Though some areas of the human brain that receive primary sensory information remain poorly defined, each of the five sensory modalities has been recognized to relate to specific groups of brain cells that begin to categorize and integrate sensory information.

The somasthetic area (SSII, BA 1, BA 2, BA 3) is across the central sulcus and behind the primary motor area configured to generally correspond with the arrangement of nearby motor cells related to specific body parts. The area includes gray matter along the central gyrus and its extension into the post-central gyrus.

The visual area (BA 17) is located on the calcarine sulcus deep within the inside folds of the occipital lobe.