Date of Award

2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

Abstract

Given the genetic complexity of schizophrenia, recent research has focused on the identification of endophenotypes as an effective method to increase our understanding of schizophrenias genetic components and potential causes. Candidate endophenotypes for schizophrenia have been suggested to included personality disturbance, and deficits in both neurocognition and social cognition. With regard to the latter, evidence indicates that impairments in emotion recognition (ER) exist among individuals with schizophrenia, their unaffected relatives, and most recently, within a psychometrically psychosis prone population. However, no studies have examined whether these impairments exist as premorbid indicators of schizophrenia spectrum illnesses while concurrently also examining the relationship between genetic risk and ER abilities. The current study is a cross-sectional component of a larger longitudinal study, and investigates whether individuals at risk (i.e., psychometric or genetic) for schizophrenia spectrum disorders possess ER deficits compared to matched controls (MC) and individuals without a family history of schizophrenia, respectively. ER performance was measured using the Penn Emotion Recognition Test-40 (ER40). Performance on the ER40 was also examined for positive versus negative schizotypes within the psychometric schizotype (PS) group. It was hypothesized that PS participants would exhibit greater ER deficits than MCs and that these deficits would be most pronounced for negative emotions and neutral expressions, and among negative schizotypes. It was also hypothesized that individuals with a family history of schizophrenia would demonstrate greater ER deficits than those without a family history. Finally, it was hypothesized that the ER deficits observed would persist after statistically accounting for neurocognitive variance as measured by the Wechsler Adult Intelligence Scale–IV (WAIS-IV) and Wechsler Memory Scale-IV (WMS-IV). Results revealed a more complex relationship between ER, neurocognition, and psychometric schizotypy than previously demonstrated. PS participants were significantly less accurate in their identification of overall emotion and negative emotion only after accounting for the variance associated with performance on the Working Memory Index (WMI) and Arithmetic subtest. The hypothesis that positive schizotypes would outperform negative schizotypes in their ability to accurately identify emotional expressions was not supported. Conversely, negative schizotypes were more accurate in their appraisal of emotional stimuli. The hypothesis that individuals with a family history of schizophrenia would perform worse than those without a similar family history on an ER task was supported. Results are discussed within the broader category of candidate endophenotypes for schizophrenia. Future directions for research include a more detailed exploration of the relationship between working memory, psychometric schizotypy, and ER; incorporation of a more heterogeneous sample; and replication with other measures of schizotypy.

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