Figure 6. Topographic distribution of sleep spindles for the 12 Hz (left) and 14 Hz (right) time frequency spot. Top plots show the spatial distribution of waveshapes obtained after MaSTiF for the 12 Hz (left) and 14 Hz (right). The sequence of maps is shown for each range to demonstrate the stability of the map sequence during the spindle. Notice that except for polarity inversions, the same scalp spatial pattern remains during the whole spindle cycle. Slower spindles show frontal distribution.