Thesis (M.A.)--University of Toronto, 2004. / Includes bibliographical references (leaves [33]-40).

Thèse (M.Ps.)--Université Laval, 2004. / Bibliogr.: f. 48-55. Publié aussi en version électronique.

The present study aimed at investigating the neuropsychological sequelae of transient ischaemic attacks. Transient ischaemic attacks are defined as those neurological disorders in which there is complete resolution of neurological symptoms within twenty·four hours. Transient ischaemic attacks may or may not reveal evidence of brain infarcts on imaging studies. In the present study, the neuropsychological sequelae of transient ischaemic attacks in the carotid circulation were investigated since, within the perspective of cognitive neuropsychology, it was assumed that localized changes in cognitive functions could be demonstrated.Since several psychological, medical and neurological factors are known to influence scores·on neuropsychological tests, regression analyses were performed to determine which factors contributed significantly to the variance of scores on neuropsychological tests in the transient ischaemic attack and control groups. Two transient ischaemic attack groups, each comprising forty left and forty right hemisphere involvement patients, were then compared with each other and with a control group of forty general medical patients. Stenosis of the carotid artery formed a significant predictor of test scores in the combined transient ischaemic attack group. When the groups were·analyzed independently, in the left transient ischaemic attack group stenosis predicted performance on the same tests reaching significance for the combined group, and for the Wisconsin Card Sorting Test (Perseverative Score). In the right transient ischaemic attack group, stenosis significantly predicted performance on Digits Forward, Backward and Total, the PASAT (2.4 seconds) and Trails B. On the other hand, education formed a significant predictor of performance on Digits Forward, Digits Backward and Digits Total and the PASAT (all levels) in the control group. Multivariate comparisons revealed that the left and right transient ischaemic attack groups performed worse than the controls on tests of attention, concentration and conceptual flexibi1ity. The left transient ischaemic attack group performed worse than the right transient ischaemic attack group on all tests of attention and concentration, but there was a significantly better performance of the former group on the Rey Auditory Verbal Learning Test (Trial 1), Block Designs and Verbal Fluency. The findings on the PASAT that left transient ischaemic attack patients performed significantly worse than the right hemisphere group ·were considered to be relatively unreported previously in the literature on transient ischaemic attacks. The findings obtained are discussed from a neurocognitive perspective of neuropsychological functioning in transient ischaemic attacks. / Psychology / Ph. D. (Psychology)

Modified administration techniques that relied on patient verbalization of reasoning on each item were devised. For the WCST, verbalized scores correlated highly with conventional scores. However, patterns of age, education, and IQ covariates for each scoring condition were very different, raising questions concerning what such verbalized scores measured. Further research based upon a prospective research design was suggested to address this question. Factor analysis of WCST scores for each scoring condition resulted in almost identical three-factor solutions in each case: (a) ineffective, perseverative responding; (b) nonperseverative number errors; and (c) Maintaining Set. A three-part hierarchy of response determinants for the CT was utilized, consisting of (a) concrete perceptual attributes; (b) cognitive organization of perceptual attributes into abstract patterns; and (c) relating abstract patterns to the corresponding number responses. Decision trees were devised to prescribe a set of rules for coding each score. Utilization of this approach yielded adequate test-retest reliability for recoding responses. Sets of variables for each subtest were factor analyzed, with second order factor analysis of all factors from each subtest in order to determine if common cognitive process scores on each subtest described cognitive process scores on other subtests. Results revealed similar factor solutions for each subtest, but subtest-specific factors were not predictive of similar factor scores on other subtests, except for Subtests V and VI, which are based upon the same principle. Factors related to Maintaining Set predicted most of the variance in subtest error scores. Factor scores related to Determinant Shifting were predictive of error scores to a much lesser degree than Maintaining Set factor scores. Determinant Shifting factor scores appeared to be independent of Maintaining Set factor scores, and also showed much more independence from age, education, and IQ covariates. The relationship between CT and WCST factor scores was slightly lower than the relationship between CT error scores and WCST summary scores. Suggestions for further research were discussed.

