Two projects are presented in this dissertation. First, we investigated the impact of false memories on the original trace and whether recovery of the original is possible. Second, we tested whether mnemonic discrimination for temporal duration is possible. Both projects incorporated fMRI techniques in order to implicate any potential neural correlates of these memory behaviors. Project One. To elicit false memories and study a potential recovery therefrom, thirty-five healthy, young adults performed multiple recognition memory tests where they were induced to make errors in a first test and then participants were tested again in a surprise, second test. These two tests allowed us to determine which memory error would be corrected, if any. Further, fMRI signal associated with the encoding and retrieval processes during the experiment allowed us to implicate the regions associated with false memory correction. We found that false memories do not overwrite the original trace in all instances, as recovery of the original information was possible. Critically, we determined that recovery of the original information was dependent on activity in regions associated with retrieval, saliency attention, and bottom-up attention during the formation of the false memory, and not on processing at the time of encoding or the second test episode. Project Two. We developed a novel paradigm to test episodic memory for temporal duration. Thirty-five healthy, young adults completed a temporal discrimination task that consisted of a continuous-recognition paradigm in which visual objects were presented one at a time for either 1 or 1.5 seconds. Certain items repeated (Targets and Lures) where Targets were presented for the same duration while the duration of Lures was altered by ±0.5 seconds. Participants were asked to identify whether the stimulus duration changed. Whole-brain high-resolution fMRI data were acquired. Behavioral results indicate that participants were sensitive to both increases and decreases in duration. Further, fMRI analyses revealed that the left entorhinal and perirhinal cortices were differentially involved in encoding and retrieval, respectively, of correct duration representations. These findings support the notion of the entorhinal cortex supporting temporal representations in memory as well as the perirhinal cortex representing the conjunction of item and context.

Pattern separation is the means by which the brain discriminates similar experiences. It enables retrieval of individuated memories without confusing them with other memories. It is the reason one remembers where one parked the car today and does not mix it up with where one parked it previously. Adult neurogenesis refers to the ongoing production of neurons in the mature brain. One of the likely roles of adult neurogenesis in the hippocampus is facilitating pattern separation. Induced reduction of adult neurogenesis in non-human animals is associated with depression- and anxiety-like behaviors. One possible explanation is that reduced neurogenesis leads to reduced pattern separation, further leading to overgeneralization of threat situations. Instead of perceiving threats where it should, the animal risks perceiving threats everywhere. Emotional resilience is the ability to recover from adversity with a minimum of lingering negative effects such as depression or anxiety. This thesis investigates whether pattern separation in the human hippocampus supports emotional resilience. I performed a systematic review of studies that used the Mnemonic Similarity Task – a memory task commonly used to measure human pattern separation – to investigate the relationship between pattern separation and anxiety. The results are inconclusive but suggest a possible interaction effect whereby pattern separation and high-arousal states like stress predict anxiety. Together with the evidence from the non-human animal studies, this suggests that reduced pattern separation as caused by reduced neurogenesis could make one vulnerable to developing anxiety disorders.

