Most contemporary schizophrenia research indicates that a heritable neurointegrative deficit may be a vulnerability marker for schizophrenia spectrum disorders. Researchers often measure this deficit in terms of impaired attention on a vigilance task, the Continuous Performance Test (CPT). Impaired attention is found not only in floridly psychotic schizophrenics, but also in remitted schizophrenics, children biologically at risk for schizophrenia, and young adults psychometrically identified as at risk for schizophrenia spectrum disorders. Findings from these investigations provide a possible link in the diathesis-stress model of schizophrenia genesis. However, little research attention has been paid to the potential interactive effects that attentional impairments and interpersonal relations may have in determining susceptibility to active schizophrenic symptomatology. In this study, 703 undergraduates completed measures of interpersonal attachment, perceived relations with parents and peers in childhood, positive schizotypy (schizophrenism) and negative schizotypy (anhedonia). Based upon their schizotypy scores, 191 of these participants were selected to complete a version of the CPT that, by degrading visual stimuli and presenting them very briefly, rapidly produces decrements in vigilance. In a staggered random design, CPT participants were assigned to one of three motivational induction conditions designed either to increase intrinsic motivation, decrease intrinsic motivation, or to replicate the standard CPT protocol. Path modelling supported a bidirectional relationship between adult attachment and schizophrenism. For female participants, recalled relations with fathers and childhood peers, but not with mothers, predicted adult attachment: for males, recalled relations with mothers, fathers, and childhood peers all predicted adult attachment. Maternal and paternal relations had no direct relationship to schizophrenism, while childhood peer relations and adult attachment were substantially related to schizophrenism for both sexes. Using signal detection indices and growth curve analysis across six blocks of CPT performance, the motivational induction designed to increase intrinsic motivation was found to attenuate the decrement in vigilance across time, while the motivational induction designed to decrease intrinsic motivation was found to augment the vigilance decrement, compared to the standard CPT protocol. Perceptual sensitivity scores were lower for high schizotypy participants than for low schizotypy participants, such that anhedonic (negative) and schizophrenism (positive) schizotypy interacted to predict the most impaired performance. High schizotypy participants had lowered perceptual sensitivity scores throughout the CPT protocol, but did not show a more rapid decrement in vigilance compared to others. Participants who reported low levels of intrinsic motivation or positive emotion, or who demonstrated diminished persistence in a hand held dynometer task, also had lowered perceptual sensitivity scores. This relationship was most strong for self-reported intrinsic motivation. Intrinsic motivation was unrelated to schizotypy, and there were no interactions between self-reported intrinsic motivation, schizotypy, and the experimental motivational inductions. High levels of motivation appeared to compensate partially for the impaired attentional performance associated with schizotypy. Contrary to expectations, no interactions between interpersonal attachment and attentional performance were predictive of schizotypal tendencies. Results indicate the importance of the experimental setting as an interpersonal occasion that can either support or undermine attentional performance. The substantial relationship between motivation and attentional performance indicates that future CPT research should include measures of motivation, and that schizophrenia-related deficits in attention may be at least partially eliminated by increasing intrinsic motivation. / This thesis was digitized as part of a project begun in 2014 to increase the number of Duke psychology theses available online. The digitization project was spearheaded by Ciara Healy.
| Identifer | oai:union.ndltd.org:DUKE/oai:dukespace.lib.duke.edu:10161/13555 |
| Date | 01 February 2017 |
| Creators | Wilson, John Seddon, 1958- |
| Contributors | Philip R. Constanzo, Supervisor |
| Source Sets | Duke University |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Dissertation |
| Format | Digitized dissertation |
| Relation | http://search.library.duke.edu/search?id=DUKE002130760 |
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