title: Resting State Effective Connectivity Allows Auditory Hallucination Discrimination.
abstract: Hallucinations are elusive phenomena that have been associated with psychotic behavior, but that have a high prevalence in healthy population. Some generative mechanisms of Auditory Hallucinations (AH) have been proposed in the literature, but so far empirical evidence is scarce. The most widely accepted generative mechanism hypothesis nowadays consists in the faulty workings of a network of brain areas including the emotional control, the audio and language processing, and the inhibition and self-attribution of the signals in the auditive cortex. In this paper, we consider two methods to analyze resting state fMRI (rs-fMRI) data, in order to measure effective connections between the brain regions involved in the AH generation process. These measures are the Dynamic Causal Modeling (DCM) cross-covariance function (CCF) coefficients, and the partially directed coherence (PDC) coefficients derived from Granger Causality (GC) analysis. Effective connectivity measures are treated as input classifier features to assess their significance by means of cross-validation classification accuracy results in a wrapper feature selection approach. Experimental results using Support Vector Machine (SVM) classifiers on an rs-fMRI dataset of schizophrenia patients with and without a history of AH confirm that the main regions identified in the AH generative mechanism hypothesis have significant effective connection values, under both DCM and PDC evaluation.
authors.affiliation: * Computational Intelligence Group, University of the Basque Country, UPV/EHU, Spain.|‡ ACPySS, San Sebastian, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Graña
authors.affiliation: * Computational Intelligence Group, University of the Basque Country, UPV/EHU, Spain.
authors.forename: Leire
authors.initials: L
authors.lastname: Ozaeta
authors.affiliation: * Computational Intelligence Group, University of the Basque Country, UPV/EHU, Spain.|† CISE Department, University of Florida, Gainesville, USA.|‡ ACPySS, San Sebastian, Spain.
authors.forename: Darya
authors.initials: D
authors.lastname: Chyzhyk
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003198:Computer Simulation; D005260:Female; D006212:Hallucinations / Q000469:parasitology* / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009434:Neural Pathways / Q000503:physiopathology*; D017711:Nonlinear Dynamics; D010100:Oxygen / Q000097:blood; D012146:Rest; D060388:Support Vector Machine
chemical_list: D010100:Oxygen
keywords: Granger causality; Resting state fMRI; auditory hallucinations; dynamic causal modeling; effective connectivity; machine learning; schizophrenia