The purpose of the study was to explore perceptual-motor differences between blind and sighted adults from a neuropsychological perspective, and to analyze differences within the blind group. Perceptual-motor abilities were examined using the Comprehensive Vocational Evaluation System (CVES), a vocational rehabilitation and neuropsychological battery designed for use with blind populations. The data were processed using Analysis of Covariance. Results showed that sighted persons had better motor abilities, while persons with blindness were more skilled at haptic identification of shape and texture. Analysis within the blind group showed that texture identification skills are better when blindness occurs earlier in life and to the extent that the blindness is total. Later onset blindness and the retention of some functional vision may not lead to a refocusing of attentional states necessary to develop haptic images. New neural connections may develop in persons with congenital/total blindness, a hypothesis in line with recent neuroradiological findings that occipital lobe activation occurs when congenitally blind individuals engage in tactile processing tasks. One implication of the findings is that teaching individuals who retain some functional vision to read Braille is probably counterproductive. These individuals would be better served by learning to use a CCTV and large print books. Future researchers should examine blindness from a multivariate perspective, examining subsets of blind groups based on age at onset, visual status, and other pertinent variables. Other implications are discussed and recommendations for future research are provided.

In this thesis I investigate blood oxygen level-dependent (BOLD) MRI methods of imaging the cerebral blood volume (CBV), mean vessel radius and oxygen extraction fraction (OEF). Through the investigation of these individual techniques a new framework is proposed for the simultaneous measurement of all three parameters, providing a comprehensive assay of the cerebral mesostructure. A new method for the segmentation of blood filled voxels from the sagittal sinus is presented. The implemented method is completely automated and thus removes user bias in voxel selection. The segmentation method is used in a volunteer study to calculate CBV from a hyperoxic challenge according to an existing technique. CBV measurements from this study are found to be significantly overestimated. However, a new derivation of the hyperoxic CBV equation is presented that reveals significant errors in the original method, corresponding to the observed overestimates in CBV. Modelling studies are presented that investigate the discrepancy in reported BOLD MRI measurement of mean vessel size. A significant degree of the variation in the results is found to arise from the noise sensitivity of the analysis methods. This finding is confirmed with experimental data from healthy volunteers that show good agreement with the modelling studies. Comprehensive modelling of the BOLD response to hyperoxia and hypercapnia is used to develop a new framework for OEF calculation. The new method is based on the calibration of the BOLD signal response against a change in intravascular susceptibility. The OEF calculation is extended by introducing a spin-echo readout into the acquisition scheme. This extension of the acquisition scheme provides a further independent probe of the BOLD signal, enabling the simultaneous calculation of the mean vessel size and CBV. The new framework is shown to provide OEF and vessel size estimates over a wider range of physiological parameters, providing greater scope for the clinical implementation of these techniques.

Thirty-two silicone breast implant patients scored in the mild to moderate range of impairment on the Halstead-Reitan Neuropsychological Battery. An unusual number of patients had positive tests for antinuclear antibody on immunological testing and a high incidence of EEG abnormalities were found. Personality testing revealed an MMPI profile which is typical for neuropsychologically impaired subjects but components were consistent with extreme emotional distress. None of the subjects were near the cutoff score for malingering or faking bad on the F-K index of the MMPI. There was no apparent relationship between length of exposure and the severity of neurological impairment. Also, explanted subjects performance was not improved when compared to subjects whose implants were still in place.

Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Abstract Neurocognitive deficits and thought disorder in schizophrenia have generally been accepted as core features of the illness, yet their underlying relationship, response to treatment, and correlations with outcome remain unclear. Most of the studies to date have used cross-sectional designs and focussed on stable patients already on treatment. The purpose of this study was to assess changes in neurocognition and thought disorder in antipsychotic naïve or minimally treated first episode psychosis (FEP) patients, over the course of 12 months of treatment according to a standard algorithm with flupenthixol decanoate (FD) long acting injectable antipsychotic. This was a prospective, non-comparative, open-label, longitudinal study of 42 patients with FEP. There was an initial wash-out phase of up to 7 days after which treatment was initiated with oral flupenthixol, 1 to 4 mg/day for 1 week prior to when the first long-acting FD was given. The starting dose of FD was 10mg every second week, with dose increases allowed at 6-week intervals. The Matrics Consensus Cognitive Battery (MCCB) and Rorschach Percerptual Thinking Index (PTI) were used as the primary co-measures for the assessment of neurocognition, thought disorder and perceptual disturbances respectively, at baseline prior to treatment, at month 6 and month 12. The main findings of this study were as follows: we confirmed the presence of significant neurocognitive impairment, thought disorder and perceptual disturbances prior to treatment, with improvement in neurocognitive performance and thought disorder from baseline to 6 months, with form perception improving later between month 6 and month 12. Improvements in symptoms were associated with improvements in neurocognitive performance, thought disorder and perceptual disturbances but a degree of residual impairment was evident at month 12. This study confirmed the association between neurocognition and form perception per se as well as their relative stability in FEP after initial improvement with treatment. We found support for the correlation between the amount of improvement in neurocognition, thought and perceptual disorder with outcome. We found the Social and Occupational Functioning Scale (SOFAS) to be a more robust measure of social and functional outcome with highest level of education (HLOE), substance abuse, reasoning-and-problem solving, form perception and Rorschach PTI emerging as predictors in a best subset regression analysis. The findings of this study suggest that neurocognitive impairments, thought disorder and perceptual disturbances have both state and trait like features, that patients benefit from treatment with a low-dose FGA, and that residual neurocognitive and perceptual impairment after treatment may indicate persisting underlying cerebral pathology. / AFRIKAANSE OPSOMMING: Abstrak Neurokognitiewe inkortinge en gedagteproses versteuring in skisofrenie word algemeen aanvaar as kern eienskappe van die siekte, tog is die onderliggende verhouding, die respons op behandeling, en die verwantskap met uitkoms onduidelik. Die meeste studies het 'n oorkruis-deursnee navorsingontwerp gebruik en gefokus op stabiele pasiёnte wat reeds op behandeling was. Die doel van hierdie studie was om die verandering in neurokognisie, gedagte vesteuring en perseptuele inkortinge te meet in eersteepisode psigose pasiёnte wat behandeling naïef was, of wat minimale behandeling gekry het, oor die verloop van 12 maande, met die toediening van 'n langwerkende, lae dosis flupenthixol inspuiting. Hierdie was 'n prospektiewe, nie-vergelykende, oop etiket, longitudinale studie van 42 eerste episode psigose pasiёnte almal op behandeling volgens 'n vaste protokol. Daar was 'n inisiёle uitwas periode van tot 7 dae waarna behandeling begin is op orale flupethixol, 1 tot 4 mg/dag vir 1 week voordat die eerste langwerkende flupenthixol inspuiting toegedien was. Die aanvangsdosis was 10mg elke tweede week met verhogings in dosis elke sesde week daarna. Die "Matrics Consensus Cognitive Battery'' (MCCB) en Rorschach "Perceptual Thinking Index" (PTI) is gebruik as die primêre instrumente vir die meting van neurokognisie, gedagte versteuring en perseptuele inkorting in noue samehang voor aanvang van behandeling, op maand 6 en op maand 12. Die hoof bevindinge van hierdie studie was as volg: Ons het die teenwoordigheid van beduidende neurokognitiewe, gedagte versteuring en perseptuele inkortinge bevestig voor behandeling, met verbetering in neurokognitiewe prestasie en gedagte versteuring tussen basislyn en maand 6, en verbetering in vorm persepsie wat later gevolg het tussen maand 6 en maand 12. Die verbetering in simptome was geassosieёr met verbetering in neurokognitiewe prestasie, gedagte versteuring en perseptuele inkortinge maar teen maand 12 was 'n graad van residuele neurokognitiewe en perseptuele inkortinge aanwesig. Hierdie studie het die verwantskap tussen neurokognisie en vorm persepsie bevestig, asook die relatiewe stabiliteit daarvan in eerste episode psigose na aanvanklike verbetering op behandeling. Ons het bewyse gevind wat die korrelasie tussen neurokognisie, gedagte en perseptuele versteuring met uitkomste ondersteun. Ons het bevind dat die "Social and Occuapational Functioning Scale" (SOFAS) 'n meer robuuste meting van sosiale en funksionele uitkoms is, en dat hoogste opvoedkundige vlak, substans misbruik, redenering-en-probleem oplossing, vorm persepsie en die Rorschach PTI as voorspellers identifiseer was in 'n beste substel regressie analise. Die bevindinge van hierdie studie suggereer dat neurokognitiewe, gedagte versteuringe en perseptuele inkortinge oor beide toestand en trek eienskappe beskik, en dat pasiёnte verbeter het met behandeling op 'n lae dosis eerste generasie antipsigotikum, en dat residuele neurokognitiewe en perseptuele inkortinge na behandeling aanduidend kan wees van onderliggende serebrale patologie.

