This study proposed an experimental test of theoretical models related to emotion and space representation in the brain. Previous research has established that emotion is represented, processed, expressed, and regulated largely by the right hemisphere. Furthermore, there is evidence from experimental paradigms and clinical case reports to suggest that the same hemisphere plays a dominant role in the processing of external space. A conceptual difficulty of clinical and neural network overlap arises when right hemisphere disorders of emotion are compared with those of spatial representation. The current experiment tested some of these hypotheses about emotion regulation and spatial representation in the right hemisphere using nonclinical subjects under a cortical stress paradigm designed to mimic the conditions of cortical duress. An additional goal was an extension of a previous study that examined emotional influence on spatial orientation. Results did not support our initial hypotheses. Subsequent analyses did provide some evidentiary support for some theories related to emotion and brain function. Additionally, patterns of subject performance were observed that support traditionally held theories of differential hemispheric function with regard to emotion and spatial behavior. These findings are discussed within the context of theories of emotion, spatial function, and disorders secondary to right hemisphere damage. / Doctor of Philosophy / This is a study examining the role of emotion and stress on the allocation of attention in the individual’s external environment. Further examined was the role that brain systems involved in attention, emotion, and spatial representation and the correlation with brain damage and syndromes that result in disruption to these systems. Conceptual difficulties regarding overlapping brain areas that contribute to different functions serve as the foundation for understanding both how these systems work and the behavioral manifestations of their dysfunction. Finally, further elucidating the role of these neural systems in contributing to self-awareness, emotion regulation, and the representation of external space was the ultimate objective of this study.

Thirty young, unmedicated, outpatient, depressed women were compared to an equal number of matching controls on a series of neuropsychological tests purported to be sensitive to the executive functions. Specifically, the measures included the Design Fluency Test, the WAIS-R Digit Span subtest, a Dynamometer task of hand grip strength, perseveration, and fatigue, the FAS Verbal Fluency Test, a Serial Sevens Test, the Stroop Color and Word Test, and the Trail Making Test, as well as a memory measure, the Rey Auditory Verbal Learning Test. Despite past research which has indicated anterior hemispheric asymmetries and impaired neurocognitive performances in depressives, this research failed to identify any reliable differences between depressed and nondepressed women on any of the neuropsychological measures. These results argue against the frequently held stereotype that depressed individuals typically display impaired performances on neurocognitive tasks. Furthermore, since the profile of the depressed sample appeared to differ significantly from past studies, a discussion is provided as to how the characteristics of this group may have impacted the results. Implications of these findings for clinical practice and future research are also provided. / Ph. D.

This study used an archival data set of 26 healthy adult immigrants from a sub-Saharan African country to the United States (Mage 39.0, SD = 11.36; Meducation 16.33, SD = 2.88; 40.7% male). Additional archival data was used for 32 healthy African American adults (Mage 34.06, SD = 11.18; Meducation 16.16, SD = 2.49; 53.1% male). A bivariate correlation indicated that acculturation to African culture, as measured by the mBIQ (M 49.29, SD = 8.66), was significantly positively correlated with ethnicity, r = .632, p = .000, ηp2 = 0.399. Two-way ANOVAs revealed that African Americans were able to name more animals than African immigrants (F(1, 54) = 4.82, p = 0.32, ηp2 = 0.82) and exhibited greater organizational skills during a task of cognitive set shifting and problem solving than African immigrants, regardless of level of acculturation (F(1, 54) = 4.47, p =.039, ηp2 = 0.078). In contrast, African immigrants scored higher than African Americans on indigenous fruit (F(1, 54) = 7.60, p =.008, ηp2 = 0.123) and object naming (F(1, 54) = 5.59, p =.022, ηp2 = 0.094). Results of the study concluded that there are small variance effects in language tasks as well as strategy-based approaches to tasks of novel problem solving. Implications of these findings are discussed relative to future research as well as clinical practice in the assessment of culturally dissimilar people across a racially homogenous population by pushing the field forward with diversified approaches to neuropsychological testing.

