PHYSIOLOGY
CENTRAL NERVOUS SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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are observed during relaxed wakeful state
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are faster than
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disappear when the person becomes alert
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are observed during REM sleep
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Detailed explanation-1: -Beta and gamma waves (20–80 Hz) occur spontaneously during REM sleep and waking and are evoked by intense attention, conditioned responses, tasks requiring fine movements, or sensory stimuli.
Detailed explanation-2: -The EEG pattern resembles sleep stage 1, except that vertex sharp waves are not prominent in the REM stage. The EEG activities specific to REM sleep are the theta wave, the sawtooth wave, 2–6 and the alpha wave. The theta wave is characterized by a frequency between 4 and 7 Hz and is dominant in central sites.
Detailed explanation-3: -Indeed, they distinguished two groups of delta waves occurring during REM sleep: slower (<2 Hz) waves, recorded in medial-occipital regions, present in both NREM and REM sleep, and faster (2.5–3 Hz), REM-sleep-exclusive, fronto-central/occipito-temporal “sawtooth” waves.
Detailed explanation-4: -Beta frequencies are generally over 13 Hz and of low amplitude. Beta is often enhanced during drowsiness, seen in a precentral distribution, and felt to be related to the functions of the sensorimotor cortex.