Assessing the effects of an 8-week mindfulness training program on neural oscillations and self-reports during meditation practice

Mindfulness training did not reduce lapses of attention or their associated theta brain oscillations during meditation, but it did slow alpha oscillations in frontal electrodes, a pattern previously seen in highly experienced meditators and thought to reflect decreased arousal. The study recorded EEG from 41 participants before and after 8 weeks of mindfulness training or a waitlist, interrupting them during meditation to report focus and drowsiness. Self-reported lapses of attention were linked to increased theta oscillations that were slower and more widespread than those during focused states. These findings clarify the neural correlates of mindfulness meditation and may inform neuromodulation protocols.

Study at a glance

Abstract

Abstract Previous literature suggests that mindfulness meditation can have positive effects on mental health, however, its mechanisms of action are still unclear. In this pre-registered study, we investigate the effects of mindfulness training on lapses of attention (and their associated neural correlates) during meditation practice. For this purpose, we recorded Electroencephalogram (EEG) during meditation practice before and after 8 weeks of mindfulness training (or waitlist) in 41 participants (21 treatment and 20 controls). In order to detect lapses of attention and characterize their EEG correlates, we interrupted participants during meditation to report their level of focus and drowsiness. First, we show that self-reported lapses of attention during meditation practice were associated to an increased occurrence of theta oscillations (3-6 Hz), which were slower in frequency and more spatially widespread than theta oscillations occurring during focused attention states. Then, we show that mindfulness training did not reduce the occurrence of lapses of attention nor their associated EEG correlate (i.e. theta oscillations) during meditation. Instead, we find that mindfulness training was associated with a significant slowing of alpha oscillations in frontal electrodes during meditation. Crucially, frontal alpha slowing during meditation practice has been reported in highly experienced meditators and is thought to reflect relative decreases in arousal levels. Together, our findings provide insights into the EEG correlates of mindfulness meditation, which could have important implications for the identification of its mechanisms of action and/or the development of neuromodulation protocols aimed at facilitating meditation practice.