by Kerry Hosking

Created on: March 23, 2009

Anyone who has been fortunate to view an ultrasound image of an unborn child would be able to see the miracle of brain development unfolding. During the early stages of human life, a tube-like structure begins to appear within the tiny embryo, signaling the early stages of the central nervous system development. The following miraculous string of events may be unrecognizable to the untrained eye; however, they are the most significant moments of initial development in human life.

The tiny tube which is filled with fluid extends directionally from posterior toward the anterior region. It is on this anterior section that three areas begin to enlarge as they become the forebrain, midbrain and hindbrain. The three areas ultimately become five as the forebrain and the hindbrain areas further divide into two sections. These divisions in order from anterior to posterior are known as; telencephalon, diencephalon, mesencephalon, metencephalon and myelencehpalon. The word encephalon means, literally "within the head"(Pinel, 2007, p.50).

Beginning in the lowest division is the myelencephalon, also known as the medulla. The medulla has is a regulatory system for many bodily functions including numerous cardiac functions, and some respiratory reflexes (Pinel, 2007, p.52). The medulla is also a part of the brain stem, and operates as a highway for signals going to and from the brain. Inside the central core of the brain stem is a complex network of nuclei which ascends from the posterior to the anterior region and into the midbrain. The reticular formation often referred to as the reticular activating system (RAS) is said to be responsible for aroused states. Because there can be under or over aroused states, psychologists find the reticular activating system to be an especially important aspect in the study of learning disabilities and attention disorders such as ADD and ADHD (Cowan, (n.d), para.3).

Above the myelencephalon is the metencephalon, which is also a part of the brain stem. A bulge at the rear of the metencephalon is known as the cerebellum; part of its purpose is to control motor skills, therefore, any damage, disease or birth defect which affects it is likely to hinder movement (Pinel, 2007, p.53).

Catherine Limperopoulos, PhD and colleagues compared two groups of toddlers. All were born prematurely, but 31 had isolated cerebellar hemorrhage identified at birth, while 31 had normal brain imaging studies. In addition to motor problems, 61 percent of the children

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