Abstract #3283

Experimental Validation of Dynamic Granger Causality for Inferring Sub-100ms Neuronal Timing Differences from fMRI Without the Confounding Effect of Hemodynamic Variability

Yunzhi Wang¹, Santosh Katwal²,³, Baxter Rogers²,⁴, John C . Gore,⁴, Gopikrishna Deshpande¹,⁵

¹AU MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States; ²Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, TN, United States; ³Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States; ⁴Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; ⁵Department of Psychology, Auburn University, Auburn, AL, United States

Dynamic Granger causality (DGC) was performed to infer sub-100ms neuronal timing differences in BOLD responses from the visual cortex. DGC connectivities were calculated from experimental fMRI data which introduced a known delay between right and left hemified stimuli and a GLM was fit between the experimental paradigm and dynamic Granger causality difference series. The results come out that dGCD significantly covaried with the paradigm for all delays except zero. Our experimental validation of DGC to detect sub-100 ms neuronal timing differences without the confounding effect of hemodynamic variability provide a reliable data-driven method for effective connectivity analysis of fMRI data.