The present study evaluates the effects of incompatible verbal behavior when engaging in the Wisconsin Card Sorting Test (WCST). The WCST is a complex task that requires participants to match stimulus cards based on self-generated rules. After a varying number of trials, the rule changes and the participant will have to self-generate a new rule. Verbal behavior, specifically joint control, is likely involved in rule-following. Seven participants took part in this study. Participants engaged in the WCST either silently or while performing a putatively incompatible behavior, counting backward from 100 to 0. Results suggest joint control might be involved as when participants engaged in the incompatible behavior their performance was affected in terms of lower accuracy and longer reaction times compared to the silent baseline.

La présente recherche porte sur l'analyse de la performance d'individus atteints de schizophrénie au Wisconsin Card Sorting Test (WCST). Cet instrument évalue la flexibilité cognitive et la capacité d'abstraction. La méthodologie proposée repose sur une approche a caractère exploratoire. Une expérience comportant une condition expérimentale et une condition contrôle est rapportée ou chacun des participants effectue la tâche proposée. Mentionnons qu'un sous-groupe de participants parmi le groupe expérimental, sélectionné sur une base volontaire, à exécuté la tâche une seconde fois afin de mesurer l'effet d'apprentissage. Soixante personnes ont participé à l'expérience, à raison de trente par groupe. Les résultats obtenus appuient l'hypothèse qui stipule que certains individus atteints de schizophrénie réussissent significativement moins de catégories et commettent plus d'erreurs "persévératives" que les participants normaux. De plus, certains patients sont capables d'apprendre sous l'effet de certains renforcements. Ces données sont compatibles avec l'hypothèse d'une dysfonction frontale dans la schizophrénie. D'autres mesures additionnelles sont également discutées.

Objectif. De récentes études suggèrent que le fonctionnement exécutif, tel qu'évalué au moyen du Test de tri de cartes du Wisconsin (WCST), influence l'adaptation sociale des personnes schizophrènes, mais les résultats demeurent controversés à ce sujet. Cette recherche étudie la corrélation entre la performance à la version modifiée du WCST (Nelson, 1976) et l'autonomie fonctionnelle d'individus schizophrènes, et évalue en quoi la relation est indépendante d'autres facteurs neuropsychologiques. Méthode. 35 individus schizophrènes ont été évalués selon une batterie de tests incluant le WCST. Leur autonomie fonctionnelle a également été investiguée. Résultats. De fortes corrélations sont observées entre la performance au WCST et l'autonomie (r = 0,39 et r = 0,50, selon la dimension de l'autonomie étudiée). La relation serait partiellement indépendante des autres fonctions neuropsychologiques. Conclusion. Le fonctionnement exécutif, tel qu'évalué au moyen du WCST, pourrait constituer une cible thérapeutique spécifique puisqu'il s'avère relié en partie à l'autonomie.

Esta dissertação consiste em dois estudos que têm por objetivo investigar a existência de disfunções executivas no envelhecimento. Estudos recentes sugerem a existência de disfunções executivas no Declínio Cognitivo Leve (DCL). O objetivo do Estudo 1 foi verificar a presença de disfunções executivas em pacientes com DCL. Os instrumentos utilizados foram o Teste Wisconsin de Classificação de Cartas (WCST) e a Iowa Gambling Test (IGT). Foram estudados dez pacientes com e 27 sem DCL. Os dados foram analisados através do teste t de Student para amostras independentes e da análise de variância (ANOVA) para medidas repetidas. Os resultados não evidenciaram diferença significativa entre os grupos nos índices de resposta do WCST e no número de cartas retiradas de cada baralho no IGT. O estudo da evolução do desempenho no IGT revelou diferença qualitativa entre os grupos. Idosos sem DCL aprendem ao longo da tarefa, enquanto idosos com DCL não o fazem, sugerindo uma interferência dos sistemas de memória na tomada de decisão. O Iowa Gambling Test tem sido um instrumento utilizado na avaliação da tomada de decisão. O objetivo do Estudo 2 foi investigar se alterações nos procedimentos de aplicação do instrumento interferem no desempenho durante a execução do teste. Foi realizado um estudo transversal comparando dois grupos de idosos saudáveis em duas variações do instrumento. O grupo I contou com 27 participantes, que executaram a tarefa sem pista de reforço visual. O grupo II foi composto por 17 participantes, submetidos à tarefa com pista. Os dados foram analisados através dos testes t de Student para amostras independentes e ANOVA para medidas repetidas. Houve diferença estatisticamente significativa entre os dois grupos na execução do teste em relação à aversão ao risco (F=2,466; p=0,05; df=2). Os resultados indicam que uma pista de reforço visual possibilita maior alocação de recursos atencionais e de memória de trabalho, permitindo que os idosos tomem decisões menos arriscadas. / This dissertation is formed by two works that aim to investigate executive dysfunction on ageing. Recent studies suggest the existence of executive dysfunctions in Mild Cognitive Impairment (MCI). The aim of the first study was to verify the presence of executive dysfunctions in patients with MCI. The instruments used were the Wisconsin Card Sorting Test (WCST) and the Iowa Gambling Test (IGT). Ten patients with and 27 without MCI were assessed. The data were analyzed through Student t test for independent samples and analysis of variance (ANOVA) for repeated measures. The results did not show significant difference between groups in the answer rates of WCST and in the number of cards withdrawn from each pack of cards in the IGT. The study of the performance evolution in the IGT revealed a qualitative difference between the groups. Elderly without MCI learn along the task, while elderly with MCI did not, suggesting an interference of memory systems in decision making. The Iowa Gambling Test has been an instrument used in the assessment of decision making. The aim of the second study was to investigate if changes in the application procedures of the instrument interfere in the performance through the test execution. A cross sectional study was carried out comparing two groups of healthy elderly in two variations of the instrument. The group I included 27 participants, which executed the task without clue of visual reinforcement. The group II was composed by 17 participants, submitted to the task with clue. The data were analyzed through the Student t test for independent samples and ANOVA for repeated measures. It was found statistically significant difference between the two groups in the execution of the test in relation to risk aversion (F=2,466; p=0,05; df=2). The results indicate that a clue of visual reinforcement permits greater allocation of attention resources and of working memory, allowing elderly to make least risky decisions.

