THIS THESIS IS IN THE EXAMINATION PROCESS The ability to locate symbols on a visual display forms an integral part of the effective use of AAC systems. Characteristics of display design and perceptual features of symbols have been shown to influence rate and accuracy of symbol location (Thistle&Wilkinson, 2009; Wilkinson, Carlin,&Jagaroo, 2006). The current study endeavoured to compare the use of two colour-coded organisational strategies (alphabetical order and subcategorisation) for their effectiveness in symbol location and to investigate if some bottom-up features influenced the performance of the participants in these tasks. 114 learners in Grade 1 to 3 in a mainstream school were randomly divided into two groups. Both of the groups were exposed to two visual search tests in alternating order. The tests involved searching for 36 visual targets amongst 81 coloured Picture Communication Symbols on a computer screen in one of two colour-coded organizational methods, namely alphabetical order or subcategorisation. The data from the research task was collected through computer logging of all mouse selections. Findings showed that locating symbols on a computer screen with a subcategorisation strategy was significantly faster and more accurate than with an alphabetical strategy for the Grade 1 to 3 participants. The differences between the rates and accuracy of target symbol location using the two strategies decreased significantly as grade increased. It was also found that although the tests in this study placed heavy top-down processing demands on the participants, there was still evidence of bottom-up factors influencing their performance. Implications for display design in AAC clinical practice were discussed. / Thesis (PhD)--University of Pretoria, 2012. / Centre for Augmentative and Alternative Communication (CAAC) / Unrestricted

The number of students that apply for studies at South African universities has increased dramatically over the past years, but the resources of the universities have stayed the same. It is therefore imperative that academic performance can be predicted on a short- and long-term basis. The Developing Expertise model might be able to predict academic performance on a short- and long-term basis. This study focussed primarily on academic performance on short-term basis by focussing on three of the model’s elements. The three elements that were investigated were: metacognition, intrinsic motivation and critical thinking. One of the contributions of this study is the refinement of some of the elements of the expertise model. The study helped to determine the validity of the instrument in a South African context. The measurement instrument can also be used as a selection meganism on short-term basis. In order to measure each of the elements of the expertise model, a measuring tool consisting of five questionnaires was compiled. A convenience sample of first year psychology students provided 326 students for the study. A second sample, compiled from the original sample, consisting of 209 first year students was used for the multiple regression analyses. These students are registered for psychology for the first time in 2005. The students were placed in three groups according to the student’s means of registering for the CBT centre. The first group was those students who completed the instrument on computers. The second group consisted of those students who completed a paper and pencil version of the measurement. The third group consisted of the Mamelodi students. These students completed a paper and pencil version of the measurement and brought it back a week later. The statistical analysis included factor analysis, correlation analysis and multiple regression analysis. Based on the literature research and the results of the statistical analysis, the expertise model was expanded to include metamemory as the functional unit for metacognition. Motivation can be divided in three subcomponents, namely: self-efficacy, intrinsic value and test anxiety. The motivational component, knowledge of cognition and external control can be used as predictors of academic performance on a short-term basis. The findings of this study can only be used as a selection meganism of academic performance on a short-term basis and therefore the results must be used with caution. / Dissertation (MA (Psychology))--University of Pretoria, 2007. / Psychology / unrestricted

Bilateral cochlear implantation is accepted medical practice since 2008 in clinically suitable adults and children to enhance bilateral processing benefits. Bilateral implantation may lead to the restoration of some bilateral hearing advantages, such as improved speech recognition in noise, localisation, head shadow effect, summation, and squelch. The majority of the advantages stated in literature, though, are characteristic of the simultaneously implanted cochlear implant population. Simultaneous implantation is not yet a reality in South Africa due to funding constraints, therefore determining the bilateral processing abilities in sequentially implanted adults is essential. Determining bilateral processing benefits achievable with sequential implantation could result in evidence-based recommendations in terms of candidacy considerations, surgery protocols, motivations for medical aid funding for simultaneous cochlear implantation, and relevant measures to determine the bilateral processing benefit attainable. Furthermore, it might enhance audiologists‟ insight regarding post-implantation performance of sequentially implanted patients and enable them to counsel prospective candidates