Open Collections

Theory of mind, social cognition, and neural functioning in schizophrenia spectrum disorders

University of British Columbia

Social cognitive functioning has been shown to be impaired in patients with schizophrenia (SZ), and these impairments are associated with functional outcomes. To better understand these deficits this dissertation investigated the neurocognitive processes associated with several social cognitive tasks. A novel irony comprehension paradigm was developed for use with electroencephalogram (EEG). The N400, a negative event related potential (ERP) that occurs 300-500 ms after the onset of a semantically incongruent word, and the P600, a positive ERP that occurs around 500-800 ms, were used to index irony comprehension. Study 1 revealed that SZ performed worse than healthy controls (HC) across three measures of social cognition – emotion perception, Theory of Mind (ToM), and irony comprehension. Furthermore, negative symptoms of SZ were associated with poor ToM performance. ERP findings showed that HC exhibited hemispheric differences in N400 amplitude in response to ironic sentences, with the left hemisphere showing smaller amplitudes to ironic compared to literal statements, whereas SZ did not show this differentiation. Although HC processed ironic statements differently compared to SZ, the direction of the effect was opposite of what was hypothesized. Study 2 examined the durability of this unanticipated finding in a larger group of HC. The N400 effect from Study 1was not replicated – there were no differences in N400 amplitude for ironic and literal statements. A difference in P600 was found whereby the P600 amplitude for literal was greater than for ironic. Self-reported schizotypal traits were associated with poor ToM performance. Study 3 examined whether computerized cognitive remediation (CCR), which has been shown to improve neurocognition, would generalize to social cognition, and whether these changes could be detected at a neural level using EEG. The CCR program implemented in this study produced no improvement in neurocognition or social cognition. Taken together, these results suggest that several aspects of social cognition are impaired in patients with schizophrenia, on a behavioural and possibly a neural level. Future studies are necessary to determine the most effective framework for CCR to minimize the deficits in interpersonal skills that are linked to both general cognitive abilities and social cognition in those with schizophrenia.

Text

2016-10-18

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/59475

Psychology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/