Figure 2.

HR analysis across sleep–wake stages.

Notes: (A) HR values calculated from stable bouts (>5 minutes) of each sleep–wake stage. There were no differences between any of the stages. The waking HR values refer to any time spent awake while in bed for the PSG recording. (B) Histogram showing the proportion (%) of the cohort with lower HR value during N2 and N3, compared to wake of at least 0, 5, or 10% dipping. (C) Distribution of HR slope calculated for stable bouts of each sleep–wake stage across the cohort. The X-axis is the slope of a linear fit to each stable bout (in units of bpm). The zero-crossing value is the proportion of stable bouts that had a positive slope, and the inset is a zoom to show that the highest value was for wake and N1; by contrast, N3 had the greatest proportion of bouts showing a positive slope (lowest zero-crossing value on the Y-axis).

Abbreviations: HR, heart rate; PSG, polysomnography; REM, rapid eye movement.