Interaction of language, auditory and memory brain networks in auditory verbal hallucinations

TY - JOUR

T1 - Interaction of language, auditory and memory brain networks in auditory verbal hallucinations

AU - Ćurčić-blake, Branislava

AU - Ford, Judith

AU - Hubl, Daniela

AU - Orlov, Natasza D.

AU - Sommer, Iris E.

AU - Waters, Flavie

AU - Allen, Paul

AU - Jardri, Renaud

AU - Woodruff, Peter W.

AU - Olivier, David

AU - Mulert, Christoph

AU - Woodward, Todd S.

AU - Aleman, André

PY - 2017/1/1

Y1 - 2017/1/1

N2 - Auditory verbal hallucinations (AVH) occur in psychotic disorders, but also as a symptom of other conditions and even in healthy people. Several current theories on the origin of AVH converge, with neuroimaging studies suggesting that the language, auditory and memory/limbic networks are of particular relevance. However, reconciliation of these theories with experimental evidence is missing. We review 50 studies investigating functional (EEG and fMRI) and anatomic (diffusion tensor imaging) connectivity in these networks, and explore the evidence supporting abnormal connectivity in these networks associated with AVH. We distinguish between functional connectivity during an actual hallucination experience (symptom capture) and functional connectivity during either the resting state or a task comparing individuals who hallucinate with those who do not (symptom association studies). Symptom capture studies clearly reveal a pattern of increased coupling among the auditory, language and striatal regions. Anatomical and symptom association functional studies suggest that the interhemispheric connectivity between posterior auditory regions may depend on the phase of illness, with increases in non-psychotic individuals and first episode patients and decreases in chronic patients. Leading hypotheses involving concepts as unstable memories, source monitoring, topdown attention, and hybrid models of hallucinations are supported in part by the published connectivity data, although several caveats and inconsistencies remain. Specifically, possible changes in fronto-temporal connectivity are still under debate. Precise hypotheses concerning the directionality of connections deduced from current theoretical approaches should be tested using experimental approaches that allow for discrimination of competing hypotheses.

AB - Auditory verbal hallucinations (AVH) occur in psychotic disorders, but also as a symptom of other conditions and even in healthy people. Several current theories on the origin of AVH converge, with neuroimaging studies suggesting that the language, auditory and memory/limbic networks are of particular relevance. However, reconciliation of these theories with experimental evidence is missing. We review 50 studies investigating functional (EEG and fMRI) and anatomic (diffusion tensor imaging) connectivity in these networks, and explore the evidence supporting abnormal connectivity in these networks associated with AVH. We distinguish between functional connectivity during an actual hallucination experience (symptom capture) and functional connectivity during either the resting state or a task comparing individuals who hallucinate with those who do not (symptom association studies). Symptom capture studies clearly reveal a pattern of increased coupling among the auditory, language and striatal regions. Anatomical and symptom association functional studies suggest that the interhemispheric connectivity between posterior auditory regions may depend on the phase of illness, with increases in non-psychotic individuals and first episode patients and decreases in chronic patients. Leading hypotheses involving concepts as unstable memories, source monitoring, topdown attention, and hybrid models of hallucinations are supported in part by the published connectivity data, although several caveats and inconsistencies remain. Specifically, possible changes in fronto-temporal connectivity are still under debate. Precise hypotheses concerning the directionality of connections deduced from current theoretical approaches should be tested using experimental approaches that allow for discrimination of competing hypotheses.

KW - Auditory verbal hallucinations

KW - Functional connectivity

KW - Anatomical connectivity

KW - fMRI

KW - EEG

KW - DTI

KW - Language

KW - Memory

KW - Auditory processing

KW - Psychosis

KW - Schizophrenia

U2 - 10.1016/j.pneurobio.2016.11.002

DO - 10.1016/j.pneurobio.2016.11.002

M3 - Article

SN - 0301-0082

VL - 148

SP - 1

EP - 20

JO - Progress in Neurobiology

JF - Progress in Neurobiology

ER -