Dear all
I want to compare the resting state connectivity of three different age groups. My problem is that one of the groups have a few scanning parameters that differ from the other two. It is TR (3 vs 2), number of slices (34 vs 32) slice scan order (ascend vs interleaved) and number of scans (120 vs 180) that differ.
My questions are: a) is it possible to still compare them in site of these differences?, b) how should I set up the pre-processing; three separate pre-processings or should I try to concatenate my data sets somehow? c) if so, how?
I'm grateful for any help and/or input.
//Eva
Forums
Hi Eva,
Hi Eva,
1. If you have to combine the two sites for statistical analysis, be sure to standardize them and model the site effects in the statistical model. (Yan, C.G., Craddock, R.C., Zuo, X.N., Zang, Y.F., Milham, M.P., 2013. Standardizing the intrinsic brain: towards robust measurement of inter-individual variation in 1000 functional connectomes. Neuroimage 80, 246-262.)
2. Seperating them might be easier. However, DPARSF supports pre-processing for different sites all together.
3. Please see http://rfmri.org/dparsf_v2_3
2. Save information of TR, Slice Number, Time Points and Voxel Size into TRInfo.tsv (under working directory) file for checking data correctness.
3. The slice order type could be specified for each participant into SliceOrderInfo.tsv (under working directory) file, thus allow different slice timing correction for different participants in a batch mode. Please find instructions for setting SliceOrderInfo.tsv from {DPARSF}/Docs/SliceOrderInfo.tsv_Instruction.txt.
It's my bad that haven't create a well documented manual yet. I plan to start a wiki, thus all of us could work together to improve the documentation of DPABI/DPARSF.
Best,
Chao-Gan
Thank you for your quick
Thank you for your quick reply Chao-Gan, I really appreciate it.
I think I will preprocess the data sets separately, it really does seem to be easier. I should still be able to compare them in further analyses (e.g., 2 sample t-test etc.)?
A wiki sounds like a really good idea, but you're already doing a great job answering all of our cries for help! Thank you.
Best,
Eva
Hi Eva,
Hi Eva,
Although you can compare them, remember you group effect is mixed with site differences.
Best,
Chao-Gan