Understanding four major parts of the brain will help explain
how it functions.
The brain stem is at the base of the brain and, since the brain develops from the bottom up, it is the first part of the brain to become active. It serves two functions, both critical for survival. First, it controls such automatic functions as heartbeat and breathing, which, for the child to live, must operate from the moment of birth. Second, it is the area associated with "fight or flight." Whenever the child feels threatened or fearful, s/he will revert to functioning in this area of the brain and act quickly, without thought or planning, to survive.
Above the brain stem is the cerebellum, which is associated with movement. This densely packed area has many connections with the parts of the brain related to abstract thinking and mental focus. When young children do not move and exercise regularly, the connections are weaker than they otherwise would be, and thinking and focus suffer. Vestibular stimulation, such as swinging and spinning, particularly supports one's ability to focus.
The limbic area, or emotional center, of the brain is next. This area of the brain works differently from the other areas in that it contains structures that secrete substances into the blood stream. These substances circulate throughout the body, affecting how we feel and act. This is the area of the brain that releases adrenaline when one is stressed.
The cerebrum is the highest part of the brain and deals with thought processes. At the top and front of the cerebrum, almost below the natural hairline, is the frontal cortex. This is the area in which abstract thought occurs. It is not fully developed until children are about eight years old. The other parts of the cerebrum, which are connected to sensory input, develop earlier. This explains young children's ability to deal with concrete objects thay can see, feel, taste and smell before they can think about abstract ideas that do not have a sensory connection.
The cerebrum is covered by the cortex (Latin for "bark"). New research indicates that the cortex varies in thickness among individuals, and the thickness of the cortex, rather than the size or weight of the entire brain, is related to how smart individuals are that is, how quickly they can solve problems and learn new tasks. We now know that the experiences a child has determine the thickness of his/her cortex. We also know what types of experience thicken the cortex and what types do not.
Certainly, genetic inheritance plays a role in children's intelligence. But rather than set an absolute level of intelligence, heredity seems to set the range within which a child's intelligence is likely to fall. The environmental experiences a child receives determine the absolute level reached within this range. It currently is thought that the range of intelligence set by heredity encompasses about 40 I.Q. points. For example, a child may be born with a possible I.Q. range of 80-120. His/her experiences in the first years of life determine where in this range s/he ultimately will fall and if, for example, high school will be a struggle or college a success.
Go on to Neurons.