Functional MRI (fMRI) is a non-invasive approach to study the brain activity. Despite its exceptional capabilities in localizing neuronal responses, applications of this technique in studying fast brain activities are limited.
In Nasr et al. (2021), we introduced a new approach to assess the link between fMRI fluctuations and fast brain responses. We showed that the level of fMRI co-fluctuations, measured between the fine-scale cross-hemispheric cortical sites, varies with the spatial organization of visual stimuli – a feature encoded by gamma-band neuronal activities. In this study, we have also assessed the impact of multiple factors on the level this co-fluctuation, including the stimulus noise and location, cognitive tasks and cortical depth.