Date of Award

2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

Abstract

Although not as prevalent as other disorders, the impact of schizophrenia is widespread and costly. Societal burden and individual suffering provide support for increased focus on the early identification of individuals at risk for developing schizophrenia spectrum disorders. Utilizing the construct of schizotypy is one method of studying the early onset of these disorders. Meehl (1962; 1990) introduced the concept of schizotypy as personality organization that results in increased vulnerability to develop schizophrenia spectrum disorders. Thus, individuals psychometrically identified to be schizotypes present a unique opportunity to study the factors that contribute to the development of schizophrenia spectrum disorders. In addition, endophenotypes, commonly described as intermediate phenotypes, provide a latent, yet measurable marker of the liability for schizophrenia. Wastler and Lenzenweger (2018) proposed that a self-referential bias in eye gaze perception could be a promising endophenotype and found support for positive schizotypes endorsing individuals in photos as looking at them over a wider range of eye gaze angles than a non-schizotypy control group. Although promising, this study did not include negative or disorganized schizotypes and no subsequent studies have been completed to examine self-referential eye gaze perception in these facets of schizotypy. This study sought to fill this gap in the literature. The final sample included 542 participants, ranging in age from 18 to 25. Positive (n = 66), negative (n = 64), and disorganized (n = 82) schizotypes were identified using the Multidimensional Schizotypy Scale. Self-referential eye gaze perception was measured using a cone of gaze task in which participants observed four series of photos. In these photos, volunteer models continuously shifted their eyes from 25 degrees to the left to 25 degrees to the right, resulting in a range of eye gaze angles in photos. Participants then identified when individuals in the photo were looking toward them and looking away from them. T-tests were completed to determine if there were any significant differences between schizotypes and control groups on when they identified individuals in photos as looking toward them and looking away from them. Compared to a non-schizotypy control group, both negative and disorganized schizotypes identified individuals in photos as looking away from them significantly later. In contrast, when compared to a more loosely defined, non-deviant control group, positive schizotypes identified individuals in photos as looking toward them significantly earlier. These findings provide support for a self-referential gaze perception bias in all schizotypes; however, it presents an important distinction between groups. This difference could be explained by differences between groups in social cognitive and neurocognitive factors. Finally, this study provides additional support for establishing self-referential eye gaze perception as an endophenotype for schizophrenia spectrum disorders.

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