Left Brain vs Right Brain
Understanding the Myth and Reality of Left Brain and Right Brain Dominance
Have you ever heard people say that they tend to be more of a right-brain or left-brain thinker? From books to television programs, you've probably heard the phrase mentioned numerous times or perhaps you've even taken an online test to determine which type best describes you.
What Is Left Brain - Right Brain Theory?
According to the theory of left-brain or right-brain dominance, each side of the brain controls different types of thinking. Additionally, people are said to prefer one type of thinking over the other. For example, a person who is "left-brained" is often said to be more logical, analytical and objective, while a person who is "right-brained" is said to be more intuitive, thoughtful and subjective.
In psychology, the theory is based on what is known as the lateralization of brain function. So does one side of the brain really control specific functions? Are people either left-brained or right-brained? Like many popular psychology myths, this one has a basis in fact that has been dramatically distorted and exaggerated.
The right brain-left brain theory grew out of the work of Roger W. Sperry, who was awarded the Nobel Prize in 1981. While studying the effects of epilepsy, Sperry discovered that cutting the corpus collosum (the structure that connects the two hemispheres of the brain) could reduce or eliminate seizures.
However, these patients also experienced other symptoms after the communication pathway between the two sides of the brain was cut. For example, many split-brain patients found themselves unable to name objects that were processed by the right side of the brain, but were able to name objects that were processed by the left-side of the brain. Based on this information, Sperry suggested that language was controlled by the left-side of the brain.
Later research has shown that the brain is not nearly as dichotomous as once thought. For example, recent research has shown that abilities in subjects such as math are actually strongest when both halves of the brain work together.
The Right Brain
According to the left-brain, right-brain dominance theory, the right side of the brain is best at expressive and creative tasks. Some of the abilities that are popularly associated with the right side of the brain include:
· Recognizing faces
· Expressing emotions
· Music
· Reading emotions
· Color
· Images
· Intuition
· Creativity
The Left Brain
The left-side of the brain is considered to be adept at tasks that involve logic, language and analytical thinking. The left-brain is often described as being better at:
· Language
· Logic
· Critical thinking
· Numbers
· Reasoning
The Uses of Right-Brain, Left-Brain Theory
While often over-generalized and overstated by popular psychology and self-help texts, understanding your strengths and weaknesses in certain areas can help you develop better ways to learn and study. For example, students who have a difficult time following verbal instructions (often cited as a right-brain characteristic) can benefit from writing down directions and developing better organizational skills.
Researchers Debunk Myth of 'Right-Brained' and 'Left-Brained' Personality Traits
Aug. 14, 2013 — Chances are, you've heard the label of being a "right-brained" or "left-brained" thinker. Logical, detail-oriented and analytical? That's left-brained behavior. Creative, thoughtful and subjective? Your brain's right side functions stronger -- or so long-held assumptions suggest.
But newly released research findings from University of Utah neuroscientists assert that there is no evidence within brain imaging that indicates some people are right-brained or left-brained.
For years in popular culture, the terms left-brained and right-brained have come to refer to personality types, with an assumption that some people use the right side of their brain more, while some use the left side more.
Following a two-year study, University of Utah researchers have debunked that myth through identifying specific networks in the left and right brain that process lateralized functions. Lateralization of brain function means that there are certain mental processes that are mainly specialized to one of the brain's left or right hemispheres. During the course of the study, researchers analyzed resting brain scans of 1,011 people between the ages of seven and 29. In each person, they studied functional lateralization of the brain measured for thousands of brain regions -- finding no relationship that individuals preferentially use their left -brain network or right- brain network more often.
"It's absolutely true that some brain functions occur in one or the other side of the brain. Language tends to be on the left, attention more on the right. But people don't tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection, " said Jeff Anderson, M.D., Ph.D., lead author of the study, which is formally titled "An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging." It is published in the journal PLOS ONE this month.
Researchers obtained brain scans for the population they studied from a database called INDI, the International Neuroimaging Data-Sharing Initiative. The participants' scans were taken during a functional connectivity MRI analysis, meaning a participant laid in a scanner for 5 to 10 minutes while their resting brain activity was analyzed.
By viewing brain activity, scientists can correlate brain activity in one region of the brain compared to another. In the study, researchers broke up the brain into 7,000 regions and examined which regions of the brain were more lateralized. They looked for connections -- or all of the possible combinations of brain regions -- and added up the number of connections for each brain region that was left- lateralized or right-lateralized. They discovered patterns in brain imaging for why a brain connection might be strongly left- or right-lateralized, said Jared Nielsen, a graduate student in neuroscience who carried out the study as part of his coursework.
"If you have a connection that is strongly left- lateralized, it relates to other strongly lateralized connection only if both sets of connections have a brain region in common," said Nielsen.
Results of the study are groundbreaking, as they may change the way people think about the old right-brain versus left-brain theory, he said.
"Everyone should understand the personality types associated with the terminology 'left-brained' and 'right-brained' and how they relate to him or her personally; however, we just don't see patterns where the whole left-brain network is more connected or the whole right-brain network is more connected in some people. It may be that personality types have nothing to do with one hemisphere being more active, stronger, or more connected," said Nielsen.
It turns out, though, that this idea of "brained-ness" might be more of a figure of speech than anything, as researchers have found that these personality traits may not have anything to do with which side of the brain you use more.
Researchers from the University of Utah found with brain imaging that people don't use the right sides of their brains any more than the left sides of their brains, or vice versa.
"It's absolutely true that some brain functions occur in one or the other side of the brain. Language tends to be on the left, attention more on the right. But people don’t tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection," study researcher Jeff Anderson, M.D., Ph.D., said in a statement.
