Dear SPM users

I am trying to do the ROI analysis in the second-level (random effect analysis). I use the VOI button in SPM to extract the 1^st Eigenvariate, thus, for example, if I have 10 subjects, the xX.u will show [10 x 1] vector in my predefine cluster.

1. My first question is, can I export these values for 1^st Eigenvariate to SPSS to calculate the statistical difference? Is it valid?

2. If yes, then I know 1^st Eigenvariate means “similar signal change”, can I use the word “signal change” as y-axis? Or I should use the beta coefficient in the beta image to extract the mean signal change. What’s the difference between the Eigenvariate and beta in ROI analysis?

3. I know a lot of ROI tool box (e.g. Marsbar or Poldrack’s ROI toolbox), is it different from the VOI function in SPM?

I am confused with the ROI analysis,

Thanks in advance,

Bo-Cheng Kuo

Dept. of Psychology

National Taiwan University