Dear experts,
I have constrasts from 2 different groups of participants (healthy and patient), and each group with unequal participant size.
I have ran the same 1st level design for each participant from both groups, and calculated constrasts of interest for each participant. I am trying to do between group comparison using these contrasts in 2nd level.
I use a two-sample t-test under 2nd level design specification.
The specification is successful. During estimation, however, I get the following error:
------------------------------------------------------------------------
Running job #2
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Running 'Model estimation'
SPM12: spm_spm (v6842) 20:15:31 - 06/12/2019
========================================================================
SPM12: spm_est_non_sphericity (v6913) 20:15:31 - 06/12/2019
========================================================================
Chunk 1/1 : ...done
Failed 'Model estimation'
Error using spm_est_non_sphericity (line 208)
Please check your data: There are no significant voxels.
In file "E:\Avi\spm12\spm_est_non_sphericity.m" (v6913), function "spm_est_non_sphericity" at line 208.
In file "E:\Avi\spm12\spm_spm.m" (v6842), function "spm_spm" at line 431.
In file "E:\Avi\spm12\config\spm_run_fmri_est.m" (v5809), function "spm_run_fmri_est" at line 33.
The following modules did not run:
Failed: Model estimation
I believe this has something to do with temporal auto-correlation? But why would this be the case, since this is 2nd level analysis there is no temporal element. I have used "Independence = yes" and "Variance = unequal". I would really like to know how to fix this.
Any help is greatly appreciated. I can email the data to anyone who may be able to help.
Thank you,
Avijit Chowdhury
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