Thanks a lot for both of your answers. The problem was fixed. But now when I reached to the second step, create PPI variable, SPM showed another error,
Warning: Matrix is close to singular or badly scaled.
         Results may be inaccurate. RCOND = 1.266417e-020.
> In spm_PEB>spm_inv at 371
  In spm_PEB at 244
  In spm_peb_ppi at 325
Does this mean that my design is not good enough to conduct PPI analysis?

From: MCLAREN, Donald
Sent: Friday, March 04, 2011 4:09 PM
To: [log in to unmask]
Subject: Re: [SPM] PPI problem


(1) You can only adjust when you have an F-test;
(2) Did you move the input images (or SPM.mat file) after doing the first level model (e.g. SPM.xY.VY.fname no longer points to the correct locations of the files)?

Best Regards, Donald McLaren
D.G. McLaren, Ph.D.
Postdoctoral Research Fellow, GRECC, Bedford VA
Research Fellow, Department of Neurology, Massachusetts General Hospital and Harvard Medical School
Office: (773) 406-2464
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From: [log in to unmask] href="">junhai xu
Sent: Friday, March 04, 2011 11:23 AM
To: Ning Ma
Subject: Re: [SPM] PPI problem

I got the same problem when I analyzed our data. Maybe you moved your original data or changed the path of your data.
You can load the SPM.mat, and find the right path.


2011/3/4 Ning Ma <[log in to unmask]>
Dear SPM users,
Recently, I started to use SPM5 to conducted PPI analysis and encountered a problem.
After selected the SPM.mat from single subject data, I went to ROI and right click to get Local Max. And then I pressed 'eigenvariate' and name the VOI. After inputting VOI name, SPM skipped the step of adjust data, directly jump to VOI definition step. After inputting the radius of the VOI, SPM reported the error as
spm_mip_ui: Jumped 6.00mm from [  0,  60,  10],
   to nearest local maxima at [ -4,  62,  14]
??? Cant open image file.
Error in ==> spm_get_data at 41
 Y(i,:) = spm_sample_vol(V(i),XYZ(1,:),XYZ(2,:),XYZ(3,:),0);
Error in ==> spm_regions at 182
y        = spm_get_data(SPM.xY.VY,xSPM.XYZ(:,Q));
??? Error while evaluating uicontrol Callback.
How to fix this problem? Thanks a lot in advance!
Best Regards,
Ning Ma