Executive Function (EF) is a highly complex, interrelated set of the cognitive process composed of multiple components: attention (sustain and selective), cognitive flexibility, working memory, inhibitory control (simple and complex) and problem-solving skill. These skills play a crucial role in the development where deficit in EF could lead to academic failure and a lifelong dissatisfaction. Research has found integral relationship between EF and emotion regulation(ER) suggesting children with weak EF skills are likely exhibit weak ER abilities. The current study is aimed to evaluate the effectiveness of a curriculum-based intervention program designed to promote EF skills and through that, increase children’s ER abilities. Program design includes group and individual activities placed in play corners within classroom setting. Seventy-eight preschoolers from 3 Hong Kong nursery schools were divided into control and program group. A multi-informant pre- and post- program evaluation including teacher questionnaires and a battery of EF and ER tasks completed by participants was used. The program group completed a 20-weeks program delivered by trained classroom teacher. Program benefits are found in promoting working memory, inhibitory control, “Hot” EF problem-solving and cognitive flexibility skills. Improvements in ER abilities and decreased of overall emotion, and behavioral post-program is also found. The gains in ER are observed to be correlates with gain in problem-solving and inhibitory control of EF components. / published_or_final_version / Educational Psychology / Doctoral / Doctor of Psychology

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Male-female differences in neuropsychological functioning and whether there exists a differential cerebral lateralization between sexes has recently received much attention in the literature. Further research is needed because much of this literature has been plagued by poor experimental design and statistical analyses, and reliance upon measures with little practical significance. The current experiment addresses the question of whether male and female adults with unilateral cerebral lesions have differing neuropsychological profiles and whether these profiles support the hypothesis of differential cerebral lateralization. Subjects were adults with independent neurological evidence of either no brain damage or a unilateral cerebral lesion of either neoplastic or vascular origin. There were 48 with right hemisphere damage, 48 with left hemisphere damage and 28 controls. Each group had equal numbers of males and females, for a total of six sub-groups. The distribution of age, education, lesion locus and severity, and handedness was controlled for all groups. Subjects were administered the Halstead-Reitan Neuropsychological Test Battery for Adults. The measures from the Halstead-Reitan Battery were divided into groups of variables representing major aspects of neuropsychological functioning. Results for each variable grouping were subjected to multivariate analysis of variance and appropriate post-hoc procedures. Intra-individual patterns of lateralization (Verbal I.Q.-Performance I.Q. differences) were also examined. Contrary to previous reports, the results failed to produce evidence of a differential lateralization of cognitive functions between sexes. Also, the intra-individual patterns of lateralization showed similar patterns among males and females with unilateral cerebral lesions, although the magnitude of the VIQ-PIQ differences were smaller for females than for males. Several significant sex differences consistent with earlier research were found. Of these, a slight female advantage was found on the Digit Symbol test as well as Tactile Finger Recognition of the right hand. Males performed better than females on Finger Oscillation with the dominant hand and made fewer mistakes in reporting on double simultaneous stimulations. It was concluded that although small differences in neuropsychological functions do exist between sexes, they do not reflect major differences in cerebral organization or overall higher cognitive abilities.

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