realistically. The aaim of this study was to determine the bilateral benefit attained by sequentially implanted adults. A quantitative, cross-sectional research approach was followed in a one group post-test-only exploratory research design. A purposive convenient sampling method with specified selection criteria was used to select 11 adult clients of an established cochlear implant programme in Pretoria. Tests of sound localisation in the horizontal plane and speech perception in noise were performed. During the test of sound localisation, performance with only the first or only the second implant was found to be very similar. For the majority of participants the second cochlear implant (CI 2) was the superior performing implant during xviii speech perception in noise testing, in spatially separated speech and noise conditions where noise was directed to the first implant, as well as in spatially coincident speech and noise. A statistical significant bilateral benefit (p < 0.05) was attained by sequentially implanted adults for sound localisation. A bilateral benefit for speech perception in noise was observed when noise was directed to the first implant and in the diotic listening condition with average benefits of 1.69 dB and 0.78 dB, respectively. It was not statistically significant (p > 0.05), however, and was smaller than bilateral benefit values achieved by simultaneously implanted adults in previous studies. The head shadow effect at 180° was found to be the strongest and most robust bilateral spatial benefit. Squelch and summation benefit values ranged from negative values to 2 dB and 6 dB, respectively. This corresponded with values found in previous studies. The improvement in speech perception in spatially distinct speech and noise from adding the ear with a better SNR (signal to noise ratio) indicated that the contribution of CI 2 seems to be greater than that of CI 1 for bilateral spatial benefit. It can be concluded that adults with sequential implants may achieve some extent of bilateral benefit even with many years of unilateral implant use, when speech processors differ, when the second implant is done ≥ 10 years after the first implant, and in cases of prelingual deafness. A key benefit of sequential implantation appears to be related to the advantage of having hearing on both sides so that the ear with the more favourable environmental signalto-noise ratio is always available. AFRIKAANS : Bilaterale kogleêre inplanting is sedert 2008 aanvaarde mediese praktyk vir klinies geskikte volwassenes en kinders, ten einde bilaterale prosesseringsvoordeel te verhoog. Bilaterale inplanting kan lei tot die herstel van sommige van die voordele van bilaterale gehoor, soos verbeterde spraakherkenning in lawaai, klanklokalisering, die kopskadueffek, sommering en selektiewe onderdrukking (“squelch”). Die meeste van die voordele wat in die literatuur bespreek word, is egter kenmerkend van dié persone by wie twee kogleêre inplantings gelyktydig gedoen is. Gelyktydige inplanting is as gevolg van beperkte befondsing nog nie in Suid-Afrika 'n werklikheid nie, daarom is dit noodsaaklik om te bepaal watter bilaterale prosesseringsvoordele by opeenvolgend-geïnplanteerde volwassenes voorkom. Die bepaling van watter bilaterale prosesseringsvoordele met opeenvolgende inplanting bereik kan word, sou kon lei tot getuienis-gebaseerde aanbevelings met betrekking tot besluite oor die geskiktheid van kandidate, protokol vir sjirurgie, motiverings vir die befondsing van gelyktydige kogleêre inplantings deur mediese voorsorgfondse, en toepaslike maatstawwe om te bepaal watter mate van bilaterale prosesseringsvoordeel haalbaar sou wees. Dit sou verder oudioloë se insig kon verbreed met betrekking tot die na-operatiewe prestasie van opeenvolgend-geïnplanteerde persone en hulle sodoende in staat stel om voornemende kandidate van realistiese raad te bedien. Die doel van hierdie studie was om te bepaal wat die bilaterale prosesseringsvoordele is wat deur opeenvolgend-geïnplanteerde volwassenes verkry kan word. 'n Kwantitatiewe navorsingsbenadering met 'n dwarsprofiel van „n enkelgroep is gevolg, met 'n post-toets verkennende navorsingsontwerp. 'n Doelgerigte gerieflikheidssteekproef met 'n gespesifiseerde seleksiekriteria is gebruik om 11 volwasse kliënte van 'n gevestigde kogleêre inplantprogram in Pretoria te selekteer. Klanklokalisering in die horisontale vlak en die waarneming van spraak in lawaai is getoets. Tydens die toets vir klanklokalisering is gevind dat prestasie met slegs die eerste of slegs die tweede inplanting soortgelyk was. Vir die meeste deelnemers aan die studie het die tweede kogleêre inplanting (KI 2) die beste prestasie gelewer tydens spraakwaarneming in lawaai, in omstandighede waar spraak en lawaai ruimtelik geskei is en die lawaai op die eerste inplanting gerig is, asook in omstandighede waar spraak en lawaai ruimtelik saamvoorkomend aangebied is. 'n Statisties beduidende bilaterale voordeel (p < 0.05) is deur opeenvolgend-geïnplanteerde volwassenes vir klanklokalisering behaal. 