Résumé : INTRODUCTION : Le rappel de douleurs passées est souvent inexact. Ce phénomène, connu sous le nom de biais mnémonique, pourrait être lié au développement de certaines douleurs chroniques. Dans une étude précédente, notre laboratoire a montré, grâce à l’électroencéphalographie, que l’activité du gyrus temporal supérieur (GTS) était positivement corrélée à l’exagération des rappels douloureux. L’objectif de cette étude était de confirmer si l’activité cérébrale du GTS est impliquée causalement dans le phénomène du biais mnémonique. MÉTHODES : Dans cette étude randomisée à double insu, la stimulation magnétique transcrânienne (TMS) fut utilisée pour perturber temporairement l’activité du GTS (paradigme de lésion virtuelle). Les participants étaient assignés aléatoirement au groupe contrôle (TMS simulée, n = 21) ou au groupe expérimental (TMS réelle, n = 21). L’intensité et l’aspect désagréable de la douleur ont été évalués grâce à des échelles visuelles analogues (ÉVA; 0 à 10) immédiatement après l’événement douloureux (stimulations électriques du nerf sural droit) et au rappel, 2 mois plus tard. L’exactitude du rappel douloureux fut calculée en soustrayant l’ÉVA au rappel de l’ÉVA initiale. RÉSULTATS : Le biais mnémonique de l’intensité de la douleur était similaire dans les deux groupes (contrôle = -0,3, expérimental = 0,0; p = 0,83) alors que le biais mnémonique de l’aspect désagréable de la douleur était significativement inférieur dans le groupe expérimental (contrôle = 1.0, expérimental = -0,4; p < 0,05). CONCLUSION : Nos résultats suggèrent que le GTS affecte spécifiquement nos souvenirs liés à l’aspect motivo-affectif de la douleur. Étant donné le lien entre l’exagération des souvenirs douloureux et la persistance de la douleur, l’inhibition du GTS pourrait être une avenue intéressante pour prévenir le développement de douleur chronique. / Abstract : INTRODUCTION: Pain memories are often inaccurate. This phenomenon, known as the mnemonic pain bias, could be related to the development of chronic pain. In a past study, our research team showed, using electroencephalography, that the activity of the superior temporal gyrus (STG) was positively correlated to the exaggeration of pain recall. The aim of this study was to confirm that the STG is causally involved in the pain mnemonic bias. METHODS: In this randomised double-blind study, single-pulse transcranial magnetic stimulation (TMS) was used to transiently disrupt (virtual lesion paradigm) the activity of the STG. Participants were either assigned to the control (sham TMS, n = 21) or experimental (real TMS, n = 21) group. Pain intensity and unpleasantness were assessed using visual analog scales (VAS; 0-10) immediately after the painful event (electric stimulations of the right sural nerve) and at recall, 2 months later. The accuracy of the pain recall was determined by calculating the difference between the VAS at recall and the initial VAS. RESULTS: The mnemonic pain intensity bias was similar in both groups (control = -0.3, experimental = 0.0; p = 0.83). However, the mnemonic pain unpleasantness bias was significantly lower in the experimental group (control = 1.0, experimental = -0.4; p < 0.05). CONCLUSION: Our results suggest that the STG affects specifically our memories of the affective component of pain. Given the link between exaggerated pain memories and the development of persistent pain, this study suggests that the inhibition of the STG could be a promising avenue for individuals at risk of developing chronic pain.

With an evermore growing threat of new malware that keeps growing in both number and complexity, the necessity for improvement in automatic detection and classification of malware is increasing. The signature-based approaches used by several Anti-Virus companies struggle with the increasing amount of polymorphic malware. The polymorphic malware change some minor aspects of the code to be able to remain undetected. Malware classification using machine learning have been used to try to solve this issue in previous research. In the proposed work, different hierarchical machine learning approaches are implemented to conduct three experiments. The methods utilise a hierarchical structure in various ways to be able to get a better classification performance. A selection of hierarchical levels and machine learning models are used in the experiments to evaluate how the results are affected. A data set is created, containing over 90000 different labelled malware samples. The proposed work also includes the creation of a labelling method that can be helpful for researchers in malware classification that needs labels for a created data set.The feature vector used contains 500 n-gram features and 3521 Import Address Table features. In the experiments for the proposed work, the thesis includes the testing of four machine learning models and three different amount of hierarchical levels. Stratified 5-fold cross validation is used in the proposed work to reduce bias and variance in the results. The results from the classification approach shows it achieves the highest hF-score, using Random Forest (RF) as the machine learning model and having four hierarchical levels, which got an hF-score of 0.858228. To be able to compare the proposed work with other related work, pure-flat classification accuracy was generated. The highest generated accuracy score was 0.8512816, which was not the highest compared to other related work.

Abstract A central problem in all language teaching is to teach the correct use of prepositions. There are grammar rules, but also a lot of exceptions and idiomatic expressions that often have to be learnt by examples or by heart. A trick for learning might be to use a mnemonic method with songs and music to memorize a correct use of prepositions. The purpose of this study is to test a language teaching didactic exercise for knowledge of preposition in Spanish with songs and music. Grammatical aspects, rules and exceptions when studying prepositions in Spanish are presented. A literature review shows the significance of music for language learning. By lesson trials the five so called “empty” prepositions in Spanish: a, con, de, en and por, are studied by 40 high school students only by listening to and singing two different songs in the beginning and at the end of each Spanish lesson during two weeks. The result of the study shows an improved knowledge of correct use of the 5 Spanish prepositions among the students using the method. Furthermore, the language teaching didactic exercise with song and music was seen as a pleasurable learning experience by the students.

