Le plongeur subit de nombreuses contraintes issues du milieu dans lequel il évolue. La narcose à l’azote par ses effets sur la performance cognitive en fait partie. Elle est impliquée dans de nombreux accidents de plongée sous-marine. Il est donc nécessaire de développer un outil fiable pour évaluer la performance cognitive sous l’eau de manière quantitative, reproductible et indépendante de la subjectivité du plongeur. Ensuite, après validation de cet outil (fréquence critique de fusion du scintillement - CFFF) préciser le rôle des facteurs modulateurs de la narcose en particulier celui de l’oxygène. Nos investigations sont réalisées chez des volontaires sains sélectionnés spécifiquement pour obtenir une population homogène (genre, âge, BMI, condition physique et expérience en plongée). L’analyse de la performance cérébrale est réalisée au moyen de tests psychométriques, d’échelles visuelles analogique et de la CFFF dans différentes conditions (normobarie, plongées simulées et réelles à 30 mètres de profondeur pendant 20 minutes) et avec différents gaz (air et Nitrox 40%). L’effet propre de l’oxygène est appréhendé par l’utilisation de la spectroscopie proche de l’infrarouge (NIRS).Nos mesures confirment d’une part la dégradation progressive de la performance cognitive tant par les tests psychométriques que par la CFFF avec un bon degré de corrélation (Pearson de 0,86 à 0,93) entre eux et d’autre part l’incapacité du plongeur à s’auto- évaluer. L’évolution de la performance cognitive est caractérisée par une amélioration lors de l’arrivée en profondeur d’autant plus marquée que la quantité d’oxygène dans le mélange respiré est importante, suivie par une dégradation qui persiste au moins jusqu’à 30 minutes après le retour en surface, surtout en respiration d’air. L’utilisation de l’imagerie fonctionnelle cérébrale (NIRS) permet d’associer l’amélioration des performances cognitives à une activation cérébrale dépendante de l’oxygène. L’oxygène semble donc être un élément important de la modulation des symptômes de la narcose à l’azote. De manière très cohérente avec la théorie neurochimique de la narcose nous suggérons que l’effet net sur la performance cérébrale dépend d’une balance entre les effets activateurs de l’oxygène et les effets inhibiteurs de l’azote. / During a dive subjects undergo many environmental stressors. Nitrogen narcosis through its effects on cognitive performance is one of them. Narcosis is indeed involved in many scuba diving accidents. It is therefore mandatory to develop a quantitative, reliable, reproducible tool to evaluate underwater diver’s cognitive performance. This tool should not be dependent on diver’s subjectivity. Once this tool (critical flicker fusion frequency - CFFF) is validated, we could then clarify the role of narcosis modulating factors in particular that of oxygen.Our investigations were performed in healthy volunteers specifically selected in a large group of recreational diver to obtain a standard population (gender, age, BMI, fitness and experience in diving). Cerebral performance analysis is carried out using psychometric tests, visual analogic scale and CFFF in different conditions (normobaria, simulated and open-water dives to a depth of 30 meters of fresh or salt water for 20 minutes) and with different gases (air and EANx 40%). The specific effect of oxygen is apprehended by use of near infrared spectroscopy (NIRS).On one hand, our measurements confirm the gradual deterioration of cognitive performance by both psychometric tests and CFFF, which share a good degree of correlation (Pearson from 0.86 to 0.93) and on the other hand diver’s inability to assess themselves.The evolution of cognitive performance is characterized by an improvement when arriving at depth followed by a progressive impairment that persists for at least 30 minutes after surfacing.The more oxygen in the breathing mixture, the better improvement in the early part of the dive and the less impairment in the following measurements are observed. Brain functional imaging (NIRS) allows us to pair the observed cognitive performance improvement with oxygen-dependent brain activation.It seems that Oxygen is an important modulator of the symptoms of nitrogen narcosis. In accordance with the neurochemical theory of narcosis we suggest that the net effect on cerebral performance depends on a balance between the activating effects of oxygen and the inhibitory effects of nitrogen.

