The word "cerebral" refers to the brain. One side of the brain usually becomes dominant by the time an individual is six years old. If a person is right-handed, the left side of the brain is dominant; if left-handed, the right side is dominant.
But, there is more to it than that. Aside from handedness, we usually prefer one leg, one ear and one eye. From his work with brain damaged adults, Dr. Orton believed that cerebral dominance has a lot to do with reading ability. More recent research with imaging has shown that in proficient readers, more than one side of the brain is used in reading. The corpus callosum, a part of the brain that helps the two sides communicate, helps this process.
A neurologist can determine whether or not an individual has developed cerebral dominance. However, there are a few simple things that a person can do to discover this. It's easy enough to determine handedness. People who can write and work equally well with both hands obviously have not developed cerebral dominance.
To see which eye is dominant, roll up a piece of paper into a narrow tube and look at an object through the tube. Most people will automatically choose the dominant eye. For the ear, ask someone to talk on the other side of a wall or turn the radio too low to determine what is being said. Put the ear against the wall or radio to hear. For the leg, run to a soccer ball and kick it. The chosen ear and leg are most likely dominant.
If a person has developed cerebral dominance, the chosen eye, hand, leg and ear will all be on the same side of the body. If he uses a combination of right and left, then the person has mixed dominance.
Mixed dominance or undeveloped cerebral dominance creates an imbalance that may affect the process of learning to read and develop fluent reading. The problem of reading disabilities at one time was called "word blindness" and more recently "dyslexia" or "reading disability." Dr. Orton's and Gillingham's program was structured, sequential and multi-sensory. If these children learn to read using a method that involves multiple senses (touch, sight, hearing, kinesthetic/movement), they will be successful readers. Many different programs for educators and parents have been developed following Orton-Gillingham principles.