What Does the Brain's Cerebral Cortex Do?

By Olivia Guy-Evans, published May 19, 2021

What is the Cerebral Cortex?

The cerebral cortex is the outermost layer of the brain that is associated with our highest mental capabilities. The cerebral cortex is primarily constructed of grey matter (neural tissue that is made up of neurons), with between 14 and 16 billion neurons being found here.

Although the cerebral cortex is only a few millimeters in thickness, it consists of approximately half the weight of the total brain mass. The cerebral cortex has a wrinkled appearance, consisting of bulges, also known as gyri, and deep furrows, known as sulci.

The many folds and wrinkles of the cerebral cortex allow for a wider surface area for an increased number of neurons to live there, permitting large amounts of information to be processed.

The cortex is also divided into two hemispheres, the right and left, which is separated by a large sulcus called the medial longitudinal fissure.

The two hemispheres are connected via bundles of nerve fibers called the corpus callosum, to allow both hemispheres of the cerebral cortex to communicate with each other and for further connections to be made.

A vast array of functions are controlled by the cerebral cortex through the use of the lobes, which are divided based on the location of gyri and sulci. These lobes are called the frontal lobes, temporal lobes, parietal lobes, and occipital lobes.

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Cerebral Cortex Lobe Functions

The cerebral cortex, which is the outer surface of the brain, is associated with higher level processes such as consciousness, thought, emotion, reasoning, language, and memory. Each cerebral hemisphere can be subdivided into four lobes, each associated with different functions.

Together the lobes serve many conscious and unconscious functions such as being responsible for movement, processing sensory information from the senses, processing language, intelligence, and personality.

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Areas of the Cerebral Cortex

The cerebral cortex can be characterised as being made up of three types of divisions, which serve different purposes: sensory, motor, and association areas.

The combination of these three areas account for most of human’s cognition and behavior.

Sensory Areas

The sensory areas of the cerebral cortex receive sensory information from the senses and environmental stimuli. This information is also processed by the sensory areas to give meaning to this information.

The sensory areas include the visual cortex, the somatosensory cortex, the auditory cortex, and the gustatory cortex. The visual cortex is an area within the occipital lobes which is essential to the conscious processing of visual stimuli.

There are two visual cortices in the brain: the cortex in the left hemisphere receives signals from the right visual field, whereas the cortex in the right hemisphere receives signals from the left visual field.

The visual cortex is important for making sense of visual information and plays a role in object recognition and representation. The somatosensory cortex is located with the parietal lobe and receives tactile information from the body.

This information can include temperature, touch, and pain, all of which is then integrated in the somatosensory cortex to produce a ‘map’ of the body. The auditory cortex is an area within the temporal lobes which is responsible for processing auditory information.

This cortex can perform basic and higher functions relating to hearing, including the ability for some people to language switch.

Finally, the gustatory cortex is a region in the frontal lobe which is responsible for the perception of taste and flavor.

Motor Areas

The motor areas of the cerebral cortex are involved in the regulation and initiation of voluntary movement. These areas are primarily found within the frontal lobes and include the primary motor cortex, premotor cortex, and the supplementary cortex.

The primary motor cortex is associated with the coordination and initiation of motor movements. Each cerebral hemisphere of the primary motor cortex contains a motor-related representation of the opposite side of the body.

There is also a representational map of the body with the primary motor cortex, called a motor homunculus. The premotor cortex is involved in preparing and executing limb movements, as well as using information from other regions of the cortex to select appropriate movements.

The premotor cortex is also necessary for learning, especially through imitation, and social cognition, specifically empathy.

The supplementary cortex is responsible for the planning of complex movements and contributes to the control of movement.

Association Areas

The association areas are spread throughout the cerebral cortex in the four lobes. These areas act by integrating information from these brain regions, often adding more complexity to their functions.

These association areas can also form connections to sensory and motor areas to give meaning to and organise information in these areas. Association areas within the frontal lobes are involved in key processes such as planning, thinking, and feeling.

These areas also play a role in personality and controlling emotional behaviors. Association areas within the parietal lobe are involved in spatial skills such as spatial awareness and reasoning, as well as being responsible for paying attention to visual stimuli in the environment.

In the temporal lobes, association areas function primarily in memory processes such as helping to process procedural and episodic memories. These areas also communicate with other lobes of the cortex so they can complete memory-related processes.

Occipital lobe association areas help to facilitate memories associated with visuals to be retained as well as enabling us to think in a visual manner.

These areas in the occipital lobes also communicate with other lobes of the cortex to assimilate visual information with memories, sounds, and language to understand visual stimuli.

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Cerebral Cortex Damage

Symptoms connected with damage to the cerebral cortex are vast and different, which all are dependent upon the area that has experienced damage:

• Frontal lobe injury symptoms can include one or more of the following: memory issues, personality changes, issues with problem-solving, difficulties with working memory, inattentiveness, emotional deficiencies, socially inappropriate behavior, behavioral changes, aphasia, weakness, and paralysis. Common causes of damage to this area of the cortex include traumatic brain injuries or neurogenerative diseases such as dementia. A literature review investigated the frontal lobe’s association with schizophrenia and found that many patients had differences in grey matter volumes and functional activity in their frontal lobes, compared to those without the disorder (Mubarik & Tohid, 2016).
• Parietal lobe injury symptoms can include one or more of the following: issues generating memories, agraphia, difficulties with mathematics, numbness, disorientation, poor hand-to-eye coordination, and left-side neglect. Damage to parietal lobes could be due to a stroke, disease, tumour, or injury to the area. It has been found that there were reduced grey matter volume of the parietal lobes in those diagnosed with schizophrenia (Zhou et al., 2007).
• Temporal lobe injury symptoms can include one or more of the following: hearing difficulties, memory issues, difficulty recognizing faces and objects, language impairments (such as Wernicke’s aphasia), difficulties with selective attention, and difficulties with understanding language. A common cause of temporal lobe damage is epileptic seizures in this region but can also result from stroke or trauma. It was found by researchers that impairments with attention within the temporal lobes are associated with developmental dyslexia (Voldois et al., 2019). It has also been suggested that early signs of Alzheimer’s disease may be noticed within the temporal lobes (Lowndes & Savage, 2007).
• Occipital lobe injury symptoms can include one or more of the following: varying types of blindness, word blindness, difficulty perceiving more than one object at once, difficulty recognizing objects by sight, and hallucinations involving vision. Damage to the visual cortex can cause total blindness. This region has been examined to see if it is related to schizophrenia in any way (Onitsuke et al., 2007). In a study, it was discovered that those with chronic schizophrenia had reduced grey matter volumes in the visual association cortex, implying that some of the visual deficits experienced by those with schizophrenia can be attributed to the occipital lobes.
• Sensory area symptoms of injury can include one of more of the following: difficulties perceiving touch, difficulty recognizing one’s own body, failure to recognize objects by touch, phantom limb pain, inability to taste food and issues with processing auditory information.
• Motor area symptoms of injury can include one or more of the following: speech impairments, motor-learning deficits, impairments in self-initiated movements, inability to associate a motor response to a visual cue, issues with social cognition, and clumsiness of body movements.
• Association area symptoms of injury can include one or more of the following: inability to recognize familiar faces, issues with forming procedural and episodic memories, distorted thinking, personality changes, lack of spatial awareness, and attentional difficulties.

APA Style References

Bailey, R. (2020, February 05). What Does the Brain’s Cerebral Cortex Do? Thought Co. What Does the Brain's Cerebral Cortex Do? (thoughtco.com)

FlintRehab. (2021, January 11). Cerebral Cortex Damage: Definition, Symptoms, and Recovery. https://www.flintrehab.com/cerebral-cortex-damage/#:~:text=Parietal%20Lobe%20Damage,problems%20with%20sensation%20and%20perception.

Guy-Evans, O. (2021, April 13). Temporal lobe: definition, functions, and location. Simply Psychology. www.simplypsychology.org/temporal-lobe.html

Guy-Evans, O. (2021, April 15). Parietal lobe: definition, functions, and location. Simply Psychology. www.simplypsychology.org/parietal-lobe.html

Guy-Evans, O. (2021, April 19). Occipital lobe: definition, functions, and location. Simply Psychology. www.simplypsychology.org/occipital-lobe.html

Guy-Evans, O. (2021, May 08). Frontal lobe function, location in brain, damage, more. Simply Psychology. www.simplypsychology.org/frontal-lobe.html

Huang, J. (2020, September). Brain Dysfunction by Location. MSD Manual. https://www.msdmanuals.com/en-gb/home/brain,-spinal-cord,-and-nerve-disorders/brain-dysfunction/brain-dysfunction-by-location

Lowndes, G., & Savage, G. (2007). Early detection of memory impairment in Alzheimer’s disease: a neurocognitive perspective on assessment. Neuropsychology Review, 17(3), 193-202.

Mubarik, A., & Tohid, H. (2016). Frontal lobe alterations in schizophrenia: a review. Trends in Psychiatry and Psychotherapy, 38(4), 198-206.

Onitsuka, T., McCarley, R. W., Kuroki, N., Dickey, C. C., Kubicki, M., Demeo, S. S., Frumin, M., Kikinis, R., Jolesz, F. A. & Shenton, M. E. (2007). Occipital lobe gray matter volume in male patients with chronic schizophrenia: A quantitative MRI study. Schizophrenia Research, 92(1-3), 197-206.

Valdois, S., Lassus-Sangosse, D., Lallier, M., Moreaud, O., & Pisella, L. (2019). What bilateral damage of the superior parietal lobes tells us about visual attention disorders in developmental dyslexia. Neuropsychologia, 130, 78-91.

Zhou, S. Y., Suzuki, M., Takahashi, T., Hagino, H., Kawasaki, Y., Matsui, M., Seto, H. & Kurachi, M. (2007). Parietal lobe volume deficits in schizophrenia spectrum disorders. Schizophrenia Research, 89(1-3), 35-48.