Includes bibliographical references. / Background and aims. Executive function (EF), defined as a set of interrelated skills and behavioural competencies required for independent, purposeful, goal-directed activity, are particularly susceptible to impairment following traumatic brain injury (TBI). Despite this knowledge, data concerning the rehabilitation of executive dysfunction in pediatric populations is lacking to date. A Goal Management Training (GMT) intervention, based on Duncan et al.’s (1996) theory of goal neglect, has been successfully implemented for the remediation of EF in adults. The current study adapted the GMT to a healthy South African sample and evaluated the efficacy in a pediatric TBI sample. Method. The study comprised of 3 parts. Part 1 involved the translation and adaptation of the pediatric GMT (pGMT) intervention so that it was suitable for use with South African children. This included the implementation of various health professionals’ evaluations of these adaptations. Part 2 involved evaluating the pGMT by implementing the programme with 3 healthy control participants. Lastly, Part 3 involved evaluating the efficacy of the revised pGMT with 3 children who had sustained a moderate to severe TBIs. For Parts 2 and 3 I employed a multiple case study approach. Data for parts 2 and 3 were analyzed using the Reliable Change Index (RCI; Jacobson & Truax, 1991) . The RCI distinguished between three levels of change, each at confidence levels of 68.2%, 95% and 99%. Outcomes were based on neuropsychological test outcomes, changes in everyday behaviour, self-report measures, and reports from parents and teachers. Results. Regarding the cognitive measures for the TBI group, all three participants did not show improvement on the same domains. Positive changes from pre- to post-intervention on a number of attention and executive function measures at confidence intervals of 68.26% to 99% were evident. Regarding the behavioural measures parents/guardians and/or teachers reported significant positive changes for all of the participants on at least one index at confidence intervals of 68.26% to 99%. In terms of real world generalization, only one participant’s teacher and parents commented on her improvements academically, behaviourally, and socially. No significant real world behavioural changes were reported for the other two participants. Results indicated that the adapted pGMT was successfully applied to the South African context for both healthy and TBI samples, although levels of success, in terms of post-intervention outcomes, varied with each TBI individual. Conclusions. These results suggest that the pGMT intervention could be an efficacious cognitive rehabilitation tool for the remediation of everyday behaviours associated 9 with executive dysfunction in South Africa. However, the variability in the results do not provide conclusive evidence at this stage. Individual, injury-related and familial factors need to be considered and may affect outcome. In addition, limitations such as the small sample size and uncontrolled confounding effects (e.g., practice or maturation effects) could also contribute to seemingly positive effects. Greater evidence from future, larger and more controlled studies, is required

Includes bibliographical references. / Children who have sustained severe traumatic brain injury (TBI) demonstrate a range of deficits in neurocognitive and behavioural domains (Anderson, Northam, Hendy, &Wrennall, 2001; Babikian & Asarnow, 2009; van’t Hooft, 2010). These impairments may have adverse effects on academic and behavioural outcomes and can therefore interfere with school re-entry, educational progress, and ultimately, quality of life of the injured child (Anderson & Yeates, 2010; Keenan & Bratton, 2006; Lallo & van As, 2004). Pre-injury characteristics may increase risk for, and play a role in, TBI outcome, however, many studies exclude children with known adverse premorbid functioning (Dennis et al., 2007; Farmer etal., 2002). There are also dearth of published studies incorporating a variety of factors affecting outcome (e.g., socio economic status (SES), age at injury, time since injury, premorbid functioning, family environment) as well as academic and/or behavioural outcome variables in the same study generally. The broad aim of the study was therefore to contribute to the existing pediatric TBI (pTBI) literature on outcomes and factors influencing outcomes. In this study, I focused on investigating both academic and behavioural outcomes in a group of South African children of school-going age who had sustained a severe TBI. This study includes two parts. For the first part of the study, the aim was to explore the relationship between commonly reported factors that influence outcome after TBI (premorbid functioning, age at injury, time since injury, family environment and SES), and academic and behavioural outcome. For the second part of the study, the aim was to investigate the specific role of premorbid functioning in academic and behavioural outcome. The sample included 27 children who had been admitted to Red Cross War Memorial Children’s Hospital (RXH) and received intracranial monitoring for closed severe TBI between 2006-2011, who were of school-going age at the time of the injury. In terms of part one of the study, the results show elevated problems with academic outcome, and behavioural and executive functioning in the sample. The results also show that in this sample, factors such as family environment and premorbid functioning are particularly important with regards outcome in the home environment; while factors such as age at injury, family environment and SES play more of a role within the classroom environment.

