Cerebral Cortex: What to Know

Medically Reviewed by Jabeen Begum, MD on September 01, 2022
4 min read

The cerebral cortex is your brain’s outermost layer. It has a wrinkled appearance due to the grooves and folds that increase its surface area. Here, we look at the anatomy of the cerebral cortex and its functions.

The cerebral cortex is the outer layer of your brain’s surface, located on top of the cerebrum. The cerebral cortex carries out essential functions of your brain, like memory, thinking, learning, reasoning, problem-solving, emotions, consciousness, and sensory functions.

The cerebral cortex is made up of 14 to 16 billion nerve cells. It's typically only a few millimeters thick but makes up roughly 50% of your total brain mass. It has a wrinkled exterior containing deep indentations and raised projections.

The deep parts in the folds are called the sulci, and the raised portions are called the gyri. The uneven surface of the cerebral cortex holds neurons vital for your brain functions. Your inability to carry out higher mental functions without this organ underlines the importance of the cerebral cortex.

Some interesting facts about the cerebral cortex:

  • It has a surface area of roughly 2,500 square centimeters.
  • It’s often called gray matter due to its gray color, and the more gray matter you have, the more information your brain can process.
  • More than two-thirds of its area is folded.
  • The larger surface area allows it to hold more neurons, thus improving brain function.

The cerebral cortex is divided into two equal halves, called the left and right hemispheres. A collection of nerve fibers called the corpus callosum connects the two hemispheres. The two regions send signals and communicate via the corpus callosum. Each hemisphere is further divided into four lobes based on their location. Your cerebral cortex controls several vital functions through these lobes.

Frontal lobes. These are the largest lobes of the cerebral cortex and are situated at the front of your brain, right behind your forehead.

Occipital lobes. These are located at the back of your head.

Parietal lobes. They’re located between the frontal and the occipital lobes on top of the temporal lobes.

Temporal lobes. These are the second-largest lobes of the cerebral cortex and are located between the frontal and occipital lobes below the parietal lobes.

The different lobes combine to complete various functions of the cerebral cortex, all of which are central to controlling your body’s senses, thinking, and other functions.

Frontal lobes. They are vital for your cognitive abilities, like decision-making and problem-solving. Other functions, like conscious thought and attention to particular tasks, are attributed to these lobes. This region of the cerebral cortex also controls your behavioral patterns, emotions, and ability to generate speech. For example, the frontal lobes come into play when you’re in social situations to ensure appropriate social behavior. They're home to Broca’s area, which manages your language abilities. The frontal lobes define your personality traits and intelligence.

Other important areas in this lobe are the prefrontal cortex and the motor cortex. While the motor cortex controls your body’s movements, the prefrontal cortex is responsible for decision-making and managing other parts of your brain.

Occipital lobes. Your occipital lobes are at the back of your head and get inputs from the retinas in your eyes. These inputs are then converted into various visual data, like color, movement, and position. The occipital lobes recognize faces and objects and perceive their depth and distance. Research about the capabilities of this region to communicate with other parts of your brain is still ongoing.

Parietal lobes. The parietal lobes carry out a critical function of combining the sensory information from all parts of your body to create an image of the world around you. They also help in perceiving your body and comprehending touch, temperature, and pressure. The parietal lobes enable you to make sense of your surroundings and manage your movements accordingly in three-dimensional space. For example, they help you move around your house or your city. They're also essential for sensing pain and vibrations.

Temporal lobes. This region is responsible for integral functions like emotion, memory, and hearing. Your left temporal lobe helps you understand languages, retain spoken information, learn, and frame speech. On the other hand, the right temporal lobe helps you retain nonverbal inputs, identify information, and recognize other people’s facial expressions. The temporal lobes combine inputs from your environment and other parts of your brain. They also help you convert sounds into visual images. When you listen to someone speak, your temporal lobes are activated to help you understand them.

Damage to any region of the cerebral cortex is typically caused by tumors, autoimmune diseases, bleeding in your brain, or a stroke. Symptoms of possible damage depend on the affected region.

Frontal lobe. Symptoms include memory issues, challenges with attention, emotional inadequacy, improper social behavior, inability to understand what others say, problems with your speech, and loss of muscle control over one side of the body.

Parietal lobe. Symptoms include inability to write or identify objects by touching them, challenges with math, numbness, loss of sensation, and lack of hand-eye coordination.

Temporal lobe. Symptoms include hearing and memory issues, inability to identify faces and objects, and difficulty in understanding languages. Damage to the temporal lobe can also lead to conditions like Alzheimer’s disease, epileptic seizures, and dyslexia.

Occipital lobe. Symptoms include color blindness, hallucinations, inability to perceive more than one object at a time, and total blindness.

The cerebral cortex contains nerve cells or neurons. The ends of these cells are called dendrites, which transport signals to nearby cells. These dendrites don’t have the typical fatty acid covering called myelin, which gives them a gray appearance. On the other hand, the white matter in your brain contains nerve bundles called axons. The longer parts of these axons are coated with myelin, which gives them a whitish color.