Left and Right Hemisphere of the Brain

The brain is the vital organ of the central nervous system. It is a complex organ consist of billions of interconnected neurons and glia. The brain has two sides and separated into unique lobes. Each lobe has a specific set of functions.

Although the brain is a complex organ – a hardworking one with a hundred billion neurons, it surprisingly weighs only three pounds. It makes up around 2% of the human weight and only takes up about 20% of the body’s total energy. 

The brain, being an intricate organ, performs a lot of functions. The two sides of the brain communicate with one another to perform all vital bodily processes. Both the left and the right side of the brain look very much alike but they too share some differences, especially in processing information.

Lack of integration between the different components of the brain could result in some forms of impairment.

The human brain has the ability to recognize itself. It has the ability to learn and adapt to change. Each side of the brain has a distinct function, which affects the person’s ability to learn and adapt. (1)

What is Brain Lateralization?

Information that enters the left hemisphere travel across the corpus callosum going to the right side of the brain and vice versa. The two hemispheres of the brain (right and left hemisphere) function interdependently.

Each of them has a role to play in the processing of information although the other is more dominant in certain functions. The process is called brain lateralization. The degree of brain lateralization is not the same in everyone. (3)

Split-brain experiment 

If you cut the corpus callosum and separate the brain’s two hemispheres of a patient suffering from severe seizer disorder, the frequency and severity of seizure attack will be reduced significantly. 

Left Brain and Right Brain Theory

A person can either be right-brained or left-brained. It means that one side of the brain is dominant. The left-brained dominant people are methodical and analytical in nature. Those right-brained dominant are creative and artistic.

The left brain and right brain theory was created in the 1960s by a psychologist named Roger W. Sperry

The Left Hemisphere of the Brain

The left side of the brain controls the right side of the body. If the left side of the brain is dominant, the person is logical and more academically inclined.

You most likely excel in academics, especially math and science. The left hemisphere of the brain is also called the digital brain. It is the one responsible for the following:

  • Verbal
  • Analytical
  • Order
  • Reading
  • Writing
  • Computations 
  • Sequencing
  • Logic 
  • Mathematics
  • Thinking in words
  • Linear thinking 
  • Visual based languages such as in mute and deaf people

Left hemisphere dominant people usually excel in the following fields:

  • Business analyst
  • Programmer
  • Reporter 
  • Scientist 
  • Network administrator 

Detailed information about the functions and characteristics of the left brain. 

  • It has the ability to understand the sum of any situation/look at things from.
  • It involves the movement of large muscles such as walking.
  • It plays an important role in maintaining balance.
  • It is responsible for non-verbal communications. 
  • It can sense smell, taste, and sound.
  • It is responsible for emotional functions. 
  • It regulates avoidance behavior. 
  • It controls the immune system.
  • It is in charge of involuntary body functions like digestion, the beating of the heart, and breathing. 
  • It is stimulated by new experiences. 
  • It affects the person’s ability to pay attention to details.
  • Fine motor skills.
  • Convert sounds to language and translates meaning. 

The Right Hemisphere of the Brain

The right side of the brain controls the left side of the body. A right hemisphere dominant person excels in arts. It is visual and intuitive. It is also called the analog brain. It is responsible for the following:

  • Creativity
  • Imagination
  • Intuition
  • Holistic thinking
  • Arts
  • Feelings visualization
  • Non-verbal cues
  • Rhythm 
  • Daydreaming 
  • Emotions 

Right hemisphere dominant people usually excel in the following fields:

  • Graphic design
  • Interior designer
  • Musician
  • Painter 
  • Psychologist
  • Counselor 
  • Manager 

Detailed Information about the Functions and Characteristics of the Right Brain 

  • It allows young children to grasp and understand the concept of more versus less. 
  • The right hemisphere of the brain is responsible for some of the cognitive functions such as attention, processing of visual shapes and patterns, emotions, verbal ambiguity, and implied meanings.
  • Children below 3 years old are predominantly governed by the right brain. (2)

Is Hemispheric Dominance Different Between People?

Hemispheric dominance varies from one person to another. The hemisphere of the brain used in every activity is not always the same for every person. Some experts believed that the activities of the brain are influenced by the person’s right-handedness or left-handedness.

