Figure 2.

Distribution of the measures of full predictability (P_η|Ω), self-predictability (P_η|η) and causal predictability (P_Φ→η) assessed for the cardiac parasympathetic component of HRV in the network Ω={Φ,η} formed by cardiac process η and the brain process Φ, and expressed as median and quartiles computed in healthy controls (CTRL), in patients with severe sleep apnoea–hypopnoea syndrome (SAHS), and in the same patients studied after prolonged continuous positive airway pressure therapy (CPAP). For each measure, the number of subjects for which it was detected as statistically significant is reported inside the bar. *p<0.05 CTRL versus SAHS or CTRL versus CPAP (Mann–Whitney U-test).