Sleep B and C

N1

Light transition between wakefulness and sleep

N2

includes sleep spindles and K-complexes

N3

deep, slow-wave sleep

REM

Rapid eye movements, vivid dreaming, temporary muscle paralysis

Sleep Spindle

Brief burst of brain activity during N2

Deep Sleep

more common earlier in night

REM lengthens

later in the sleep cycle

Night terror

intense fear/arousal during deep non-REM sleep

REM Rebound

increased REM after deprivation

Dream

occurs in more than one sleep stage but more vivid in REM

Manifest content

remembered storyline or surface content in dreams

Latent content

hidden symbolic meaning in Freud

Activation-synthesis theory

brain makes sense of internally generated activity during sleep

Information-processing view

dreaming may relate to processing memories and experiences