Mapping directed influence over the brain using Granger causality and fMRI.
We propose Granger causality mapping (GCM) as an approach to explore directed influences between neuronal populations (effective connectivity) in fMRI data. The method does not rely on a priori specification of a model that contains pre-selected regions and connections between them. This distinguishes it from other fMRI effective connectivity approaches that aim at testing or contrasting specific hypotheses about neuronal interactions. Instead, GCM relies on the concept of Granger causality to define the existence and direction of influence from information in the data. Temporal precedence information is exploited to compute Granger causality maps that identify voxels that are sources or targets of directed influence for any selected region-of-interest. We investigated the method by simulations and by application to fMRI data of a complex visuomotor task. The presented exploratory approach of mapping influences between a region of interest and the rest of the brain can form a useful complement to existing models of effective connectivity.
Roebroeck
Alard
A
Department of Cognitive Neuroscience, Faculty of Psychology, University of Maastricht, The Netherlands.
Formisano
Elia
E
Goebel
Rainer
R
D001288:Attention / Q000502:physiology; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D003198:Computer Simulation; D004292:Dominance, Cerebral / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data*; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D009415:Nerve Net / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012044:Regression Analysis
D010100:Oxygen