The concept of 'consciousness' in the search for neural correlates of consciousness (NCC) is problematic, and the term 'correlates' is also confused. Brain events that covary with conscious experience can be neural substrates of the experience, but they can also be neural prerequisites or neural consequences. This work disentangles these different sorts of brain processes conceptually and proposes a concrete multi-pronged research program to distinguish them empirically in near-future consciousness research.
Mind-wandering, a common daily mental activity, varies uniquely from person to person. In three individuals who each reported hundreds of mind-wandering episodes during multiple fMRI sessions, reliable links between mind-wandering and default mode network (DMN) activation emerged when brain networks were analyzed within each person. However, the timing of spontaneous DMN activity relative to subjective reports, and the broader networks activated or deactivated during mind-wandering, differed across individuals. Whole-brain connectivity patterns that predicted mind-wandering within an individual did not fully generalize to others, and predictive models from larger datasets largely failed when applied to these densely-sampled individuals. This work demonstrates both conserved and variable neural representations of mind-wandering, highlighting the value of personalized approaches.