The corpus callosum sits between the two hemispheres of the human brain and acts as a conduit for nerve signals between them. According to About.com, this bridge allows motor, sensory, and cognitive information to flow between the left and right hemispheres.
The corpus callosum is located very close to the center of the human brain. It is positioned inferior to the cerebrum and runs superior to the hippocampus. From this position, the corpus callosum carries important information across the centerline divide of the cerebrum, allowing the two hemispheres to function as a unit, according to About.com. This structure's position makes it critical to any body function that involves the two sides of the brain working together, such as coordinated eye movements, and maintaining the balance between arousal and attention.
The corpus callosum is also important to a sense called tactile discrimination, which is the ability of the brain to tell, without looking, exactly where on the body a stimulus such as cold, pressure or touch is applied. According to Wikipedia, tactile discrimination tests are often carried out by neurologists to help diagnose the higher functioning of the cerebral cortex and its ability to discriminate between locations on the body's surface.