Prefrontal contributions to the stability and variability of thought and conscious experience
Carhart-Harris, R. L., Christoff, K., Zamani, A.
This review (2021) examines how the prefrontal cortex and other brain networks influence the variability and stability of mental phenomena, such as executive functions, mind-wandering, and psychedelic experiences. Specifically, they highlight how different brain networks contribute to these dynamics in the short and long term while acknowledging that the stability of conscious experiences are also contingent upon the stability or variability of the internal and external environments. Since most research on psychedelics has mostly focussed on investigating large-scale brain networks, the authors conclude that future research should also study how specific regions contribute to the variability and stability of conscious experiences depending on their functional specialization.
Abstract
The human prefrontal cortex is a structurally and functionally heterogenous brain region, including multiple subregions that have been linked to different large-scale brain networks. It contributes to a broad range of mental phenomena, from goal-directed thought and executive functions to mind-wandering and psychedelic experience. Here we review what is known about the functions of different prefrontal subregions and their affiliations with large-scale brain networks to examine how they may differentially contribute to the diversity of mental phenomena associated with prefrontal function. An important dimension that distinguishes across different kinds of conscious experience is the stability or variability of mental states across time. This dimension is a central feature of two recently introduced theoretical frameworks-the dynamic framework of thought (DFT) and the relaxed beliefs under psychedelics (REBUS) model-that treat neurocognitive dynamics as central to understanding and distinguishing between different mental phenomena. Here, we bring these two frameworks together to provide a synthesis of how prefrontal subregions may differentially contribute to the stability and variability of thought and conscious experience. We close by considering future directions for this work.