Fig. 3.

REM^ABD+ epochs are longer and display increased respiratory variability compared with REM^ABD− epochs. Averaged pooled respiratory rate (BPM), respiratory variability (coefficient of variation of the period, CV), length of REM epochs (in seconds), and duration of apneas (in seconds) in REM epochs that display (REM^ABD+; black) or not (REM^ABD−; grey) expiratory ABD muscle recruitment. REM^ABD+ epochs are usually longer, and they are characterized by an increased respiratory variability. *Statistical significance (P < 0.05) between values.