Fig. 4

Cognitive tests, physiological responses, performance perception and positive affect between intervention and control trials. Individual data is shown for intervention (blue) and control (red) for SpO₂ (a), ScO₂ (b), HR (c), PVT mean RT (d), DSST number of correct responses (g, VAS performance (h), and PANAS-P (i). Measurements of the same participant are connected by lines. Violin plots with 95% confidence intervals for the mean are shown in (e) for the within-person difference in reaction time in PVT separately for participants who had a baseline reaction time below or above 281 ms. A scatter plot with the respective regression line between SpO₂ and the RT residual of the GEE model, when correcting for daytime, sequence, sex, age, ISI, HR, BR, and baseline RT, is shown in (f)