The present study examined the possibility that reading books might support declarative memory, and potentially contribute to the cognitive reserve and thereby minimize age-related decline in memory functions. It was a crosssectional study, where data were taken from 566 Betula Study participants, as well as the scores of declarative memory assessment tasks, and book reading reports. The tasks of episodic memory were sentence learning with and without encoding enactment –free and cued recall. The tasks of semantic memory were word fluency, initial letter A, M fivewords, B profession names, and SRB –vocabulary. Three-way analysis of variance was performed for hypothesis testing. The results showed that book reading might support declarative memory. There was a significant relationship between education and book reading. Was not found if book reading might minimize age-related decline. In conclusion, the study showed that book reading and years of education might support declarative memory. / Denna studie undersökte om läsandet av böcker stödjer deklarativt minne, och eventuellt främjar den kognitivareserven, vilket medför en minimerad åldersbaserad reduktion i minnesfunktioner. I denna tvärsnittsstudie ingick datafrån 566 deltagare i Betulaprojektet som testats med avseende på deklarativa minnesfunktioner, samt enlitteraturanalys. Utvärderingarna som baserades på episodiskt minne var; menings-inlärning med och utan 'encodingenactment' -både fri och stödd återgivning. Test av semantiskt minne var ordflöde med första bokstav A, M fem-ord,B yrkesnamn, och SRB-ordförråd. Tre-vägs variansanalyer genomfördes för hypotestestning. Resultaten visade på enkoppling mellan utbildning och läsandet av böcker. Det är dock fortfarande oklart om läsandet av böcker minimeraråldersbaserad minnes-reducering. Sammanfattningsvis, visade studien att läsning och utbildning kan stödja deklarativtminne.

People with a diagnosis of schizophrenia have been found to perform poorly on tasks assessing semantic memory, and these impairments have been proposed to be related to certain symptoms, in particular Formal Thought Disorder (FTD). A systematic literature review and meta-analysis identified the need a) to determine whether semantic memory is a primary impairment in schizophrenia and not secondary to other cognitive impairments and b) what cognitive models could provide the best explanation for the impairment. With these aims, Studies One and Two compared the performance of a group of people with schizophrenia across a battery of semantic memory tests (Hodges, Salmon and Butters, 1992). In order to eliminate confounding variables, two clinical control groups were recruited for comparison, one with a probable degraded semantic memory arising from Alzheimer‘s Dementia (AD) and the other with a primary dysexecutive syndrome caused by acquired brain injury (ABI). From these comparisons, it was possible to profile the semantic memory impairment in schizophrenia with the conclusion that any deficits are task-specific. Unlike the AD group, the impairment did not seem to arise from a loss of stored knowledge but nor did a retrieval problem, in its simplest terms, offer the best explanation. Since the ABI group performed normally on the battery it is clear that a dysexecutive syndrome does not necessarily explain poor semantic memory performance. Qualitatively, the associations and categories formed by people with schizophrenia on tasks of semantic categorisation e.g. the Category Generation Test (CGT) (Green, Done, Anthony, McKenna and Ochocki, 2004) often resemble loosening of associations and psychotic speech. In order to understand more about the processes involved in the formation of these bizarre categories, I compared performance on the CGT of groups of people with schizophrenia, AD and ABI. I found that the people with AD performed fairly similarly to the people with schizophrenia in that they sorted cards in an idiosyncratic way but the ABI group performed normally, adhering to taxonomic categories. Although this result might suggest that the bizarre associations on the CGT in people with schizophrenia are caused by a deficit in semantic memory (and not a dysexecutive syndrome), further analysis found important differences between the AD and the schizophrenia group in the way the card sorts were formed. In addition, both these groups showed intact semantic memory knowledge of the items they mis-sorted, indicating that categorisation problems do not necessarily arise from a degraded memory store. The difficulties people with schizophrenia appear to have on tests of associations and categorisation (e.g. CGT) could arise from a disorganised semantic memory i.e. differences in the way in which concepts are interconnected. On the CGT, patients with schizophrenia were far more likely to sort