To examine whether mindfulness training is associated with changes in objective attention performance.
Three meta-analyses were conducted: (a) a meta-analysis comparing the effects of mindfulness interventions with those of control treatments (109 effect sizes from 40 studies); (b) a meta-analysis comparing attention performance of long-term meditators with that of meditation-naïve participants (59 effect sizes from 18 studies); and (c) a meta-analysis comparing correlations between trait mindfulness and attention (197 effect sizes from 28 studies).
Average effect sizes were significant (Hedges’ g = 0.29 for intervention studies, 0.32 for long-term meditation practice; r between trait mindfulness and attention = 0.12). All three analyses found significant effects on inhibition/executive control. Two out of the three analyses showed significant effects on updating and sustained attention. Shifting yielded significant effects only for interventions. Effects were larger for accuracy than for speed. Within intervention studies, focused attention led to significant effects, but inclusion of a yoga component decreased effects significantly. Number of sessions was positively related to attention performance. In long-term meditators, type of meditation practiced did not significantly moderate the effect size. Within trait mindfulness studies, only unidimensional measures and measures of acting with awareness yielded an average correlation that was significantly different from zero.
Mindfulness training as an intervention and a long-term practice is indeed associated with reliable changes in objective attention performance. The finding that this is also true for trait mindfulness suggests that mindfulness is a key mechanism.