Habilitationsschrift--Munich. / Bibliography: p. 353-367.

Thesis (Ph.D. (Psychiatry))--University of Pretoria, 2003. / Summary in English and Afrikaans. Includes bibliographical references.

Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2009. / Directed by Rosemery O. Nelson-Gray; submitted to the Dept. of Psychology. Title from PDF t.p. (viewed May 17, 2010). Includes bibliographical references (p. 72-92).

Thesis (Ph. D.)--University of California, San Diego, 2006. / Vita. Includes bibliographical references.

Thesis (M.A.)--University of Alabama at Birmingham, 2007. / Description based on contents viewed Oct. 5, 2007; title from title screen. Includes bibliographical references (p. 31-34).

Thesis (M.A.)--York University, 2004. Graduate Programme in Interdisciplinary Studies. / Typescript. Includes bibliographical references (leaves 137-144). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11760

The first objective in this dissertation was to use microanalysis and a dyadic approach to investigate infant social responsiveness. Therefore, I developed a method that used a projective pairs framework: Parental social actions towards infants (i.e., overtures) projected particular infant behaviours. I analyzed whether infant behaviours following these overtures matched what the overture had projected; if they matched, the infant’s behaviours were a response. The data were one family’s home videos of their triplet infants (two males, one female), filmed when the infants were 6 to 15 months old. When the triplets were approximately three years old, clinical assessment indicated that one of the males had Autism Spectrum Disorder (ASD), which impairs an individual’s social behaviors. The second objective here was to test whether the projective pairs framework would reveal early social deficits in the infant with ASD. This result would hold potential for earlier diagnosis (and thus earlier intervention). Researchers have used home videos to look for signs of ASD retrospectively, but these studies have been vulnerable to variability in the data, and often analyses of infant social behaviours did not connect these behaviours to their social, dyadic context. In this dissertation, the home videos were from one family; therefore the data were more homogeneous, and the projective pairs framework preserved the immediate context. The data for Study I were 23 minutes of excerpts (infants’ age 11-15 months). The microanalysis focused on overall infant responsiveness (i.e., the number of times each infant responded over the number of overtures that infant received). The infant with ASD was significantly less responsive than his two siblings. The data for Study II were all of the family’s home videos from when the infants were 6-15 months old (approximately 6 hours). Study II included (1) an exploration of specific functions of overtures (e.g., greeting the infant, getting the infant’s attention), and (2) an analysis of infant behaviours preceding overtures (e.g., looking at the parent, actively engaged elsewhere). The findings from Study II replicated Study I, they also painted a more complex picture. First, like his siblings, the infant with ASD responded to all non-social overtures, almost all helping overtures (e.g., taking a bottle that the parent had passed), and approximately half of overtures that served to seek his attention or to tell him to do something. Second, the infant with ASD was significantly less responsive to parental overtures that were more ambiguous (e.g., playing with the infant, narrating the infant’s actions). Third, regardless of the overture’s function, the infant with ASD was more likely to respond if he had looked at the parent immediately before the overture or if the overture included his name. A dyadic approach to the microanalysis of infant responsiveness identified those social interactions in which (1) the infant with ASD was as responsive as his siblings; (2) the infant with ASD was significantly less responsive than his siblings; and (3) the infant with ASD was the most responsive.

Adolescence heralds a unique period of vulnerability to depressive symptoms. The current study examined relational victimization, targeting adolescents’ interpersonal relationships, as a unique predictor of depressive symptoms in a broad age range of adolescents. Past research shows that interpersonal resources—particularly emotional support—are negatively related to depression. In this study, the moderating effects of emotional support from mothers, fathers, and peers on the association between relational victimization and depressive symptoms were investigated. As expected, high levels of maternal and peer emotional support buffered the association between relational victimization and depressive symptoms. Emotional support from fathers did not moderate this relationship. Findings also suggest that while support from peers is protective against concurrent depressive symptoms, it can be detrimental to adolescent’s mental health over time. In contrast, maternal emotional support buffers future depressive symptoms associated with past experiences of relational victimization.

This research examined the impact of eyewitness identification decisions on student-investigators. Undergraduates played the role of police investigators and interviewed student-witnesses who in Studies 1 and 2 had been shown either a good or poor view of the perpetrator or in Study 3 viewed either a Caucasian or an Asian criminal, in a video-taped crime. Based on information obtained from the witness, student-investigators then chose a suspect from a database containing information about potential suspects and rated the probability that their suspect was the culprit. Investigators then administered a photo lineup to witnesses, and re-rated the probability that their suspect was guilty. Student-investigators were highly influenced by eyewitness identification decisions, typically overestimating the information gained from the identification decision (except under conditions that led witnesses to be very accurate), and generally did not differentiate between accurate and inaccurate witnesses.

Attentional set-shifting tasks, consisting of multiple stages of discrimination learning, have been widely used in animals and humans to investigate behavioural flexibility. However, there are several learning criteria (e.g., 6-correct-choice-in-a-row, or 10-out- of-12-correct) by which a subject might be judged to have learned a discrimination. Furthermore, the currently frequentist approach does not provide a detailed analysis of individual performance. In this PhD study, a large set of archival data of rats performing a 7-stage intra-dimensional/extra-dimensional (ID/ED) attentional set- shifting task was analysed, using a novel Bayesian analytical approach, to estimate each rat's learning processes over its trials within the task. The analysis showed that the Bayesian learning criterion may be an appropriate alternative to the frequentist n- correct-in-a-row criterion for studying performance. The individual analysis of rats' behaviour using the Bayesian model also suggested that the rats responded according to a number of irrelevant spatial and perceptual information sources before the correct stimulus-reward association was established. The efficacy of the Bayesian analysis of individual subjects' behaviour and the appropriateness of the Bayesian learning criterion were also supported by the analysis of simulated data in which the behavioural choices in the task were generated by known rules. Additionally, the efficacy was also supported by analysis of human behaviour during an analogous human 7-stage attentional set-shifting task, where participants' detailed learning processes were collected based on their trial-by-trial oral report. Further, an extended Bayesian approach, which considers the effects of feedback (correct vs incorrect) after each response in the task, can even help infer whether individual human participants have formed an attentional set, which is crucial when applying the set-shifting task to an evaluation of cognitive flexibility. Overall, this study demonstrates that the Bayesian approach can yield additional information not available to the conventional frequentist approach. Future work could include refining the rat Bayesian model and the development of an adaptive trial design.