items on the basis of thematic (situational) information suggesting a preference for thematic over taxonomic associations. To test this, participants were tested using a triadic comparison task which requires choosing whether an item is best associated with a taxonomic, thematic or perceptually related item. On this test patients performed comparably to controls suggesting that their semantic memory is organised normally and that the abnormalities in the way in which items are associated on some semantic memory tests, including the CGT, are task-specific. It has been proposed that one of the core problems in schizophrenia is that there is ―an aberrant assignment of salience‖ (Kapur 2003) to contextually inappropriate concepts due to a dysregulated dopamine system (Kapur 2003; Kapur et al 2005). It is possible that this could also explain the semantic memory impairments in schizophrenia i.e. certain less relevant concepts/ associations are chosen because they are experienced as more salient. To test this, a group of patients with schizophrenia were assessed using a test of semantic salience. Compared to controls, the patients made significantly more errors of salience including significantly more errors where large aberrant attributions of importance were given to items. The tendency to make errors on the salience test was highly correlated with errors on the CGT and also the semantic association tests, indicating a common underlying mechanism. Therefore, it can be concluded that the semantic memory impairments in schizophrenia are task-specific, not caused by a loss of semantic knowledge or a dysexecutive syndrome, but due to an aberrant assignment of salience to less relevant semantic concepts. More work is needed to understand the cognitive processes underlying this aberrant attribution process, and also the biological substrates involved.

L'une des capacités humaines fondamentales est la capacité d'interpréter des symboles. Malgré plusieurs décennies de travaux en neuropsychologique et neuroimagerie sur le substrat cognitif et neuronal des représentations sémantiques, de nombreuses questions restent sans réponse. Les présents travaux de thèse tentent de démêler l'un de ces mystères: les substrats neuronaux des différentes composantes du mot sont-ils dissociables? Ce travail comporte deux composantes principales : l'une théorique et l'autre empirique. Dans la première partie, nous passons en revue les différentes positions théoriques concernant les corrélats cognitifs et neuraux des représentations sémantiques. De plus, nous proposons une distinction opérationnelle entre les dimensions moto-perceptives (c'est-à-dire les attributs des objets auxquels les mots se réfèrent perçus par les sens) et conceptuelles (c'est-à-dire l'information construite par l'intégration des multiples caractéristiques perceptives). Dans la deuxième partie, nous présentons les résultats des études menées afin d'étudier l'automaticité de la récupération, l'organisation topographique et la dynamique temporelle des dimensions moto-perceptives et conceptuelles de la signification des mots. Tout en contribuant à notre compréhension de la manière dont le sens des mots est codé dans le cerveau, les travaux présentés dans cette thèse ont des implications méthodologiques et théoriques importantes. En particulier, ils soulignent l'importance d'une intégration fructueuse entre les théories cognitives et les méthodes statistiques avancées afin d'éclairer les mystères entourant les représentations sémantiques. / One of the core human abilities is that of interpreting symbols. Notwithstanding decades of neuropsychological and neuroimaging work on the cognitive and neural substrate of semantic representations, many questions are left unanswered. The research in this dissertation attempts to unravel one of them: are the neural substrates of different components of concrete word meaning dissociated? In the first part, I review the different theoretical positions and empirical findings on the cognitive and neural correlates of semantic representations. Crucially, I propose an operational distinction between motor-perceptual dimensions (i.e., those attributes of the objects referred to by the words that are perceived through the senses) and conceptual ones (i.e., the information that is built via a complex integration of multiple perceptual features). In the second part, I present the results of the studies I conducted in order to investigate the automaticity of retrieval, topographical organization, and temporal dynamics of motor-perceptual and conceptual dimensions of word meaning. The results suggest that the neural substrates of different components of symbol meaning can be dissociated in terms of localization and of the feature of the signal encoding them, while sharing a similar temporal evolution.

