Which brain structure connects the two hemispheres and carries messages between them?

• A. Amygdala
• B. Corpus Callosum
• C. Cerebellum
• D. Hippocampus

Answer: (B)

Interhemispheric communication is the process of sharing information between the left and right sides of the brain. The structure that serves this role is the corpus callosum, a large bundle of nerve fibers that bridges the two hemispheres. It carries messages, coordinating sensory input, motor commands, and higher-level processing that require integrated activity across both sides. In split-brain cases, where the corpus callosum is severed, information cannot easily cross between hemispheres, underscoring its role as the main communication highway. The amygdala focuses on emotions, the cerebellum coordinates movement and balance, and the hippocampus forms new memories, but none primarily connect the two hemispheres like the corpus callosum does.