'n Bilaterale voordeel vir spraakwaarneming in lawaai is waargeneem waar lawaai op die eerste inplanting gerig is en ook in diotiese luistertoestande, met 'n gemiddelde voordeel van 1.69 dB en 0.78 dB, onderskeidelik. Dit was egter nie statisties beduidend nie en was ook kleiner as die bilaterale voordeelwaardes wat in vorige studies deur gelyktydig-geïnplanteerde volwassenes behaal is. Die kopskadu-effek by 180° was die sterkste en mees robuuste bilaterale ruimtelike voordeel. Voordeelwaardes vir selektiewe onderdrukking en sommering het gewissel van negatiewe waardes tot 2 dB en 6 dB onderskeidelik. Dit stem ooreen met waardes wat in vorige studies gevind is. Die verbetering in spraakwaarneming in ruimtelik geskeide spraak en lawaai wat verkry is deur die oor met 'n beter STR (sein-tot-ruis ratio) by te voeg, het daarop gedui dat die bydrae van KI 2 tot bilaterale ruimtelike voordeel waarskynlik groter as die bydrae van KI 1 is. Die gevolgtrekking kan gemaak word dat volwassenes met opeenvolgende inplantings 'n mate van bilaterale voordeel verkry selfs na vele jare van unilaterale inplantingsgebruik, wanneer die spraakprosesseerders in die twee inplantings van mekaar verskil, wanneer die tweede inplanting ≥ 10 jaar na die eerste plaasvind, en in gevalle van prelinguale doofheid. 'n Sleutelvoordeel van opeenvolgende inplanting hou klaarblyklik verband met die voordeel van gehoor aan albei kante te hê sodat die oor met die gunstigste sein-tot-lawaai ratio altyd beskikbaar is. / Dissertation (MCommunication Pathology)--University of Pretoria, 2011. / Speech-Language Pathology and Audiology / Unrestricted

Text in Afrikaans / Uit 'n literatuurstudie en empiriese ondersoek wat onderneem is, blyk dit dat 15-40% van alle adolessente subkliniese depressie ervaar. Veranderinge en toenemende druk en eise eie aan die adolessente-fase, bring by baie adolessente depressiewe gevoelens mee. Ten spyte van hierdie omstandighede is daar egter ook baie adolessente wat hierdie fase van ontwikkeling sonder enige noemenswaardige probleme deurloop. Aaron Beck is van mening dat dit nie die omstandighede opsigself is wat tot depressie aanleiding gee nie, maar wel die betekenis wat individue aan omstandighede gee. Beck noem dat depressiewe persone tot irrasionele oortuigings, foutiewe inligting-prosessering en disfunksionele outomatiese gedagtes geneig is. Om hierdie probleem aan te spreek is ses adolessente, wat subkliniese depressie ervaar, aan Beck se kognitiewe terapie onderwerp. Die primere doel van Beck se terapie is die regstelling van bogenoemde disfunksionele kognisies. Die gevolgtrekking is dat wanneer adolessente wat subkliniese depressie ervaar, se disfunksionele kognisies reggestel word, hulle depressiewe gevoelens opgehef word. / From a literature study and empirical research which was undertaken, it seems that 15-40% of all adolescents experience subclinical depression. Changes and increasing pressure and demands, typical of the adolescent phase, causes many adolescents to experience depressing emotions. In spite of these circumstances there are also many adolescents who go through this phase in development without any significant problems. Aaron Beck is of opinion that it is not the circumstances in and of itself that lead to depression but rather the meaning that individuals attached to these circumstances. Beck mentions that depressive people are inclined to irrational beliefs, erroneous information-processing and dysfunctional automatic thoughts. To address this problem, six adolescents who experience subclinical depression, were subjected to Beck's cognitive therapy. The primary target of Beck's therapy is the correction of above mentioned dysfunctional cognitions. The conclusion is that when the dysfunctional cognitions of adolescents who experience subclinical depression can be corrected, their depressive feelings will diminish. / Educational Studies / M. Ed. (Voorligting)

Text in Afrikaans / Uit 'n literatuurstudie en empiriese ondersoek wat onderneem is, blyk dit dat 15-40% van alle adolessente subkliniese depressie ervaar. Veranderinge en toenemende druk en eise eie aan die adolessente-fase, bring by baie adolessente depressiewe gevoelens mee. Ten spyte van hierdie omstandighede is daar egter ook baie adolessente wat hierdie fase van ontwikkeling sonder enige noemenswaardige probleme deurloop. Aaron Beck is van mening dat dit nie die omstandighede opsigself is wat tot depressie aanleiding gee nie, maar wel die betekenis wat individue aan omstandighede gee. Beck noem dat depressiewe persone tot irrasionele oortuigings, foutiewe inligting-prosessering en disfunksionele outomatiese gedagtes geneig is. Om hierdie probleem aan te spreek is ses adolessente, wat subkliniese depressie ervaar, aan Beck se kognitiewe terapie onderwerp. Die primere doel van Beck se terapie is die regstelling van bogenoemde disfunksionele kognisies. Die gevolgtrekking is dat wanneer adolessente wat subkliniese depressie ervaar, se disfunksionele kognisies reggestel word, hulle depressiewe gevoelens opgehef word. / From a literature study and empirical research which was undertaken, it seems that 15-40% of all adolescents experience subclinical depression. Changes and increasing pressure and demands, typical of the adolescent phase, causes many adolescents to experience depressing emotions. In spite of these circumstances there are also many adolescents who go through this phase in development without any significant problems. Aaron Beck is of opinion that it is not the circumstances in and of itself that lead to depression but rather the meaning that individuals attached to these circumstances. Beck mentions that depressive people are inclined to irrational beliefs, erroneous information-processing and dysfunctional automatic thoughts. To address this problem, six adolescents who experience subclinical depression, were subjected to Beck's cognitive therapy. The primary target of Beck's therapy is the correction of above mentioned dysfunctional cognitions. The conclusion is that when the dysfunctional cognitions of adolescents who experience subclinical depression can be corrected, their depressive feelings will diminish. / Educational Studies / M. Ed. (Voorligting)