Meditation research has rarely examined how brain structure, function, and self-reports relate. This study demonstrates such a relationship for Mindfulness meditation (MM), which aims to reduce thought-related processes and enhance bodily awareness, thereby reducing identification with thought content and deconstructing maladaptive self-schema. The authors hypothesized that the structure of default mode network (DMN) regions, associated with spontaneous thoughts and self-representation, would negatively correlate with MM experience and self-reported positive affect, while positively correlating with DMN resting-state function.
Functional connectivity within the default mode network (DMN) and visual network was higher in control participants than in long-term mindfulness meditators. Meditators showed increased connectivity between the DMN and visual networks compared to controls. During meditation, connectivity both within and between these networks decreased relative to resting-state. A significant negative correlation existed between DMN connectivity and meditation expertise, indicating that more experienced meditators had lower DMN connectivity.
Long-term mindfulness meditation practitioners show opposite changes in two brain networks compared to non-meditators: heightened spontaneous fluctuations in the visual cortex and reduced fluctuations in the default mode network (DMN) during rest. During a visual recognition memory task, meditators had stronger visual cortex responses and weaker negative responses in the DMN, and they performed the task significantly faster. These findings support the spontaneous trait reactivation hypothesis, which proposes that resting-state brain activity patterns can reflect individual differences in personality, talents, and lifestyles.
Repeating a single word silently for a short period reduces brain activity broadly, especially in the default mode network, which is linked to self-related thoughts. This reduction occurred without the usual compensatory increase in other brain networks. A behavioral test confirmed that participants experienced fewer spontaneous thoughts during the repetition task compared to rest. The findings suggest that simple repetitive speech can trigger a global inhibitory effect in the brain, which may explain the calming effects reported in mantra meditation practices.