Since the 1970s there has been a rising trend in South Africa for legal professionals to use the services of psychologists in legal proceedings. Psychologists have therefore increasingly started to appear as expert witnesses in court cases. Despite this, the field of forensic psychology in South Africa has yet to be defined and delineated. Currently there are no set guidelines or regulations regarding who is qualified to do forensic work, and no standards against which this work can be measured. Psychology in the courtroom has begun to receive a notorious reputation as a result of this. The Professional Board for Psychology (PBP) of the Health Professions Council of South Africa (HPCSA) is investigating the creation of a new category of registration, that of Forensic Psychologist, partly in an effort to manage and address this problem. However, to date little, if any, research has been conducted on the scope of the work presented to the courts by psychologists appearing as expert witnesses. This research aimed to address this gap by analysing a sample of forensic psychological reports. The following aspects were investigated: <ul><li>Who (category or registration, length of registration, etc.) is doing sentencing reports;</li> <li>How (interviews, collateral information, psychometric tests, etc.) these reports are compiled; and</li> <li>Whether these reports measure up to professional expectations as well as adhere to the guidelines of the HPCSA.</li></ul> It is clear from the results of this research that some of the psychologists doing forensic assessments and writing reports do so in an idiosyncratic way. Besides the fact that no uniformity exists, forensic work is sometimes done by psychologists who are not qualified to do so in terms of their registration category and thus their scope of practice. The reports analysed did not always measure up to guidelines or professional standards from abroad (in lieu of local standards or guidelines for reports) and/or transgressions were made in terms of HPCSA policies and guidelines. This situation is understandable in the light of two shortfalls in this field, namely training and regulation. The following recommendations can be made on the basis of this study: <ul><li>That psychologists who are adequately trained and have the proven experience in forensic work, be accredited by the PBP;</li> <li>That guidelines and standards for forensic work be drawn up by the PBP; in addition, that more complete ethical guidelines than those contained in chapter 7 of the PBP’s Rules of Conduct Pertaining Specifically to Psychology also be drawn up;</li> <li>That adequate training at MA level in basic forensic issues be made compulsory, with the option of advanced training for those wishing to specialise in the field; and</li> <li>That lawyers be trained in basic concepts of psychology so as to allow for better selection of an appropriate psychologist to assist them and also to assure effective cross-examination regarding psychological issues in court.</li></ul> If these recommendations were implemented, they could aid in regulating the field, thus producing forensic work of a consistently high quality. This will hopefully help to narrow the gap between the expected and actual interaction between law and psychology. Copyright / Dissertation (MA)--University of Pretoria, 2008. / Psychology / unrestricted

Background: Due to the deficit of knowledge on fine motor skill far transfer from one domain of expertise to another, piano performance and surgical training serve as a relevant, interdisciplinary context in which to study the transfer of motor skills given both have relatively well-established levels of performance and require complex fine motor skills. Musicians tend to demonstrate greater ease in all aspects of procedural knowledge which are known to contribute to the early stages of motor learning. Previous research in the Piano Pedagogy Research Laboratory (PPRL) found that extensive piano training was correlated with faster learning of surgical knot-tying skills. However, the short-term two-day timeline was a limitation of the study. Objective: Our project has built on previous work in the PPRL to address the short-term nature of previous studies by measuring a long-term performance curve as well as retention of surgical training and also expanded on the previous project by focussing this time on laparoscopic tasks. This study compared performance curves of two participant groups (pianists and controls) over five consecutive days and retention one week later, as measured by speed and accuracy of task completion. Laparoscopic training consisted of six tasks repeated at every session. Since laparoscopy involves a variety of abilities concurrently, we also administered a battery of ten psychometric tests to isolate and measure specific aspects of non-motor and fine motor skills. Results: There was no statistical difference between participant groups on the majority of laparoscopic training and psychomotor assessments based on two-way mixed ANOVA and Mann-Whitney U test analysis, respectively. There were also little to no significant correlations between abilities and laparoscopic performance. The only significant confounding variable was that the control group was significantly more interested in surgery than the musician group (p = .037). Conclusion: Overall, these results demonstrate that piano performance training did not far transfer to laparoscopic surgery. This is relevant to the debate on far transfer of motor skills given this study’s robust design which addressed previous shortcomings by including a longer timeline and more specifications of musicians’ characteristics. Our findings indicate that fine motor skills are domain specific to music and surgery, respectively.

