BOLD percent signal change

 Dear all,

I would like to plot the time courses for two regions in the DMN -- Posterior cingulate cortex and medial prefrontal cortex -- so I can graphically see if the two regions are positively or negatively correlated over time.  I am running voxel-wise analyses and I am getting the ROI_FC... text file outputs.  I am a little confused about what these values are and if I plotted them, what would the y-axis be labeled and if these are even the true representation of signal changes over time?  Also, I would like anyone's opinion on if this type of graph would even be meaningful?  I would like to show the graph and the zmap overlayed on subjects' T1 volumes.

You're help is much much appreciated!!

Brett

Hi!

If you want to "plot the time courses for two regions in the DMN", then you can use REST->Utilities->Extract ROI Signals to extract the time course for PCC and MPFC. The values are the preprocessed BOLS signals, and the y-label is an arbitrary unit. You can see such a graph in Fox et al., 2005, they demonstrated the negative/positive correlation with the graphic time seres.