, and rapid eye movement sleep, indicating dreaming.
By the 17th week of pregnancy, the fetus has about 1 billion brain cells, and they are proliferating rapidly, but they are not yet organized into a brain structure as such (Porter 2003). At birth the distinct areas of the brain are in place, but much growth still has to occur, and the brain is the only organ in the human that is not completely developed at birth. After birth, development in the brain consists of wiring and rewiring of synapses between neurons. Between birth and the age of eight months, these synapses are formed more quickly, and by this age there are about one trillion synapses. After the first birthday, the rewiring of the brain takes place more quickly, and by age 10 years, there are roughly 500 trillion synapses in the childÆs brain - about the same as in the average adult. This wiring occurs for approximately 12 years, but the brain remains flexible throughout life, making it available for future learning.
The brain operates on what is known as the ôuse it or lose itö principle, and those pathways that are used frequently are the ones that are retained, so both positive and negative earl...