Final answer:
According to the neuronal workspace hypothesis, brain structures may not communicate well with each other during sleep due to disrupted global workspace integration.
Step-by-step explanation:
The brain structures cannot communicate well with each other when you're asleep because of disrupted global workspace integration. The neuronal workspace hypothesis suggests that during sleep, particularly non-REM sleep, there is a reduction in the brain's ability to integrate information across different neural regions. This leads to a state where conscious experiences are greatly diminished or nonexistent. During sleep, brain activity patterns change significantly—different stages are characterized by specific brain waves, and overall there is increased neural synchrony and a decline in connectivity between brain regions. This disrupted integration likely contributes to the disconnect between different parts of the brain, explaining a reduced capacity for various cognitive processes that require global brain communication.