There exists a substantial number of studies exploring the misconceptions of TBI and concussion in various geographical regions, but an insufficient number of studies have focused on why this may be the case and what can be done to improve the knowledge amongst different populations. The current study attempted to explore low cost psychoeducation interventions around misconceptions, which can hinder TBI-related prevention, help-seeking behaviours, and recovery. This study includes both quantitative and qualitative components. The study is divided into three parts: Part A: the pre-test component, which seeks to measure TBI knowledge and misconceptions through survey format. Part B: the implementation of different types of psychoeducation interventions delivered through a lecture, video or pamphlet. It also includes the re-administration of the survey (post-test). Part C: an online survey exploring the participants' experiences with the various interventions. All undergraduate students enrolled in the first year psychology PSY1005/7S course at the University of Cape Town (UCT) were invited to participate through the use of convenience sampling and the Student Research Participation Program (SRPP). Statistical analyses included descriptive statistics, one-way and repeated measures ANOVAs, and thematic analyses, related to parts A-C of the study, respectively. The results of the study suggested the positive impact of all three interventions. Each intervention was shown to increase knowledge gain in both TBI and concussion knowledge, at least descriptively. A between-groups analysis showed a significance of p = 0.01 where the lecture intervention yielded the greatest results followed by the video and pamphlet intervention respectively. Adequate awareness, knowledge and understanding of TBI are paramount to the prevention and recovery of trauma-related brain injuries, which is particularly relevant in countries with (probable) high rates of TBI, such as South Africa.

Advances in pharmacological treatment and medical management of HIV have resulted in decreases in HIV-associated mortality and morbidity for people living with HIV worldwide. However, many HIV+ individuals continue to experience some degree of neurocognitive impairment, particularly in the domain of executive functioning. HIV-related executive deficits are particularly pertinent in the adolescent population as individuals transition into adulthood and assume greater responsibility for their daily functioning. Despite the high prevalence of HIV in South African adolescents, neuropsychological rehabilitation interventions are largely absent. Currently, metacognitive approaches such as Goal Management Training (GMT) demonstrate the best evidence base for improving executive functions. The main aim of this study was to evaluate the effectiveness of a pGMT intervention for HIV+ adolescents in South Africa. A secondary objective was to provide commentary on the feasibility of conducting cognitive rehabilitation interventions in low resourced settings such as those commonly found in South Africa. This quantitative study used a pre-test post-test quasi experimental research design to investigate the effectiveness of a 7-week pGMT intervention in HIV+ adolescents in South Africa. Participants included 18 HIV+ adolescent (aged 14-17) first language Xhosa speakers from low socio-economic backgrounds. Participants formed two groups: a pGMT intervention (n = 10), and a Control (n = 8) group. A neuropsychological test battery was administered pre- and post- intervention to assess executive functions. Neuropsychological test scores were sorted into four executive function composite domains. To assess the efficacy of the pGMT intervention, these executive function domains were analysed using a mixed-design ANOVA and Mann-Whitney U analysis of difference scores. No significant effects were detected, suggesting that the pGMT intervention demonstrated limited efficacy in the study sample. However, the successful implementation of the intervention supports the use of the GMT protocol in low-resourced settings such as those commonly found in LMICs like South Africa. Findings of the current study contribute valuable insights into the limitations and opportunities relevant not only to research in this field, but also more broadly to the implementation of cognitive rehabilitation interventions in LMICs such as South Africa.

