Benefits of brief mindfulness induction on heart rate variability only significant among participants with low executive functioning

This study investigated whether a single mindfulness induction enhances heart rate variability (HRV) following a sad mood induction compared to an active control group. Secondly, it was examined whether participants in the mindfulness group would report lower state anxiety, state rumination, negative affect and higher positive affect. Exploratory analyses tested whether baseline executive functions (EF) (inhibition, working memory and cognitive shifting) moderated these effects. 71 university students (75% females; mean age = 22.1 ± 1.9 years) completed either a mindfulness induction or listening to a lecture excerpt (active control) before undergoing a sad mood induction. Executive functions and pre-induction HRV were assessed at baseline; self-report measures and post-induction HRV were collected afterwards. Manipulation checks confirmed that the inductions were successful, however, no main effect of condition on HRV was found. However, individuals with weaker working memory and inhibitory control exhibited greater improvements in HRV following the mindfulness induction as compared to the control group. These findings suggest that mindfulness inductions are not equally effective for all: individual differences in baseline EF seem to have a role in how responsive someone is to brief mindfulness exercises. Future research could help further clarify for whom and under what conditions mindfulness exercises are most effective.