Introduction
MM’s cognitive benefits, MM’s cognitive effects, MM
In the last 15 years, mindfulness meditation (MM) has become a legitimate area of research in behavioral and brain sciences [In the field of cognitive psychology, the trait of mindfulness is described as a metacognitive skill supported by two main components, that is, the orientation to experience and the self-regulation of attention [In the current scientific literature several studies support the benefits of long-term MM practice on cognitive functions, especially those involved in mindfulness, namely attention (e.g., [These conflicting results regarding MM’s cognitive benefits (for reviews see [A first possible confounding factor could be the familiarity with MM practice, which is not systematically accounted for in the literature. For instance, the studies investigating acute cognitive effects of MM provide no comparison between meditators and meditation-naïve participants, to whom we refer here as novices. A second possible confounding factor could be the individual-dependant response to MM, i.e., individuals being more or less disposed to benefit from this practice. The distinction between responders and non-responders to interventions has already been successfully applied in the context of physical exercise [We contend that studying the acute effects of short-term practice while taking into account the above-mentioned cofounding factors would help in clarifying MM’s cognitive effects and mechanisms of action, while guiding the investigation of longer-term cognitive benefits. Accordingly, the present study, we compared the acute cognitive effects of a guided MM session to that of an active control intervention, isolating thereby the specific effects of MM. Participants with (meditators) and without (novices) previous MM experience were enrolled in the study to determine whether the familiarity with mindfulness practice could affect the observed outcomes. Additionally, to limit the bias related to the individual-dependant response, we used a within subject design in which all participants followed both interventions in a randomized order. Furthermore, we used both objective (heart rate) and subjective (self-reported questionnaire) measures to evaluate whether participants managed to follow the MM intervention. A self-reported questionnaire was implemented to measure the extent to which the participant succeeded in following the proposed mindfulness session. The participants’ heart rate (HR) was measured at rest and during both the MM and the control interventions. Although there is so far no absolute robust objective measure, the literature appears to be supportive of HR as a helpful indicator of meditation effects. Indeed, it has been shown to be significantly lowered during meditation when comparing meditators to a passive control group [To assess the cognitive functions of interest, we used a computerized version of the Stroop word-color task [We expected to observe an improved cognitive performance after the MM session, reflected by faster reaction times in the Stroop task, compared to baseline and to after the control intervention. We also expected to observe a possible interaction between the intervention effect and the familiarity with the practice, which could be explained through the indicators of the engagement in the MM session (self-reported questionnaire and HR).