Date of Degree

10-2014

Document Type

Dissertation

Degree Name

Ph.D.

Program

Psychology

Advisor(s)

Deborah J. Walder

Subject Categories

Clinical Psychology | Psychiatric and Mental Health | Psychology

Keywords

Dermatoglyphics, Neuropsychology, Schizotypy, Somatosensory

Abstract

A core feature of schizophrenia spectrum disorders (SSDs) is a basic sensory (e.g., visual, auditory) processing disruption, yet few studies have examined somatosensation. The current dissertation project examined somatosensory processes among individuals at varying degrees of psychometric risk for psychosis using tactile texture and spatial discrimination and letter recognition tasks. Differential patterns of associations of somatosensory abilities with schizotypal trait dimensions (positive, negative, disorganized), independent of anxiety and depressive symptoms, and the relative contributions of bottom-up (peripheral and morphologic features) versus top-down (error types) processing were examined. It was hypothesized that: 1) performance on somatosensory tasks would account for significant variability in total schizotypal traits; 2) somatosensory performances would be differentially associated with schizotypal trait dimensions, and somatosensory performances would account for variability in schizotypal traits beyond mood symptoms; and, 3) central and peripheral mechanisms may contribute to somatosensory performance, but they were not expected to fully account for the associations between basic somatosensory processing and schizotypal traits. Participants were 125 (37 Male/88 Female) young adults (Mage = 20.55, SD = 3.27) recruited from the City University of New York human subjects pool. Participants were asked to complete somatosensory tasks and mood and personality self-report measures. Fingerprints were obtained to assess morphologic features. Anxiety and depressive symptoms were included as covariates, as they accounted for a significant proportion of variability schizotypal traits. Contrary to hypotheses, after accounting for the relative contributions of mood symptoms, better spatial discrimination and rough texture discrimination abilities were associated with more disorganized and negative schizotypal traits, respectively, at the trend level. Exploratory analyses demonstrated some differential contributions of dermatoglyphic features and letter recognition confusion errors in accounting for variability in schizotypal traits. Specifically, more isomorphic errors were significantly associated with fewer negative (and total) schizotypal traits, and, at trend level, more minutiae were associated with more positive schizotypal traits. Findings are discussed in the context of theories regarding neural substrates of somatosensory processing disruptions in SSDs. Implications for understanding SSD etiology and using somatosensory measures as possible indicators of risk for psychosis are posited.

 
 

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