Vividness of Visual Imagery Supported by Intrinsic Structural-Functional Brain Network Dynamics

Abstract

Vividness of visual imagery is subject to individual variability, a phenomenon with largely unexplored neurobiological underpinnings. By analyzing data from 273 participants we explored the link between the structural-functional organization of brain connectomes and the reported intensity of visual imagery (measured with VVIQ-2). Employing graph theory analyses we investigated both the structural (DTI) and functional (rs-fMRI) connectomes within a network of regions often implicated in visual imagery. Our results indicate a relationship between increased local efficiency and clustering coefficients in the structural connectome in individuals who experience more vivid visual imagery. Increased local efficiency and clustering coefficients were mirrored in the functional connectome with increases in left inferior temporal regions, a region frequently identified as a critical hub in the visual imagery literature. Furthermore, individuals with more vivid imagery were found to have lower levels of global efficiency in their functional connectome. We propose that the clarity and intensity of visual imagery are optimized by a network organization characterized by heightened localized information transfer and interconnectedness. Conversely, an excessively globally integrated network might dilute the specific neural activity crucial for generating vivid visual images, leading to less locally concentrated resource allocation in key regions involved in visual imagery vividness.