- altered state- when quantitative and qualitative changes in mental processes are extensive enough that person or objective observers notice significant differences in psychological and behavioral functioning.
Sleep.
- we spend about one-third of our lives.
Two main stages of sleep:.
1. Non-REM (NREM) sleep .
Stages of NREM sleep.
o stage 1 Falling Sleep.
- transition state between sleep and wakefulness .
- eyes begin to roll slightly .
- consists mostly of theta waves (high amplitude, low frequency (slow) .
- brief periods of alpha waves, similar to those present while awake .
- lasts only for a few minutes before moving on to next stage-very short stage, usually occurring a few minutes after bedtime. .
- brain waves become irregular.
- the heart rate begins to slow, and muscles relax.
- easy to awaken and may not realize that he or she has been asleep.
o stage 2 Deeper stage.
- peaks of brain waves become higher and higher (sleep spindles) .
- k-complexes (peaks suddenly drastically descend and then pick back up) follow .
o stage 3 Deeper sleep.
- also called delta sleep or deep sleep .
- very slow brain waves, called delta waves (lower frequency than theta waves) 20 to 50% of brain waves are delta waves; the rest are theta waves.
o stage 4 Delta sleep.
- again, also called delta sleep or deep sleep .
- more than 50% of brain waves are delta waves; the rest are theta waves .
- last (and deepest) of the sleep stages before REM sleep; stages reverse and then REM sleep begins.
To measure the voltage of the electrical impulses being given of by the brain's neurons, technicians can use an EGG machine.The type of brain wave, defined by amplitude and frequency, helps determine the type of sleep that the sleeper is experiencing. The state of falling asleep is called the hypnagogic state. .
2. REM (Rapid Eye Movements) sleep .
paradoxical sleep.
- Deep sleep but with specific waves .
REM waves .
- high frequency, low amplitude waves .
