Speculation and fascination about the structure and function of the human brain has gone on for thousands of years. The discovery of hemispheric specialisation has its roots in ancient Greece. As early as 400 BC, Hippocrates noted that injuries to the left side of the head often resulted in impaired function to the right side of the body and vice versa. Hippocrates concluded from these observations the 'human brain of man is double'.

In the 19th Century, researchers began to focus on the left hemisphere as the possible location of our ability to speak. A doctor named Marc Dax presented a short paper in 1836 describing his observation of patients who had lost their ability to speak, or aphasia. He noticed that many of these patients who had lost their ability had sustained damage to the left side of the brain. He concluded that the hemispheres controlled different functions. The left side controlled speech. Gradually, interest increased in the scientific community as to whether or not the functions of the brain were localised. After conducting post mortem studies on the victims of aphasia, the French surgeon, Paul Broca, came to the conclusion in 1864 that the location of speech is in the left hemisphere.

Shortly thereafter, the British neurologist, John Hughlings Jackson, proposed the concept of cerebral dominance and stated that the left side of the brain was the “leading” hemisphere. Later research has shown that this is not always the case. However, the left language centre hemisphere does show itself more strongly as it contains the centre for speech.

In the early 1940’s Willian Van Wagenen performed the first “split brain” surgery to control epileptic seizures. These early operations were not very successful, mostly because only parts of the corpus callosum (the bundle of nerves that connect the left and right hemispheres) were severed, and not the entire bundle of nerves. Later experiments by surgeons Philip Vogel and Joseph Bogen were highly successful in controlling epileptic seizures. Later testing of these patients by Roger Sperry and his associates resulted in much of the knowledge of the specialisation of the hemispheres as we know it. That is, that the left hemisphere is responsible for speech, linear, analytic and rational thought, and that the right hemisphere is more holistic, conceptual, emotive and spatial.

In the 1950’s, Paul Maclean developed the concept of the triune brain. His research indicated that the human brain consisted of three layers – each layer corresponding to a different stage of evolution and responsible for different kinds of mental processing. The inner-most layer, he identified as the reptilian brain. This part of the brain is the earliest to develop and the most primitive. The middle layer of the brain is known as the limbic system and controls mostly emotional behaviour. The outer, or cerebral layer, is the most recent to develop. Most of our conscious thought takes place in the cerebral part of the brain.

Ned Herrmann began his research in 1976 as a result of his personal interest in locating the source of creativity. His search led to him trying to find an instrument or method of testing that would measure brain dominance or our preferred ways and modes of thinking. Not finding any, Ned developed the Herrmann Brain Dominance Instrument. His first attempts to measure brain dominance were based on EEG measurements of brain waves generated by individuals doing specific tasks. Although the results of these tests showed differentiation between the hemispheres, the method proved to be slow, expensive and difficult for the subject involved. Ned shifted his attention to a pencil and paper instrument as a potentially more successful approach. The results of this application led to the design of the Herrmann Brain Dominance Instrument, which has now been completed by over 1,000,000 individuals. It has proven to be extremely useful in a variety of applications, most notable staffing, team building, teaching and learning, creativity, and self-understanding.