A M/EEG-fMRI Fusion Primer: Resolving Human Brain Responses in Space and Time

Any cognitive function is mediated by a network of many cortical sites whose activity is orchestrated through complex temporal dynamics. To understand cognition, we need to identify brain responses simultaneously in space and time. Here we present a technique that does this by linking multivariate response patterns of the human brain recorded with functional magnetic resonance imaging (fMRI) and with magneto- or electroencephalography (M/EEG) based on representational similarity. We present the rationale and current applications of this non-invasive analysis technique, termed M/EEG-fMRI fusion, and discuss its pros and cons. We highlight its wide applicability in cognitive neuroscience and how its openness to further development and extension gives it strong potential for a deeper understanding of cognition in the future. Cichy and Oliva present the workings, promises, and limitations of a technique called M/EEG-fMRI fusion, which combines measurements from different imaging modalities for a view of human brain function that is resolved simultaneously in space and time.