Question

Further evidence of the corpus callosum's function has come from studies of patients with severe, even life-threatening, forms of epilepsy. Epilepsy is caused by electrical "brainstorms" that flash uncontrollably across the corpus callosum. In one famous case, neurosurgeons severed the corpus callosum of an epileptic patient, now known as W. J., in a final attempt to reduce his unbearable seizures. Sperry (1968) examined W. J. and found that the corpus callosum functions the same in humans as in animals—cutting the corpus callosum seemed to leave the patient with "two separate minds" that learned and operated independently.

As it turns out, the right hemisphere receives information only from the left side of the body, and the left hemisphere receives information only from the right side of the body. When you hold an object in your left hand, for example, only the right hemisphere of your brain detects the object. When you hold an object in your right hand, only the left hemisphere of the brain detects it. In individuals with a normally functioning corpus callosum, both hemispheres receive this information eventually, as it travels between the hemispheres through the corpus callosum. In fact, although we might have two minds, we usually use them in tandem.

Answer 1

Split-brain surgeries for severe epilepsy sever the corpus callosum, resulting in 'split brain' patients who provide insights into the independent functions of the brain's hemispheres. These cases have shown that, for example, the left hemisphere is typically responsible for language, while both hemispheres can carry out certain functions redundantly.

Step-by-step explanation:

The corpus callosum performs vital functions in coordinating information and activity between the two hemispheres of the brain. In cases of severe epilepsy, split-brain surgery, which involves severing the corpus callosum, can significantly reduce the incidence of seizures. Post-surgery, patients exhibit unique behaviors that provide insights into how the two hemispheres function independently. For example, split-brain patients may not be able to verbally identify an object seen in their left visual field because the sensory information is processed by the right hemisphere, which is generally nonverbal. Yet, they can pick up the correct object with their left hand, controlled by the right hemisphere, showing that the brain's hemisphere possess specialized functions that are normally shared through the corpus callosum.

Split-brain studies have revealed much about cerebral lateralization, demonstrating that the left hemisphere is typically responsible for language functions. However, it should be noted that while the brain has functions that are localized more to one hemisphere than the other, the functions of the two hemispheres are largely redundant, and people can often still function well even if one hemisphere is impaired or absent, especially when this occurs in childhood.