TABLE 3

Results summary for the subjective and physiological measures

	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)	0.223
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)	0.221
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)	0.336
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)	0.064
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)	0.302
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)	0.053
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)	0.810

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).