Neural correlates of pure presence

Abstract

Pure presence (PP) is described in several meditative traditions as an experience of a vast, vivid space devoid of perceptual objects, thoughts, and self. Integrated information theory (IIT) predicts that such vivid experiences may occur when the cortical substrate of consciousness is virtually silent. To test this, we analyzed high-quality 256-electrode high-density electroencephalography (hdEEG) from twenty-two long-term Vajrayana and Zen meditators who reported reaching PP during a week-long retreat. Because neural activity typically increases gamma power, we predicted PP would show widespread gamma reductions. Across both traditions, PP was associated with broadband power decrease compared to within-meditation mind-wandering, most consistent in the gamma range (30- 45 Hz). Source reconstruction revealed widespread gamma decreases, strongest in posteromedial cortex. PP gamma power was lower than in all other control states, including watching or imagining a movie, active thinking, and open-monitoring. PP delta power (1-4Hz) was also markedly reduced compared to dreamless sleep. Meditative states resembling PP--with minimal perceptual contents or accompanied by bliss-- showed similar signatures. Overall, PP appears to be a state of vivid consciousness during which the cortex is highly awake (low delta) yet widely quiescent (low gamma), in line with IITs predictions.