Scene: Supplementary Figure 21

Temporal ICA in Functional MRI Data


Supplementary Figure 21

Supplementary Figure 21 shows the effect of sICA+FIX cleanup on the Language Story contrast.  Top row is the standard analysis (i.e., ‘minimal preprocessing,’ ‘MPP’).  Middle Row is after sICA+FIX.  The negative bias in the contrast map is eliminated and consequently a positive activation in area 9m in the superior medial frontal cortex is revealed (red arrows).  The volume slices also demonstrate how CSF signal is especially affected by the bias (likely from incomplete T1 steady state relaxation in the fMRI data because an insufficient number of volumes were discarded from the beginning of the run, which also is the only baseline period in this particular task).  Even if the grey matter were not at all affected (it does appear to be somewhat affected), partial volume effects would lead to a bias within some grey matter voxels near the surface.  The bottom row shows the difference between MPP and sICA+FIX.

Modality:T1-weighted, Registration:MSMAll, Modality:Myelin Map, Surface Mesh:32k fs LR, Modality:T2-weighted, Species:Human