Dreaming

1. The sleep disorder that makes it difficult for people to stay awake during the day
7. The sleep stage that is characterised by decreased blood flow
8. A common dream symbol associated with anxiety and stress
9. It causes the feeling of falling while sleeping
12. A bothersome dream

2. The type of brain activity which characterises sleep stage 2?
3. The brain wavelength characteristic of deep sleep
4. The philosopher thought that "disguised fulfilments of repressed infantile wishes"
5. The sleep stage in which we dream
6. The sleep disorder that makes it hard to fall asleep, to stay asleep, or causes people to wake up too early?
8. The region that much of the brain activity during sleep has been attributed to
10. The percentage of the world that dreams in black and white
11. The average duration of a sleep cycle