EEG rhythms + sleep stages and REM vs. NREM Flashcards
(17 cards)
what EEG rhythm is associated with waking state?
beta rhythm: small amplitude, fast frequency (15–30 Hz), with muscle tone and eye movement.
what is alpha rhythm and when does it occur?
large amplitude, slow frequency (7–11 Hz), in a relaxed state with closed eyes.
what rhythm characterizes the drowsy state?
theta rhythm: slower frequency (4–7 Hz), muscle tone present, eyes not moving.
what rhythm occurs during deep sleep?
delta rhythm: large, slow EEG waves (1–3 Hz), no eye movement, reduced consciousness.
what is atonia and when does it occur?
complete muscle inactivity during REM sleep.
how does the body regulate temperature during REM sleep?
it doesn’t—temperature regulation mechanisms shut off.
what happens to REM and deep sleep throughout the night?
earlier cycles have more deep sleep (S3/S4); REM increases as the night progresses.
what is the difference in dream quality between REM and NREM?
REM dreams are vivid and story-like; NREM dreams are less vivid except for night terrors.
when do vivid dreams typically occur?
REM sleep
what characterizes REM sleep?
fast brain activity, vivid dreams, muscle atonia (paralysis), and irregular body temperature control.
what happens during NREM sleep?
body movements like grinding teeth or flailing, and dreams are less vivid (except night terrors).
what is the typical sleep cycle progression?
stage 1 → stage 2 → stage 3 → stage 4 → REM, repeated in ~90 min cycles.
what EEG pattern is seen in waking state?
beta rhythm – fast, low amplitude waves.
what EEG pattern is seen in deep sleep (stage 3/4)?
delta waves – slow, high amplitude.
what are the main purposes of sleep?
conserve energy, restore the body, and consolidate memories.
how does REM sleep affect memory?
helps organize and process emotional and skill-based memories.
how does NREM sleep affect memory?
strengthens factual and knowledge-based memories.