Die Arbeit untersucht die Annahme einer unterschiedlichen Gewichtung von distinktiven enzyklopädischen, funktionalen und sensorischen Merkmalen innerhalb der Repräsentationen von Objekten der belebten und unbelebten semantischen Domäne. Hierzu wurde ein Reaktionszeitexperiment zur Merkmalsverifikation durchgeführt. Vorab wurden deutsche Normen über das geschätzte Erwerbsalter für 244 Stimuli aus dem Korpus von Snodgrass & Vanderwart (1980) erhoben. Weiterhin wurde eine Datenbank von Merkmalsnormen für 80 konkrete Objektbegriffe erstellt. Insgesamt wurden zwei Reaktionszeitexperimente durchgeführt, die sich lediglich durch die Darbietungsdauer des Konzeptbegriffes unterschieden. Der Konzeptbegriff wurde entweder 1000 ms (lange Darbietung) oder 250 ms (kurze Darbietung) präsentiert, bevor das zu verifizierende semantische Merkmal erschien. Bei langer Präsentationszeit des Objektbegriffes zeigten sich für Objekte der unbelebten Domäne schnellere Reaktionszeiten beim Verifizieren von distinktiven funktionalen Merkmalen als beim Verifizieren von distinktiven enzyklopädischen Merkmalen. Dieser Effekt wurde bei kurzer Darbietungsdauer des Konzeptbegriffes repliziert. Bei kurzer Darbietung konnten für Objekte der unbelebten Domäne zusätzlich kürzere Reaktionszeiten beim Verifizieren distinktiver funktionaler Merkmale als beim Verifizieren distinktiver sensorischer Merkmale beobachtet werden. Für Objekte der belebten Domäne lagen weder nach kurzer noch nach langer Präsentation des Objektbegriffes Unterschiede in den Reaktionszeiten beim Verifizieren der semantischen Merkmale vor. Die Ergebnisse werden vor dem Hintergrund aktueller neurolinguistischer Modelle zur Organisation des semantischen Gedächtnisses diskutiert. Die Ergebnisse deuten darauf hin, dass innerhalb der Objektrepräsentationen belebter Objekte alle drei Merkmalstypen interkorrelieren. Für Objekte der unbelebten Domäne werden starke Interkorrelationen zwischen funktionalen und sensorischen Merkmalen angenommen. Zusätzlich wird davon ausgegangen, dass distinktive funktionale Merkmale innerhalb der Repräsentationen unbelebter Objekte besonders stark gewichtet sind. / The study investigates the assumption of a differential weighting of distinctive encyclopaedic, functional and sensory semantic attributes within the concept representations of living and nonliving objects. A speeded feature verification task was conducted. In order to control the stimuli for various aspects, German norms were collected of estimated age of acquistion for 244 stimuli of the Snodgrass and Vanderwart (1980) pictures. In addition, a feature listing study was carried out for 80 concrete living and nonliving concepts. Two reaction time experiments were conducted with different duration times of the presented object name. In Experiment 1 (long duration time), the object name was presented for 1000 ms, whereas in Experiment 2 (short duration time), the object name was presented for 250 ms before the semantic feature appeared. With long duration time, distinctive functional features of nonliving objects were verified faster than distinctive encyclopaedic features. This effect was replicated in Experiment 2 after short presentation of the object names. In addition, in Experiment 2, shorter reaction times were observed for functional features than for sensory features of nonliving objects. For living objects, no differences were observed in verifying the different feature types neither in Experiment 1 nor in Experiment 2. The results are discussed within the framework of different models of semantic memory. The results suggest that within the category of living objects, distinctive encyclopaedic, functional and sensory features are highly intercorrelated. For nonliving objects, it is assumed that distinctive sensory and functional but not encyclopaedic features are highly intercorrelated. In addition, distinctive functional features of nonliving objects seem to be weighted more strongly than distinctive sensory features within the object representations of nonliving objects.

