Addressing Positioning Induced Variabillity in VBM Analyses

Costin Tanase¹, Tyler Lesh¹, Cameron Carter¹

VBM studies have suggested the presence of reduced gray matter (GM) in relatively focal lateral and medial prefrontal and temporal cortical regions that are present at the first episode schizophrenia and which appear to become more extensive with illness progression. However there are a number of methodological concerns that impact the interpretation of studies using the VBM approach. In this work we address two of the major sources of variability, such as the accuracy of normalization of GM to a standard template and the positioning in the scanner.