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¥Data Preparation: Co-Registration (AKA ÒSpatial NormalizationÓ)
HGroup analyses are performed on a voxel-by-voxel basis
HAll data sets used in the analysis must be aligned and defined over the same spatial domain.
åTalairach domain for volumetric data
íLandmarks for the transform are set on high-res. anatomical data using AFNI
íFunctional data volumes are then transformed using AFNI interactively or adwarp from command line (use option -dxyz with about the same resolution as EPI data Ñ do not use the default 1 mm resolution!)
åStandard meshes and spherical coordinate system for surface data
íSurface models of the cortical surface are warped to match a template surface using Caret/SureFit (http://brainmap.wustl.edu) or FreeSurfer (http://surfer.nmr.mgh.harvard.edu)
íStandard-mesh surface models are then created with SUMA (http://afni.nimh.nih.gov/ssc/ziad/SUMA) to allow for node-based group analysis using AFNIÕs programs
åOnce data is aligned, analysis is carried out voxel-by-voxel or node-by-node
íThe percent signal change from each subject in each task/stimulus state are usually the numbers that will be compared and contrasted
íResulting statistics (voxel-wise or node-wise) can then be displayed in AFNI and/or SUMA