Background. HIV remains a significant global public health concern. South Africa is one of the hardest-hit countries, housing more than 7 million people living with HIV (PLWH), a figure that represents more than 12% of the global infected population. Globally, HIV-associated cognitive impairment is present in almost 45% of PLWH, with 72% of that total burden found in Sub-Saharan Africa (Wang et al., 2020). The severity and trajectory of that impairment is, however, influenced by numerous risk and protective factors. This study aimed to investigate the strength of influence that two of these factors (cognitive reserve and age) have in a sample of HIV-positive South African adults. Method. Participants were 32 HIV-infected and virally suppressed adults (27 women; Mage = 41.13±9.34). They were administered the Cognitive Reserve Index Questionnaire (CRIq) and a comprehensive neuropsychological battery that assessed performance on tests of motor function, attention and working memory, information processing speed, language, memory, and executive function. They also provided 3T magnetic resonance imaging data. Bivariate correlations, independent-sample t-tests, and hierarchical regression models tested the prediction that age and cognitive reserve (as indexed by CRIq scores, fractional anisotropy, white and gray matter volume, education level, and IQ score), both independently and in interaction, will have significant effects on cognitive test performance (i.e., that increasing age and lower levels of cognitive reserve will be independently associated with poorer performance, and that older adults with lower levels of cognitive reserve will display the worst performance). Results. Regarding the association of age with global cognitive function (average performance across all tests), analyses detected a moderate negative correlation (r = -.425, p = .015.), a significant between-group difference (participants ≥ 45 years worse than those < 45 years, p = .012), and a significant proportion of variance accounted for (R 2 = .18, p = .016). There were no significant main effects of cognitive reserve, and no significant age x cognitive reserve interaction effect, on cognitive test performance. Conclusion. The current analyses confirmed the influence of age on cognition in PLWH but did not provide support for the same influence of cognitive reserve. Although neuroscience research attaches increasing importance to the construct of cognitive reserve, the lack of a universally-applied definition (and hence a standard measure) of the construct hampers investigations such as this and makes cross-study comparisons difficult. From a policy-making perspective, the contrasting findings regarding age and cognitive reserve is crucial because it is imperative that intervention efforts focus only on those modifiable factors that significantly impact cognitive function, especially in countries such as South Africa that are characterized by high HIV disease burden and limited clinical and infrastructural resources.

Includes bibliographical references. / Adolescents are at risk for antisocial behaviour as well as for sustaining traumatic brain injuries (TBI; Moffitt, 1993; Williams, Cordan, Mewse, Tonks & Burgess, 2010). International literature has long made known the explicit link that exists between TBI and delinquent behavior (Eslinger, Flaherty-Craig, & Benton, 2004; S. Anderson, Bechara, Damasio, Tranel, & Damasio, 1999). The onset of antisocial behaviour post-TBI may not be surprising given the vulnerability of the frontal lobes in sustaining such an injury. Considering the strong overlap between the behaviour of offenders and the behavioural outcomes of sustaining TBIs, the high prevalence rates of TBI in offending populations is not surprising (Perron & Howard, 2008; Slaughter, Fann, & Ehde, 2003; Turkstra, Jones, & Toler, 2003; Williams et al., 2010). In this study, I investigate the prevalence of TBI in an offending population and the overlap between offending behaviour and outcomes of sustaining TBIs.

Includes bibliographical references. / Life History Theory (LHT) predicts that natural selection favours a degree of developmental plasticity when it comes to sexual strategies and mating displays. Individuals should develop a faster life history strategy (showing, for example, higher mating effort and a preference for a variety of mates) when they are raised in a relatively unstable environment with high extrinsic mortality. In contrast, individuals should develop a slower life history strategy (showing, for example, lower mating effort and a preference for investment in longterm parenting) when they are raised in a relatively stable environment with low extrinsic mortality. Most previous research examining predictions derived from LHT regarding sexual strategies and mating displays has used survey designs and self-report instruments exclusively. The current study represents a departure from such designs in that I used a quasiexperimental design to examine sexual strategies and mating displays in virtual chatrooms, and to test LHT-based predictions about those strategies and displays. Specifically, I tested the hypotheses that, in the chatrooms, individuals would adopt sexual strategies and mating displays reflective of their different life history strategies, and that these behaviours would manifest in the virtual world much like they have been documented to manifest in the real world. I used the Mini-K Short Form questionnaire, a 20-item instrument designed to measure both cognitive and behavioural aspects of life history strategy, to designate undergraduate males (n = 44) and females (n = 47) as having either a fast or a slow life history. Ten separate groups of these participants, each featuring 3-5 men and 4-5 women, then interacted in separate 1-hour online chat sessions. Results showed that LHS accurately predicted the ways in which male and female participants engaged with one another. Furthermore, men that remained consistent in their LHS presentation (i.e., they behaved in ways consistent with what their LHS predicted they should) were more popular among women than men who were not consistent in this presentation. These results demonstrate the power of evolutionary-based theories of sexual interaction to predict sexual strategies and mating displays in online settings. Further, the 'pure' environment of the online platform, without extraneous real-world constraints, provided an opportunity to document and examine sexual strategies and mating displays in new and exciting ways.