Text in Afrikaans, abstract in Afrikaans and English / Wanneer psigometriese toetsing op groepe uit verskillende sosio-ekonomiese agtergronde toegepas word, presteer individue uit agtergeblewe omgewings swakker as bulle ewekniee uit meer ontwikkelde omgewings. Hierdie individue se toegang tot hoofstroom loopbaangeleenthede word dikwels bemoeilik as gevolg van die beperking. Die leerpotensiaal benadering word aangebied as belowende alternatief om die probleem, wat 'n sosio-ekonomiese oorsprong het, te oorbrug. Die resultate van die studie bewys die stelling gedeeltelik waar, maar met buitengewone inspanning. In die finale ontleding van die resultate is dit duidelik dat die verbeterde voorspelling eerder toegeskryf kan word aan die optimale vlak van ontwikkeling wat die individu bereik net voor die toetsing, en nie soseer sy/haar leerpotensiaal nie. / Applying psychometric tests to groups from different socio-economical backgrounds, inevitably result in the individuals from deprived backgrounds performing noteably poorer than their counterparts from more developed backgrounds. These individuals also find enterance to the mainstream careers difficult because of this restriction. The learning potential approach to assessment is presented as a promising alternative to overcome the problem that is related to the socio-economic background of the individual. The results of this study partly confirm the value of the learning potential approach, but only with extra-ordinary effort. In the final analysis of the results it is clear that the improved predictive accuracy was rather due to the optimal level of development the individuals reached just before the testing, and not so much their learning potential. / Psychology / M. Sc. (Sielkunde)

Psychology / M.A. (Psychology)

Text in Afrikaans, abstract in Afrikaans and English / Wanneer psigometriese toetsing op groepe uit verskillende sosio-ekonomiese agtergronde toegepas word, presteer individue uit agtergeblewe omgewings swakker as bulle ewekniee uit meer ontwikkelde omgewings. Hierdie individue se toegang tot hoofstroom loopbaangeleenthede word dikwels bemoeilik as gevolg van die beperking. Die leerpotensiaal benadering word aangebied as belowende alternatief om die probleem, wat 'n sosio-ekonomiese oorsprong het, te oorbrug. Die resultate van die studie bewys die stelling gedeeltelik waar, maar met buitengewone inspanning. In die finale ontleding van die resultate is dit duidelik dat die verbeterde voorspelling eerder toegeskryf kan word aan die optimale vlak van ontwikkeling wat die individu bereik net voor die toetsing, en nie soseer sy/haar leerpotensiaal nie. / Applying psychometric tests to groups from different socio-economical backgrounds, inevitably result in the individuals from deprived backgrounds performing noteably poorer than their counterparts from more developed backgrounds. These individuals also find enterance to the mainstream careers difficult because of this restriction. The learning potential approach to assessment is presented as a promising alternative to overcome the problem that is related to the socio-economic background of the individual. The results of this study partly confirm the value of the learning potential approach, but only with extra-ordinary effort. In the final analysis of the results it is clear that the improved predictive accuracy was rather due to the optimal level of development the individuals reached just before the testing, and not so much their learning potential. / Psychology / M. Sc. (Sielkunde)

Psychology / M.A. (Psychology)

Student selection is particularly challenging in South Africa. Heterogeneous educational backgrounds require that it is necessary to assess prospective students' potential rather than their current abilities that crystallised from inadequate school education. Dynamic assessment assesses learning potential versus traditional psychometric measures, which are static measures of cognitive ability, measuring what a person has already learned. The aim was to determine the predictive validity of a selection battery. The following predictors were included in the study; matric results, Potential Index Battery, LPCAT, bridging course status and gender. The results confirmed that static measures of intelligence and matric results showed lower predictive validity than learning potential tests. The learning potential measure appeared to be a more valid predictor of academic performance and is suitable to include in a selection battery. Gender and bridging course factors did not reflect significant differences in academic performance. There were indications that students perform better in successive years of study, once they have adjusted to tertiary education. / Industrial and Organisational Psychology / M. Comm. (Industrial and Organisational Psychology)

