front 1 Circadian rhythm | back 1 the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle. |
front 2 Dreams | back 2 stories and images that our minds create while we sleep. |
front 3 Electroencephalograph (EEG) | back 3 a test that measures electrical activity in the brain using small, metal discs. |
front 4 Hypersomnia | back 4 a condition in which you feel extreme daytime sleepiness despite getting sleep that should be adequate (or more than adequate). |
front 5 Insomnia | back 5 a common sleep disorder. |
front 6 Melatonin | back 6 a hormone that your brain produces in response to darkness. |
front 7 Napping | back 7 a midday nap can enhance alertness, mood, memory, and reduce stress. |
front 8 Narcolepsy | back 8 a chronic neurological disorder that affects the brain's ability to control sleep-wake cycles. |
front 9 Night Terrors | back 9 a sleep disorder in which a person quickly awakens from sleep in a terrified state. |
front 10 Nightmares | back 10 bad dreams that wake you up. |
front 11 Parasomnia | back 11 occur in a state that lies between sleep and wakefulness. |
front 12 Restless Legs Syndrome | back 12 a condition that causes a very strong urge to move the legs. |
front 13 Sleep | back 13 a period during which the brain is engaged in a number of activities necessary to life |
front 14 Sleep apnea | back 14 a potentially serious sleep disorder in which breathing repeatedly stops and starts. |
front 15 Sleep deprivation | back 15 when you aren't getting enough sleep, or your sleep is of poor quality. |
front 16 Sleep paralysis | back 16 a feeling of being conscious but unable to move. |
front 17 Sleep study | back 17 a test used to diagnose sleep disorders. |
front 18 Snoring | back 18 the hoarse or harsh sound that occurs when air flows past relaxed tissues in your throat, causing the tissues to vibrate as you breathe. |
front 19 Stage 1 (Non-REM) sleep | back 19 when heartbeat, eye movements, brain waves, and breathing activity begin to taper down. |
front 20 Stage 2 (Non-REM) sleep | back 20 still light sleep, but deeper than stage 1. |
front 21 Stage 3 (Non-REM) sleep | back 21 deep sleep. |
front 22 Stage 4 (REM Sleep) | back 22 an even deeper sleep where the brain waves further slow and sleepers are very difficult to wake. |
front 23 Somnambulism | back 23 sleepwalking |
front 24 Wakefulness | back 24 a daily recurring brain state and state of consciousness in which an individual is conscious and engages in coherent cognitive and behavioral responses to the external world. |