How is N3 sleep primarily characterized in terms of brain activity?

N3 sleep, also known as slow-wave sleep or deep sleep, is primarily characterized by slow brain activity dominated by delta waves. Delta waves have a frequency of 0.5 to 4 Hz and are associated with the deepest stages of sleep, where the body is in a state of rest and rejuvenation.

During N3 sleep, the body undergoes important processes such as physical recovery, hormone release, and memory consolidation. The presence of delta waves indicates significant synchrony in brain activity, which contributes to the restorative aspects of this sleep stage. Therefore, the correct characterization of N3 sleep reflects the slow activity marked by delta waves, highlighting the physiological significance of this phase in the sleep cycle.