Less is more and more is less: fMRI connectivity demystified

COEX 

Caio Seguin will demystify some misconceptions related to the use of fMRI connectivity to infer underlying patterns of brain activity and brain communication. Specifically, empirical evidence of topographic convergence between structural and functional connectivity has prompted the widely held assumption that local axonal output drives fMRI connectivity. Within this framework, reduced or increased activity in a brain region should thus result in reduced (hypo-) or increased (hyper) connectivity with the region's targets. This talk will illustrate the result of recent chemogenetic and electrophysiological studies in mice that challenge this simple framework. Specifically, he will show how fMRI hyper- and hypoconnectivity may in fact counterintuitively reflect reduced and increased cortical activity, respectively. This updated framework may offer novel opportunities to biologically decode fMRI (dys)connectivity in human disorders.