Figure 4.

Association of spindles with slow-wave up-states. A, Example of a single spindle associated with a slow-wave up-state as recorded in the depth EEG of the anterior cingulate cortex. B, Number of detected spindles around slow-wave down-states (left, positive peaks in depth EEG) and up-states (right, negative peaks in depth EEG). Blue traces show average slow waves (n = 13 individuals). Red shading, SEM across channels; green horizontal lines, confidence interval (α = 0.05). Thicker green bars, significant deviations from chance. Note that around slow waves, spindles occur more often after transition to the up-state. C, Regional differences in association of spindles with slow-wave up-states. Note that fast centroparietal spindles (regions 4–5, red-brown colors) are more tightly associated with slow-wave up-states. Asterisks mark the average time to up-states for each region.