SP(pure) and SP(ripple) were characterized by comparable spindle frequency power (11–16 Hz) in both thalamic nuclei (ANT and MD) between 0-500 ms from the onset of sleep spindles, while increased power was observed between 5-15 Hz later, beginning from 500-1200 ms for the slow sleep spindles in the ANT (Figure 5). Similar results were found for the ANT fast spindles, however, the low-frequency difference was less pronounced (see Supplementary material). The 100–200 Hz power of ANT slow and fast SP(ripple) exceeded the corresponding power values of SP(pure) up to around 1000 ms. In the MD, the same contrast resulted in significant differences for fast spindles, but not for slow spindles. Thalamic SP(pure) and SP(ripple) did not differ in terms of concomitant scalp EEG time-frequency power (see Figure 5. for ANT slow sleep spindles, the ANT fast and MD spindles are presented in the Supplementary material).