Brain Profile is based on Nobel Prize-winning research into the nature and processes of the human brain. In 1981 Roger Sperry received the Nobel Prize in Physiology "for his discoveries concerning the functional specialization of the cerebral hemispheres"

What is a Brain Profile

Physiologically, the brain consists of two halves, or hemispheres. Each hemisphere controls the movement and vision on the opposite side of the body.

Early scientists found that the human brain consists of millions of small cells called neurons. Each of these cells has a central nucleus from which octopus-like tentacles move outwards. Prof Pyotir Anokhin (a student of Pavlov) found that it is not the number of cells that determine intelligence and creativity, but the ability of the brain (the tentacles of the neurones) to make connections and so create new systems and patterns.

In 1981 Roger Sperry received the Nobel Prize in Physiology "for his discoveries concerning the functional specialization of the cerebral hemispheres". Sperry, his student Michael Gazzinga and the neurosurgeon Joseph Bogden, performed the first 'split brain operation', and can be credited with some of the most important insights we have of the physiology of the brain today.

After the first successful 'split brain' operation on a patient suffering from severe epilepsy, similar operations were performed on numerous other patients. The operation entails the severing of the corpus callosum, which is the main connection between the left- and right hemispheres of the brain.

The corpus callosum consists of more than 200 million nerve fibres. Without this connection, each of the two hemispheres of the brain functions virtually independently, largely unaware of the other hemisphere. Sperry's operation made it possible, for the first time, to study the separate functions of the two hemispheres of the brain. A large number of experiments followed Sperry's success, and were mostly focused on the identification of the processes of thought associated with each of the hemispheres.

Sperry discovered that each hemisphere had it's own specialist functions, confirming a hypothesis that had existed for a number of years. Sperry himself declared, 'Each disconnected hemisphere appears to have a mind of its own'. A very practical example of this came when one of Sperry's patients got involved in an argument with his wife. The patient reached out to grab her with his one hand, but to everyone's surprise, the other hand immediately grabbed the aggressive hand back.

Although the average person is not confronted with this extreme kind of behavior (largely because our corpus calossum is still in place), it has become clear that most of us prefer the functions and processes of one of the two hemispheres to the other.

The first four-quadrant instrument was developed by Ned Herrman in 1981. Herrman's studies of Sperry's split brain studies and Paul McLean's 'Triune Brain Model' lead to a combination theory, based on a metaphorical model of four quadrants.

Building on the work of Herrman and Paul Torrance, Kobus Neethling determined that both the left and right brain processes (as originally categorized by Sperry) could be divided into two definitive categories, effectively dividing the brain into four quadrants.

Between 1988 and 1991, 2000 adults and 1500 pupils (with an equal distribution between 10 and 19 years of age) were included in research groups to test Neethling's model. A question with four possible responses was posed to each of the subjects, who then had to arrange their personal thinking preferences from the strongest to the lowest. The choices for each question were based on the thinking processes belonging to the four different quadrants. Neethling found that thinking preferences fell equally into four preference-clusters, corresponding to the four quadrants. Both the validity and reliability levels of each of the quadrants were found to be higher than 80.