Electroencephalography-Based Measures to Understand Meditation and Mindfulness: Bibliometric Scoping Review of Randomized Controlled Trials.

OBJECTIVES

Despite the dramatic growth in the number of clinical trials of meditation and/or mindfulness-based interventions (MMBIs), most trials focus on self-reported or psychological outcomes, less is known about the potential neuroplastic effects of MMBI practice and benefits for brain health. In this review, we aimed to map the extent and nature of existing research on this topic, identify subdomains, and determine the feasibility of conducting further systematic reviews.

METHODS

We conducted a bibliometric scoping review and summarized characteristics of randomized controlled trials (RCTs) with electroencephalography (EEG)-based measures for MMBIs, including publication year, country, participant characteristics, sample size, trial arms, intervention duration and components, EEG experimental design, and reported EEG-based outcomes.

RESULTS

From 3401 retrieved publications through a systematic search, we identified 142 eligible publications from 31 countries. More than half (54.6%) were published in the past five years. Ninety studies (63.4%) included healthy participants. Clinical conditions varied, but the majority included psychiatric/mental disorders, followed by pain or substance use, neurological disorders, sleep disturbances or insomnia, cancer/tumor, and age-related cognitive decline. Most studies focused on cognitive function/performance, memory/learning, executive function, attention/vigilance, sensory/perception, emotional/affective, or distress/stress. The two main types of EEG assessments were spectral analysis and measures from event-related potential.

CONCLUSIONS

Despite the large number of RCTs on MMBIs with EEG outcomes, our synthesis shows significant heterogeneity in study populations, research aims, experimental designs, performed tasks, and reported outcomes. Further systematic reviews and meta-analyses will require accumulation of additional original studies to allow a meaningful focus on specific topics with sufficient amount of evidence. Future research examining neuroplastic effects of MMBI practice utilizing objective physiological EEG-based measures are warranted and encouraged to advance the mind-body field.