What is Left Brain Mean?

This article will help you understand what is meant by the left brain. The article will talk in detail about what the hemispheres of the brain are, what they control, and their functions. In the end, the article will answer some frequently asked questions.

What is Left Brain Mean?

The left brain, quite literally, means the left side of the brain. This side of the brain is often associated with analytical and rational thinking. The left hemisphere of the brain is dominant when it comes to controlling mathematical processing, language, and logical processing.

Functions of the left and right hemispheres

The brain has two hemispheres, the right and the left. Both hemispheres specialise in several distinct functions (Kosslyn et al., 1995). We highlight the same below.

Right Hemisphere

The right hemisphere controls the left side of the body. It is responsible for the artistic and creative functions of the brain. In general, it controls our awareness of art, creative thinking, imagination, intuitive thoughts, insight, spatial reasoning, awareness of music, holistic thinking, interpretation of 3D objects, and control over the left hand.

Left Hemisphere

The left hemisphere of the cerebrum is responsible for controlling the right side of the body. It is logical and rational, and more academic-oriented. It is responsible for logic, language, reasoning, processing of science and math, writing, and right-hand control.

Lateralization of Brain Function

The two hemispheres of the brain are connected by the corpus callosum. Both the hemispheres have strong symmetry when it comes to the structure as well as functions. 

For example, when it comes to the structure, the lateral sulcus is found to be longer in the left hemisphere whereas the Broca’s and Wernicke’s area is located in the left hemisphere for 95% of people who are right-handers and 70% of people who are left-handers. 

Roger Sorry has done commendable work on lateralisation as well as split-brain functions and has also received a Nobel Prize for the same.

What is the Cerebrum and how is it related to the hemispheres of the brain?

The cerebrum is responsible for controlling artistic and mathematical abilities. The cerebrum is composed of the right and the left cerebral hemispheres. It is believed that the hemispheres are tied down at the bottom and have multiple connections running within them (Clements, 2004). 

It is also suggested that the right cerebral hemisphere is responsible for the movement and functions of the left side of the body. The left cerebral hemisphere is responsible for overlooking the functions of the right side of the body. 

The right cerebral hemisphere is in control of one’s artistic and creative abilities, while the left hemisphere is in control of logic and rational thinking.

The cerebrum is the largest part of the brain and is located in the front. It is responsible for movement, maintaining the temperature of the body, sense of touch, vision, and hearing. It is also involved in judgement, reasoning, problem-solving, emotions, and learning. 

The cerebral cortex is responsible for thinking and consciousness. Humans have a larger cerebral cortex compared to others. The cerebral cortex is the outer brake-like layer of the brain and allows individuals to use complex skills, live in social settings, use language as well as create tools (Gibson, 2002).

Corticalization is known as the folding of the cerebral cortex. Compared to other animals, humans have a wrinkled and folded cerebral cortex, this creates a greater size and surface area, which allows for enhanced learning, thinking and remembering. 

Each hemisphere of the cerebral cortex is divided into two hemispheres and subdivided into four lobes, each of them is separated by folds known as fissures. 

The frontal lobe is responsible for memory, thinking, judgement, and planning, this starts from the front of the brain and moves over the top in the cortex. 

The parietal lobe follows the frontal lobe, this part of the brain extends from the midsection of the skull. This is primarily responsible for processing information about sensations such as touch. 

At the back of the skull comes the occipital lobe, which is responsible for processing visual information. The temporal lobe is located right in front of the occipital lobe, this section of the brain is responsible for language and hearing.

The brain is further divided into four lobes (Casillo et al., 2020):

The Frontal Lobe

The frontal lobe is in charge of problem-solving, judgment, decision-making, and motor functions (Stuss & Alexander, 2000).

The Parietal Lobes

The parietal lobes handle sensation, handwriting, as well as the position of the body.

The Temporal Lobes

The temporal lobes are responsible for memory and hearing.

The Occipital Lobes

The occipital lobes include the visual processing system of the brain.

What are the results of damage to either of the hemisphere of the brain?

People can get either side of the brain damaged if they undergo an injury or get a stroke. When the damage is on the left hemisphere, it can make it difficult for people to acquire spoken or written language. They report not seeing things on the right side of their bodies. They also have a condition of limb apraxia, or motor skills problems (Samnia et al., 2000) and they tend to move slower and more carefully. 

Damage to the right hemisphere of the brain can cause people to have difficulties with visual perception as well as spatial orientation (Newcombe & Russell, 1969). 

They can’t see the left side of their body at times, they can also become impulsive and make wrong or bad decisions. They have short attention spans, bad reading abilities (Neininger & Pulvermüller, 2003), and difficulty in being creative. They also report problems in learning new skills. 

More Information About the Human Brain

The brain is comprised of well-specialised areas which work together in unison:

• The cortex is in charge of thinking and voluntary movements and is situated in the outermost layer of the brain.
• The brainstem is situated between the spinal cord and the brain. It is responsible for the functions of breathing and sleep.
• The basal ganglia situated in the centre of the brain is responsible for the coordination of messages between several parts of the brain.
• The cerebellum is situated at the base and the back of the brain and is in charge of coordination and balance (Strick et al., 2009). 

Conclusion

This article helped you understand what is meant by the left brain. The article also talks in detail about what the hemispheres of the brain are, what they control, and their functions. In the end, the article will answer some frequently asked questions.

Frequently Asked Questions: What if left brain mean?

What are brains made up of?

Soft tissue, including the grey matter, white matter, nerve cells, and non-neuronal cells make up the brain. The brain also includes small blood vessels. Brains also have high water content and nearly 60% of fat.

What is the most important part of the brain?

Although all the parts of the brain are important. The largest part of the brain is called the cerebrum which has two hemispheres which control voluntary movement, speech, memory, emotion, processing of sensory information, and intelligence.

What area of the brain controls mathematical and artistic skills?

The cerebrum is responsible for controlling artistic and mathematical abilities. 

References

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Gibson, K. R. (2002). Evolution of human intelligence: The roles of brain size and mental construction. Brain, behavior and evolution, 59(1-2), 10-20.

Kosslyn, S. M., Maljkovic, V., Hamilton, S. E., Horwitz, G., & Thompson, W. L. (1995). Two types of image generation: Evidence for left and right hemisphere processes. Neuropsychologia, 33(11), 1485-1510.

Yang Zhou, David J. Freedman. Posterior parietal cortex plays a causal role in perceptual and categorical decisions. Science, 2019 DOI: 10.1126/science.aaw8347

Newcombe F, Russell WR. Dissociated visual perceptual and spatial deficits in focal lesions of the right hemisphere. J Neurol Neurosurg Psychiatry. 1969 Apr;32(2):73–81. PMCID: PMC496446.

Neininger B, Pulvermüller F. Word-category specific deficits after lesions in the right hemisphere. Neuropsychologia. 2003;41(1):53-70. doi: 10.1016/s0028-3932(02)00126-4. PMID: 12427565.

Smania N, Girardi F, Domenicali C, Lora E, Aglioti S. The rehabilitation of limb apraxia: a study in left-brain-damaged patients. Arch Phys Med Rehabil. 2000 Apr;81(4):379-88. doi: 10.1053/mr.2000.6921. PMID: 10768524.

Stuss, D. T., & Alexander, M. P. (2000). Executive functions and the frontal lobes: a conceptual view. Psychological research, 63(3), 289-298.