In other words, the neural communiqués prevent one hemisphere from interfering with the other more often than they involve both hemispheres. Interestingly, most of the interconnected wiring is inhibitory rather than excitatory. In the mid-1900s, surgeons would sever this connective bundle to stop epileptic seizures-with remarkably few side effects. Well into the 20th century, scientists assumed the corpus callosum maintained structural integrity, but more recent research has established that it’s more a bridge than a scaffold, forming interhemispheric lines of communication. The brain’s hemispheres are connected through a network of hundreds of millions of nerve fibers called the corpus callosum. And unlike the skull, which begins as supple interlocked plates that fuse and harden over time, the brain within it undergoes a partial fission rather than a fusion.

The hemispheric differences are immense, have civilization-shaping ramifications, and reveal to us fundamental aspects of the human condition-some of which, as we will see, get short shrift in Western culture.ĭuring gestation, the hemispheric division emerges fairly quickly (for humans, within the first five weeks). It is true that both hemispheres are involved in numerous cognitive processes, but it would be a colossal mistake to argue there are no differences between the hemispheres. In their attempt to debunk the left brain-right brain myth, however, they propagated another. Numerous disheartened neuroscientists concluded that both hemispheres are involved in these functions and that there are no meaningful distinctions between them. Many neuroscientists had given up on laterality studies (looking at the hemispheres of the brain) after numerous assumptions about the left and right hemisphere functions were more or less disproven-though not before getting hijacked by pop psychologists misinforming the public. In some cases the functions described are just the opposite of what is commonly supposed. The problem with this breakdown is that it is wrong-completely wrong. Popular conceptions run along these lines: Left brain uses logic, right brain uses feelings left brain is detail-oriented, right brain sees the big picture left brain majors in language and words whereas right brain operates in terms of images and symbols the left brain is reality based whereas the right brain is fantasy based the left brain develops strategies while the right brain offers up possibilities the left brain is risk-averse, whereas the right brain is risk-taking. For decades, pop psychology has heralded the differences between the left brain and the right as a key to understanding people and their mental processes.

The master and his emissary