[TED] What hallucination reveals about our minds

Oliver Sacks talks about hallucinations, how they seem to come from somewhere outside, not like a regular imagination where we can control what we think.

He once saw a patient who was blind yet completely sane with no medical problems, but was seeing things by hallucination. The patient said that her hallucinations seem to have nothing to do with what she's thinking, feeling, or doing, and that they were silent. Also she could not recognize anyone or anything in her hallucination. Then he talks more about other patients who see aliens, common objects, people they don't recognize, and movie-like scenes.

He said that hallucinations are just starting to reveal how our minds work, because they don't occur just to people with some kind of medical problem, but also to ordinary people.

Question: Mostly hallucinations are said to be one of 'bad' symptoms of many diseases. But if you experience it without any medical conditions, is it safe?

Word: unknown - we still know so little about our brains, when it is something that is critical to human beings.

[TED] Arianna Huffington: How to succeed? Get more sleep

The power of a good night's sleep is more than just relieving stress, but also has to do with succeeding. We can sleep our way to increased productivity and happiness -and smarter decision-making.

These days I don't get enough sleep, and I do feel that it's bad for me. I get sleepy at school and sometimes can't concentrate well. So I should sleep more!

Word: Ideal
What is better? Getting more sleep and working more efficiently, or sleeping less and getting more work done? (Quality vs. Quantity)

Question: What happens if you don't get enough sleep for a long period of time???? or what if you can't sleep?