ABSTRACT
BACKGROUND: False-belief (FB) tasks are used to assess the theory of mind (ToM) functioning, which has been found to be impaired in schizophrenia. FB task stimuli used so far in neuroimaging studies in schizophrenia have been sentence-based ones. We aimed to validate an Indian, colour-comic based FB task by using an online-electroencephalogram (EEG) paradigm discriminating schizophrenia patients and healthy controls. MATERIALS AND METHODS: Fifteen schizophrenia patients and 15 healthy controls performed online FB task during a 256-channel-EEG recording. 'Content' and 'known-groups' validity were examined using offline behavioural measures. Evoked gamma spectral-power in four regions of interest (ROIs) was compared between groups. Social functioning was also assessed. RESULTS: Strength of classifying the groups was significant for both the number of correct responses and the reaction-times on the FB tasks. Social functioning was found to be poorer in patients. On the comparative analysis of evoked gamma spectral-power in the ROIs, very small effect size and observed power were noted. CONCLUSION: 'Content' and 'known-groups' validity of the culturally undermined comic-based FB task are good. Our findings reiterate that ToM functioning is impaired in schizophrenia. Our results were inconclusive in inferring whether evoked gamma spectral-power could be used as a neural validator for poor ToM functioning.
