To answer your question, the mind stops working properly after about 72 hours of no sleep. It depends on your body and how much you usually sleep, so it can vary up to 24 hours. Me and a few friends tried it in highschool over spring break one year.. We all stayed up for 4 days straight and the myths are true let me tell you. It was a lot like a bad "froom" trip. We experienced mild hallucinations and found out afterwards that apparently after 72 hours of no sleep your brain starts to produce the same chemicals found in acid. Free drugs!

The best form of torture is called "sense deprivation". I was watching a torture documentary years ago on discovery or national geographic I can't remember, but I love both of those channels with all my heart. Last week we watched this documentary on tigers that was filmed BY ELEPHANTS. It was nuts man, the pack of elephants each had a big camera fixed to their trunks. And it was in HD. I was in fucking heaven. But anyways.. sense deprivation is exactly what it sounds like. Eyes, ears and nose were all taped shut, and there was just a breathing tube in the guy's mouth. Then he was put in a styrofoam mold of his body and that was taped shut. He couldn't see, hear, taste, smell, or touch anything. It only took a few hours for him to start freaking out.