Perturbation or Function? Intrinsic brain dynamics in the Default Mode Network predict involuntary fluctuations of visual awareness


Brain activity is intrinsically organised into spatiotemporal patterns, but it is still not clear whether the intrinsic dynamical patterns are functional or epiphenomenal. Using a simultaneous fMRI-EEG implementation of a well-known bi-stable visual task, we showed that the latent transient states (~100-ms) in the intrinsic EEG oscillations can predict the upcoming involuntarily perceptual transitions. The critical state predicting a dominant perceptual transition was characterised by the phase coupling between the precuneus (PCU), a key node of the Default Mode Network (DMN), and the primary visual cortex (V1). The interaction between the lifetime of this state and the PCU->V1 causal effect is correlated with the rate of perceptual fluctuation. Our study suggests that the brain’s endogenous dynamics are phenomenologically relevant, as they can trigger a diversion between potential visual processing pathways, while external stimuli remain the same. In this sense, the intrinsic DMN dynamics pre-empt the content of consciousness.