Wednesday, August 28 2013, 06:43 PM MDT
Dr. Jeff Anderson on "Left Brain" & "Right Brain" Personality Traits
(KUTV) You may have heard the term "right brained" or "left brained", but new research has unveiled that these terms are just a common myth.
Dr. Jeff Anderson from the University of Utah's Neuroscience department is here to explain, what are the "left brain" and "right brain" personality traits?
Q: Why did you decide to study left brain-right brain personality traits? What did you discover?
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.
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.
Q: How did you conduct this study? What is lateralization of the brain?
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.
Q: Why is this a big deal?
Results of the study are groundbreaking, as they may change the way people think about the old right-brain versus left-brain theory.
Q: How did the left brain-right brain myth originate?
Although I haven't studied how the idea of left-dominant vs. right-dominant personalities has become so prevalent, it is based in some fascinating science. More than 30 years ago, work by the likes of Roger Sperry and Michael Gazzaniga studied "split-brain" patients. Roger Sperry received the Nobel Prize for this work. These were epilepsy patients who had a neurosurgical procedure to cut the connections between the brain's hemispheres to keep seizures from spreading. Clever experiments found that one could present stimuli to different sides of the brain, and discovered that the hemispheres have many different functions. We also know from lesions like strokes that affect one side of the brain that the hemispheres do different things. An enormous amount of work characterizing the function of left and right hemispheres has been done, and we know pretty well what these differences are. The left hemisphere is dominant for language function in 90-95% of individuals, and the right hemisphere is more active in processing attention to stimuli in the outside world. Although left-brain and right-brain stereotypes get many of the details wrong, there is no doubt that specialization of the hemispheres is real and important. And it has captured the imagination of popular psychology enthusiasts. The neuroscience community has never accepted the idea of "left-dominant" or "right-dominant" personality types. Lesion studies don't support this. It would be inefficient for one half of the brain to be consistently hypoactive. But yet, we haven't had good tools to evaluate this possibility formally that left-brain or right-brain networks might be stronger in some individuals compared to others.
Q: Do you think there's a scientific reason for the difference in personalities and logic? Or is it just experiential/left to chance?
Almost all neuroscientists, myself included, believe that there is a basis in neurobiology for personality types. We don't know if this arises from experience and as the brain learns and changes these experiences are "imprinted" in the way connections in the brain are formed, or to what extent some of these traits are based in genetic factors that predispose a person toward a personality type. Almost certainly both genes and experience contribute to personality. I believe the best current hypothesis is that subtle differences in the strength of brain connections between specific brain regions will be strongly correlated with personality traits. I think these will be distributed across the left and right hemispheres and not preferentially stronger connections in one or the other hemisphere.
Q: Is there more research to be done to determine differences in personalities?
We don't know yet exactly which brain regions are involved, or how the differences among people are coded in the brain, but this is an active field of research with exciting early possibilities now in the literature. I think this research will be fruitful over the next 5-10 years for a few reasons. Our tools are better, with rapidly expanding techniques in functional brain imaging. The open neuroscience movements, with rapidly expanding databases of brain imaging data contributed freely to the public by scientists all over the world, are making it possible to study large enough sample sizes that these questions are statistically approachable. And several labs around the world, such as Randy Buckner's lab at Harvard, are acquiring rich datasets of personality differences and high-quality brain imaging that will give researchers data to find these answers.
(Copyright 2013 Sinclair Broadcasting Group)