Inferring functional connectivity using spatial modulation measures of fMRI signals within brain regions of interest

We propose inferring functional connectivity between brain regions by examining the spatial modulation of the blood oxygen level dependent (BOLD) signals within brain regions of interest (ROIs). This is motivated by our previous work, where the spatial distribution of BOLD signals within an ROI was found to be modulated by task. Applying replicator dynamics to our proposed spatial feature time courses on real functional magnetic resonance imaging (fMRI) data detected task-related changes in the composition of the brain´s functional networks, whereas using classical mean intensity features resulted in little changes being detected. Thus, our results suggest that intensity is not the only co- activating feature in fMRI data. Instead, spatial modulations may also be used for inferring functional connectivity.