Go with the (Blood) Flow: A Systematic Review on the Relationship Between Dynamic Functional Connectivity and Information Processing Speed.

Dynamic functional connectivity (dFC) methods could shift understandings about brain-behavior relationships. Information processing speed (IPS) may be of particular interest to dFC analyses as dFC is able to capture time-sensitive FC changes. The present systematic review aims to explore the association between IPS and dFC of resting-state functional magnetic resonance imaging (rsfMRI) data in healthy individuals. Included papers were published through July 24, 2023. Searches conducted on ProQuest and ScienceDirect used the search terms processing speed AND fMRI AND resting state AND dynamic functional connectivity OR dynamic functional network connectivity. Studies were eligible based on the following inclusion criteria: empirical research, published in English, use of a well-characterized healthy population (n > 30), use of rsfMRI, calculation of dFC, measurement of IPS, and a statistical test between dFC and IPS. Results reveal mixed findings. Five studies report no relationship between dFC and IPS, whereas eight report mixed or positive findings. We noted several trends in findings that may be driving inconsistencies. Over half of the reviewed studies used the Human Connectome Project data. Second, IPS was more likely to be related to dFC if images were acquired using an eyes open procedure with fixation on a crosshair. As all included IPS measures involved a visual component, IPS and dFC measurement might both be capturing information about visuoperceptual connections. Future work that addresses these biases and trends may illuminate the nature of the relationship between dFC and IPS.