Split-brain observations suggest what about consciousness across hemispheres?

• A. There is a single unified consciousness across both hemispheres
• B. The rest of the brain can be conscious but not accessible to the other parts of the mind
• C. The hemispheres share identical conscious states
• D. Consciousness must reside in the brainstem

Answer: (B)

Split-brain observations reveal that when the fiber bundle connecting the two hemispheres is severed, each hemisphere can maintain its own stream of conscious experience. That means information processed in one side of the brain can be conscious there but not accessible to the other side, effectively creating separate pockets of awareness within the same head. For example, if a visual signal is shown to the left side of the field, the right hemisphere processes it and may respond nonverbally (like with the left hand), while the language-dominant left hemisphere cannot verbalize or even access that content. This demonstrates that consciousness is not automatically a single, unified experience across both hemispheres once their communication is cut. Thus, the rest of the brain can be conscious but not accessible to the other parts of the mind.