The general aim of the thesis was to investigate potential differences in memory performance between participants across the adult life span with and without self-reported musculoskeletal pain. Chronic musculoskeletal pain is a major health related problem in our society. A common complaint related to chronic pain is about cognitive difficulties in attention, memory, and decision making. A number of studies have demonstrated that people with pain also perform wors on tasks measuring, for example episodic memory, semantic memory, and working memory. The present thesis aimed at replying these findings, by using a non-clinical population based sample. the potential differences in memory performance between people with and without pain were examined across the adult life span, in order to disentangle potential pain by age interactions. This was made by using both cross-sectional and longitudinal data. Study I aimed at studying differences in episodic memory performance, semantic memory performance, and implicit memory performance, between people with and without musculoskeletal pain. Differences were found for all three memory systems, but disappeared after controlling for years of formal education. In Study II an extension of the first study was made, in which performance on a range of cognitive tests were analysed. General differences were demonstrated , but yet again, years of education together with depression ruled out the effects. The most robust effects were found for word comprehension and construction ability. Finally, Study III used 5- and 10 year follow up studies to examine change over time in cognitive performance as a function of pain. The main finding from this study was that semantic memory for the oldest is impaired over time as a function of pain. An additional analysis showed similar patterns, regardless of age, for construction ability.

Memory impairments are common in individuals with temporal lobe epilepsy (TLE). This is understandable given that temporal lobe brain structures involved in TLE play a central role in encoding memories. It is widely accepted that individuals whose seizure focus is in the left temporal lobe (LTLE) tend to have verbal memory impairments, whereas individuals whose seizure focus is in the right temporal lobe (RTLE) tend to have visuospatial memory impairments. However, evidence of functional subdivisions within the left and right temporal lobes in both the animal and human literature suggest that more specific subtypes of memory impairment may exist in TLE based on differences in seizure foci. The aim of this study was to identify more specific subtypes of memory-impairments in patients with intractable TLE using several measures of memory functioning and cluster analysis. Identification of more specific memory subtypes in TLE could have prognostic significance for patients and contribute to our knowledge about the organization of memory systems of the human brain. Four memory subtypes were identified in this sample: 1) patients with mild to moderate figural memory deficits; 2) patients with moderate to severe figural memory deficits, mild facial recognition deficits, and mild attention/concentration deficits; 3) patients with severe figural memory deficits and mild verbal episodic memory deficits; and 4) patients with no episodic or semantic memory deficits. Unexpectedly, the subtypes found did not exhibit the expected pattern of verbal memory impairments with left temporal lobe damage/dysfunction or visuospatial memory impairments with right temporal lobe damage/dysfunction. However, consistent with the literature, there was a trend towards some clusters with better verbal memory having higher left hippocampal volumes; and a trend towards one cluster with facial recognition deficits having lower anterior temporal lobe volumes. Small sample sizes in this study limited the ability to clearly validate many of the cluster differences, particularly differences in brain volumes. Nevertheless, the results of this study support the hypothesis that subtypes of memory impairment do exist in patients with TLE. With larger sample sizes, it is plausible that additional subtypes may be found, or the characteristics of the subtypes found may become clearer.

Orientadora: Profa. Dra. Maria Teresa Carthery-Goulart / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2016. / Introdução: Na prática neuropsicológica há pouco material investigativo disponível para analisar o processamento semântico de verbos. Um dos poucos testes utilizados nesta análise é o Kissing and Dancing - KDT (Bak & Hodges, 2003), que apenas avalia associações semânticas. Apesar de haver valores de referência do KDT no Brasil, três limitações motivaram a construção de uma nova versão ampliada: 1) necessidade de adequação a fatores socioculturais; 2) alta probabilidade de acerto ao acaso e 3) tendência a efeito teto, quando excluídos itens socioculturalmente inadequados. O presente trabalho, portanto, desenvolveu, por meio da adaptação do KDT e da criação de tarefas adicionais, uma bateria de testes que objetiva investigar estes aspectos. Neste trabalho, os testes criados foram utilizados em