It is well known that crystallized measures of intelligence are highly susceptible to educational, resource, language and socio-economic influences, and that the implications of using these kinds of measures are manifold affecting school and university entrance as well as employment opportunities. In South Africa, wherein tests are regarded with suspicion as a consequence of test misuse during the Apartheid era, there is an urgent need for the development of measures which are resilient to these influences. In answer to this, working memory measures have been identified as possible measures which minimize these biases. Consequently the following study investigated whether working memory tests were less susceptible to socioeconomic influences than the more traditional, crystallized measures of vocabulary and non-verbal IQ in a volunteer sample of 60 grade one learners from schools identified as high and low in socioeconomic status. The results demonstrated that working memory measures were consistently less affected by socio-economic status as compared to the traditional vocabulary and non-verbal IQ measures. However, socioeconomic status and language were found to be so closely correlated that it is not clear whether test performance in the vocabulary measures, was related one or both of these variables. In light of the fact that this study was correlational in nature, it is recommended that future studies focus on limiting the impact of extraneous variables to better understand the impact of socioeconomic status on test performance. Furthermore future studies should test children in their home language to avoid language contamination effects.

Thesis (Ph.D.)--Ohio University, March, 2010. / Title from PDF t.p. Release of full electronic text on OhioLINK has been delayed until April 2012. Includes bibliographical references.

With 10% of the population being infected with Human Immunodeficiency Virus (HIV), South Africa has the highest number of infections in the world (StatsSA, 2013). HIV results in cognitive and motor deficits in children as the severe compromise of the immune system leads to neurodevelopmental dysfunction peri-natally (Ruel, Boivin, Boal, Bangirana, Charlebois, & Havlir, 2011). Neurocognitive deficits affect overall general intellectual abilities and include difficulties with attention and speed of information processing, verbal language, executive –abstraction, complex-perceptual motor function, memory and motor and sensory function (Dawes & Grant, 2007). Developmentally, it is evident that working memory provides a crucial interface between perception, attention, memory and action (Baddeley, 1996; Baddeley 2003). Therefore the purpose of the study was to investigate the working memory profiles of both an HIV positive children and a control sample, on cognitive tasks (Automated Working Memory Assessment), general intellect tasks (Raven’s Colored Progressive Matrices) and language competence tasks (Sentence Repetition Test). The current study compared 26 HIV positive children (mean age = 6.58 years) to 26 matched controls (mean age = 6.73 years). It was found that both non-verbal IQ and language proficiency were correlated to HIV status and thus were used as covariates in the study. MANCOVA’s were conducted on the data and produced findings that showed that there were only significant differences in visuo-spatial short-term memory between the two groups. Furthermore, it was also found that there were significant differences between the groups on nonverbal IQ and language proficiency. Therefore, the results showed that HIV may have an overall effect on non-verbal ability and language proficiency and a few aspects of working memory such as visuo-spatial short-term memory. Together with future studies focused on larger sample sizes and children who are not currently on HAART, early developmental interventions can be formulated to assist South African HIV-infected children so that the neurocognitive effects are lessened and their overall lifestyle is improved.