They would stay up for as long as they could trying to achieve "free" hallucinations. One guy said he got there after 3 whole days and nights being awake.
At psychiatric hospitals arriving sleepless patients are put to sleep for a day or two because after a few days and up to three weeks of sleeplessness the hallucinations become bizarre and dangerous. After the sleeep therapy, the patients are more at baseline.
I'm interested in hearing that and thank you for sharing. I have more than an average curiosity about it myself, since I awaken almost every night between 3 and 4 a.m. Also, I work downtown and there are homeless people there all hours of the day and night - I can't fathom how or if they sleep.