What you'll learn
How sleep is structured and why we dream.
Key ideas
- The circadian rhythm (~24 hours) and REM (rapid eye movement) sleep.
- Melatonin promotes sleep.
- Theories of dreaming: Freud (wish-fulfilment) vs activation-synthesis (random brain activity).
- Jet lag and sleep deprivation.
Exam tips
- Contrast the two dream theories.
- Link melatonin to the sleep cycle.
Common mistakes
- Confusing the two dream theories.
- Forgetting what REM stands for.