população de idosos cognitivamente saudáveis e, a partir dos resultados obtidos, futuras análises poderão auxiliar na melhor compreensão de algumas divergências teóricas sobre o processamento semântico lexical de verbos, inclusive em situações patológicas, bem como na identificação de perfis específicos que podem auxiliar no diagnóstico clínico de algumas dessas situações. Objetivos: desenvolver, baseando-se no KDT, um instrumento abrangente para avaliação do processamento semântico de verbos, criando testes complementares, que avaliem, além da associação semântica, a compreensão e a nomeação de ações, a fim de: investigar o funcionamento da memória semântica de verbos em idosos cognitivamente saudáveis e a relação entre a acurácia - registrada em cada um dos testes na bateria ¿ o funcionamento cognitivo global e as variáveis sociodemográficas Metodologia: A adequação do KDT previu a criação de um único instrumento balanceado em relação à complexidade pictórica, adequabilidade/padronização de nomeação, familiaridade, imageabilidade e categorização verbal (verbos de mão e corpo, com e sem instrumentos; verbos abstratos; ambientais e feitos por animais). Estes mesmos itens foram também utilizados na criação de outros dois subtestes ¿ tarefa de nomeação e compreensão auditiva. Na adaptação do teste de associação semântica, para evitar o citado efeito teto e possibilitar análises dos tipos de erros, foram ampliadas as alternativas associadas ao alvo ¿ de duas para quatro ¿ e criados distratores específicos. A consistência interna dos testes também foi avaliada e para a tarefa de associação e nomeação foi criada uma versão abreviada da bateria. Para a amostra estudada, investigou-se a relação entre o desempenho nos três subtestes e variáveis sociodemográficas (idade, escolaridade e nível socioeconômico) e o funcionamento cognitivo global (MEEM e ACE-R). Após a identificação das variáveis correlacionadas significativamente com a acurácia, um modelo de regressão foi gerado a fim de apontar qual das variáveis melhor predizem o desempenho nos testes. Para aferição de adequabilidade da bateria, os parâmetros propostos foram avaliados previamente em 20 jovens de alta escolaridade (padrão-ouro), a fim de eliminar estímulos inadequados. Após adequação, a segunda versão foi também aplicada a outros 20 universitários em estudo piloto, a fim de atestar sua adequabilidade. Finalmente, o instrumento adaptado foi aplicado em população de idosos cognitivamente saudáveis, propondose, em relação ao teste original, tarefas adicionais de compreensão auditiva e nomeação, avaliando-se a influência de escolaridade, nível socioeconômico, idade e funcionamento cognitivo global sobre o desempenho nas tarefas. Recrutaram-se 92 indivíduos idosos e 65 preencheram os critérios de inclusão/exclusão do estudo. Todos foram avaliados individualmente no Laboratório de Cognição Humana da UFABC. No teste de associação, os estímulos foram apresentados usando-se o programa e-prime (2.0) para registrar tanto a acurácia quanto o tempo de resposta. Nas provas de compreensão e nomeação, os estímulos foram apresentados em slides e analisou-se acurácia. Resultados: Entre os 65 avaliados (46 mulheres), 66% pertencem ao nível socioeconômico "B" e têm idade e escolaridade média de 67,7 e 10,8 anos, respectivamente. Nos resultados da tarefa de associação semântica, verificou-se acurácia média de 82% (42/51 pranchas), correlação significativa com escolaridade (R=0,463, p<0,001), nível socioeconômico (R=0,524, p<0,001), desempenho no MEEM (R=0,521, p<0,001) e desempenho no ACE-R total (R=0,508, p<0,001) e correlação negativa com idade (R=-0,400, p=0,001). Ao incluir todas estas variáveis em um modelo de regressão linear, apenas a variável idade se mostrou significante (p=0,038). Nos resultados do teste de nomeação, a média de acertos é de 90% (58/64 pranchas) e há correlação significativa apenas entre a acurácia e a classe socioeconômica (R=0,34, p=0,02), sendo não significativa para idade (R=-0,135 e p=0,39), escolaridade (R=0,13 e p=0,40), desempenho no MEEM (R=0,10 e p=0,52) ou no ACE-R (R=0,03 e p= 0,80). Neste teste, apenas 3 das 64 fichas apresentaram índice de respostas não-padrão maiores do que 20%, sendo motivados predominantemente por aspectos semânticos. No teste de compreensão, a média de acertos é de 98% (13,75/14 pranchas) e a acurácia não se correlaciona à idade (R=-0,16 e p= 0,30), à escolaridade (R=0,13 e p=0,41), ao nível socioeconômico (R=-148, p=0,499), ao ACE-R (R=0,22 e p=0,15), nem ao MEEM (R=0,06 e p=0,69). 