Increased amygdala and parahippocampal gyrus activation in schizophrenic patients with auditory hallucinations: an fMRI study using independent component analysis.
OBJECTIVE
Hallucinations in patients with schizophrenia have strong emotional connotations. Functional neuroimaging techniques have been widely used to study brain activity in patients with schizophrenia with hallucinations or emotional impairments. However, few of these studies have investigated the association between hallucinations and emotional dysfunctions using an emotional auditory paradigm. Independent component analysis (ICA) is an analysis method that is especially useful for decomposing activation during complex cognitive tasks in which multiple operations occur simultaneously. Our aim in this study is to analyze brain activation after the presentation of emotional auditory stimuli in patients with schizophrenia with and without chronic auditory hallucinations using ICA methodology. It was hypothesized that functional connectivity differences in limbic regions responsible for emotional processing would be demonstrated.


METHODS
The present functional magnetic resonance imaging (fMRI) study compared neural activity in 41 patients with schizophrenia (27 with auditory hallucinations, 14 without auditory hallucinations) with 31 controls. Neural activity data was generated while participants were presented with an auditory paradigm containing emotional words. The comparison was performed using a multivariate approach, ICA. Differences in temporo-spatial aspects of limbic network were examined in three study groups.


RESULTS
Limbic networks responded differently in patients with auditory hallucinations compared to healthy controls and patients without auditory hallucinations. Unlike control subjects and non-hallucinators, the group of hallucinatory patients showed an increase of activity in the parahippocampal gyrus and the amygdala during the emotional session.


CONCLUSIONS
These findings may reflect an increase in parahippocampal gyrus and amygdala activity during passive listening of emotional words in patients with schizophrenia and auditory hallucinations.
Escartí
María Jose
MJ
Psychiatric Unit, Clinic Hospital, Avda. Blasco Ibáñez, 17, 46010 Valencia, Spain. mescartifabra@hotmail.com
de la Iglesia-Vayá
Maria
M
Martí-Bonmatí
Luis
L
Robles
Montserrat
M
Carbonell
Jose
J
Lull
Juan Jose
JJ
García-Martí
Gracián
G
Manjón
Jose Vicente
JV
Aguilar
Eduardo Jesús
EJ
Aleman
André
A
Sanjuán
Julio
J
D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D006212:Hallucinations / Q000150:complications* / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D020534:Parahippocampal Gyrus / Q000503:physiopathology*; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology*; D012720:Severity of Illness Index