# Exports from Granger Causality

I have calculated Bivariate Granger Causality for ERFs based sources. Calculated GC between 4 ROIs that showed significance on the source space analyses. Calculated GC matrix for each subject / btw 4 ROIs

1. I just want to know what is the value I obtain when exporting the connections values matrix after GC.

2)Also, does it make sense to statistically contrast those values between the two directions of connectivity (ie. scout1 to scout2 vs. scout2 to scout1)? Hence, I obtain a t-value to assure the actual direction. 12>21 for example.

Thank you very much in advance
Elena

Hi Elena,

I just want to know what is the value I obtain when exporting the connections values matrix after GC.

R(i,j) is the Granger Causality value from i to j.
(I encourage you to double-check with the graph display of your connectivity results, the directionnality of the GC values is represented with connection lines with changing colors: from blue to red)

PTE: How is the connectivity matrix stored?

https://neuroimage.usc.edu/brainstorm/Tutorials/Connectivity#Granger_Causality_-_Mathematical_Background

2)Also, does it make sense to statistically contrast those values between the two directions of connectivity (ie. scout1 to scout2 vs. scout2 to scout1)? Hence, I obtain a t-value to assure the actual direction. 12>21 for example.

I think it does, I've heard about people doing this before.
@hossein27en?

Thank you!

Hi,
Yeah. GC is a directional measure so you can compare 1-->2 vs 2-->1.

Thank you