Table 1.
Behavioral data for the three groups, shown as mean and standard deviation collected pre and post-intervention.
Fig 1.
Group means of RMSSD (ms.) during daytime (left panel) and nighttime (right panel) for the chronic phase (i.e. pre and post measurement). The mindfulness-group showed at pre a mean RMSSD during daytime of 30.16ms. (SD = 12.2) and of 36.35ms. (SD = 15.6) during nighttime. At post-measurement the group showed a RMSSD mean of 40.65ms. (SD = 13.8) during daytime and 54.76ms. (SD = 19.0) during nighttime. The music group showed at pre a RMSSD-mean of 31.64ms. (SD = 10.7) during daytime and of 37.82ms. (SD = 12.7) during sleep. At post measurement the group showed a RMSSD-mean of 32.64ms. (SD = 10.2) during daytime and 37.0ms. (SD = 11.8) during nighttime. The control-group had a mean RMSSD at pre-measurement of 31.40ms. (SD = 8.2) during daytime and 35.61ms. (SD = 8.8) during nighttime. The control group showed a mean RMSSD at post measurement of 27.62ms. (SD = 8.8) at daytime and of 35.14ms. (SD = 9.2) during nighttime. Error bars are 95% CI.
Fig 2.
Group mean of acute RMMSD during the acute phase across the 10 intervention days.
Visual representation of the mindfulness groups’ (left panel) and the music groups’ (right panel) acute RMSSD (grey line) on each of the 10 days of the music or mindfulness intervention as well as their pre-intervention daytime RMSSD shown as the mean from the chronic 48-hour pre-intervention phase (black line). Error bars are ±2 SD.
Fig 3.
Group respiration rate for both the chronic and acute phase across groups.
The mindfulness, music and control group’s mean respiration rate (times/min) measured during the chronic 48-hour pre- and post-intervention phase, and the mean respiration rate during the daily mindfulness or music sessions measured during the acute phase. The mindfulness group’s mean respiration rate was 17.10 times/min (SD = 1.67) at pre-intervention and 17.04 times/min (SD = 1.56) at post. The music group’s mean respiration rate was 17.18 times/min (SD = 1.31) at pre and 16.97 times/min (SD = 1.38) at post-intervention. For the control group the mean respiration rate at pre-intervention was 16.93 times/min (SD = 1.54) and 17.03 times/min (SD = 1.44) at post. Error bars are ±2 SD.
Fig 4.
Correlation between home practice and the delta function of the chronic RMSSD phase.
Correlation coefficients for the mindfulness group between total minutes of home practice and delta RMSSD during daytime (left panel) R = .47 and nighttime (right panel) R = .44. Each datapoint represents a participant.
Table 2.
Chronic and acute frequency-domain HRV data for the three groups, shown as mean and standard deviation collected pre and post-intervention.