Measuring the surface area is important in that it appears to be closer to gene action than the cortical volume, which is influenced by cortical thickness and folding. The method allows investigation of the area at every point in the cortex, thus giving localising power otherwise unavailable with regions of interest, and giving a result that is interpretable on its own right.
The main references for the presentation are:
- 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.
Neuroimage. 2012 Mar 15;61(4):1428-43.
- Cortical thickness or grey matter volume? The importance of selecting the phenotype for imaging genetics studies.
Winkler AM, Kochunov P, Blangero J, Almasy L, Zilles K, Fox PT, Duggirala R, Glahn DC.
Neuroimage. 2010 Nov 15;53(3):1135-46.
The scripts and instructions to run pycnophylactic brain surface area analyses are available here.