Stage N2 of sleep is primarily dominated by which brain wave activity?

Stage N2 of sleep is characterized primarily by the presence of theta waves. These waves have a frequency of about 4 to 7 Hz and are indicative of a lighter stage of sleep compared to the deeper sleep stages. During N2 sleep, the brain begins to display sleep spindles and K-complexes, which are also associated with theta activity.

Theta waves generally reflect a transition from alert wakefulness to deeper sleep and indicate a state where the body is preparing for restorative processes. This includes both physical repair and memory consolidation. Recognizing the dominance of theta waves in stage N2 helps in understanding sleep cycles and the investigations involved in polysomnography, as identifying the correct sleep stage is crucial in evaluating sleep disorders.