Which structure connects the left and right hemispheres of the brain?

The corpus callosum plays a crucial role in integrating the activities of the left and right hemispheres of the brain. This large band of neural fibers sits beneath the cerebral cortex and is the primary conduit through which the two hemispheres communicate. It facilitates the transfer of information between the two sides, allowing for coordinated functioning, such as ensuring that motor commands, sensory data, and cognitive processes are shared and unified within the brain.

The cerebellum, while essential for motor control and functions related to coordination and balance, does not connect the hemispheres of the brain. Instead, it operates as a separate structure that processes information from various parts of the brain.

The thalamus serves as a relay station for sensory information before it reaches the cerebral cortex but is not responsible for connecting the left and right hemispheres directly.

The amygdala is involved in emotional processing and fear responses, but it is not structurally related to the inter-hemispheric communication accomplished by the corpus callosum. Thus, the corpus callosum is the only structure among the choices provided that specifically connects the left and right hemispheres.