3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item The impact of alcohol on the different components of working memory(2018) Opperman, IAlcohol consumption related deficits on complex executive functions and short-term memory have been reported in the literature, usually based on group comparisons. A repeated measures design was used, assessing 21 to 35 year old male participants (n = 16) on the Automated Working Memory Assessment’s twelve verbal and visuo-spatial short-term and working memory subtests. A low dose of alcohol (13.6 grams) was administered, breath alcohol concentration (BAC) was measured and subjective feelings of stimulation were assessed on the Brief Biphasic Alcohol Effects Scale (B-BAES). Repeated measures analysis of (co)variance models indicated that performance improved on the working memory processing tasks, particularly in the verbal domain. This may have been related to changes in attention functions, stimulus evaluation task demands and tacit recall. However, several of the short-term memory tasks deteriorated under the experimental condition, where Word Recall was significant when age was controlled for. This may have been due to alcohol-related changes in stimulus representations. Partial correlation coefficients suggested that higher BACs were related to deficits in performance if participant age was controlled for. The structure of the B-BAES was consistent with the literature, but subjective feelings of stimulation were not associated with performance changes. Shorter test-retest delays were slightly associated with improved performance, but the research data did not fully support practice effects or a mitigating influence of alcohol consumption. Based on the findings, the specific influence of alcohol consumption on working memory could depend on methodological design, task types, memory domain and other sources of variance.Item The effect of temperature and headspace on the determination of ethanol in post-mortem blood specimens: A South African perspective(2019) Southon, BiancaThe Forensic Chemistry Laboratories in South Africa have, between the year 2014 and 2017, endured a lot of media scrutiny surrounding a backlog of specimens for blood alcohol and toxicology analyses and the poor environmental and storage conditions in which these specimens are kept. Many studies have been performed on the stability of alcohol in blood, since environments are not standard, to gain a better understanding on whether the backlog issues significantly impact on the integrity of the blood-alcohol concentration (BAC) results by evaluation of conditions, especially variables such as temperature and headspace. The aim of this study was therefore, to assess the stability of ethanol concentrations in post-mortem blood specimens by evaluating temperature (room and refrigerator) and headspace (4mL and 8mL) variables at 3 months and 6 months respectively. Blood from 119 decedents was collected, analysed and subjected to the varied volumes and storage conditions. Blood alcohol was determined and quantified using a G1888 Headspace Auto sampler (Agilent Technologies®) coupled to a 6890N Agilent® Gas Chromatography instrument utilising a Flame Ionization Detector on an Agilent HP-Innowax® column. A general decrease in alcohol concentration was observed over a storage period of 6 months regardless of the storage temperature, whilst headspace was found to have no significant effect on the BAC results. It is, therefore, important that Forensic Pathologists, investigators and scientists are aware of factors such as temperature and headspace and consider them when interpreting blood alcohol results from a post-mortem environment.Item The impact of adolescence initiated alcohol and cannabis abuse/ dependence on the level of activity participation in adult males suffering from a pyschotic disorder(2014) Wolhuter, Kristyn AshleighBackground: Individuals suffering from both a psychotic disorder and a substance abuse disorder have shown to have poorer occupational outcomes. This study aimed at determining the exact consequences of substance abuse on occupational performance in order to tailor more specific treatment interventions in the future. Methodology: A non-experimental design and observational study was used. This involved a once off occupational therapy assessment using the Activity Participation Outcome Measure (APOM) as the recoding tool. The participants were divided into three groups: Alcohol abuse, cannabis abuse and no substance abuse. Methodology: A non-experimental design and observational study was used. This involved a once off occupational therapy assessment using the Activity Participation Outcome Measure (APOM) as the recoding tool. The participants were divided into three groups: Alcohol abuse, cannabis abuse and no substance abuse. Results: A statistically significant difference was noted between the alcohol and cannabis groups. The alcohol group achieved a higher level of activity participation in all eight APOM domains (Role performance, life skills, communication, motivation, process skills, self esteem, balanced lifestyle, and affect). The no substance abuse group (individuals diagnosed with schizophrenia) showed the lowest level of activity participation. Conclusion: Cannabis adolescent abuse/dependence appears to have a more negative impact on activity participation when compared to alcohol abuse.