Advanced meditators often report experiences of nondual awareness—a state without boundaries between self and environment. This review of functional magnetic resonance imaging studies across meditation types and experience levels finds that meditation reorganizes the brain's spatial topography. Key neural changes include decreased activity in the posterior default mode network (DMN), increased activity in the central executive network (CEN), reduced connectivity within the posterior DMN and between posterior and anterior DMN, increased connectivity within the anterior DMN and CEN, and significantly altered connectivity between DMN and CEN, likely nonlinear. These changes suggest a shift from mental-self-processing toward interoceptive and exteroceptive self-processing, enabling explicit nondual awareness. The authors propose a topographic reorganization model of meditation (TRoM) linking neural and experiential effects.
Meditation practices with a wider attentional focus, such as Shoonya meditation, are associated with longer intrinsic neural timescales (INTs) in the brain, measured as the autocorrelation window (ACW) of EEG signals, compared to practices with a narrower focus like Mantra or Vipassana meditation. The study compared three groups of highly proficient practitioners from different traditions and a meditation-naïve control group. The results indicate a correspondence between the width of attentional scope and the duration of neural temporal windows, suggesting that subjective attentional width relates to objective neural activity patterns.