Impact of gray matter reductions on theory of mind abilities in patients with schizophrenia

Abstract

To identify the brain regions involved in the interpretation of intentional movement by patients with schizophrenia, we investigated the association between cerebral gray matter (GM) volumes and performance on a theory of mind (ToM) task using voxel-based morphometry. Eighteen patients with schizophrenia and thirty healthy controls participated in the study. Participants were given a moving shapes task that employs the interpretation of intentional movement. Verbal descriptions were rated according to intentionality. ToM performance deficits in patients were found to be positively correlated with GM volume reductions in the superior temporal sulcus and medial prefrontal cortex. Our findings confirm that divergent brain regions contribute to mentalizing abilities and that GM volume reductions impact behavioral deficits in patients with schizophrenia.

Keywords:

• Theory of mind
• Schizophrenia
• Gray matter
• Voxel-based morphometry
• Superior temporal sulcus
• Medial prefrontal cortex

We would like to thank Uta and Chris Frith and their staff members for kindly providing the “Moving Shapes” paradigm and rating descriptions. We are also grateful to all the subjects for their participation in this study and to the staff involved in data acquisition.

This work was supported by research fellowships from the Japan Society for the Promotion of Science (JSPS) [PE 07550 and BR100104 to K.K.], grants for the initiation of bilateral cooperation of the DFG (German Research Foundation) [KO 4038/1-1 and KO 4038/2-1 to K.K.] and the Medical Faculty of the University of Muenster [12–002 and KOE 221108], grants-in-aid for scientific research from the Japan Society for the Promotion of Science [21890119 to J.M.], the Ministry of Education, Culture, Sports, Science and Technology, Japan [20691401 to T.M.], a grant from the Ministry of Health, Labor and Welfare, Japan [20E-3 to T.M.], a research grant from the Research Group for Schizophrenia sponsored by Astellas Pharma Inc., and a research grant from the Mitsubishi Pharma Research Foundation.