On 06/10/2013 02:18 AM, Andreas Berger wrote:
Hi,
basically, i would like to use the area measure for group analysis, but i'm not sure whether that's ok to do. my questions would be:
is it suitable for group analysis?
yes
what should i cite if i do?
We don't have a citation specifically for it. It is used by this paper, but it does not describe it in detail. Greve, D. N., Van der Haegen, L., Cai, Q., Stufflebeam, S., Sabuncu, M. R., Fischl, B., & Brysbaert, M. (2013). A Surface-based Analysis of Language Lateralization and Cortical Asymmetry. /Journal of cognitive neuroscience/, (Early Access), 1-16.
is surface area represented vertex-wise, with a vertex' adjacent face's area added and divided by 3?
That is how the ?h.area file is created.
What happens when resampling to the standard mesh:
The method assures that total area (or volume) is preserved when mapping
between subjects was that referring to the method described by Winkler or the default FreeSurfer way of doing it?
No, his way is more elaborate and probably much better but harder to implement and slower. The currently implemented version effectively preserves area over any given patch when mapping to fsaverage. I don't know what the size of the patch is but is probably on the order of 5mm (probably smaller). doug
andreas
On Wednesday, June 05, 2013 23:22:46 Douglas N Greve wrote:
Hi Andreas, it is not the same method but somewhat related. The method assures that total area (or volume) is preserved when mapping between subjects. How much detail do you need? doug
On 06/04/2013 05:21 AM, Andreas Berger wrote:
Hello FreeSurfers,
after reading this [1] paper about measuring surface area, i realized i don't know what the default way of measuring surface area is in FreeSurfer. Is it similar to what's described in the paper? Could you point me to the right documentation or publication? Forgive me if i've overlooked it, i found something for thickness, but not for area. To clarify, i don't mean parcellation-based areas, i mean the measure that i find in /surf/hemi.area.
thanks, regards, Andreas
[1] Measuring and comparing brain cortical surface area and other areal quantities. Winkler AM, Sabuncu MR, Yeo BT, Fischl B, Greve DN, Kochunov P, Nichols TE, Blangero J, Glahn DC (2012). Neuroimage 61(4):1428-43 _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer