45 research outputs found
Language effects on semantic fluency test performance among South African adults
No full textIssues around the cultural fairness of cognitive tests and their administration are becoming increasingly important as the global spread of neuropsychological practice quickens. Most of these tests are developed and standardized in high-income countries of the global north, and so when used in low- and middle-income countries (LAMICs) of the global south they are susceptible to influence by non-organic factors. Of relevance for this thesis is that these factors include language of test administration (e.g., whether the test is administered in the participant's home language or language of education) and the language profile of the test-taker (e.g., whether the person is multilingual). Semantic fluency tests are a standard component of many neuropsychological test batteries (e.g., those used to detect various forms of dementia), and are commonly administered in LAMICs without due regard for language influences on performance. Hence, the aim of this research was to investigate the influence of language of test administration on semantic fluency test performance in a sample of multilingual students from an English-medium South African university. Participants were 75 balanced English-isiXhosa bilinguals who were administered singlelanguage and forced-switching semantic fluency tests in both languages, as well as a freeswitching semantic fluency test. Results showed that, across test conditions, participants generated more words when administered the tests in English than in isiXhosa. Analyses also showed that, during the isiXhosa but not English administration, participants performed better under free-switching than forced-switching or single-language conditions. The strongest conclusion one can draw from these observations is that test administrators must ensure that test takers are assessed in a language that allows them to demonstrate their optimal cognitive capacity, and that therefore a determination of language proficiency in each of the test-taker's languages is a necessary prerequisite for assessment. This step is especially important in countries, like South Africa, that are home to many multilingual individuals
Executive function in adolescents with fetal alcohol spectrum disorders: a developmental perspective
No full textObjective: Children with fetal alcohol spectrum disorders (FASD) have well-documented deficits in executive function. However, few previous studies have examined executive deficits displayed by children with FASD within a developmental framework. This longitudinal study explored the manifestation of executive function in both alcohol-exposed and typically developing adolescents from a low socioeconomic community in a low-and middle-income country. Method: 110 participants (48 with FASD, mean age 14.65 years, SD = 0.65 and 62 controls, mean age 14.49 years, SD = 0.44) were assessed at two time points, 18 months apart. Participants completed a battery of neuropsychological tests to measure executive function. Parents and teachers provided ratings of participants' everyday executive function on the Behavior Inventory of Executive Function (BRIEF). Principal component analysis examined the underlying components of the neuropsychological measures of executive function in the control group. Composite executive function test scores were computed for both groups, and ANCOVA was used to examine whether a) cognitive performance of the FASD group differed from that of the control group, and b) whether there was a change in scores across the two time points. Chi-square and ANCOVA analyses assessed group differences on the BRIEF. Finally, correlations and regressions investigated whether composite cognitive scores were significant predictors of behaviour, as measured by the BRIEF. Results: Neuropsychological measures of executive function clustered into four distinct factors reflecting the domains of Generativity, Attentional Control, Working Memory, and Processing Speed. The FASD group performed significantly worse than the control group on the Working Memory domain (p < .01). On the BRIEF, a significantly higher proportion of the FASD group was rated as having scores in the clinically impaired range by both parents (p < .001) and teachers (p < .01) compared to controls. Significant differences were found between the FASD and control groups on the Emotional Control and Organization of Materials scales of the BRIEF Teacher. Significant differences were found for the Global Executive Composite and the Plan/Organize and Monitor scales on the BRIEF Parent. The cognitive composites Attentional Control and Generativity were significantly negatively correlated with scores on several of the BRIEF Teacher clinical scales for the FASD group. Conclusion: Performance on working memory tasks emerged as the only domain of executive function that distinguished the FASD group from the control group. There was no notable developmental change in executive abilities over the course of the 18- month period in either group. Both parents and teachers reported that the FASD group displayed significantly more executive deficits, but only teacher ratings were correlated with neuropsychological test results. This suggests that children with FASD have more difficulties with executive functioning in their everyday lives than what is being detected on neuropsychological measures alone
Executive Function in Adolescents with Fetal Alcohol Spectrum Disorders: A Developmental Perspective
No full textObjective: Children with fetal alcohol spectrum disorders (FASD) have well-documented
deficits in executive function. However, few previous studies have examined executive
deficits displayed by children with FASD within a developmental framework. This
longitudinal study explored the manifestation of executive function in both alcohol-exposed
and typically developing adolescents from a low socioeconomic community in a low-and
middle-income country. Method: 110 participants (48 with FASD, mean age 14.65 years, SD
= 0.65 and 62 controls, mean age 14.49 years, SD = 0.44) were assessed at two time points,
18 months apart. Participants completed a battery of neuropsychological tests to measure
executive function. Parents and teachers provided ratings of participants’ everyday executive
function on the Behavior Inventory of Executive Function (BRIEF). Principal component
analysis examined the underlying components of the neuropsychological measures of
executive function in the control group. Composite executive function test scores were
computed for both groups, and ANCOVA was used to examine whether a) cognitive
performance of the FASD group differed from that of the control group, and b) whether there
was a change in scores across the two time points. Chi-square and ANCOVA analyses
assessed group differences on the BRIEF. Finally, correlations and regressions investigated
whether composite cognitive scores were significant predictors of behaviour, as measured by
the BRIEF. Results: Neuropsychological measures of executive function clustered into four
distinct factors reflecting the domains of Generativity, Attentional Control, Working
Memory, and Processing Speed. The FASD group performed significantly worse than the
control group on the Working Memory domain (p < .01). On the BRIEF, a significantly
higher proportion of the FASD group was rated as having scores in the clinically impaired
range by both parents (p < .001) and teachers (p < .01) compared to controls. Significant
differences were found between the FASD and control groups on the Emotional Control and Organization of Materials scales of the BRIEF Teacher. Significant differences were found
for the Global Executive Composite and the Plan/Organize and Monitor scales on the BRIEF
Parent. The cognitive composites Attentional Control and Generativity were significantly
negatively correlated with scores on several of the BRIEF Teacher clinical scales for the
FASD group. Conclusion: Performance on working memory tasks emerged as the only
domain of executive function that distinguished the FASD group from the control group.
There was no notable developmental change in executive abilities over the course of the 18-
month period in either group. Both parents and teachers reported that the FASD group
displayed significantly more executive deficits, but only teacher ratings were correlated with
neuropsychological test results. This suggests that children with FASD have more difficulties
with executive functioning in their everyday lives than what is being detected on
neuropsychological measures alone.
Keywords: fetal alcohol spectrum disorder, executive function, Behavior Rating Inventory of
Executive Function, adolescents, longitudinal stud
Assessing type 2 diabetes associated NeuroCognitive impairment using an e-screening tool in a South African population
No full textBackground: Type 2 diabetes has been found to be associated with cognitive impairments in planning, problem solving, organization, and working memory and also with an increased risk of dementia. Neurocognitive impairment may impact self-care and other health behaviours increasing the risk of poor health outcomes in this patient population. Detection of neurocognitive impairment in low and middle-income settings is challenging; there is a lack of validated screening tools suitable for local use in primary care and outpatient settings and access to formal neuropsychological testing services is limited. The inability to easily identify people with type 2 diabetes with neurocognitive impairments is constraining the development of context appropriate interventions to improve the care and outcomes in this sub-group of patients. Aim: The aim of the current analysis is to explore associations between neurocognitive function and measures of diabetes control (HbA1c, disease duration, type of blood glucose lowering treatment) at baseline in a population of people with type 2 diabetes participating in a clinical trial of treatment adherence support using SMS-text messages. Materials and Methods: Sms text Adherence suppoRt for type 2 Diabetes (StAR2D) is a randomised clinical trial testing if a system of SMS-text messages to support treatment adherence is more effective than usual care for controlling blood sugar among people with type 2 diabetes in sub-Sahara Africa (ISRCTN70768808). We have embedded neurocognitive assessment sub-studies into the Cape Town trial site. At baseline participants in the StAR2D trial complete a novel mobile-device based cognitive assessment, NeuroScreen, assisted by a field research assistant. The assessment contains 9 variants of tests found in the gold-standard neuropsychological test battery that have been adapted and normed for use in South Africa. It is available in English or isiXhosa. The assessment takes between 20 to 40 minutes depending on participant error rate. This cross-sectional analysis of baseline data uses linear and logistic regression models to explore associations between neurocognitive function and measures of diabetes control. Results: Six hundred participants eligible for enrolment in the StAR2D trial were recruited from the Cape Town trial site; 499 participants completed the baseline neurocognitive screening assessment (20 to 40 minutes to complete); 101 participants did not complete the assessment (commonly due to eyesight, hearing or motor difficulties e.g. hemiplegia due to previous stroke or technical difficulties.) We found differences in the scores in some but not all the neuropsychological tests. Using cut points suggested by an earlier validation study of NeuroScreen tool more than half of study participants would be scored as having at least mild neurocognitive impairment. HbA1c, duration of disease, type of blood glucose lowering treatment were not significantly associated with individual or overall neuropsychological test scores or odds of neurocognitive impairment. Conclusions: The prevalence of neurocognitive impairment may be substantial in this patient population. A novel tablet based neurocognitive screening tool was broadly feasible and acceptable to lay researchers and trial participants. There was no evidence that HbA1c, duration of disease, or type of blood glucose lowering treatment (oral agents alone or insulin containing regimens) was significantly associated with individual or overall neuropsychological test scores or odds of neurocognitive impairment. Validating this tool for this patient population and optimising its role in routine clinical care need further study
Neuropsychological, functional and behavioural outcome and predictors of outcome in a sample of traumatic brain injury litigants
No full textIncludes abstract.Includes bibliographical references (leaves 147-162).Generally, this study aimed to explore whether financial settlement in litigation influences outcome and recovery from closed head injury in a sample of traumatic brain injured (TBI) litigants who were tested and interviewed both during litigation (at time 1, or T1) and 1 year or more after case settlement (at time 2, or T2). More specifically, my major goals were to assess (a) changes between TI and T2 on outcome variables such as neuropsychological test scores and self- and other-reported cognitive function, behaviour, activities of daily living (ADL), and physical dependency (PD), and (b) the impact of demographic (e.g., years of education, employment status) and clinical (e.g., severity of injury, degree of post-traumatic amnesia, Glasgow Coma Scale score) variables on the aforementioned outcome variables
