On the Importance of Being Flexible: Dynamic Brain Networks and Their Potential Functional Significances

Abstract

In this theoretical review, we begin by discussing brains and minds from a dynamical systems perspective, and then go on to describe methods for characterizing the flexibility of dynamic networks. We discuss how varying degrees and kinds of flexibility may be adaptive (or maladaptive) in different contexts, specifically focusing on measures related to either more disjoint or cohesive dynamics. While disjointed flexibility may be useful for assessing neural entropy, cohesive flexibility may potentially serve as a proxy for self-organized criticality as a fundamental property enabling adaptive behavior in complex systems. Particular attention is given to recent studies in which flexibility methods have been used to investigate neurological and cognitive maturation, as well as the breakdown of conscious processing under varying levels of anesthesia. We further discuss how these findings and methods might be contextualized within the Free Energy Principle with respect to the fundamentals of brain organization and biological functioning more generally, and describe potential methodological advances from this paradigm. Finally, with relevance to computational psychiatry, we propose a research program for obtaining a better understanding of ways that dynamic networks may relate to different forms of psychological flexibility, which may be the single most important factor for ensuring human flourishing.

Human electromagnetic and haemodynamic networks systematically converge in unimodal cortex and diverge in transmodal cortex

“…We find that cross-modal correspondence between MEG and fMRI functional networks is associated with structure-function coupling measured from MRI functional and structural connectivity networks, suggesting that the cross-modal map may be constrained by structural connectivity. Previous reports demonstrate that unimodal, sensory regions have lower neural flexibility compared to transmodal, association areas and are more stable during development and evolution [115, 124, 149]. This suggests that the underlying anatomical network constrains neural activity and functional flexibility in a nonuniform manner across the cortex, resulting in higher degrees of freedom in structure-function coupling in regions related to highly flexible cognitive processes.…”

Human electromagnetic and haemodynamic networks systematically converge in unimodal cortex and diverge in transmodal cortex

“…We find that cross-modal correspondence between MEG and fMRI functional networks is associated with structure–function coupling measured from MRI functional and structural connectivity networks, suggesting that the cross-modal map may be constrained by structural connectivity. Previous reports demonstrate that unimodal, sensory regions have lower neural flexibility compared to transmodal, association areas and are more stable during development and evolution [ 24 , 115 , 116 ]. This suggests that the underlying anatomical network constrains neural activity and functional flexibility in a nonuniform manner across the cortex, resulting in higher degrees of freedom in structure–function coupling in regions related to highly flexible cognitive processes.…”

Neural Mechanisms and Psychology of Psychedelic Ego Dissolution

“…Observations associating behavioral responses to psychedelics (i.e., positive or negatively felt ego dissolution) and measures of flexibility may offer clinical insight. For example, measures of flexibility can be measured as disjointed or cohesive flexibility and have been associated with different behavioral outcomes (Safron et al, 2022). Uncovering the specific dynamics of neural flexibility in regions and networks and their correspondence to behavioral properties may be vital to understanding the effects of psychedelics.…”

“…Uncovering the specific dynamics of neural flexibility in regions and networks and their correspondence to behavioral properties may be vital to understanding the effects of psychedelics. For further review of forms of flexibility in brain dynamics and their functional significance, readers are directed to Safron et al (2022).…”