4 das 14 fichas apresentaram erros acima de 10%, sendo motivados, também, por aspectos semânticos. Conclusão: Diante das análises, o novo instrumento apresenta-se como estratégia eficiente para avaliação do funcionamento de memória semântica de verbos no envelhecimento saudável. A idade é a variável que contribui para explicar o desempenho no teste de associação semântica, contrariamente aos pressupostos de que este tipo de memória não sofre alterações no processo de envelhecimento, todavia, a amostra precisa ser ampliada com maior número de indivíduos mais velhos e com mais baixa escolaridade e classe socioeconômica a fim de: verificar se os resultados obtidos para esta amostra não sofrerão alterações e permitir que etapas adicionais referentes ao processo típico de estandartização de baterias neuropsicológicas possam ser cumpridas. / Introduction: In neuropsychology, there is little investigative material available to analyze the processing verbs. One of the few tests used in this analysis is the Kissing and Dancing - KDT (Bak & Hodges, 2003), which only evaluates semantic associations. Although there are KDT reference values in Brazil, three limitations led to the construction of a new enhanced version: 1) adequacy need to sociocultural factors; 2) high probability of success at random and 3) tend to ceiling effect when inappropriate socio-cultural items are excluded. This paper, therefore, developed through a KDT adaptation and the creation of additional tasks, a battery of tests that aims to investigate the performance of healthy elderly individuals in various tasks involving semantic processing verbs. Analyzes from the results can improve the understanding of some theoretical differences over the lexical semantic processing of verbs, including pathological conditions. Objectives: to develop a new set of tests based on the KDT and suitable for the Brazilian context in order to investigate the functioning of semantic memory verbs in healthy elderly individuals. Methodology: The adequacy was accomplished by creating a single balanced instrument in relation to the pictorial complexity, suitability/standardized naming, familiarity, imageability and verbal categorization (hand and body verbs, with and without instruments; abstract verbs, environmental and made by animals) and capable to be configured as a battery test that analyze, in a correlational study and multivariate regression, the results obtained in order to compare them to the theoretical postulates that it was intended to investigate. In the adaptation of semantic association test, in order to avoid the aforementioned ceiling effect and enable analysis of the types of errors, it was enhanced the alternatives associated with the target - from two to four - and created specific distractors. For battery suitability assessment, the proposed parameters were previously evaluated in 20 young people with higher education (gold standard) in order to eliminate improper stimuli. After adjustment, the new version has also been applied to other 20 university students in a pilot study in order to prove its suitability. Finally, the adapted instrument was applied in population of healthy elderly individuals, proposing additional tasks from the original test: listening and naming to evaluating the influence of education, socioeconomic status and age on task performance. It was recruited 92 elderly and 65 met the criteria for inclusion/exclusion of the study. All are individually evaluated in Human Cognition Laboratory at UFABC. In association test, the stimuli were presented using the program e-prime (2.0) to register both the accuracy and the response time. The number of items raised in a minute was the measure analyzed in verbal fluency task. Results: Among the 65 evaluated (46 women), 66% belonging to the socioeconomic level "B" and have age and average education of 67.7 and 10.8 years respectively. The results of semantic association task, equivalent to the original KDT, there was an average accuracy of 82% (42/51 boards), significantly correlated with education (R = 0.463, p <0.001), socioeconomic status (R = 0.524, p <0.001), MMSE scores (R = 0.521, p <0.001) and the total performance ACE-R (R = 0.508, p <0.001) and negatively correlated with age (r = -0.400, p = 0.001). The linear regression model indicates that the result in accuracy can be mainly explained by age (p = 0.038). In the results of the naming test, the average score is 90% (58/64 boards) and there is only significant correlation between accuracy and socioeconomic status (R = 0.34, p = 0.02), with no significant correlation for age (R = -0.135, p = 0.39), educational level (R = 0.13 and p = 0.40), performance on the MSME (R = 0.10 and p = 0.52) nor on the ACE-R (R = 0.03 and p = 0.80). In this test, only 3 out of 64 boards had higher error rate than 20%, being predominantly motivated by semantic aspects. In the comprehension test, the mean score is 98% (13.75 / 14 boards) and accuracy is not correlated to age (R = -0.16, p = 0.30), educational level (R = 0, 13 and p = 0.41), the ACE-R (R = 0.22 and p = 0.15), nor the MSME (R = 0.06 and p = 0.69). 4 out of the 14 board had errors over 10% being also driven by semantic aspects. Conclusion: based on the analysis, the new instrument presents as an efficient approach to evaluate the semantic verbs memory in healthy aging. Age is the variable that helps to explain the performance in semantic association test, in contrast to assumptions that semantic memory does not change during the aging process. However, the sample needs to be expanded and better paired with sociodemographic variations in order that the results obtained here are verified and that additional steps for typical standardization process for neuropsychological batteries can be fulfilled.

