Functional and structural brain correlates of theory of mind and empathy deficits in schizophrenia.
BACKGROUND
Patients affected by schizophrenia show deficits in social cognition, with abnormal performance on tasks targeting theory of mind (ToM) and empathy (Emp). Brain imaging studies suggested that ToM and Emp depend on the activation of brain networks mainly localized at the superior temporal lobe and temporo-parietal junction.


METHODS
Participants included 24 schizophrenia patients and 20 control subjects. We used brain blood oxygen level dependent fMRI to study the neural responses to tasks targeting ToM and Emp. We then studied voxel-based morphometry of grey matter in areas where diagnosis influenced functional activation to both tasks. Outcomes were analyzed in the context of the general linear model, with global grey matter volume as nuisance covariate for structural MRI.


RESULTS
Patients showed worse performance on both tasks. We found significant effects of diagnosis on neural responses to the tasks in a wide cluster in right posterior superior temporal lobe (encompassing BA 22-42), in smaller clusters in left temporo-parietal junction and temporal pole (BA 38 and 39), and in a white matter region adjacent to medial prefrontal cortex (BA 10). A pattern of double dissociation of the effects of diagnosis and task on neural responses emerged. Among these areas, grey matter volume was found to be reduced in right superior temporal lobe regions of patients.


CONCLUSIONS
Functional and structural abnormalities were observed in areas affected by the schizophrenic process early in the illness course, and known to be crucial for social cognition, suggesting a biological basis for social cognition deficits in schizophrenia.
Benedetti
Francesco
F
Department of Clinical Neurosciences, Scientific Institute and University Vita-Salute San Raffaele, Milan, Italy. benedetti.francesco@hsr.it
Bernasconi
Alessandro
A
Bosia
Marta
M
Cavallaro
Roberto
R
Dallaspezia
Sara
S
Falini
Andrea
A
Poletti
Sara
S
Radaelli
Daniele
D
Riccaboni
Roberta
R
Scotti
Giuseppe
G
Smeraldi
Enrico
E
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping; D004645:Empathy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010552:Personality Assessment; D010554:Personality Disorders / Q000209:etiology / Q000473:pathology / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications* / Q000473:pathology*; D012565:Schizophrenic Psychology; D013223:Statistics as Topic; D056345:Theory of Mind / Q000502:physiology*; D055815:Young Adult
D010100:Oxygen