title: Modality-Dependent Impact of Hallucinations on Low-Frequency Fluctuations in Schizophrenia.
abstract: Prior resting-state functional magnetic resonance imaging (fMRI) analyses have identified patterns of functional connectivity associated with hallucinations in schizophrenia (Sz). In this study, we performed an analysis of the mean amplitude of low-frequency fluctuations (ALFF) to compare resting state spontaneous low-frequency fluctuations in patients with Sz who report experiencing hallucinations impacting different sensory modalities. By exploring dynamics across 2 low-frequency passbands (slow-4 and slow-5), we assessed the impact of hallucination modality and frequency range on spatial ALFF variation. Drawing from a sample of Sz and healthy controls studied as part of the Functional Imaging Biomedical Informatics Research Network (FBIRN), we replicated prior findings showing that patients with Sz have decreased ALFF in the posterior brain in comparison to controls. Remarkably, we found that patients that endorsed visual hallucinations did not show this pattern of reduced ALFF in the back of the brain. These patients also had elevated ALFF in the left hippocampus in comparison to patients that endorsed auditory (but not visual) hallucinations. Moreover, left hippocampal ALFF across all the cases was related to reported hallucination severity in both the auditory and visual domains, and not overall positive symptoms. This supports the hypothesis that dynamic changes in the ALFF in the hippocampus underlie severity of hallucinations that impact different sensory modalities.
authors.affiliation: Neuroscience Institute, Georgia State University, Atlanta, GA, USA.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Hare
authors.affiliation: Department of Psychiatry, San Francisco VA Medical Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Judith M
authors.initials: JM
authors.lastname: Ford
authors.affiliation: Department of Psychology, Georgia State University, Atlanta, GA, USA.
authors.forename: Aral
authors.initials: A
authors.lastname: Ahmadi
authors.affiliation: Mind Research Network, Albuquerque, NM, USA.
authors.forename: Eswar
authors.initials: E
authors.lastname: Damaraju
authors.affiliation: Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA.|Department of Psychology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Aysenil
authors.initials: A
authors.lastname: Belger
authors.affiliation: Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Bustillo
authors.affiliation: Department of Computer Science and Engineering, Chonbuk National University, Jeonju, South Korea.
authors.forename: Hyo Jong
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, San Francisco VA Medical Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Mathalon
authors.affiliation: Department of Psychiatry, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Bryon A
authors.initials: BA
authors.lastname: Mueller
authors.affiliation: Department of Psychiatry and Human Behavior, University of California, Irvine, Irvine, CA, USA.
authors.forename: Adrian
authors.initials: A
authors.lastname: Preda
authors.affiliation: Department of Psychiatry and Human Behavior, University of California, Irvine, Irvine, CA, USA.
authors.forename: Theo G M
authors.initials: TG
authors.lastname: van Erp
authors.affiliation: Department of Psychiatry and Human Behavior, University of California, Irvine, Irvine, CA, USA.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Potkin
authors.affiliation: Mind Research Network, Albuquerque, NM, USA.|Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA.
authors.forename: Vince D
authors.initials: VD
authors.lastname: Calhoun
authors.affiliation: Neuroscience Institute, Georgia State University, Atlanta, GA, USA.|Department of Psychology, Georgia State University, Atlanta, GA, USA.|Mind Research Network, Albuquerque, NM, USA.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Turner
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D058256:Brain Waves / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods*; D006212:Hallucinations / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D012720:Severity of Illness Index; D014796:Visual Perception / Q000502:physiology*
keywords: ALFF; fMRI; hallucinations; hippocampus; resting-state