Left Brain vs. Right Brain

Medically Reviewed on 7/21/2022

What is the right brain vs. left brain theory? What is brain lateralization (split-brain)?

Illustration of Left Brain vs. Right Brain
Illustration of Left Brain vs. Right Brain. Other researchers believe that the hemisphere of the brain in charge of certain operations is more dependent upon which hemisphere is dominant for an individual.

Some neuroscience researchers believe that the function of the human brain is best explained by the concept of lateralization, meaning that the right and left hemispheres of the brain perform very different functions and that the two communicate through their connections.

Other researchers believe that the hemisphere of the brain in charge of certain operations is more dependent upon which hemisphere is dominant for an individual.

Brain hemisphere dominance for a person often is predicted by whether he or she is right- or left-handed, and the way in which a person learns best often is categorized as left brain or right brain functioning.

What are the differences between the left brain and right brain (hemispheres)?

Many neuroscientists consider the concept of purely left-brain vs right-brain characteristics a myth. There are numerous theories and concepts that exist to explain how the right and left hemispheres of the human brain function. Many of which, have merits, and limitations.

Researchers Michael Gazzaniga and Roger Sperry proposed the concept of lateralization. In lateralization, the left hemisphere and right hemispheres of the brain have very different functions, but they communicate with each other through their physical connections.

  • An example of lateralization is language. For most people language function is located in the left hemisphere of the brain, particularly for right-handed people.
  • The foundation for this split-brain theory often is based on research that has been performed on patients who had their right and left hemispheres of their brain surgically disconnected to treat severe epilepsy.
  • The split-brain theory describes the left side of the brain as giving rational orders to the right side of the brain, and the right hemisphere as giving emotionally based commands.

Brain lateralization occurs in certain brain functions. In brain lateralization, certain regions of the brain perform specific functions. Many recent studies have shown that the right and left halves of the brain mostly are used equally, which shows the functional and physical connections between both the right and left hemispheres of the brain.

Regions of the brain that are in charge of functions like memory seem to vary depending upon which hemisphere is dominant for a particular person. While people's brain becomes more left-brained or right-brained (lateralized) with age, there is no difference in physical appearance (phenotype) that is correlated to being more left- (left-lateralized) or -right-brained (right-lateralized).


Left Brain vs. Right Brain (Characteristics, Differences, and Functions) See brain scan pictures of Alzheimer's and types of dementia See Images

Which side of the brain is dominant (characteristics and functions)?

Differences between right brain vs. left brain characteristics and functions

While no single theory completely explains the multiple complexities of brain functions, neuroimaging techniques show some distinct differences (asymmetries) between the left and right brain hemispheres, which is referred to as lateralization.

  • Examples of these differences include language function in the Broca surface area (sulcus) and Wernicke area of the left side of the brain, and emotional and nonverbal functions in the right side of the brain.
  • The areas responsible for language tend to be on the dominant side of the brain, and the opposite of the handedness of a person. For example, if you are left-handed, the language function areas of your brain are more likely to be located on the right side of your brain.
  • Moreover, if you are right-handed, your speech functions are more likely to be located on the left side of your brain.

Left-brain characteristics and functions

Left-brain functions are thought to include:

  • Understanding the sum of any situation, getting "the big picture”
  • Large muscle movements like walking
  • Sensing where one’s body is in space
  • Balance
  • Nonverbal communication
  • Emotional functioning
  • Sensing smells, sounds and taste
  • Regulating avoidance behaviors

According to neuroscience research, the left side of the brain or hemisphere:

  • Is positively stimulated by new experiences.
  • Controls the immune system.
  • Is responsible for involuntary bodily functions, for example, breathing, heart rate, and digestion.

Left-brain and right-brain psychology further describe left-brain functions as including

  • the ability to pay attention to details,
  • fine motor movement skills, and
  • the ability to convert sounds to language and translate their meaning.
  • Left-brain networks also are thought to control analytical/logical thinking, including a person's mathematics ability and problem-solving skills.

Right brain characteristics and functions

  • The right brain hemisphere is thought to allow young children to understand concepts of more versus less, but the understanding of specific number values involves the left hemisphere.
  • Other cognitive activities that tend to be governed by the right hemisphere of the brain include
    • attention to, and processing of the overall visual shape of items,
    • understanding verbal ambiguity, and
    • emotional and implied meanings.
  • In terms of brain development, neuroscience research indicates that until about 3 years of age, the right brain hemisphere tends to have the primary role (is dominant) in brain function.

Is there a right brain vs. left brain test?

While recent research often contradicts the concept of strict right-brain vs. left-brain laterality, the way a person learns most effectively may be described by what is often categorized as left-brain or right-brain functioning.

  • Brain Works software is thought to be an effective left-brain vs right-brain test.
  • The test uses questions in the form of written text and graphs to calculate the dominant side of a person’s brain.

How does left-brain vs. right-brain dominance effect learning styles?

Understanding which brain hemisphere is dominant in the way a person learns can help determine the most effective way to teach that person, and how they most efficiently study and acquire information.

  • Specifically, left-brainers are thought to be more visual learners, and right-brainers more auditory learners.
Medically Reviewed on 7/21/2022

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