Parkinson's disease and the influence of the forebrain dopaminergic system on dreaming
No full textBibliography: leaves 32-37.The purpose of the study was to investigate a hypothesis proposed by Solms (2000) to the effect that a forebrain dopaminergic mechanism is the final common path to dreaming. It was hypothesised that sufferers of Parkinson's disease (PO) would have decreased intensity and frequency of dreams - that is that PO disease may lead to cessation or reduced dreaming, reduced duration of dreams, reduced narrative complexity of dream and a change in dream emotion and that this will further decrease with the duration of the disease irrespective of the medication that the patient is taking. Self-report questionnaires (N=40) and the Most Recent Dream Report (Oomhoff, 1996) was used for assessment. PO patients were found to have shorter as well as more pleasant dreams. A correlation (p &amp;lt; .05) was found in the PO sample between duration of illness and emotional quality of dreams and dream duration. The specific hypothesis of the study was not fully supported. However, the findings do support the suggestion that dreaming is generated by the mesocortical-mesolimbic dopamine system
HIV testing and sero‐prevalence among methamphetamine users seeking substance abuse treatment in Cape Town
No full textMethamphetamine use is highly prevalent in parts of South Africa, and there is concern this will contribute to the country's substantial HIV epidemic. We examined the feasibility of implementing routine HIV testing at a community-based substance abuse treatment centre in Cape Town and determined the HIV sero-prevalence among methamphetamine users seeking treatment at this site.
In this cross-sectional study, 293 participants completed measures of demographics, substance use and HIV treatment. HIV sero-prevalence was determined by a rapid finger-prick HIV test, and prior HIV diagnosis was confirmed via clinic records.
The majority of participants were male and self-identified as 'Coloured', with a mean age of 28 years. The HIV sero-prevalence was 3.8%. Of the 11 participants who tested HIV positive, four were newly diagnosed. HIV-positive and HIV-negative participants were comparable on demographic and substance use factors. Uptake of HIV testing among all clients at the drug treatment centre increased from <5% prior to study initiation to 89% after study completion. Measures implemented to ensure high rates of HIV testing were regarded as sustainable.
Our study suggests that integrating routine HIV testing into substance abuse treatment is feasible in a community-based health centre. The low HIV prevalence among this sample of treatment-seeking methamphetamine users highlights the potential benefits of supporting expanded efforts to optimise HIV prevention with this young adult population. [Gouse H, Joska JA, Lion RR, Watt MH, Burnhams W, Carrico AW, Meade CS. HIV testing and sero-prevalence among methamphetamine users seeking substance abuse treatment in Cape Town. Drug Alcohol Rev 2016;35:580-583]
Assessment of neurocognitive deficits in people living with HIV in Sub Saharan Africa: A systematic review.
No full textObjective: People living with HIV (PLWH) are at risk for HIV-Associated Neurocognitive Disorders (HAND)/Neurocognitive Impairment (NCI). HIV prevalence in Sub-Saharan Africa (SSA) is high, but neuropsychological screening and testing for NCI among HIV-infected individuals is not done frequently. This systematic review aims to establish how NCI among HIV-infected individuals is being assessed in SSA, if and how the tests are adapted, if norms exist and identify personnel who administer them.Method: We searched PubMed, Medline, EBSCO, PsycINFO, and Web of Science. Two reviewers screened the articles for inclusion and risk of bias. We included studies from SSA with a comprehensive neuropsychological assessment battery.Results: We retrieved 212 articles and 23 articles met inclusion criteria. The most commonly used tests were the Color Trails Test 1, Color Trails Test 2, and the WAIS III Digit Symbol Test. Some tests were translated into French (Cameroon), Luganda (Uganda), Chichewa (Malawi), isiXhosa (South Africa), and Afrikaans (South Africa). Some verbal learning tests were adapted to reflect culturally appropriate language. Test administrators were either non-specialized personnel supervised by clinical neuropsychologists or clinical psychologists.Conclusion: Overall, the tests used are similar to the tests being used globally to assess NCI among HIV-infected individuals and there is a general consistency across countries. However, there is generally a lack of norms for the tests and the process of adaptation is not always well described. Future research should establish whether these tests measure neuropsychological constructs as successfully as they do in western populations where the tests were developed
Adding a brief self-report cognitive tool to the IHDS improves effectiveness of identifying patients with HIV-associated dementia in South Africa
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