Functional deficit in the medial prefrontal cortex during a language comprehension task in patients with schizophrenia

Sonia Dollfus (1, 2) , Annick Razafimandimby (1) , Olivier Maiza (1, 2) , Pierrick Lebain (1, 2) , Perrine Brazo (1, 2) , Virginie Beaucousin (1) , Laurent Lecardeur (1, 2) , Pascal Delamillieure (1, 2) , Bernard Mazoyer (1, 3, 2) , Nathalie Tzourio-Mazoyer (1)

1 GIN - UMR 6194 - Groupe d'imagerie neuro-fonctionnelle
2 Service de psychiatrie [CHU Caen]
3 IUF - Institut Universitaire de France

Objective We and others have observed that patients with schizophrenia commonly presented a reduced left recruitment in language semantic brain regions. However, most studies include patients with leftward and rightward lateralizations for language. We investigated whether a cohort comprised purely of patients with typical lateralization (leftward) presented a reduced left recruitment in semantic regions during a language comprehension task. The goal was to reduce the inter-subject variability and thus improve the resolution for studying functional abnormalities in the language network. Methods Twenty-three patients with schizophrenia (DSM-IV) were matched with healthy subjects in age, sex, level of education and handedness. All patients exhibited leftward lateralization for language. Functional MRI was performed as subjects listened to a story comprising characters and social interactions. Functional MRI signal variations were analyzed individually and compared among groups. Results Although no differences were observed in the recruitment of the semantic language network, patients with schizophrenia presented significantly lower signal variations compared to controls in the medial part of the left superior frontal gyrus (MF1) (x = − 6, y = 58, z = 20; Zscore = 5.6; p < 0.001 uncorrected). This region corresponded to the Theory of Mind (ToM) network. Only 5 of the 23 patients (21.7%) and 21 of the 23 (91.3%) control subjects demonstrated a positive signal variation in this area. Conclusions A left functional deficit was observed in a core region of the ToM network in patients with schizophrenia and typical lateralizations for language. This functional defect could represent a neural basis for impaired social interaction and communication in patients with schizophrenia.

Keywords: Schizophrenia fMRI Language Lateralization Hemispheric specialization Theory of mind

Domains: Psychiatrics and mental health; Neuroscience

Sonia Dollfus, Annick Razafimandimby, Olivier Maiza, Pierrick Lebain, Perrine Brazo, et al.. Functional deficit in the medial prefrontal cortex during a language comprehension task in patients with schizophrenia. Schizophrenia Research, 2008, 99 (1-3), pp.304-311. ⟨10.1016/j.schres.2007.11.016⟩. ⟨hal-00995718⟩