Distinct cortical profiles underlie the common reportability of thought-free experiences

Mind blanking (MB) refers to moments of seemingly no reportable thought content, challenging the view of a constant thought-full mind. What remains unclear is which brain modes can lead to MB and why. Here, we aimed at delineating the nuances of MB by combining EEG-fMRI with experience-sampling of thought content and self-reported vigilance. Using a dynamic framework, we show that MB is linked to a "rich" fMRI connectivity pattern of regional anticorrelations, while low vigilance is linked to a "simple" pattern of overall positive connectivity. Put together, an interaction appears: when people are alert, connectivity around MB resembles the hyperconnected pattern, indicating that the neural correlates of MB depend on vigilance levels. This hyperconnected pattern further correlated with EEG slow-wave-like activity, tying MBs topology to sleep-like electrophysiology. We conclude that MBs neurophysiological correlates vary with vigilance, and a more refined characterisation of the neural correlates of thought-free states exists.