We have heard so much about the left vs. right brain being dominant that it's become the norm in media, on the internet, and even in how we talk about brain function. But is the idea of left or right brain dominance correct? The answer, in short, is no. However, there's some truth behind what has become a well known (and believed) myth.
As early as the 1960s, studies were done on individuals that had lost access to one hemisphere of the brain as a result of surgical intervention to address epilepsy. The work done by Roger W. Sperry (1982) found that the left hemisphere was specialized for language, while the right supported emotional and non-verbal functions. This work resulted in Sperry receiving the Nobel Prize for Physiology and Medicine in 1981. From there, though, popular media stepped in and explained the study in more simple terms...and like a game of "telephone," pretty soon everyone had turned the science of these specializations within the brain into the left vs. right legend we have today.
Over the years, many studies have demonstrated that the brain is not quite that simple. The basic premise still remains the same - that each hemisphere is specialized for specific functions, as outlined below.
Language - The left hemisphere of the brain, specifically the Broca's and Wernicke's areas, are associated with speech production, language, and writing.
Emotion - Emotion remains primarily the domain of the right hemisphere, where it is responsible for the expression of emotion and how it feels. The left hemisphere also has a role in emotion, though. It focuses on the "what" of the emotion - categorizing and labeling what was said or done in the moment the emotion is being felt.
Sign language - Interestingly, visually based languages are the domain of the left hemisphere. Studies of the hearing impaired show that they process sign language in the speech center of the brain.
Handedness - Left- vs. right-handed individuals use the left and right brain differently. Left-handed people process language equally distributed throughout the brain, while right-handed people utilize only the left hemisphere. This is one reason left-handed individuals recover more quickly after a stroke. Handedness itself has been shown to be present in the womb. Genetic studies have shown that the PCSK6 gene is “intimately involved in turning a spherical ball of equally oriented cells into an embryo that has discernible left and right sides.”
Male vs. Female - Male and female brains develop differently from before they are born. Females tend to have verbal centers in both hemispheres, while males tend to have only one verbal center, in the left hemisphere. Many studies in the past have suggested that male and female brains have structural differences, as well, but as of this writing, more recent studies have proven them to be false. Instead, it is the functioning of the male vs. female brain, as outlined earlier that seems to be coming forward in the literature.
Intuition and Psychic Ability - Some evidence suggests that intuition and psychic ability are primarily the domain of the right hemisphere. Sensing paranormal activity and mediumship have also been linked to the right hemisphere of the brain. I'll be sharing more of these studies in future posts as I know they are of great interest as we work to improve our abilities!
As you can see, there is a great deal of truth to the left vs. right brain attributes and functions, however, the idea that there is a dominant hemisphere of the brain is unfounded. I hope this helps clarify what is science vs. what has simply become an accepted belief. I am excited about bringing lots more information about how we process information, particularly our intuitive, psychic, and paranormal senses, in future posts.
Till then, thanks for stopping by!
Corballis M. C. (). Left brain, right brain: facts and fantasies. PLoS biology, 12(1), e1001767. doi:10.1371/journal.pbio.1001767
Roll WG, Persinger MA, Webster DL, Tiller SG, Cook CM. Neurobehavioral and neurometabolic (SPECT) correlates of paranormal information: involvement of the right hemisphere and its sensitivity to weak complex magnetic fields. Int J Neurosci. 2002 Feb;112(2):197-224.
Sperry, R. Some effects of disconnecting the cerebral hemispheres. Science. 1982 Sep 24; 217(4566):1223-6.