That's part 1 of DrEaMs. Hope you enjoy it. 

 Sleep spindles are bursts of neural oscillatory activity that are generated by the 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).