The prefrontal cortex contains multiple subregions linked to different large-scale brain networks, supporting a wide range of mental phenomena from goal-directed thought and executive functions to mind-wandering and psychedelic experiences. A key dimension distinguishing conscious experiences is the stability or variability of mental states over time, which is central to the dynamic framework of thought (DFT) and the relaxed beliefs under psychedelics (REBUS) model. This review synthesizes these frameworks to explain how prefrontal subregions may differentially contribute to the stability and variability of thought and conscious experience, and suggests future research directions.
The default mode network (DMN) is linked to self-referential thinking, memory, and goal-directed cognition. Its functional connectivity with frontoparietal networks involved in attention and executive control may indicate cognitive health. This review examines DMN connectivity metrics as potential biomarkers across states like attention, mind wandering, and meditation, and in conditions such as Alzheimer's disease, Parkinson's disease, depression, and ADHD. It also addresses the reliability of network estimation and offers recommendations for using functional connectivity measures as biomarkers of cognitive health.