Vascularization's Impact on Neuronal Metrics in Human Visual Cortex

Motivation: We aimed to unravel the intricate relationship between neuronal metrics and vascularization in human visual cortex, addressing the need for a deeper understanding of these factors' impact on fMRI data. Goal(s): Our study sought to determine if differences exist in pRF sizes between micro- and macro-vascular compartments and the influence of extra- and intra-vascular effects. Approach: We obtained pRF estimates across cortical depth using different fMRI scan sequences (SE/GE) at varying field strengths (7T/3T). Results: While our findings confirmed typical pRF size trends and vascularization-dependent amplitude effects across cortical depth, we did not find that vascularization or magnetic field strength affected pRF sizes. Impact: This study's findings challenge the conventional understanding of how vascularization affects neuronal metrics in functional brain imaging. The research underscores the complexity of neurovascular interactions and their implications for the interpretation of fMRI data.