The Neurodynamic Core of Meditation: Dissociating Meditation from Rest and Task in a Reliability-based EEG study

BackgroundElectroencephalographic (EEG) studies attempting to characterise the neural signature of meditation typically rely on contrasts with passive rest or comparisons among practitioners based on experience. However, these approaches rarely include active control states and seldom establish the reliability and robustness of identified quantitative EEG features. Consequently, the validity of proposed neurophysiological markers of meditative state remains uncertain. The present study addressed these limitations by using a reliability-informed, multi-session within-subject design to characterise distinct state-dependent EEG dynamics in experienced meditators from the Brahmakumaris Rajayoga tradition. MethodsThirty long-term meditators underwent repeated EEG recordings over two days, comprising two meditation sessions per day. Each meditation block was flanked by rest periods, with a cognitive task between sessions to reduce carryover effects. We quantified broadband spectral power, aperiodic slope and intercept, and nonlinear dynamical measures, including detrended fluctuation analysis (DFA), Higuchi fractal dimension, and permutation entropy (PE), across meditation, rest, and task conditions. ResultsCompared with both rest and task states, meditation was associated with increased theta-alpha power, an elevated aperiodic intercept, and systematic modulation of nonlinear indices (DFA, Higuchi, PE). Further meditative core features demonstrated high inter-session test-retest reliability, strong inter-individual consistency, stability across guided and silent meditation states, and were not moderated by years of meditative experience. ConclusionThe present framework identifies a reproducible neurodynamic core of meditation, distinct from passive and active control states, spanning spectral, aperiodic, and nonlinear EEG domains in long-term meditators. These findings enhance the construct validity and measurement reliability of meditation-specific neural markers.