Final answer:
The 'great relay station' of the brain referred to by the psychology professor is the thalamus, which relays most sensory and motor signals to various parts of the cerebral cortex.
Step-by-step explanation:
The part of the brain that is often referred to as the “the great relay station” is the thalamus. This structure in the forebrain acts as a central hub for sensory and motor signals. All sensory information, excluding olfactory signals, are routed through the central nervous system directly to the thalamus. From there, these signals are relayed to specific regions of the cerebral cortex for further processing. The thalamus plays a critical role in controlling the flow of information in the brain and is crucial for sensory perception, motor functions, and alertness.