Semantic memory is part of the long-term memory system, and there are several theories concerning this type of memory. Some of these will be described in this essay. There are also several types of neuropsychological semantic memory deficits. For example, test results have shown that patients tend to have more difficulties naming living than nonliving things, and one probable explanation is that living things are more dependent on sensory than on functional features. Description of concrete concepts is a new test of semantic memory, in which cueing is used, both to capture the maximum performance of patients, and to give insight into the access versus storage problem. The theoretical ideas and empirical results relating to this new test will be described in detail. Furthermore, other tests of semantic memory that have been commonly used will also be briefly described. In conclusion semantic memory is a complex cognitive system that needs to be studied further.

Episodic memory enables us to remember and recall life events from the past. Episodic memory is a specific type of long-term declarative memory, which undergoes changes in ontogeny. To examinate of episodic memory, "episodic-like memory model", was developed. This model focuses on three basic components of episodic memory: "What happened", "Where did it happen" and "When did it happen". The aim of this diploma thesis is to develop and to validate of particular tests of episodic memory with consideration for their feasibility for preschool children. In order to study episodic memory we used an "episodic-like memory model" and experiments which focused on: children's verbal ability, differentiation of two perspectives during remembering of events and timing memories on an autobiographical axis. We aimed to inspect the effect of age on performance in these tests, possible links between performance in these experiments and the effect of level and the three components of episodic memory on number of errors made. In our dataset we found a significant effect of the age of children in Sentence repetition test and in test of Object collection in the virtual house, in the same test we found a effect of the level on number of errors. We also found a significant correlation between correct responses in verbal...

Bien que l’on ait longtemps considéré que les substrats cérébraux de la mémoire sémantique (MS) demeuraient intacts au cours du vieillissement normal (VN), en raison d’une préservation de la performance des personnes âgées à des épreuves sémantiques, plusieurs études récentes suggèrent que des modifications cérébrales sous-tendant le traitement sémantique opèrent au cours du vieillissement. Celles-ci toucheraient principalement les régions responsables des aspects exécutifs du traitement sémantique, impliqués dans les processus de recherche, de sélection et de manipulation stratégique de l’information sémantique. Cependant, les mécanismes spécifiques régissant la réorganisation cérébrale du traitement sémantique au cours du VN demeurent méconnus, notamment en raison de divergences méthodologiques entre les études. De plus, des données de la littérature suggèrent que des modifications cérébrales associées au vieillissement pourraient également avoir lieu en relation avec les aspects perceptifs visuels du traitement des mots. Puisque le processus de lecture des mots représente un processus interactif et dynamique entre les fonctions perceptuelles de bas niveau et les fonctions de plus haut niveau tel que la MS, il pourrait exister des modifications liées à l’âge au plan des interactions cérébrales entre les aspects perceptifs et sémantiques du traitement des mots. Dans son ensemble, l’objectif de la présente thèse était de caractériser les modifications cérébrales ainsi que le décours temporel du signal cérébral qui sont associés au traitement sémantique ainsi qu’au traitement perceptif des mots en lien avec le VN, ainsi que les relations et les modulations entre les processus sémantiques et perceptifs au cours du VN, en utilisant la magnétoencéphalographie (MEG) comme technique d’investigation. Dans un premier temps (chapitre 2), les patrons d’activation cérébrale d’un groupe de participants jeunes et d’un groupe de participants âgés sains ont été comparés alors qu’ils effectuaient une tâche de jugement sémantique sur des mots en MEG, en se concentrant sur le signal autour de la N400, une composante associée au