A Method of Measuring the Ability of Disengagement From Mind-Wandering Using Electroencephalogram and Its Relationship to Mindfulness and Depressive Symptoms

Objective: Mindfulness meditation might improve the ability of disengagement from mind-wandering (MW), that is, the ability to shift attention from MW. Disengagement from MW could mediate the relationship between mindfulness and reduced depression. However, no studies have confirmed this relationship because of limitations in measurement methodology. Since the mindfulness-based intervention, which instructs participants to be aware of the occurrence of, and their own engagement in,MW, might bias self-reports of MW, a measurement method that does not rely on participants’ verbal report is needed. Therefore, we propose a novel method to evaluate the ability of disengagement from MW, based on MW intensity estimation by machine-learning using electroencephalography. Method: Mind-wandering (MW) intensity was estimated using 1-s electroencephalogram samples and a machine-learning model developed in previous research. Thus, fluctuations in MW were observed during a 14-min meditation and the time required to shift attention fromMWwas defined as an index of MWdisengagement. Two experiments were performed: The first targeted experienced meditators and the second assessed nonmeditators before and after participating in a mindfulness-based intervention. Results: The experiments revealed that disengagement from MW correlated with the extent of meditation experience. A correlation was also found between the magnitude of change in disengagement and severity of depression following the intervention. Conclusions: Though further verification of validity is required, this study suggested the possibility that disengagement from MW has a mediating function on reducing depression by mindfulness-based intervention, and that improved disengagement from MW is more essential for mindfulness than trait MW.