Summaries in Afrikaans and English / Text in Afrikaans / Die waarde van visueel-perseptuele skoling of terapie vir visueel-perseptueel gestremde leerlinge as 'n subgroep van leergestremdheid, is reeds vir dekades 'n omstrede aangeleentheid. Hierdie omstredenheid is ondersoek aan die hand van sewe internasionaal erkende psigometriese toetse. Die interne konsekwentheidskoeffisiente van hierdie toetse het vir die huidige studie van 0,62 tot 0,95 gestrek. 'n Faktorontleding van die toetsinterkorrelasies het 'n gemeenskaplike faktor blootgele. Ses toetse was primer visueel-perseptueel, en Goodenough <1926> se skaal is vir die bepaling van intelligensie gebruik. Bykomend hiertoe, is leerlinge se prestasies in hul eerste taal, wiskunde en skrif gebruik om die effek van terapie te bepaal. Proefpersone is as visueel-perseptueel gestremd gediagnoseer deur 'n opvoedkundige sielkundige en 'n visuele skolingsentrum in Pretoria, waar eksper imentele leerlinge terapie ontvang het. Hierdie diagnoses is deur die Test for Visual Analysis Skills wat beduidend tussen normale en visueelperseptueel gestremdes onderskei, bevestig. Die toets se geldigheid vir Suid-Afrikaanse omstandighede is in 'n voorstudie bepaal. Honderd en ses, ses- tot negejarige proefpersone (82 seuns en 24 dogters>, van normale intelligensie, gesigskerpte en gehoor, is betrek. Drie en vyftig het die eksperimentele groep gevorm wat onderverdeel is in 32 wat terapie voltooi het, en 21 wat nie het nie. Hierdie leerlinge is individueel afgepaar met kontroleleerlinge van dieselfde geslag, ouderdom, huistaal, sosio-ekonomiese status en skoolstanderd. Eksperimentele leerlinge het visuele terapie in n breer groepsverband vir een uur per week ontvang. Terapieperiodes het van 4 tot 15 maande gewissel. Die eksperimentele ontwerp was 'n voortoets-natoets-tweegroepontwerp. t-Toetse vir afhanklike (afgepaarde) groepe is uitgevoer op die verskille tussen voor- en natoetstellings, asook tussen die eksperimentele en kontrolegroepe. Geeneen van die primer visueel-oerseptuele meettegnieke het beduidende resultate opgelewer nie. Dit is aanduidend van die ondoeltreffendheid van visueel-perseptuele terapie om die tekorte waarop dit gemik is, reg te stel. Die waarde van visueel-perseptueie terapie is inteendeel beperk tot 'n oorhoofse verbetering in konseptualisering en intellektuele ryping by die groep wat terapie voltooi het. Skrif was die enigste vak wat by dieselfde groep beduidend verbeter het. Hierdie resultaat is egter twyfelagtig vanwee beoordelingstekorte. / The value of visual perceptual training or therapy, to visually perceptually impaired pupils as a subgroup of the learning disabled, has been a controversy far decades. This controversy was investigated by means of seven internationally recognised psychometric tests. The internal consistency coefficients of these tests for the present study ranged from 0,62 to 0,95. A factor analysis of test intercorrelations revealed a common factor. Six tests were primarily visual perceptual, whilst the Goodenough (1926) scale determined intelligence. Additionally, pupils' performance in their first language, mathematics and writing, was used to assess the therapeutic effect. Subjects were diagnosed as visually perceptually impaired by an educational psychologist and a visual training centre in Pretoria where experimental pupils received therapy. These diagnoses were confirmed by the Test for Visual Analysis Skills, which significantly differentiates between the normal and visually perceptually impaired. This test's validity for South African circumstances was determined in a prestudy. One hundred and six, six to nine year old subjects <82 boys and 24 girls>, of normal intelligence, visual acuity and hearing, were involved. Fifty three formed the experimental group which was subdivided in 32 who completed therapy, and 21 who did not. These pupils were individualiy matched with controls of similar sex, age, home language, socio economic status and school standard. Experimental pupils received visual therapy within a broader group context for one hour per week. Therapy periods fluctuated between 4 and 15 months. The experimental design was a pretest-posttest two group design. t-Tests for dependant <matched) groups were conducted on the differences between pre and oosttest scores, as well as between the experimental and control groups. None of the primarily visual perceptual tests revealed significant results. This signifies the inefficiency of visual perceptual therapy to rectify the deficits at which it is directed. The value of visual perceptual therapy is, on the contrary, restricted to an overall improvement in conceptualization and intellectual maturation within the group which completed therapy. Writing was the only subject which improved significantly within the same group. However, this result is dubious, due to evaluation deficits. / Psychology / D.Litt. et Phil. (Psychology)

Text in English / The literature review indicated similarities between education and chess playing and possible transfer of knowledge between these two different domains. A link was then suggested between some aspects of intellectual abilities and chess instruction in children, but not in adults (Frydman & Lynn, 1992; Waters, Doll & Mayr, 1987). In this research study the aim was to explore the relationship between chess playing and cognitive and intellectual development in Grade R learners at Garsieland. Therefore the positive influence that chess playing brings to bear on the intelligence of 64 Grade R learners (as measured on intelligence scales) was investigated. The data was collected through short biographical questionnaires and psychometric tests and the participants in both groups were assessed on two occasions. The study suggested that chess instruction exerted a positive (small) effect on Performance intelligence and subsequently on the Global scale of the Junior South African Intelligence Scales. The children in both groups also exhibited improved cognitive development after the 40 week period during 2009. / Psychology / M.A. (Psychology)