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

Abstract:

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.