Hi all,
Is there any way to extract out something like the raw percentage BOLD
signal change (say as deviation from average signal) corresponding to a
component?
In my understanding, timeseries stored in say t1.txt is normalised to
variance =1 - so gives no information for such comparison.
MELODIC_IC.img maps are already Z-scores (divided by error estimate given
as the data variance UNEXPLAINED by the extracted components).
Even if I visually detect say motor area network component in two datasets
and extract the MELODIC z-stat maps, direct comparison is ambiguous, since
the difference in MELODIC z-stats can be attributed to different levels of
fluctuation of motor network as well as different levels of unexplained
noise variance (more unexplained movement, different condition of
scanner,...), which raw ICAs are divided by.
(The only way I have on mind is "filtering out" the component from initial
data, substracting the filtered from initial data, and dividing this by
initial data - but am not sure about how exactly the command line
filtering option works)
Thanks a lot for any suggestions,
Jaroslav Hlinka
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