The default mode network (DMN) is not functionally uniform during episodic memory retrieval. Using fMRI, parietal regions inside and outside the DMN were examined. Memory retrieval activated posterior DMN nodes, especially the angular gyrus, and also separate anterior/dorsal parietal regions outside the DMN. DMN regions responded sooner, while non-DMN regions showed sustained activity until a memory judgment. A parahippocampal region with strong resting-state connectivity to parietal DMN showed similar task-evoked activity. DMN parietal regions directly supported memory retrieval; non-DMN regions were involved in postretrieval decision-making. A dissociation within the DMN emerged: angular gyrus and posterior cingulate/precuneus were activated, but medial prefrontal cortex was deactivated, demonstrating functional heterogeneity.
Long-term meditation practice reshapes functional connectivity patterns in large-scale brain networks, and the specific patterns depend on the type of meditation used. Using fMRI and multivariate pattern analysis, researchers found that connectivity patterns in key brain networks could predict both a meditator's expertise and age. Expertise-related patterns differed between Focused Attention (FA) and Open Monitoring (OM) meditation: FA involved networks for attention, while OM involved networks for cognitive control and emotion regulation. Age-related patterns were unaffected by meditation style. The findings indicate that intensive mental training induces neuroplastic changes in brain network connectivity that are specific to the form of meditation practiced.