You can break the aparc.annot into individual labels with mri_annotation2label, then merge the labels of each lobe into a single lobe label with mri_mergelabels, then combine the lobe labels into an annotation with mris_label2annot. The 3rd link below is probably the most useful one for this.
doug
Allison Stevens wrote:
Mustafa, There are a couple of relevant pages with information on this. These: http://surfer.nmr.mgh.harvard.edu/fswiki/PALS_B12
http://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg13908.html
http://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg04901.html Allison