Figure 1

Latency to REMS and NLMT. Distribution of REMS latencies (black bars) in 63 night (A) and 63 morning (B) sleep episodes. Grey bars: latency to the second REMS episode (after a SOREMS episode) measured from sleep onset. C: Distribution of intervals (i.e. length of first NREMS episode) between SOREMS episodes and subsequent REMS episodes. Distribution of the latency to the first occurrence of low muscle tone in NREMS (NLMT) that occurred prior to the first REMS episode in 60 night (D) and 61 morning (E) sleep episodes. In 3 night and 19 morning sleep episodes, no NLMT was observed prior to the first REMS episode. Zero on the abscissa represents sleep onset defined as the first epoch of stage 2 or REMS. Negative values correspond to stage 1. Data were plotted in 10-min bins.