Tools of the Trade Region of interest analysis for fMRI

INTRODUCTION The first step in fMRI statistics is almost invariably to create a thresholded statistical map, showing which regions are ‘activated’ above some particular threshold. For simple comparisons, it is often sufficient to stop there and simply report the results of the thresholded map. However, there are often reasons to look further into particular regions of interest (ROIs). In this brief review, I will outline several approaches to ROI analysis and discuss the advantages and drawbacks of each.