Current study & hypotheses
neuroticism, anxiety
The current study aimed to help researchers and clinicians better apply the principles of precision medicine to the design of MBIs. Towards that end, we conducted a randomized controlled experiment to evaluate dose–response relationships and moderators of the effect of a single-session mindfulness meditation session. We specifically compared 10 versus 20 min of mindfulness meditation versus control conditions, and tested their effects on outcomes including state mindfulness, anxiety, negative affect, and positive affect. Participants were randomly assigned to either a: (1) 10-min mindfulness meditation, (2) 20-min mindfulness meditation, (3) 10-min control condition, or (4) 20-min control condition. Moderator variables included trait mindfulness, neuroticism, and prior meditation experience. By assessing acute changes in state mindfulness and affect, this study may help elucidate the proximal mechanisms by which MBIs with meditations of different lengths may exert their beneficial effects.We hypothesized that both meditation conditions would yield significant improvements in state mindfulness, state anxiety, and negative affect relative to control conditions, with no effect on positive affect. We expected no difference in positive affect because prior research has shown that changes in positive affect in a single-session MBI were moderated by prior meditation experience. Given that we expected the sample to be comprised of meditation-naïve individuals as well as individuals with prior meditation experience, we expected that, at an aggregate level, we would not see significant changes in positive affect. We also hypothesized that participants in the 20-min meditation condition would report greater improvements in state mindfulness, state anxiety, and negative affect, but not positive affect, relative to participants in the 10-min meditation condition. Although this hypothesis may seem to contradict the aforementioned findings of Strohmaier et al., specifically that five minutes of meditation resulted in greater increases in state mindfulness than did twenty minutes, the sample from that study was comprised entirely of people with either no or limited prior meditation experience. We expected to recruit a more diverse sample with respect to prior meditation experience (i.e., more prior meditation experience at an aggregate level), and therefore hypothesized that there would be a dose–response relationship in favor of longer durations of meditation for all outcomes, except for positive affect. Relatedly, we hypothesized that participants’ prior meditation experience would interact with “dose,” such that people with prior meditation experience would experience greater improvements in state mindfulness, state anxiety, negative affect, and positive affect from the 20-min meditation compared to meditation-naïve individuals.