Participants
MM, psychiatric, alcoholism
DISORDERS
The sample size was chosen based on G*Power analysis. It indicated that for repeated measure ANOVA (2 groups, 3 tests) at least 28 participants would be required for a medium effect size (f = 0.25, α = 0.05, 1-β = 0.080, ρ = 0.5, [Forty-two healthy adults volunteered to participate in the study. None of them had previous or current neurological or psychiatric disorders, recent or current musculoskeletal problems of the dominant upper-limb, ongoing psychopharmacological medication, uncorrected vision, an addiction to illegal substances or alcoholism. They were recruited through advertisements in a newspaper, a sports club and via instructors of MM. Twenty-two participants were regular meditators (mean age ± SD: 49.23 ± 13.19 years, 14 women) and twenty had no prior experience in meditation practice, which we called novices (41.50 ± 13.28 years, 11 women). In the meditators’ group, participants practiced MM, or a form of meditation with mindfulness exercises, for at least three-times a week (mean frequency ± SD: 5.53 ± 1.68 sessions per week), since minimally four months (mean experience: 63.5 months, range: 5–250 months). Accordingly, the meditators and novices groups differed regarding their experience in meditation, but were not statistically significantly different regarding sex (chi-square test: χPrior to their enrolment, all participants were given detailed written information about the study, without stating its precise objective or the underlying hypotheses. They all gave their written informed consent to the experimental procedure that agreed with the Declaration of Helsinki and was approved by the ethics committee of Aix-Marseille University.