At its very simplest, mind mapping identifies the control of the actions of the right side of the body by the left hemisphere of the brain and vice versa. There is a school of thought, mainly in popular psychology, that asserts that the left hemisphere dominates quantification and analysis and the right is responsible for holistic and integrative thinking: in general, mathematicians, engineers, and scientists are left-brain people; artists and writers are right-brain people.
Since the early observation from brain-damaged patients that there was at least some localization of function within the brain, a vast amount of information has been accumulated by neurologists, both by experiment and by observational correlation. Experiments have been carried out on animals, principally on rats but also on primates, by deliberately disconnecting a part of the brain and then testing the animal’s functions, both bodily and mental. In this way clues have been obtained, but the human brain is distinctly different from any other animal brain, and mapping the areas that control specific functions has been slower and more difficult, but still continues. At first, it was thought that each control area would be independent of the others, but it was soon realized that this is not the case; some specific functions are usually located in certain areas of the cerebrum but, except for a very few areas, if any moderate-sized portion of the cortex is destroyed, other segments gradually take over the lost functions. For example, stroke victims suffer function loss, but some function, sometimes all, returns, providing there are no further strokes. It is possible to make a map of the brain showing the following: (a) the sensory areas visual, auditory, olfactory, and so on; (b) the motor areas both to stimulate and inhibit the many muscles; and (c) the association areas the mental processes: memory, intelligence, learning, and so on. Recent developments in non-invasive techniques such as Positron Emission Tomography (PET) have added to our ability to identify and locate brain function.
It is, however, important to emphasize the interdependence of these locations. There are voluntary, involuntary, and learned motor reactions. Examples of each are the heartbeat, withdrawal from a painful touch, and kicking a football and the latter two involve communication between motor, sensory, and association areas.