Have you ever been told you’re right or left brained? Have you ever been posed with this question in a job interview or major declaration? Should these important decisions really be based off of an idea that one side of your brain is more dominant than the other? Most people can agree that there are more factors that make up our personalities, the decisions we make, and how we take in the world around us than which side of our brain is more dominant. There may be some truth to the idea that each hemisphere is responsible for different functions, but whether or not one is more dominant, and thus more prominent, in our personalities is something that needs to be investigated more thoroughly. There is evidence, however, that one hemisphere may be more dominant in the way that we process information. This could play a major part in our personalities and thus how we interpret our surroundings.
Dominance in the Brain
What exactly is “hemispheric dominance” and where did the idea come from? To put it simply, hemispheric dominance is the idea that the two hemispheres of the brain are specialized to perform different functions and that individuals show a preference towards using one hemisphere more than the other. It is widely believed that hemispheric dominance originated from the misinterpretations of Roger Sperry’s split-brain experiments. Split brain is a term used to describe individuals who have had their corpus callosum severed (in response to epileptic seizures), which stops most, if not all, communication from the left and right hemispheres. Patients who have had this procedure show no loss of cognitive ability, however they have been known to show odd behavioral and linguistic responses. These experiments did demonstrate the existence of hemispheric dominance for some functions, but not all.
Is it Written in the Stars?
The idea of hemispheric dominance has been perpetuated largely due to people striving to better understand themselves. For many people, there is a comfort in saying “I’m a left-brained thinker”. The human mind likes to organize and categorize information. Therefore, when people are able to “categorize” their personalities into either left-brain or right-brain dominant, they are able to have a better “understanding” of how they take in and process information…or so they think.
An abundance of brain dominance tests have been developed that attempt to dissect people’s brains into categories as either left or right brain dominant. One can search “hemispheric dominance” on Google and find that nearly half of the first page consists of links to brain dominance tests. The other half contains links to websites explaining myths about hemispheric dominance. However, people tend to care less about disproving theories. Instead, they scroll aimlessly through the various quizzes available as part of the journey to “discover” more about themselves.
Many of the theories behind left and right brain dominance vary extremely in their understanding, scientific evidence, and audience. Some theories are driven by psychological differences in personality. Others are driven by ideas as extreme as astrology signs. Astrological principles have been applied to map out the left and right sides of the brain. Through this particular theory, it aims to explain left and right brain “dominance” by incorporating psychological classifications of personality, including thinking/doing and seeing/feeling. There is a “cross-over” that occurs so left and right sides of the body can interact, but it is “dominated” by one hemisphere depending on astrological signs. For example, earth and air signs such as Leo or Gemini are dominated by left-brain ideas such as logic and material thought.
Although some sources have more scientific validity than others, individuals tend to find comfort in “understanding” how they think and how their brains “work”. Additionally, such tests allow individuals to attain a baseline from which they may train their brains and become smarter. Most tests supply a “guide” of sorts on their results page describing how, for example, a right-brained thinker can strengthen their left-brain by practicing making lists or more set schedules, therefore becoming “smarter” by strengthening the weak side of their brain.
The idea of “brain training” is a very popular one and is now being utilized by companies for profit. Most notably, the website Lumosity claims to train your brain to enhance things like attention, speed, memory, and problem-solving, all for a small fee of $13 a month. With over 70 million subscribers, Lumosity is the web’s most popular “brain-trainer,” which is interesting since a study has found that the video game Portal 2 proved to be more effective in improving cognitive skills. A video game. But hey, Lumosity says their training is based on neuroscience so it must be true! (The power of play: The effects of Portal 2 and Lumosity on cognitive and non-cognitive skills, Computers & Education, Volume 80, January 2015, Pages 58–67.)
So, what’s the real deal?
Well, we know that the brain does in fact have two distinct hemispheres that are each responsible for performing certain tasks and cognitive functions. We know that both sides connect but the way information is processed is different. For example, areas designated to understanding and producing language are highly lateralized in a consistent fashion. Over 90% of people show significant left hemisphere dominance for language. This consistency however is affected by other factors, like handedness (70% of left handed people are left-brain dominant for language vs 90) and gender (males are more lateralized than females in general). Though there is a factor of variance, the majority of people demonstrate this consistent laterality.
Though the left hemisphere dominates language processing, the right hemisphere has its own contribution to understanding language. The right hemisphere is focused on visuospatial processing (guiding, grasping,manipulations of objects, facial recognition, and recognizing emotional cues). In summation, though the left hemisphere may be dominant for language processing, the right hemisphere helps with interpreting the information given. when someone is talking, you need your left hemisphere to understand and interpret the words that they are saying, but you need your right hemisphere to recognize who you’re talking to, what you’re talking about, and catch any subtle undertones that the other hemisphere might miss. therefore, one may be dominant in its own way, but both are necessary for complex processing. It seems safe to say that both hemispheres work together to form our personalities, behaviors, and the decisions we make, but that the way we think about things and the way we process things around us may suggest a slight hemispheric dominance in that area.
Sources
- http://rationalwiki.org/wiki/Hemispheric_dominance
- http://s3.amazonaws.com/Edcanvas/9007/local/split%20brain%20in%20man.pdf
- http://s3.amazonaws.com/Edcanvas/9007/local/split%20brain%20in%20man.pdf
- http://lucenaturale.com/HowAstrologyMapsToTheHemishperes.htm
- http://www.livescience.com/32935-whats-the-difference-between-the-right-brain-and-left-brain.html