PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -Along with another wave pattern called K-complexes, sleep spindles are considered a hallmark of stage 2 NREM sleep.

Detailed explanation-2: -Sleep spindles are short (<2 s), synchronous bursts of activity between 11 and 17 Hz. They are found throughout NREM sleep but are particularly numerous in NREM stage 2 (NREM2) sleep.

Detailed explanation-3: -Sleep spindles are short bursts of brain activity lasting 0.5 to three seconds. Occurring every three to six seconds during stage 2 sleep and occasionally during other stages sleep spindles are essential for memory and learning.

Detailed explanation-4: -Sleep spindles are bursts of neural oscillatory activity that are generated by interplay of the thalamic reticular nucleus (TRN) and other thalamic nuclei during stage 2 NREM sleep in a frequency range of  11 to 16 Hz (usually 12–14 Hz) with a duration of 0.5 seconds or greater (usually 0.5–1.5 seconds).