system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why when we get little sleep, throughout the day we may experience moments of feeling delusional (especially when trying to concentrate) ?
gpt
Essentially, it's because you ARE sleeping/dreaming. If you deprive your brain of sleep long enough, different parts of it will shut off to rest at different times during the day (fun fact, even at night during sleep not all areas of the brain are actually resting, hence dreaming). So mostly people experience low concentration and slower reflexes, because not all of your brain is alert. Functional studies have been done and no particular order or pattern has been found, so depending on which section is asleep at the time, you experience the symptoms like fatigue and the occasional (very short) delusional/hallucination like episodes if you're that sleep deprived.