In split-brain patients, which statement is true about hemispheric access?

• A. The left hemisphere has no access to the right hemisphere
• B. The right hemisphere has no access to the left hemisphere
• C. Language is localized to the right hemisphere
• D. Cross-hemisphere communication is normal via the corpus callosum

Answer: (B)

Split-brain brains reveal what happens when the main bridge between the two halves of the brain is cut. The corpus callosum normally lets information travel between hemispheres, so each side can share what it’s processed. When it’s severed, each hemisphere largely operates in isolation.

Language is typically housed in the left hemisphere. That means information processed there can be reported verbally, especially when it’s received from the right visual field. But information processed on the right side can’t be conveyed to the language centers because the pathway between hemispheres is disrupted. So the right hemisphere ends up with no access to the left hemisphere’s information, which is why cross-hemisphere communication isn’t normal in split-brain patients.

To see this in action, imagine something seen in the left visual field (processed by the right hemisphere): the person might be able to draw or select it with the left hand, but often cannot name or describe it aloud because that information can’t reach the language-dominant left hemisphere.