Final answer:
If the corpus callosum is destroyed, it hinders communication between the brain's hemispheres, impairing the left side of the brain from controlling movements of the right hand due to the disrupted transmission of motor commands and verbal instructions.
Step-by-step explanation:
If your corpus callosum is destroyed, the left side of your brain could not control the movements of your right hand. The corpus callosum is a bundle of nerve fibers that facilitates communication between the two hemispheres of the brain. In individuals with split-brain condition, typically resulting from surgery to treat severe epilepsy where the corpus callosum is severed, each hemisphere can no longer communicate. This leads to a range of unique behaviors and deficits. Since the left hemisphere, which controls language in about 95 percent of the population, is responsible for motor commands that affect the opposite side of the body, damage to the corpus callosum can disrupt the ability to carry out verbal commands with the right hand. Sensory information received by one side of the brain must also cross the corpus callosum to be processed into verbal communication by the left hemisphere.
Instances of split-brain patients illustrate how crucial the corpus callosum is for coordinating functions between the two hemispheres. For example, when an object is shown to a split-brain patient's left visual field, which is processed by the right hemisphere, they may be unable to name the object because speech processing occurs in the left hemisphere. However, the split-brain patient can draw the object with their left hand, which is controlled by the right hemisphere, and once the left hemisphere sees the drawing, they can often name what is depicted.