A protocol for a randomised active-controlled trial to evaluate the effects of an online mindfulness intervention on executive control, critical thinking and key thinking dispositions in a university student sample Chris Noone & Michael J. Hogan School of Psychology, NUI Galway Introduction Procedure Critical Thinking (CT) is recognised as an important higher-order cognitive process which involves successful evaluation and analysis of evidence and arguments. According to default interventionist dual-processing accounts, such responses require the intervention of executive function (EF) to interrupt automatic processing. While EF was recently shown to mediate the relationship between mindfulness and CT performance (Noone, Bunting, & Hogan, 2016), no study has examined this relationship in a randomised controlled trial.   Enrolment Baseline Post-allocation Close-out TIMEPOINT: t1 t2 t3 t4 ENROLMENT: Eligibility screen X Informed consent Allocation Debrief INTERVENTIONS: t1 – 2 weeks Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Mindfulness Meditation Sham Meditation ASSESSMENTS: Five Factor Mindfulness Questionnaire Halpern Critical Thinking Assessment Actively Open-minded Thinking Need for Cognition Sternberg Working Memory Task Heuristics and Biases Tasks Warwick-Edinburgh Mental Wellbeing Scale Positive Affect and Negative Affect Schedule Real-World Outcomes Practice Quality- Meditation Technology Acceptance Model Questionnaire Intervention Acceptability Method The design employed is a randomised-controlled 2 (condition) X 2 (time) parallel-group design which is explanatory in nature. A sample of at least 78 participants will be recruited from the pool of students at NUI Galway, with those between the ages of 18 and 65 with an adequate level of English included. Participants will be randomly assigned following screening, using block randomisation with a fixed block of 6 and a 1:1 ratio, to either the mindfulness meditation group or a sham meditation group. Both groups will be given access to the Headspace app. This is an app which provides guided meditations to users. Participants in each group will receive unique codes granting access to either the experimental or active-control intervention materials. Group allocation will be double-blinded. Measures Primary Five Facet Mindfulness Questionnaire – Observing and Non-reactivity sub-scales Measures tendency to engage in present-moment attention and non-reactivity. Halpern Critical Thinking Assessment Measures critical thinking ability through open and closed questions. Actively Open-minded Thinking Measures tendency to process information in a flexible manner. Need for Cognition Measures tendency to put active effort into thinking and problem-solving activities. Secondary Warwick-Edinburgh Mental Wellbeing Scale Measures subjective well-being and psychological functioning. Positive Affect and Negative Affect Scale Measures experiences of positive and negative emotion. Real-world Outcomes Inventory This is a behavioural checklist focused on life outcomes from many domains. Hypotheses Outcomes Variable Measure   Hypothesis Analysis Primary Mindfulness Five Facet Mindfulness Questionnaire 1 Mindfulness will increase more for the mindfulness meditation (MM) group than for the sham meditation (SM) group from t1 to t4 Mixed ANOVA Critical Thinking Halpern Critical Thinking Assessment1, Heuristic and Biases items2 2 Critical thinking will increase more for the MM group than for the SM group from t1 to t4 (a 1,2) and this effect will be moderated by baseline endorsement of thinking dispositions (b1,2) Mixed ANOVA, ANCOVA Thinking Dispositions Actively Open-minded Thinking1, Need for Cognition2 3 Endorsement of critical thinking dispositions will increase more for the MM group than for the SM group from t1 to t4 (a 1,2) Executive Control Sternberg Working Memory Task 4 Executive control will increase more for the MM group than for the SM group from t1 to t4 (a) and this increase will mediate the relationship between levels of mindfulness and critical thinking performance following the intervention (b) Mixed ANOVA, SEM Secondary Wellbeing Warwick-Edinburgh Mental Wellbeing Scale 5 Wellbeing will increase and negative affect will decrease more for the MM group than for the SM group from t1 to t4 Positive Affect and Negative Affect Positive Affect and Negative Affect Schedule subscale 6 Positive affect will increase more for the MM group than for the SM group from t1 to t4 (a) Real-world Outcomes Real-world Outcomes Inventory 7 Negative real-world outcomes will decrease more for the MM group than for SM group from t1 to t4 Discussion If this intervention proves effective, it will show the potential of mindfulness practice to facilitate everyday critical thinking and should stimulate more interest in this line of research. If ineffective, claims regarding mindfulness and thinking skills should be tempered. This research was funded by a Galway Doctoral Research Scholarship awarded to the first author and was facilitated by Headspace Inc. who provided the intervention materials. The trial is registered in the ISRCTN registry and any protocol amendments will be recorded there (RCT ID: ISRCTN16588423. Registered 7th January 2016). Contact Email - noonec@gmail.com Twitter - @chris_ _noone Researchgate - Chris_Noone Read the full protocol paper at http://bit.ly/NooneHoganBMC