Theory of Mind and Schizophrenia: A Positron Emission Tomography Study of Medication-Free Patients
Journal Title: Schizophrenia Bulletin - Year , Vol 34, Issue 4
Abstract
Background: “Theory of mind” (TOM) refers to the ability to attribute mental states (ie, beliefs and goals) to one's self and others and to recognize that behaviors are guided by these mental states. This capacity, critical for social competence, is impaired in schizophrenia. We undertook a study of TOM in a group of patients with schizophrenia and healthy controls. Method: We used positron emission tomography to identify the neural circuits recruited during a verbal task that required participants to attribute mental states to a character in a story of their creation. The comparison task consisted of reading aloud a neutral story, controlling for the speech component of the task. Results: Patients and controls generated the same percentage of TOM utterances. However, the two groups had markedly different patterns of brain activation. Compared with controls, patients had a lower blood flow in multiple regions in the left hemisphere including the frontal and visual association cortices, posterior hippocampus, and insula. The flow was also lower in contralateral areas in the lateral cerebellum and vermis, thalamus, and posterior insula. On the other hand, the flow was higher in the patients predominantly in the right hemisphere, including multiple frontal and parietal regions, insula, visual association cortex, and pulvinar. Discussion: The areas of lower flow are consistent with previous studies indicating impairment in recruiting cortical-cerebellar circuitry in schizophrenia. The areas of higher flow may reflect a need to draw on the right hemisphere to compensate for deficits in left hemisphere networks that include frontal cortex, anterior cingulate, cerebellum, and thalamus.
Authors and Affiliations
Nancy C. Andreasen, Chadi A. Calage, Daniel S. O'Leary
Making Progress in Schizophrenia Research
Building a Clinically Relevant Cognitive Task: Case Study of the AX Paradigm
Tasks developed for basic cognitive neuroscience are often ill suited for experimental psychopathology. The development of the expectancy variant of AX continuous performance task to test theories about context processin...
Imitation, Simulation, and Schizophrenia
The social significance of imitation is that it provides internal tools for understanding the actions of others by simulating or forming internal representations of these actions. Imitation plays a central role in human...
Comparing Genes and Phenomenology in the Major Psychoses: Schizophrenia and Bipolar 1 Disorder
Twin studies show that the concordance rate for schizophrenia is higher in monozygotic twins (47%–56%) than in dizygotic twins (12%–16%), suggesting a strong heritability component for the illness. Some s...
The Translation of Cognitive Paradigms for Patient Research
Many cognitive tasks have been developed by basic scientists to isolate and measure specific cognitive processes in healthy young adults, and these tasks have the potential to provide important information about cognitiv...