14:00-14:45 Julio Rodriguez Larios
Meditation practice entails moments of distraction dominated by task-unrelated thoughts (i.e. mind wandering). Initial studies assessing the neural correlates of mind wandering in the context of meditation practice have identified an important role of alpha (8-14 Hz) and theta (4-8 Hz) neural oscillations. However, unlike controlled cognitive processing, alpha-theta cross-frequency dynamics during mind wandering have not been explored yet. In this study, we assessed both power modulations in the alpha/theta frequency range and alpha-theta cross-frequency dynamics during mind wandering in the context of meditation practice. Electroencephalography (EEG) was measured in 25 novice meditation practitioners during a breath focus task in which they were repeatedly probed to report whether they were focusing on their breath or thinking about something else. In line with previous studies, we show an increase in theta amplitude and a decrease in alpha amplitude during self-reported mind wandering compared to breath focus. In addition, mind wandering was associated with changes in the center frequency of alpha and theta rhythms that fostered 2:1/3:1 harmonicity and cross-frequency phase synchrony. Together, these results suggest that transient spectral changes in the alpha-theta range during mind wandering relative to breath focus are aimed at facilitating cross-frequency interactions (via phase synchrony) between alpha and theta rhythms. Since similar spectral modulations have been reported during tasks involving retrieval, storage and manipulation of information, we conclude that mind wandering and controlled cognitive processes could share some neurocognitive mechanisms.