A short history of brain hemisphere research
Early scientists found that the human brain consists of millions of small cells, called neurons. Each of these neurons has a central nucleus from which octopus-like tentacles move outwards.
Prof. Pyotr Anokhin (a student of Ivan Pavlov) found that it is not the number of neurons that determines intelligence and creativity, but the ability of the brain (the tentacles of the neurons) to make connections and so create new systems and patterns.
The human brain is divided into several regions, each with its own functions. The physical brain is made up of three major parts: the cerebrum, the cerebellum and the brain stem. The cerebrum, the largest of these parts, is divided into two hemispheres. The hemispheres are linked by a bundle of nerve fibres, called the corpus callosum.
In 1861, French surgeon Paul Broca published the case of his patient, Tan, who had a lesion in the left frontal lobe and had suffered severe speech loss. Broca was the first to present anatomical proof for the localisation of a particular brain function.
The concept ‘cerebral dominance’ began to emerge within ten years of Broca’s initial findings. During a 1930 study of 200 patients with brain damage, findings showed that damage to the left hemisphere resulted in poor verbal ability, and that right hemisphere damage resulted in poor non-verbal ability – in other words, tasks involving spatial ability and distance relationships.
Myers and Sperry started to experiment on animals about a decade later. Their research convinced them that the two hemispheres of the brain can be trained independently. When Sperry received a Nobel Prize in 1981 for his split-brain work, he summed up his belief in the complexity of the brain and the need for education to take individual differences into account:
The more we learn, the more we recognize the unique complexity of any one individual intellect, the stronger the conclusion becomes that the individuality inherent in our brain networks makes that of fingerprints or facial features gross and simple by comparison. The need for educational tests and policy measures to identify, accommodate, and serve the differentially specialized forms of individual intellectual potential becomes increasingly evident.
Brain research had revealed the individuality of the brain, and researchers such as Sperry were starting to call on education to take note of these findings. These early breakthroughs in brain research encouraged others to probe hemispheric differences, their impact on behaviour and the implications for education. |
