Brain Connectivity Studies on Structure-Function Relationships: A Short Survey with an Emphasis on Machine Learning

Figure 7

Correlation-based functional connectivity describes the temporal coherence of activity profiles in two brain regions and and therefore yields undirected graphical representations of brain networks (a). On the contrary, directed connectivity measures such as Granger causality provide a data-driven perspective on potentially causal dependencies among brain regions, i.e., if one region drives region , or vice versa (b).

(a)

(b)