Neuropsychologists are becoming increasingly aware that there is a complex interplay of cognitive, personality, and sociocultural factors that affect an individual's performance on neuropsychological tests. The current study investigated the effect of one aspect of the sociocultural environment, that is, quality of education, on performance on neuropsychological tests of executive function. The sample included 40 high school learners: Group A comprised learners with a high quality of education and Group B comprised learners with a low quality of education. Four tests of executive function were administered: the Verbal Fluency Test, the Design Fluency Test, the Stroop Test and the Wisconsin Card Sorting Test. Results indicated that quality of education significantly affected the participants' performance with Group A performing significantly better than Group B on all the tests of executive function. These findings have implications for the interpretation of neuropsychological test performance in cross-cultural research and practice. / Psychology / M.A. (Clinical Psychology)

Executive Function is conceptualized in this study as the ability to form (the planning functionality obtained through initiation and working memory), maintain (response selection and the ability to self-regulate and inhibit) and switch (cognitive flexibility, mental tracking, organization and sequencing) mental processes in order to effect a positive outcome. The present research is a quasi-experimental study embedded in the Positivist tradition that sets out to empirically evaluate the Executive Function profile of seropositive adolescents (n = 29) emerging from a low socio-economic background and currently on a managed ART programme when compared to a healthy contrast group (based on age, socio-demographic and educational system). As a quantitative study, Executive Function was operationalized through the use of multiple tests of Executive Function such as the Delis-Kaplan Executive Function Colour Word Interference Test (D-KEFS CWIT), the Wisconsin Card Sorting Test (WCST) and the Trail Making Test Part B (TMT-B). As the study formed part of a larger study that included additional neurocognitive tests, including the WISC-R, selected subtests from the WISC-R were used to validate specific arguments relating to the study. The results showed that HIV positive adolescents were inclined to have poorer Executive Function performance especially under situations of higher cognitive load when compared to the unaffected group. The implications of these results are discussed in this research.

Alexandria Luria's approach to neuropsychological assessment and his theory of brain functioning have been exploited in order to develop a neuropsychological evaluation procedure for children which incorporates a conceptualization of brain-behaviour development. Luria's Neuropsychological Investigation for adults was administered to intact children aged eight to 14 years in order to ascertain which tasks were beyond their capabilities. These were then adapted or deleted. The adapted version of the protocol was then administered to a second group of intact children to determine that the proposed adaptations were appropriate. This process was guided by the results of a statistical analysis which revealed significant findings with respect to age, socioeconomic status, and task performance. A model of brain-behaviour development and interpretive protocol were devised. Together these provide a conceptual and interpretive framework for the battery. Developmental trends which emerged whilst developing Luria's Neuropsychological Investigation for Children (LNI-C) were consistent with the progressive development of successively more complex forms of information processing as depicted in this model. They were also in keeping with prominent developmental theories such as those of Piaget and Vygotsky. These trends revealed that children made most mistakes on adult LNI tasks involving abstract reasoning, the simultaneous synthesis of data, and complex goal-directed behaviour - all of which apparently reflect tertiary cortical zone functioning. Fewer mistakes were related to a lack of training and inability to process the same quantity of information as adults - difficulties which seemed related to secondary zone functioning. None of the mistakes made appeared to reflect subcortical or primary zone functioning. The LNI-C was applied to brain-damaged children who had had a CT scan in order to demonstrate its application and the hypothetico-deductive process of interpreting findings using the concepts of syndrome analysis and double dissociation. The LNI-C findings were consistent with the general pattern of symptoms Luria described for different brain disorders and lesion localities in children, although additional insight into the nature of the sequelae present was gained in each case. In early brain damage, the most frequent disturbances were a disruption in the role played by executive functions and the ability to process data simultaneously - both of which are associated with the tertiary zones of the brain. Furthermore, these disturbances appeared to be important factors underlying disturbances to language and educationally acquired skills. The qualitative, process-orientated nature of the LNI-C proved effective for identifying the factors underlying disturbances described in paramedical reports. These seemed to be the linchpins on which retraining should focus. It was argued that the CT scan was limited in its ability to identify the type of diffuse and/or multifocal brain pathology frequently found in children. The usefulness of the model of brain-behaviour ontogeny and interpretive protocol for diagnosis, understanding and predicting the developmental consequences of childhood brain pathology was demonstrated on the basis of nine brain disorders. Finally, areas of future research were highlighted by the study. / Thesis (Ph.D.)-University of Natal, Durban, 1989.

