Are you organized or creative? Questions like these are designed to determine whether you are right- or left-brained, an idea based on brain lateralization.
You’ll learn how brain functions are lateralized and whether there really is such a thing as being right- or left-brained.
Your Brain and You
Think about your right and left hands. If you are right-handed, like the majority of the population, your right hand is more skilled at writing, drawing, or reaching for different things. In contrast, your left hand has a little more trouble forming perfect letters and making the correct movements to cut with scissors or pour water.When we look at the brain, we also see differences based on the right and left hemispheres (or sides) of the brain. Like many other body parts, we have two brains: one on the right side and one on the left side.
The brain is also similar to our hands in that the right and left brains are skilled at different functions. The idea that each hemisphere of the brain is specialized for certain skills or behaviors, is known as brain lateralization.
Definition of Lateralization
Brain lateralization, as we just learned, refers to the idea that the right and left sides of the brain are specialized for certain skills.
It represents a basic principle of the brain’s organization. The division of labor between the right and left hemispheres is thought to allow for more complex behavior, although pop psychology overgeneralizes this idea to suggest that different people are defined as right- or left- brained based (like saying someone musically oriented is right-brained or someone who is a rational thinker is left-brained). While some research evidence does suggest that these generalizations are somewhat supported by brain activity measures, it does not mean that a certain thinking style lies solely within each hemisphere.Despite the fact that lateralization is the division of tasks in the brain, there is not a complete separation into the left or right; both sides are almost always involved in any given task. The sides of the brain are in constant communication despite the existence of two distinct hemispheres.
Any time you are using your left brain, your right brain is aware of what’s going on. To see how connected the right and left brains are, try patting your head with one hand and rubbing your stomach with the other hand. Doing this is almost impossible because each side of the brain is sending a different message to each arm.
As those messages conflict, we tend to end up either rubbing or patting, but not both at the same time.
Right and Left Brain Functions
For many years, scientists have wanted to understand the different functions of the right and left brains. This is difficult to study because in a normal brain the two hemispheres are connected by the corpus callosum, a band of fibers between the right and left sides. Because of this, perhaps the most important information about brain laterilization comes from studying split-brain patients.
Split-brain patients are individuals who have had their corpus callosum removed. When it is removed, the right and left hemispheres cannot communicate. This poses no issue for the patients in normal circumstances, but it gives researchers special insight into the inner workings of the brain.Two famous psychologists, Gazzaniga and Sperry, conducted several of the first specialized tests that allowed them to see how the left and right brains work independently. In doing so, they discovered that the right and left brains perform different functions.
In the years that have followed their work, other psychologists have continued to examine brain lateralization. Let’s check out the functions that each side of the brain is reported to perform based on behavioral and imaging studies.First, we’ll examine the right brain:
- Controls the body’s left side
- Music & rhythm
- Facial recognition
- Holistic thought (seeing the big picture)
- Spatial orientation
Now, let’s look at the left brain:
- Controls the body’s right side
- Logical thinking
- Math skills
Remember that the some of the first research on the right and left brains was conducted by Gazzaniga and Sperry. Their experiments were based on the idea that the information that is presented to the left visual field crosses over and is processed by the right brain and vice versa. In the image below, you can see how information from the crossed axon and the uncrossed axon comes from one side of the eye (the right or the left). As a result, all the information that falls on the left side of the eyes goes to the right brain, while the information on the right side of the eyes goes to the left brain.
This type of organization exists throughout the brain with information from one side being processed in the brain on the opposite side. This extends to physical body control; the right brain drives the left side of the body, and the left brain drives the right side of the body. This is referred to as contralateral control.
Psychologists look at brain lateralization for information on different functions. To examine how language or emotion might be lateralized, a psychologist could use dichotic listening. In this procedure, sounds are presented to the right and left ears at the same time.
Participants are most likely to report hearing speech sounds at the right ear and emotional sounds at the left ear. Indicating that the left brain processes language while the right brain processes emotion. Brain lateralization can also be examined with imaging.
Scientists can compare the activation of the right or left brain during a specific task using methods like PET scans, fMRI scans, or EEG recordings.
We looked at the different principles of brain lateralization. Remember that the right and left hemispheres of the brain are specialized for certain behaviors, but this specialization does not equate to being right- or left-brained. Instead, it illustrates how labor is divided in the brain so that behavior can be more complex.
Psychologists use specialized tests to examine the way the right and left brains work. These tests might include specialized visual presentation, dichotic listening, or imaging.