The following section explains how to transform a recorded 3D dataset into Talairach space, an alternative to MNI normalization. The example dataset used in this support document is part of the BrainVoyager Getting Started Guide and can be downloaded from: https://www.brainvoyager.com/bv/sampledata/. This dataset has been recorded as sagittal slices and thus fits into BrainVoyager’s standard orientation. 3D datasets recorded axially or coronally must be transformed to a sagittal orientation first. Furthermore, it is advised to use brain-extracted and inhomogeneity corrected datasets for Talairach transformation.
Talairach transformation is performed in two major steps. In the first step, the cerebrum is translated and rotated into the AC-PC plane (AC = anterior commissure, PC = posterior commissure). In the second step, the borders of the cerebrum are identified; in addition to the AC and PC points and the size of the brain is fitted into standard space.
Note: Talairach transformation can be performed either automatically or manually. By default, the automatic Talairach transformation option is checked in BrainVoyager. However, for some non-standard data sets (e.g., lesion data, data sets from children or elderly) it might be advised to perform the Talairach transformation manually.