The primary role of the thalamus in the brain is to act as a relay station for sensory information. It processes and transmits sensory signals from the body to the appropriate areas of the cerebral cortex, including information related to touch, pain, temperature, and visual and auditory stimuli. Additionally, the thalamus plays a critical role in regulating sleep and consciousness. By filtering and prioritizing sensory inputs, the thalamus helps maintain focus and attention, contributing to various higher cognitive functions and overall sensory integration.