title: Paradoxical results of adaptive false discovery rate procedures in neuroimaging studies.
abstract: Adaptive false discovery rate (FDR) procedures, which offer greater power than the original FDR procedure of Benjamini and Hochberg, are often applied to statistical maps of the brain. When a large proportion of the null hypotheses are false, as in the case of widespread effects such as cortical thinning throughout much of the brain, adaptive FDR methods can surprisingly reject more null hypotheses than not accounting for multiple testing at all-i.e., using uncorrected p-values. A straightforward mathematical argument is presented to explain why this can occur with the q-value method of Storey and colleagues, and a simulation study shows that it can also occur, to a lesser extent, with a two-stage FDR procedure due to Benjamini and colleagues. We demonstrate the phenomenon with reference to a published data set documenting cortical thinning in attention deficit/hyperactivity disorder. The paper concludes with recommendations for how to proceed when adaptive FDR results of this kind are encountered in practice.
authors: Department of Child and Adolescent Psychiatry, New York University School of Medicine, New York, NY 10016, USA. phil.reiss@nyumc.org
authors: Philip T
authors: PT
authors: Reiss
authors: Armin
authors: A
authors: Schwartzman
authors: Feihan
authors: F
authors: Lu
authors: Lei
authors: L
authors: Huang
authors: Erika
authors: E
authors: Proal
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001289:Attention Deficit Disorder with Hyperactivity / Q000473:pathology*; D001921:Brain / Q000254:growth & development / Q000473:pathology / Q000502:physiology*; D002540:Cerebral Cortex / Q000254:growth & development / Q000473:pathology; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D059906:Neuroimaging / Q000379:methods*; D011336:Probability; D055815:Young Adult