One is a map-based/voxel-wise analysis, each voxel is treated separately. The aparc stats table is an average over all vertices in the ROI. If you have an effect that does goes across the ROI boundary, it could be lost in the ROI analysis. On the other hand, the ROI analysis may be more powerful because of the averaging across space and fewer issues with registration across subject
On 08/23/2016 04:59 PM, miracooloz@gmail.com wrote:
Hello freesurfer experts, What's the difference between GLM surface based cortical thickness analysis and the cortical thickness analysis performed when using regions extracted from aparcstat table? Best, Paul
Sent from my BlackBerry 10 smartphone.
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Thanks doug. Also, let's say I extract the aparcstat table and perform t -test using spss and a ROI become significant, is it possible the significant effect will be lost using GLM surface based? Best, Paul
Sent from my BlackBerry 10 smartphone. Original Message From: Douglas N Greve Sent: Wednesday, August 24, 2016 5:39 PM To: freesurfer@nmr.mgh.harvard.edu Reply To: Freesurfer support list Subject: Re: [Freesurfer] GLM surface based cortical thickness analysis vs aparcstat table cortical thickness
One is a map-based/voxel-wise analysis, each voxel is treated separately. The aparc stats table is an average over all vertices in the ROI. If you have an effect that does goes across the ROI boundary, it could be lost in the ROI analysis. On the other hand, the ROI analysis may be more powerful because of the averaging across space and fewer issues with registration across subject
On 08/23/2016 04:59 PM, miracooloz@gmail.com wrote:
Hello freesurfer experts, What's the difference between GLM surface based cortical thickness analysis and the cortical thickness analysis performed when using regions extracted from aparcstat table? Best, Paul
Sent from my BlackBerry 10 smartphone.
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Yes, that is possible, but you should see some sort of trend, eg, most the ROI should have a certain sign
On 08/24/2016 06:47 PM, miracooloz@gmail.com wrote:
Thanks doug. Also, let's say I extract the aparcstat table and perform t -test using spss and a ROI become significant, is it possible the significant effect will be lost using GLM surface based? Best, Paul
Sent from my BlackBerry 10 smartphone. Original Message From: Douglas N Greve Sent: Wednesday, August 24, 2016 5:39 PM To: freesurfer@nmr.mgh.harvard.edu Reply To: Freesurfer support list Subject: Re: [Freesurfer] GLM surface based cortical thickness analysis vs aparcstat table cortical thickness
One is a map-based/voxel-wise analysis, each voxel is treated separately. The aparc stats table is an average over all vertices in the ROI. If you have an effect that does goes across the ROI boundary, it could be lost in the ROI analysis. On the other hand, the ROI analysis may be more powerful because of the averaging across space and fewer issues with registration across subject
On 08/23/2016 04:59 PM, miracooloz@gmail.com wrote:
Hello freesurfer experts, What's the difference between GLM surface based cortical thickness analysis and the cortical thickness analysis performed when using regions extracted from aparcstat table? Best, Paul
Sent from my BlackBerry 10 smartphone.
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
freesurfer@nmr.mgh.harvard.edu
-
Douglas N Greve -
miracooloz＠gmail.com