traitement sémantique. Les résultats démontrent que des modifications cérébrales liées à l’âge touchent principalement les structures impliquées dans les aspects exécutifs du traitement sémantique. Une activation plus importante du cortex préfrontal inférieur (IPC) a été observée chez les participants jeunes que chez les participants âgés, alors que ces derniers activaient davantage les régions temporo-pariétales que les jeunes adultes. Par ailleurs, le lobe temporal antérieur (ATL) gauche, considéré comme une région centrale et amodale du traitement sémantique, était également davantage activé par les participants âgés que par les jeunes adultes. Dans un deuxième temps (chapitre 3), les patrons d’activation cérébrale d’un groupe de participants jeunes et d’un groupe de participants âgés sains ont été comparés en se concentrant sur le signal associé au traitement perceptif visuel, soit dans les 200 premières millisecondes du traitement des mots. Les résultats montrent que des modifications cérébrales liées à l’âge touchent le gyrus fusiforme mais aussi le réseau sémantique, avec une plus grande activation pour le groupe de participants âgés, malgré une absence de différence d’activation dans le cortex visuel extrastrié entre les deux groupes. Les implications théoriques des résultats de ces deux études sont ensuite discutées, et les limites et perspectives futures sont finalement adressées (chapitre 4). / While it has long been assumed that the organization of the brain network underlying semantic processing remains intact in normal aging, mainly due to older adults’ intact behavioral performance on semantic tasks, several recent studies suggest that brain changes underlying semantic processing operate during aging. These changes appear to affect mainly the brain regions responsible for the executive aspects of semantic memory (SM), involved in semantic search and selection processes, as well as the strategic manipulation of semantic knowledge. However, the specific mechanisms underlying cerebral reorganization of semantic processing in normal aging are not well understood, partly because of methodological differences among studies. Recent literature also suggests that brain changes may be observed in relation to visual perceptual aspects of word processing in older adults. Since reading words is a dynamic interactive process between low-level perceptual functions and higher-order processes such as semantic processing, there may be age-related changes in terms of brain interactions between perceptual and semantic aspects of word processing. The general aim of this thesis was to characterize the cortical changes and the time course of brain signal associated with semantic and perceptual processing of words, as well as the modulations between semantic and perceptual processes in normal aging, using magnetoencephalography (MEG) as the investigative method. Firstly (Chapter 2), the patterns of brain activation of two groups of healthy younger and older adults were compared relative to a semantic task participants carried out during MEG acquisition, by focusing on the signal around the N400, a component associated with semantic processing. The results indicate that brain changes associated with normal aging mainly affect structures involved in the executive aspects of semantic processing. Greater activation was observed in prefrontal cortex for younger relative to older adults, while the latter group of participants activated the temporoparietal region to a greater extent than young adults. Moreover, the left anterior temporal lobe (ATL), considered to be a central and amodal region of semantic processing, was also more activated by older than younger participants. Secondly (Chapter 3), specific patterns of brain activation of younger and healthy older adults were compared in relation to visual perceptual processing, by focusing on the 200 first milliseconds of cortical signal during word processing. The results show that the age-related brain changes affect the fusiform gyrus, as well as the semantic network, with greater activation found in these regions in the group of older participants relative to younger participants, while no difference in activation of the visual extrastriate cortex was found between groups. The theoretical implications of the results of these two studies are discussed. Finally, limitations of this thesis and future perspectives are addressed (Chapter 4).