Circadian Rhythm

3. A state of being awake and aware of external stimuli and one's own mental activity
5. sequence of images, emotions, and thoughts passing through a sleeping person's mind
7. associated with normal waking consciousness and a heightened state of alertness, logic and critical reasoning
9. the unconscious thoughts and desires that underlie the manifest content of dreams
14. suggests that sleep is necessary for the body and mind to recover and restore from daily activities
15. the relatively slow brain waves of a relaxed, awake state
17. A common sleep disorder that can make it hard to fall asleep or stay asleep or cause you to wake up too early and not be able to get back to sleep
18. a hormone that helps regulate sleep cycles, also known as circadian rhythms

1. vivid sensations that seem real even though they are not
2. small organ located near the center of the brain that produces melatonin
4. a drug that slows down or depresses the central nervous system and therefore slows down both the physical and mental processes in the body
6. a family of practices that train attention to heighten awareness and bring mental processes under greater voluntary control
8. the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle
10. brain waves are also recorded in trances, hypnosis, and daydreams
11. a chronic neurological disorder that causes people to experience uncontrollable sleep attacks, often without warning
12. the actual events and imagery that occur within a dream, as remembered by the dreamer
13. the large, slow brain waves associated with deep sleep
16. the tendency for REM sleep to increase following REM sleep deprivation