β (95% CI) | p-value | |

Breathing comfort | ||

Main effect of synchrony^{#} | 0.542 (0.046–1.037) | 0.033 |

Asynchronous first^{¶} | 0.25 (−0.627–1.127) | 0.223 |

Synchronous first^{+} | −0.583 (−1.544–0.378) | |

Breathing difficulty | ||

Main effect of synchrony^{#} | −0.5 (−1.064–0.064) | 0.080 |

Asynchronous first^{¶} | −1.333 (−2.260– −0.407) | 0.221 |

Synchronous first^{+} | −0.667 (−1.760–0.427) | |

Agency | ||

Main effect of synchrony^{#} | 1.583 (0.335–2.832) | 0.014 |

Asynchronous first^{¶} | −0.667 (−1.922–0.589) | 0.336 |

Synchronous first^{+} | 1.167 (−1.285–3.618) | |

Awareness | ||

Main effect of synchrony^{#} | 2.167 (1.068–3.266) | <0.0001 |

Asynchronous first^{¶} | 0.167 (−0.894–1.227) | 0.064 |

Synchronous first^{+} | 2 (−0.121–4.121) | |

Control (Q2) | ||

Main effect of synchrony^{#} | 0.042 (−0.042–0.125) | 0.312 |

Asynchronous first^{¶} | −3.000 (−3.135– −2.865) | 0.302 |

Synchronous first^{+} | 0.083 (−0.080–0.246) | |

Control (Q5) | ||

Main effect of synchrony^{#} | Did not converge because data were similar in both conditions | |

Asynchronous first^{¶} | ||

Synchronous first^{+} | ||

Respiration rate | ||

Main effect of synchrony^{#} | −0.275 (−1.748–1.198) | 0.704 |

Asynchronous first^{¶} | 23.346 (19.460–27.231) | 0.053 |

Synchronous first^{+} | 2.685 (−0.041–5.410) | |

Respiration rate variability | ||

Main effect of synchrony^{#} | −0.295 (−0.779–0.190) | 0.222 |

Asynchronous first^{¶} | 4.594 (3.344–5.843) | 0.810 |

Synchronous first^{+} | −0.114 (−1.082–0.854) |

Subjective ratings were measured using a 7-point Likert scale with −3=strongly disagree; −2=disagree; −1=somewhat disagree; 0=neither agree nor disagree; 1=somewhat agree; 2=agree; and 3=strongly agree. ^{#}: mean difference between synchronous and asynchronous conditions, regardless of the sequence, and 95% CI estimated by the linear mixed model (p-value corresponds to the test of this difference being equal to zero); ^{¶}: mean difference between synchronous and asynchronous conditions and 95% CI estimated by the linear mixed model for the experimental sequence “Asynchronous first” (p-value corresponds to the result of the interaction test); ^{+}: mean difference between synchronous and asynchronous conditions and 95% CI estimated by the linear mixed model for the experimental sequence “Synchronous first” (the p-value corresponds to the result of the interaction test).