Which brain region is primarily involved in processing all senses except for smell?

The thalamus is primarily responsible for processing all sensory information, with the notable exception of olfactory (smell) information. It acts as a relay station, receiving signals from sensory pathways and transmitting them to the appropriate areas of the cerebral cortex for further interpretation and processing. For instance, visual, auditory, and tactile signals are routed through specific nuclei within the thalamus before reaching the cortical areas responsible for those modalities.

Other brain regions mentioned in the options play different roles. The cerebral cortex is indeed involved in sensory processing but does not serve as the primary relay station for incoming sensory data; rather, it is where higher-level processing occurs. The hippocampus is primarily associated with memory formation and spatial navigation, not direct sensory processing. The brainstem oversees basic life functions and some reflexive responses but does not have a central role in processing the senses in the way the thalamus does. Thus, the thalamus stands out as the key hub for sensory relay, making it the correct choice.