Left Brain vs. Right Brain: The Science Behind Hemispheric Dominance

Have you ever blamed your lack of imagination or failure to grasp basic math on your brain? Specifically, because you’re a “left brain” or a “right brain” thinker? If you believe we were all born with a dominant brain hemisphere that determines whether you’re destined to be a rocket scientist or a starving artist, the evidence may surprise you.

Popular culture promotes the idea that our cognitive styles and personality traits are divided between the right and left brain. While the left hemisphere is often associated with logic, language, and analytical thinking, the right hemisphere is linked to creativity, intuition, and spatial awareness.

But that’s not what the research shows. Learn what’s really different about the left and right sides of the brain, along with expert tips on keeping both sides of your brain healthy and functional.

The brain is the control center of you and your body. It interprets information from your senses and allows you to think, speak, and move, while also regulating breathing, heart rate, and other “automatic” functions.

The brain is divided into three main parts: the cerebrum, cerebellum, and brain stem. The cerebrum takes up the majority of our brain space — close to 80 to 90 percent of it, says Grace Tworek, PsyD, a health psychologist at the Mellen Center at Cleveland Clinic in Ohio.

“What happens in the cerebrum is the interpretation of sound, sight, touch, regulation of emotion, reasoning, learning — all these really important functions,” says Dr. Tworek.

Structure and Function of the Left Hemisphere

The left hemisphere of the brain is often labeled as the "logical" side, primarily responsible for processing language, analytical reasoning, and problem-solving. Key functions include:

• Language Processing The Broca's area, located in the left hemisphere, is associated with speech production and the ability to articulate ideas. Wernicke's area (usually on the left side) connects to Broca’s area via a neural pathway and is associated with written and spoken language processing.

  [2]

• Analytical Thinking This hemisphere excels in tasks requiring detail-oriented analysis, critical thinking, and problem solving.
• Basic Tasks Activities like writing, math, and memorization often engage left-brain functions.

  [3]

Structure and Function of the Right Hemisphere

The right hemisphere is known as the more artistic and creative side of the brain. Key functions include:

• Creativity and Intuition The right brain plays a pivotal role in artistic endeavors, imaginative thinking, and holistic processing.
• Spatial Awareness It helps us navigate our environment and understand spatial relationships.

  [3]

• Emotional Response The right brain is more closely linked to how we respond to both pleasant and unpleasant stimuli.

  [4]

The left and right hemispheres are each linked to different brain activities, but they work together, says Tworek.

Neuroscientific Research

Research shows that while certain functions are more prominent in one hemisphere, both sides of the brain work together.

So while some people may be more analytical thinkers, and others may be more creative or artsy, it’s not because one side of the brain is stronger or more dominant, the authors concluded.

Hemispheric dominance (also called the lateralization of brain function) refers to the tendency for one hemisphere to outperform the other in specific cognitive tasks, explains Tworek.

“When we talk about hemispheric dominance, we’re essentially referring to the tendency for certain neural functions or cognitive processes to take place on one side of the cerebrum,” says Tworek.

“Typically, one dominant hemisphere will be responsible for language and speech, and most often this is the left hemisphere. Most people who are right-handed are left hemisphere dominant, and the right hemisphere would typically be responsible for processing surroundings and facial awareness,” she says.

But this is not the case for everybody.

“There are some left-handed folks out there, and it would typically be vice versa for them,” says Tworek.

The corpus callosum is the group of cells deep within the middle of the brain that serve as the wiring that connects the left and right sides of the brain and facilitates communication between them.

The corpus callosum allows nerve signals to move between the two sides of the brain and allows coordination of the senses, movement, and cognitive function so that we’re able to perform all the complex tasks that require both sides of the brain.

In pop culture and social media, we often see a lot about left brain versus right brain, and people have the idea that it’s a set of strengths and weaknesses that dictates who we are as a person, says Tworek.

“That’s actually not as accurate as many people have been led to believe,” she says.

The Myth of ‘Creative Right Brain’ vs. ‘Logical Left Brain’

The concept that most people fit neatly into left-brain or right-brain categories isn’t really backed up by evidence, says Tworek.

“There’s this idea that left-brain thinkers are more logical and rigid, and right-brain thinkers are more artistic or free-spirited. While it’s true that different parts of the brain are responsible for different things, that doesn’t mean that one side is significantly stronger or plays an outsize role in your personality,” says Tworek.

Early studies of how the brain worked may have contributed to this misperception that has since been proved inaccurate.

Individual Differences and Brain Functionality

“In terms of cognitive functioning, there’s a lot of variability from person to person in terms of what their relative strengths might be,” says Tworek.

Some of that we may be born with, as is the case when very young children have a specific preference for one hand over the other, usually their right hand, she says.

“But our brains are also programmed to change and grow in response to our environment and learning because of something called neuroplasticity. Oftentimes I say the more we’re out there living life and being challenged with new experiences, the more our brain is fine-tuning, responding, and flexing itself because of neuroplasticity,” says Tworek.

This concept is really important in people who have damage, such as a head trauma or a stroke, she says.

Because of neuroplasticity, our brains have the ability to adapt and form new neural connections to work around an injury.

Are there things you can do to make sure that both sides of your brain are challenged for optimum brain health?

“I get that question a lot: Is there something I can do to make sure that I have a good balance between the right and left?” says Tworek.

Practice is the key, she says. “And by that, I mean practice a new skill: Challenge yourself to do something that maybe you felt you weren't all that great at in the past, and find ways to flex your current skill set.”

“Our brains have the ability to hone different skills at any given time throughout our life, and so by allowing yourself to have novel experiences, you're actually encouraging your brain to step out of its ‘comfort zone,’” says Tworek.

“So traveling somewhere you've never been before, cooking a new recipe, taking an art class in a modality you've never tried before, these sorts of things are actually going to help with that, and also are fun experiences to have, too,” she says.

• The idea of people being strictly "left-brained" or "right-brained" is oversimplified; both hemispheres work together for cognitive functions.
• Brain function can vary from person to person, and strengths are influenced by genetics and experiences, not solely by hemispheric dominance.
• Engaging in new activities is good for your brain health, promoting adaptability and growth in cognitive skills throughout life.