Includes bibliographical references (leaves 23-26). / This study explores the short term cognitive outcome of percutaneous transluminalcoronary angioplasty with intra-coronary stenting. Participants were assessed cognitively using specific neuropsychological tests used to measure performance in the seven cognitive domains. Forty people took part in the study, with twenty of them making up the stented group, and twenty of them making up the control group. The stented group were assessed a few days before, and then a few weeks after their procedures. The control group were simply assessed whenever they agreed to participate, and then again a few weeks later. There were ten males and ten females in each group. The participants were all between the ages of 34 and 75, and the sample had an average age of 57. The researchers were given access to patients at Groote Schuur Hospital and Gatesville Medical Centre. Analysis of variance was used in order to assess differences between the groups with respect to changes in cognitive performance in all seven cognitive domains. Results indicated that there were not significant differences between the groups, with respect to changes in cognitive performance between the first and second interviews.

Traumatic brain injury (TBI) is one of the major causes of mortality and morbidity among children and adolescents all over the world and studies suggest a higher incidence of pediatric TBI (pTBI), as well as poorer post-TBI outcomes, in countries with extreme levels of socioeconomic inequality such as South Africa. pTBI leads to a multitude of long-term adverse outcomes in a wide range of domains and in general, a dose-response pattern is evident. Multiple acute and post-acute stage predictors of outcome have been investigated, however acute stage neurological and neurosurgical variables are relatively absent from this knowledge base. This study was conducted to better understand the heterogeneity in outcomes of pTBI: it aimed to investigate the nature and severity of neuropsychological deficits in pTBI patients one year after injury and to investigate the association between acute stage physiological changes in intracranial pressure (ICP) and brain tissue oxygenation (PbtO2) and neuropsychological outcomes one year after pTBI. Results of the study indicated that children who sustained TBI performed significantly poorer than healthy, matched controls on multiple cognitive, behavioural and quality of life domains, however, neither acute ICP nor PbtO2 reliably predicted within-TBI group performance. The results of the study emphasise the poor relationship of ICP and PbtO2, and the complexity of the relationship between acute physiological variables and outcomes after pTBI. Further studies of this kind should be done on large sample sizes and include multiple physiological variables.

Includes bibliographical references. / Asymmetry in the vasculature arising from the human aortic arch seems the obvious place to look for an anatomical basis for lateralized cerebral functions, but this relationship has never systematically been investigated. This study explored the relationship between handedness and the anatomical and hemodynamic characteristics of the carotid arteries, analysing potential asymmetries between the left and right common, internal and external carotid arteries in leftha-nded versus right-handed individuals. The study is separated into two chapters: geometric (n = 199) and hemodynamic (n = 234). A revised version of the Edinburgh Handedness Inventory classified all participants into relevant handedness preference categories. For the geometric study, detailed measurements of the common carotid arteries in computed tomography angiography scans were obtained using Radiant DICOM Viewer (64-bit) imaging software. Selected geometric parameters of the vessels measured included minimum, mean, and maximum diameters, length, angle and calculated resistance to blood flow. Cases of unconventional branching patterns were analysed separately. For the hemodynamic study, Speed and Accuracy Target Tests quantified the participants’ handedness performance. Doppler ultrasound was performed using the Vivid i GE Ultrasound system, on the common, internal and external carotid arteries. Hemodynamic parameters of the Doppler waveform were recorded, including Peak systolic and end-diastolic velocity, Resistive index, Pulsatility index, volume flow rate, and vessel diameter. The data was analysed with mixed design ANOVAs, discriminant function analyses, multiple regressions, and paired and independent t-tests, to investigate the asymmetries and predictive properties of the measured variables