M.A. (Psychology)

Indiana University-Purdue University Indianapolis (IUPUI) / Toxoplasma gondii is an intracellular parasite that causes persistent, lifelong infection in one-third of humans worldwide. The parasite converts from a lytic, actively replicating form (tachyzoite) into a latent tissue cyst form (bradyzoite) that evades host immunity and is impervious to current drugs. While acute infection can be life threatening to immunosuppressed individuals, chronic infection has been linked to behavioral changes in rodents and neurological disease in humans. Notably, chronic infection in mice leads to hyperactivity in an open field. Whether these behavioral changes are due to parasite manipulation of the host or the host response to infection remains an outstanding question. We have previously shown that the anti-hypertensive drug guanabenz reduces Toxoplasma cyst burden in the brains of BALB/c mice, providing a means to examine whether brain cyst depletion reverses behavioral changes. We used two mouse strains (BALB/c and C57BL/6) differing in their susceptibility to infection. Following drug treatment of chronically infected mice, locomotor activity in an open field was assessed. In both mouse strains, the increased hyperactivity seen during chronic infection returned to normal levels following guanabenz treatment. Guanabenz reduced brain cyst burden ~70% in BALB/c mice as expected, but it increased cyst burden 49% in C57BL/6 mice. Examination of the brains showed that guanabenz decreased inflammation and perivascular cuffing in both infected mouse strains. Our study shows for the first time that it is possible to reverse a key behavioral change associated with chronic Toxoplasma infection. Surprisingly, the rescue from parasite-induced hyperactivity correlates with a decrease in neuroinflammation instead of cyst counts, suggesting that some behavioral changes arise from host responses to infection rather than a parasite-driven process. / 2022-03-10

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In recent years there has been a notable increase in the number of students being identified with Attention Deficit/Hyperactivity Disorder (AD/HD) in American schools. Although there is a tremendous amount of research being done in the area of AD/HD, parents, educators and individuals with AD/HD are ill-equipped to deal with the demands of the disorder. Only through extensive research and a better understanding of what AD/HD is can we expect to develop more effective means of dealing with AD/HD on a daily basis at home and in school. The primary purpose of this book is to bridge the gap between research knowledge and the knowledge in use by educators on AD/HD. The book is a review and interpretation of selected studies on the causes, co-occurrence with other disorders, diagnosis, and treatments of AD/HD. It provides the reader with the opportunity to gain an understanding of AD/HD for making mindful, informed decisions on approaches best suited to meet the challenges presented by this disorder. Five misconceptions are identified and refuted by research presented in chapters two through five. The findings of these studies lend support to: (a) a genetic and environmental basis for AD/HD; (b) a comorbid and hetergeneous nature to the disorder; (c) a need for educators to approach AD/HD from an educational perspective; (d) the need to consider a variety of interventions in addition to medication for the treatment of AD/HD; and (e) the unique response to interventions by individuals with AD/HD. In conclusion, educators are seeking information on this disorder because they are faced with an ever-increasing number of students with AD/HD, and they want to effectively meet the needs of this growing population of children. The emphasis in chapter six is on using a collaborative team approach, involving all persons who have an impact on the life of the student with AD/HD. Only through knowledge, understanding, and collaboration can educators be empowered to do the job that so desperately needs to be done. / Ph. D.

Thesis (Ph.D.)--Marshall University, 2008. / Includes bibliographical references (leaves 39-43).

Thesis (M.A.)--Marshall University, 2002. / Title from document title page. Document formatted into pages; contains viii, 48 p. with illustrations. Includes bibliographical references (p. 42-43).

Ward's method of cluster analysis was utilized to partition the clinical profiles of 74 students completed at a midwestern university's school psychology training clinic. The Conners' Continuous Performance Test and the Parent Rating Scale of the Behavioral Assessment System for Children provided the clustering variables. The neuropsychological literature predicted three groups; ADHD - Primarily Inattentive Type, ADHD - Primarily Hyperactive-Impulsive Type, and ADHD - Mixed Type based on errors of omission and commission on measures of vigilance, along with parental rankings on internalized and externalized behavior.Cluster Analysis 1 (N = 74) identified three clusters but failed to support the initial hypothesis. Clusters differentiated between clinical, at risk, and average range behavioral rankings, especially on those behaviors that are immediately noticeable and conflict with structured situations.Cluster Analysis 2 (n = 26) was limited to those with initial referral questions of an attentional disorder. All procedures of analysis 1 were repeated with this subset. Three clusters supported the inattentive and hyperactive profiles predicted. / Department of Educational Psychology

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Jon S. Bailey, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed June 16, 2005). Document formatted into pages; contains ix, 85 pages. Includes bibliographical references.

The present research examines three central issues in the context of ADIHD. First, a theory of attribution proposing that parents' causal attributions affect ADIHD children's locus of control is assessed. Second, ADIHD children's locus of control is linked to their psychological profiles. Finally, ADIHD is looked at from a cross-cultural perspective norms, highlighting the significance of parents' knowledge versus ignorance of the disorder. The main population of interest consists of unmedicated and untreated ADIHD children in Greece whose parents had no prior knowledge of the disorder. Initially, the impact of Greek parents' causal attributions about their ADIHD children's academic performance and behaviour on those children's locus of control is examined. Qualitative and quantitative analyses of the attributions made by parents were found to be associated with specific patterns of locus of control beliefs in their children. In-depth measures of the children's psychological profiles were found to be associated with their locus of control, and a detailed discussion compares these results with other research findings linking internalising and extemalising behaviours with biases in locus of control and attributional style. Then the possible implications of knowledge and socio-cultural beliefs are discussed in relation to the findings on two socio-culturally different populations - Greek and British ADIHD children's locus of control. Finally in an attempt to compare attributional differences, the role of locus of control is examined in an experimental test of task persistence and children's self-evaluations before and after a failure experience. It is concluded that socio-cultural norms influence the ways in which parents formulate causal explanations for their children's behaviour, which, in turn, influence the locus of control, the psychological profiles, the task persistence, and the self-evaluations of ADIHD children.

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.