Esta dissertação consiste em dois estudos que têm por objetivo investigar a existência de disfunções executivas no envelhecimento. Estudos recentes sugerem a existência de disfunções executivas no Declínio Cognitivo Leve (DCL). O objetivo do Estudo 1 foi verificar a presença de disfunções executivas em pacientes com DCL. Os instrumentos utilizados foram o Teste Wisconsin de Classificação de Cartas (WCST) e a Iowa Gambling Test (IGT). Foram estudados dez pacientes com e 27 sem DCL. Os dados foram analisados através do teste t de Student para amostras independentes e da análise de variância (ANOVA) para medidas repetidas. Os resultados não evidenciaram diferença significativa entre os grupos nos índices de resposta do WCST e no número de cartas retiradas de cada baralho no IGT. O estudo da evolução do desempenho no IGT revelou diferença qualitativa entre os grupos. Idosos sem DCL aprendem ao longo da tarefa, enquanto idosos com DCL não o fazem, sugerindo uma interferência dos sistemas de memória na tomada de decisão. O Iowa Gambling Test tem sido um instrumento utilizado na avaliação da tomada de decisão. O objetivo do Estudo 2 foi investigar se alterações nos procedimentos de aplicação do instrumento interferem no desempenho durante a execução do teste. Foi realizado um estudo transversal comparando dois grupos de idosos saudáveis em duas variações do instrumento. O grupo I contou com 27 participantes, que executaram a tarefa sem pista de reforço visual. O grupo II foi composto por 17 participantes, submetidos à tarefa com pista. Os dados foram analisados através dos testes t de Student para amostras independentes e ANOVA para medidas repetidas. Houve diferença estatisticamente significativa entre os dois grupos na execução do teste em relação à aversão ao risco (F=2,466; p=0,05; df=2). Os resultados indicam que uma pista de reforço visual possibilita maior alocação de recursos atencionais e de memória de trabalho, permitindo que os idosos tomem decisões menos arriscadas. / This dissertation is formed by two works that aim to investigate executive dysfunction on ageing. Recent studies suggest the existence of executive dysfunctions in Mild Cognitive Impairment (MCI). The aim of the first study was to verify the presence of executive dysfunctions in patients with MCI. The instruments used were the Wisconsin Card Sorting Test (WCST) and the Iowa Gambling Test (IGT). Ten patients with and 27 without MCI were assessed. The data were analyzed through Student t test for independent samples and analysis of variance (ANOVA) for repeated measures. The results did not show significant difference between groups in the answer rates of WCST and in the number of cards withdrawn from each pack of cards in the IGT. The study of the performance evolution in the IGT revealed a qualitative difference between the groups. Elderly without MCI learn along the task, while elderly with MCI did not, suggesting an interference of memory systems in decision making. The Iowa Gambling Test has been an instrument used in the assessment of decision making. The aim of the second study was to investigate if changes in the application procedures of the instrument interfere in the performance through the test execution. A cross sectional study was carried out comparing two groups of healthy elderly in two variations of the instrument. The group I included 27 participants, which executed the task without clue of visual reinforcement. The group II was composed by 17 participants, submitted to the task with clue. The data were analyzed through the Student t test for independent samples and ANOVA for repeated measures. It was found statistically significant difference between the two groups in the execution of the test in relation to risk aversion (F=2,466; p=0,05; df=2). The results indicate that a clue of visual reinforcement permits greater allocation of attention resources and of working memory, allowing elderly to make least risky decisions.

