help > RE: Leave one out
Aug 22, 2016  01:08 PM | Jennifer Barredo
RE: Leave one out
Hi Alfonso,

Thank you for posting the CONN version of your SPM cross-validation scripts.  The scripts work very nicely, but I have a few questions and could use some guidance on reporting the LOOCV output.

1) Are the values stored in the CV_DATA variable the GLM prediction errors after leaving out a given subject, or are they correlations between PE estimated using the full dataset vs. the LOOCV data set?  

2) Would running a t-test against zero on the CV_DATA be the correct way to validate a cluster extracted from a seed-to-voxel analysis?  

3) If a t-test were used and the cluster of interest was extracted from a between-groups contrast, a statistically significant t-test would be interpreted as positive evidence of validity.  If the cluster was extracted from a single group or condition however, a null rather than significant finding would be considered positive evidence.  Is this correct?


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David White May 18, 2016
Jeff Browndyke Jan 10, 2019
Jeff Browndyke May 18, 2016
Thomas DeRamus May 18, 2016
Alfonso Nieto-Castanon Jun 23, 2016
RE: Leave one out
Jennifer Barredo Aug 22, 2016
Jeff Browndyke Dec 28, 2018
Helene Hopman Nov 13, 2019