title: A cluster overlap measure for comparison of activations in fMRI studies.
abstract: Most fMRI studies use voxel-wise statistics to carry out intrasubject as well as inter-subject analysis. We show that statistics derived from voxel-wise comparisons are likely to be noisy and error prone, especially for inter-subject comparisons. In this paper we propose a novel metric called weighted cluster coverage to compare two activation maps. This metric is based on the intersection of spatially contiguous clusters of activations. It is found to be more robust than voxel-wise comparisons and could potentially lead to more statistical power in fMRI-based group studies.
authors.affiliation: IBM T. J. Watson Research Center, NY, USA.
authors.forename: Guillermo A
authors.initials: GA
authors.lastname: Cecchi
authors.forename: Rahul
authors.initials: R
authors.lastname: Garg
authors.forename: A Ravishankar
authors.initials: AR
authors.lastname: Rao
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D016000:Cluster Analysis; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity