What Is the Cuneus?

The cuneus is part of the cerebral cortex, found in the human brain's occipital lobe beneath the parieto-occipital fissure, where the parietal and occipital lobes meet, and above and also within the calcarine fissure located at the lower section of the occipital lobe. It's involved in processing visual information, and is part of the dorsal and ventral visual streams. It's synonymous with Brodmann Area 17. The Latin word cuneus describes the area's wedge-like shape.

The brain's outermost tissue is called the cerebral cortex or the cerebrum. The top layer of the cerebral cortex is made up of several layers of neural tissue commonly called gray matter. Just under it is several layers of bundled neural tissue called white matter. The exterior of the cerebral cortex is marked by many convolutions, or ridges, called gyri, and depressions, or fissures, called sulci.

The cerebral cortex is divided into two halves, commonly referred to as hemispheres, by the longitudinal cerebral fissure. Both of the brain's hemispheres can be further divided into four lobes: the frontal, parietal, temporal, and occipital lobes. The occipital lobe is located at the very back of the head underneath the cranial occipital bone, from which it derives its name.

The occipital lobe is known as the visual processing center of the brain. Within the occipital lobe is an area called the primary visual cortex, which is also known as Brodmann Area 17, the striate cortex, the cuneus, and visual 1 (V1). The area of the striate cortex marks the beginning of the visual pathways called the dorsal and ventral streams. Visual information is gathered by the eyes and sent to the primary visual cortex, or the cuneus. It's believed that this information then gets sent along the visual streams for further analysis.

The dorsal stream begins in the cuneus and travels upward into the parietal lobe, and is thought to be involved in processing spatial awareness, which is the cognizance of the body's position in a given space as well as the awareness of objects in space relative to the body. The ventral stream also begins in the cuneus, but travels to the temporal lobe located on the side of the head, and is thought to be involved in object recognition. Because the ventral steam is connected to the medial temporal lobe, which is associated with memory storage, it's involved with visually associated memory, or the ability to recognize objects from memory.