Understanding which part of the brain is dominant in a person is essential in determining which learning style is more effective. Left hemisphere dominant people are visual learners. On the other hand, right-hemisphere dominant people are auditory learners. (5)

Right brain hemisphere vs left brain hemisphere

The left brain hemisphere is needed for rational thinking and logical skills such as mathematics and language. On the other hand, the right side of the brain is responsible for creative activities like arts and connecting to others in an emotional way. So, a person who is left brain dominant is logical while the right brain dominant is more emotional. (5)

Brain injury and effects on the body

Brain injury or also known as stroke can significantly affect the body. As you know, the brain is involved in most of the vital processes of the body.

However, the hemisphere of the brain that is affected by the injury can determine what specific symptoms and problems the body could have. 

Injury in the Left Hemisphere of the Brain.

Since the left hemisphere of the brain controls the right side of the body, any injuries in it could lead to right-sided weakness. The following problems could arise:

  • Difficulty understanding both written and spoken words.
  • Difficulty expressing both written and spoken words.
  • The person finds it difficult to coordinate or program motor movements for speaking or medically called apraxia.
  • Slurred speech or change in the sound of the voice (dysarthria).
  • Difficulties with numbers.
  • Difficulty in dealing with complex problems. (4)

Injury in the Right Hemisphere of the Brain.

The right hemisphere of the brain controls the left side of the body. Any injuries on the right side of the brain could result in left-sided weakness. The following problems could arise:

  • The patient finds it challenging to focus on concentrate on a task.
  • The left side of the body can’t attend to things.
  • Difficulty in processing the information on the left visual field. 
  • The patient can’t recall the previously learned information as well as difficulty in learning new information.
  • The person fails to identify problems or even generate solutions.
  • The person’s social communication skills are affected such as interpreting abstract language, understanding jokes, making inferences, and understanding non-verbal cues. 
  • Difficulty in recalling significant events such as the time, date, and place.
  • Difficulty in organizing things such as arranging information and planning. (4)

A detailed comparison between the right brain hemisphere and the left brain hemisphere is shown in the table below.

FunctionsLeft Brain HemisphereRight Brain Hemisphere
FunctionsSpeech and languageMathematical computationsRational reasoningLogical analysis
IntuitionSpatial awarenessMusicCreativityFacial recognitionArtRhythm 
Personality LogicalAttention to detailsAnalytical ArtisticCreativeOpen-minded
Traits Rational decision-makingLinear thinkingReality-oriented Random thoughtsNon-verbal processingHolistic thinkingFantasy-oriented
Thought process Verbal and sequential Non-verbal random thoughts
Problem-solving ability Solve problems in the most logical waySolve problems in the most intuitive way
Overall thinking Detail-orientedHolistic approach
Strengths Language both verbal and writtenMathematics and analytics SequencingReading, writing, spelling ArtsMusic CoordinationMulti-dimensional thinkingRemembering a place, faces, or events
Difficulties VisualizationAbstract thinking Organizing a huge body of informationDifficulty in following a sequenceRemembering names
Parts of the body being controlled It controls the right side of the body.It controls the left side of the body. 
Effects on the body when damagedNot able to understand both spoken and written wordsCan’t see or perceive things on the right side of the body. Slow movements Visual perception is impairedCan’t see or perceive things on the left side of the body.Short attention span.Poor decision-making Slow learning processImpulsiveness 

The brain’s two lateral halves also known as left hemisphere and right hemisphere have neurons/receptors which are used for various bodily functions. The left hemisphere of the brain is in-charge of the cognitive functions such as speech and language.

The right hemisphere of the brain is more on creativity and face recognition. Although the functions of the brain is divided based on its hemisphere, even a particular functions to be executed, it would still need the entire brain.

The brain is used holistically although some personality types are more analytical than artistic. For many people, it is possible to be logical and creative at the same time. 

References

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897366/
  2. https://www.jneurosci.org/content/34/14/5003
  3. https://bjgp.org/content/66/642/44
  4. https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/mood-change-following-bilateral-hemisphere-brain-injury/AAC5D637093914B36C1EA54EE7C5D446
  5. https://www.eurekalert.org/pub_releases/2018-11/rb-trf110518.php