Esta dissertação consiste em dois estudos que têm por objetivo investigar a existência de disfunções executivas no envelhecimento. Estudos recentes sugerem a existência de disfunções executivas no Declínio Cognitivo Leve (DCL). O objetivo do Estudo 1 foi verificar a presença de disfunções executivas em pacientes com DCL. Os instrumentos utilizados foram o Teste Wisconsin de Classificação de Cartas (WCST) e a Iowa Gambling Test (IGT). Foram estudados dez pacientes com e 27 sem DCL. Os dados foram analisados através do teste t de Student para amostras independentes e da análise de variância (ANOVA) para medidas repetidas. Os resultados não evidenciaram diferença significativa entre os grupos nos índices de resposta do WCST e no número de cartas retiradas de cada baralho no IGT. O estudo da evolução do desempenho no IGT revelou diferença qualitativa entre os grupos. Idosos sem DCL aprendem ao longo da tarefa, enquanto idosos com DCL não o fazem, sugerindo uma interferência dos sistemas de memória na tomada de decisão. O Iowa Gambling Test tem sido um instrumento utilizado na avaliação da tomada de decisão. O objetivo do Estudo 2 foi investigar se alterações nos procedimentos de aplicação do instrumento interferem no desempenho durante a execução do teste. Foi realizado um estudo transversal comparando dois grupos de idosos saudáveis em duas variações do instrumento. O grupo I contou com 27 participantes, que executaram a tarefa sem pista de reforço visual. O grupo II foi composto por 17 participantes, submetidos à tarefa com pista. Os dados foram analisados através dos testes t de Student para amostras independentes e ANOVA para medidas repetidas. Houve diferença estatisticamente significativa entre os dois grupos na execução do teste em relação à aversão ao risco (F=2,466; p=0,05; df=2). Os resultados indicam que uma pista de reforço visual possibilita maior alocação de recursos atencionais e de memória de trabalho, permitindo que os idosos tomem decisões menos arriscadas. / This dissertation is formed by two works that aim to investigate executive dysfunction on ageing. Recent studies suggest the existence of executive dysfunctions in Mild Cognitive Impairment (MCI). The aim of the first study was to verify the presence of executive dysfunctions in patients with MCI. The instruments used were the Wisconsin Card Sorting Test (WCST) and the Iowa Gambling Test (IGT). Ten patients with and 27 without MCI were assessed. The data were analyzed through Student t test for independent samples and analysis of variance (ANOVA) for repeated measures. The results did not show significant difference between groups in the answer rates of WCST and in the number of cards withdrawn from each pack of cards in the IGT. The study of the performance evolution in the IGT revealed a qualitative difference between the groups. Elderly without MCI learn along the task, while elderly with MCI did not, suggesting an interference of memory systems in decision making. The Iowa Gambling Test has been an instrument used in the assessment of decision making. The aim of the second study was to investigate if changes in the application procedures of the instrument interfere in the performance through the test execution. A cross sectional study was carried out comparing two groups of healthy elderly in two variations of the instrument. The group I included 27 participants, which executed the task without clue of visual reinforcement. The group II was composed by 17 participants, submitted to the task with clue. The data were analyzed through the Student t test for independent samples and ANOVA for repeated measures. It was found statistically significant difference between the two groups in the execution of the test in relation to risk aversion (F=2,466; p=0,05; df=2). The results indicate that a clue of visual reinforcement permits greater allocation of attention resources and of working memory, allowing elderly to make least risky decisions.