Simon Thibault

Hi, I am trying to extract the time course of beta estimates in specific ROIs. However I have some issues to do it properly. Indeed, let's say my ROI contain 124 voxels, I should get a vXYZ matrix of 3x124 dimensions and Y matrix of n x 50. However for some ROIs I do not get n x 123 but rather n x 49 or even n x 4 depending on where is localized the ROI. What could be the origin of this problem? Best, Simon