Event-related delta, theta, alpha and gamma correlates to auditory oddball processing during Vipassana meditation.
Long-term Vipassana meditators sat in meditation vs. a control (instructed mind wandering) states for 25 min, electroencephalography (EEG) was recorded and condition order counterbalanced. For the last 4 min, a three-stimulus auditory oddball series was presented during both meditation and control periods through headphones and no task imposed. Time-frequency analysis demonstrated that meditation relative to the control condition evinced decreased evoked delta (2-4 Hz) power to distracter stimuli concomitantly with a greater event-related reduction of late (500-900 ms) alpha-1 (8-10 Hz) activity, which indexed altered dynamics of attentional engagement to distracters. Additionally, standard stimuli were associated with increased early event-related alpha phase synchrony (inter-trial coherence) and evoked theta (4-8 Hz) phase synchrony, suggesting enhanced processing of the habituated standard background stimuli. Finally, during meditation, there was a greater differential early-evoked gamma power to the different stimulus classes. Correlation analysis indicated that this effect stemmed from a meditation state-related increase in early distracter-evoked gamma power and phase synchrony specific to longer-term expert practitioners. The findings suggest that Vipassana meditation evokes a brain state of enhanced perceptual clarity and decreased automated reactivity.
Department of Psychiatry, University of California, Irvine, Irvine, CA 92868, USA. rael.cahn@gmail.com
B Rael
BR
Cahn
Arnaud
A
Delorme
John
J
Polich
D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D001364:Awareness / Q000502:physiology; D001921:Brain / Q000502:physiology*; D058256:Brain Waves / Q000502:physiology*; D004192:Discrimination, Psychological; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D008297:Male; D019122:Meditation / Q000379:methods*; D008875:Middle Aged; D055815:Young Adult