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help > RE: seed-to-voxel coordinate for F-contrast
Jan 11, 2017 01:01 AM | Alfonso Nieto-Castanon - Boston University
RE: seed-to-voxel coordinate for F-contrast
Dear Teddy,
You are exactly right about this issue, sorry I did not realize it in my previous mail. This was in fact a bug in the way negative-effects peak coordinates were being reported when using two-sided analyses. For negative-effect clusters, the correct coordinates were being reported when using the "one-sided negative" option, but not when using the "two-sided" option. I am attaching a patch to fix this issue (this patch is for release 17a, simply copy this file to the conn distribution folder overwriting the file with the same name there). This issue affected both the peak coordinates being reported as well as the peak-level statistics for negative effects when using two-sided analyses (cluster-size values and cluster-level statistics were not affected by this issue, for neither one-sided nor two-sided analyses). Thank you very much for reporting this (and for the follow-up after I failed to notice), and let me know if this seems to be working fine now
Best regards
Alfonso
Originally posted by Theodore Turesky:
You are exactly right about this issue, sorry I did not realize it in my previous mail. This was in fact a bug in the way negative-effects peak coordinates were being reported when using two-sided analyses. For negative-effect clusters, the correct coordinates were being reported when using the "one-sided negative" option, but not when using the "two-sided" option. I am attaching a patch to fix this issue (this patch is for release 17a, simply copy this file to the conn distribution folder overwriting the file with the same name there). This issue affected both the peak coordinates being reported as well as the peak-level statistics for negative effects when using two-sided analyses (cluster-size values and cluster-level statistics were not affected by this issue, for neither one-sided nor two-sided analyses). Thank you very much for reporting this (and for the follow-up after I failed to notice), and let me know if this seems to be working fine now
Best regards
Alfonso
Originally posted by Theodore Turesky:
Dear Alfonso,
Many thanks for your prompt reply! The reason for the different cluster sizes absolutely makes sense and I can understand why going from one-sided positive to two-sided would not change the peak coordinates of these clusters. What concerns me is the discrepancy between the positive and negative aspects: i.e., the peak coordinates for one-sided positive and two-sided results are the same, but the peak coordinates for one-sided negative and two-sided are different. In my attachment, I have screenshots of the two-sided result (p-height: .001), positive one-sided (p-height: .0005), and negative one-sided (p-height: .0005). The little red arrows in the coordinate box of the two-sided screenshot indicates positive results. If you compare the coordinates next to these arrows with the coordinates from the one-sided positive coordinates, you will notice that they are identical. Meanwhile, if you compare the coordinates from the two-sided results that are not accompanied by an arrow with the one-sided negative coordinates, you will notice that every coordinate is different.
Many thanks,
Teddy
Many thanks for your prompt reply! The reason for the different cluster sizes absolutely makes sense and I can understand why going from one-sided positive to two-sided would not change the peak coordinates of these clusters. What concerns me is the discrepancy between the positive and negative aspects: i.e., the peak coordinates for one-sided positive and two-sided results are the same, but the peak coordinates for one-sided negative and two-sided are different. In my attachment, I have screenshots of the two-sided result (p-height: .001), positive one-sided (p-height: .0005), and negative one-sided (p-height: .0005). The little red arrows in the coordinate box of the two-sided screenshot indicates positive results. If you compare the coordinates next to these arrows with the coordinates from the one-sided positive coordinates, you will notice that they are identical. Meanwhile, if you compare the coordinates from the two-sided results that are not accompanied by an arrow with the one-sided negative coordinates, you will notice that every coordinate is different.
Many thanks,
Teddy
Threaded View
| Title | Author | Date |
|---|---|---|
| Theodore Turesky | Jan 7, 2017 | |
| Alfonso Nieto-Castanon | Jan 10, 2017 | |
| Theodore Turesky | Jan 10, 2017 | |
| Alfonso Nieto-Castanon | Jan 11, 2017 | |
| Theodore Turesky | Jan 11, 2017 | |