Distributions of the durations of RISE episodes and the distances between successive RISE episodes for waking and all sleep stages, F3-F4. Results for one patient. The distributions can be approximated by a log-normal distribution. The median duration (p50) of synchronization phases is 350–450 ms and does not change with the state of vigilance. A shorter duration of the intervals separating elevated synchronization phases (ca. 1000 ms) is visible in N3 versus W, N1, N2, and R (1900–2200 ms). The 90% percentile (p90) is clearly reduced in N3 compared to the other stages, indicating a predominant reduction of long unsynchronized phases. This indicates a methodological rather than a physiological effect (see Section 4).