its hard to say without more details, but if i'm reading your email correctly, one notable difference is that you state that you extracted the cortical thickness data for an ROI and conducted the analysis in SPSS using that data. that would not be the same analysis as what qdec is doing. qdec is conducting a whole-brain analysis, not an ROI analysis. you would need to export the thickness data for the whole cortex (actually, ?h.cortex.label, which excludes the medial wall) to SPSS. This will be about 150000 data points per hemi. also, you would need to ensure the contrasts are the same.
n.
On Mon, 2010-11-08 at 16:06 +0800, liyari5018 wrote:
Hi all,
I do group analysis using QDEC to detect the difference betweenthe normal group and the patient group, the result shows some significant difference brain area (normal > patient, red, uncorrected p=0.001). I extract the average cortical thickness in this area(ROI), then export those thickness data into SPSS to do statistic analysis, but I do not find the difference between two groups in this areas, even find some opposite results.
（I checked my data carefully!）
So I want to know how does this happen?
Thanks for your reply!
Best,
LJ
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