Thesis (Doctoral)--Ludwig-Maximilians-Universität. / eContent provider-neutral record in process. Description based on print version record.

Epilepsy represents the most common neurological disease, its prevalence reaching up to 1%, and around 30% of patients become refractory to treatment. In these patients, epilepsy surgery is often their only chance for disease-free life. Aetiology of epilepsy is heterogenous; we recognize genetic, structural- metabolic epilepsy and epilepsy with unknown aetiology. Patients with focal pharmacoresistant epilepsy may become candidates for epilepsy surgery; the same does not apply to patients with metabolic or neurodegenerative disease. Multiple factors influence decision about epilepsy surgery, the most important ones being (i) the type of known or presumed structural lesion and (ii) the possibility to precisely delineate the epileptogenic zone (the area of seizure generation). Another factor that needs to be accounted for is the proximity of epileptogenic zone to the eloquent cortical areas (the areas with important neurological functions, e.g. motor or speech functions). Epilepsy surgery principally aims for complete removal the epileptogenic zone, and subsequently for complete freedom from seizures. Hypothesis on the localization of the epileptogenic zone arises from the combined information gained from various diagnostic, mostly neuroimaging, methods. Cognitive profile examination includes...

Neuropsychologists are becoming increasingly aware that there is a complex interplay of cognitive, personality, and sociocultural factors that affect an individual's performance on neuropsychological tests. The current study investigated the effect of one aspect of the sociocultural environment, that is, quality of education, on performance on neuropsychological tests of executive function. The sample included 40 high school learners: Group A comprised learners with a high quality of education and Group B comprised learners with a low quality of education. Four tests of executive function were administered: the Verbal Fluency Test, the Design Fluency Test, the Stroop Test and the Wisconsin Card Sorting Test. Results indicated that quality of education significantly affected the participants' performance with Group A performing significantly better than Group B on all the tests of executive function. These findings have implications for the interpretation of neuropsychological test performance in cross-cultural research and practice. / Psychology / M.A. (Clinical Psychology)

The aim of the study was to investigate the neurobiological and psychosocial factors that influence neuropsychological test performance in children with epilepsy from a non-Western rural background. The sample comprised 100 children with tonic-clonic seizures and 100 children with simple partial seizures between the ages of eight to twelve years. A third group of 100 children with chronic renal problems was used as a comparison to control for the effects of having a chronic illness. The findings of the present study indicate that in the epilepsy groups, seizure variables such as the age of onset, frequency of seizures and duration of seizures have an impact on self-esteem, adjustment and NEPSY scores. However, psychosocial and emotional factors appear to have a greater impact than neurobiological variables on the measured neuropsychological domains (attention/executive, language, sensorymotor and learning/memory functions). These findings are consistent with the theoretical perspectives used, combining the view of Piaget (1955) that cognitive development proceeds as a result of the child’s own activities, with Luria’s (1973) model of brain functioning and the stance of Vygotsky (1978) that development is a socially mediated process. The findings regarding the influence of neurobiological and psychosocial factors on neuropsychological test performance in children with epilepsy from non-Western backgrounds are similar to those of Western studies. Epilepsy presents with unique problems relative to other chronic illnesses. The three groups are separated according to differences in psychosocial (maternal attitudes), emotional (adjustment and self-esteem) as well as neuropsychological functioning (attention/executive, language and visual-spatial skills). The renal group is characterised by the highest levels of psychosocial, emotional and neuropsychological functioning, while the simple partial seizure group have lower levels of psychosocial and emotional functioning, and the tonic-clonic seizure group have the lowest levels of neuropsychological functioning and adjustment. / Psychology / D.Litt et Phil. (Psychology)