What Are Projection Areas?

Projection areas are areas within the cortex of the brain responsible for all of the motor and sensory processing. There are several such areas within the brain. Large areas include the pre-central gyrus and the post-central gyrus. Additionally, the parietal, frontal, temporal, and occipital lobes each have individual roles they contribute to.

As one of the large projection areas, the pre-central gyrus is the main control of motor functions and is also known as the primary motor area. This brain region is responsible for controlling voluntary movements of the skeletal muscles. All of the muscles within the body, in all areas, are being controlled by a part of the pre-central gyrus. The area of the pre-central gyrus that controls a muscle is designated by how much activity a muscle has as well as how much control a muscle will need. Facial muscles, for example, require more control and have more activity than a foot muscle.

The second of the large projection areas is the post-central gyrus. This area is responsible for sensory perception and is also known as the somatosensory area. It is responsible for processing all the information sent from the senses. Light, sound, pain, pressure, and touch as well as other sensations are controlled by this area. Sensory information is processed by the type of sensation and its intensity instead of the size of the body part experiencing sensations.

One of the smaller projection areas, the occipital lobe is one of the four brain lobes. It has the primary responsibility of processing all of the visual information that travels throughout the brain. This lobe receives the information sent from the eyes, so it is also called the visual cortex. The occipital lobe is above the cerebellum at the back of the brain.

Another one of these areas located within a lobe is the temporal lobe. This lobe is found above the brainstem and connects to the occipital lobe. It has the responsibility of processing auditory information and memory. Sound information is received through the cochlea and sent to a part of the cortex called the primary auditory cortex.

Connected to the occipital lobe on one end, the parietal lobe sits above the temporal lobe. This lobe is another one of the smaller projection areas. It takes all of the sensory information required for a person to have proper spatial judgment and the ability to navigate.

Located at the front of the brain, the frontal lobe is the final one of the smaller projection areas. It is connected to both the parietal and temporal lobes. The frontal lobe is responsible for associating sensory information from the other three lobes with specific motor functions, temperament, and control of emotions.