The right cerebral hemisphere receives sensory input from and controls muscular activity in the left half of the body. The left cerebral hemisphere receives input from and controls muscles in the right half of the body. Sensory information received by one hemisphere is shared with the other through connections between the two hemispheres called commissures (kom′ ı̆-shūrz; joining together). The largest of these commissures is the corpus callosum (kōr′ pus kă-lō′ sŭm), a broad band of nerve tracts at the base of the longitudinal fissure (see figures 8.21 and 8.23).
Language and perhaps other functions, such as artistic activities, are not shared equally between the two hemispheres. Researchers believe the left hemisphere is the more analytical hemisphere, emphasizing such skills as mathematics and speech, whereas the right hemisphere is more involved in functions such as three-dimensional or spatial perception and musical ability.