Which waves is predominantly seen in EEG with eyes closed in normal alert adult?
Ans. A. Alpha wavesBandFrequency (Hz)Location NormallyDelta<4frontally in adults, posteriorly in children; high-amplitude waves* adult slow-wave sleep* in babiesTheta4-7Found in locations not related to task at hand* higher in young children* drowsiness in adults and teensAlpha8-15posterior regions of head, both sides, higher in amplitude on dominant side.* relaxed/reflecting* closing the eyesBeta16-31both sides, symmetrical distribution, most evident frontally; low-amplitude waves* range span: active calm - intense - stressed - mild obsessive* active thinking, focus, high alert, anxiousGamma>32Somatosensory cortex* Displays during cross-modal sensory processing (perception that combines two different senses, such as sound and sight)* Also is shown during short-term memory matching of recognized objects, sounds, or tactile sensations
Alpha waves
Beta waves
Theta waves
Delta waves
Sleep Disorders