The aim of this thesis is to analyse a foreign language teaching regarding the use of mnemonics as special procedures which lead to memorize the curriculum. The thesis deals with types and phases of the memory and with the process of forgetting. It defines the term learning, describes learning styles and characterizes aspects of effective learning. Subsequently the thesis is concerned with the procedures for consolidation of information in the memory, the attributes of effective revision and above all the mnemonic procedures. The attention is payed to principles, types and effectiveness of mnemonics and their implementation into the foreign language teaching. The next part deals with the aspects of andragogical didactics, their specific application and with androdidactic principles. Afterwards the thesis pursues the qualitative research whose aim was to analyse the use of mnemonics within the foreign language teaching. It is based on observation method in courses for adults at two language schools.

[pt] Trabalhando na transversalidade entre memória e memorialização, esta tese propõe um engajamento com a materialidade a fim de explorar a memória como uma fusão de corpos (humanos e não-humanos se misturando), lugares (configurações espaço-temporais frágeis e provisórias) e práticas (ações sempre permeadas por performances e traduções), formando assemblagens mnemônicas (Freeman; Nienass; Daniell, 2016) em Ruanda no pós-genocídio. Como a memorialização em Ruanda está profundamente permeada por um tipo particular de matéria - restos humanos -, adotamos um foco corpóreo, olhando para os enredamentos entre pessoas e coisas, considerando seu embaçamento. Indo além das práticas de representação, exploramos os movimentos de fricção entre uma ampla gama de entidades que se agrupam (e desmontam) em memoriais, enfatizando seu caráter imprevisível e sublinhando suas configurações espaço-temporais provisórias. Com este movimento, esperamos energizar a paisagem com outras possibilidades além da concepção da matéria e do lugar como passivo ou estável e em direção a uma transformação mais fluida encenada no encontro entre essas entidades materiais-semióticas. Explorando encontros afetivos entre corpos e lugares, argumentamos que é apenas nesse processo que os lugares memoriais são encenados. Trabalhando sob a rubrica do novo-materialismo, sugerimos uma bricolagem de abordagens, dando conta do político em uma sensibilidade mais cooperativa-experimental (Thrift, 2008) em relação à materialidade generativa. Tal esforço nos permite lembrar e esquecer com e por meio de outros corpos, reconhecendo a importância das coisas/matéria e lugares nas práticas de memorialização em Ruanda, e convidando a participar do chamado para um envolvimento teórico e metodológico com a experiência vivida em Relações Internacionais. Mais especificamente, esta dissertação se engaja com o movimento e o fluxo dos lugares e da matéria por meio de memoriais como locais de fricção e da circularidade do corpo morto. Buscando compreender diferentes modos de agrupamentos de memória, oferecemos duas assemblagens para explorar essas diferenças: memoriais nacionais cuidadosamente projetados (Kigali, Murambi e Bisesero) e um lugar de memória espontâneo – o Rio Nyabarongo. A pesquisa destes espaços heterogêneos construídos como locais de memória é baseada em trabalho de campo realizado em Ruanda em 2011 e 2014. / [en] Working within the transversality of memory and memorialization, this dissertation proposes an engagement with materiality in order to explore memory as a fusion of bodies (human and nonhuman intermingling), places (fragile and provisional spatiotemporal configurations), and practices (actions always embedded in performances and translations), forming mnemonic assemblages (Freeman; Nienass; Daniell, 2016) in post-genocide Rwanda. As memorialization in Rwanda is deeply embedded in a particular type of matter – human remains –, we adopt a corporeal focus, looking into the entanglements between persons and things considering their blurriness. Going beyond practices of representation, we explore the movements of friction between a wide range of entities assembling (and disassembling) in memorials, stressing its unpredictable character and underlining their provisional spatiotemporal configurations. With this move, we hope to energize the landscape with other beyond the conception of matter and place as passive or stable and towards a more fluid transformation enacted in the encounter between these material-semiotic entities. Exploring affective encounters between bodies and places, we argue that it is only in this co-becoming that memorial places are enacted. Working under the rubric of new materialism, we suggest a bricolage of approaches, accounting for the political in a more co-operative-cum-experimental sensibility (Thrift, 2008) towards generative matter. Such effort enables us to remember and forget with and through other bodies, acknowledging the importance of things/matter and places in memorialization practices in Rwanda, and inviting to join the call for a theoretical and methodological engagement with the lived experience in International Relations. More specifically, this dissertation engages with movement and flux of places and matter through memorials sites as places of friction and through the circularity of the dead body. Trying to grasp different modes of memory gatherings, we offer two assemblages to explore these differences: carefully designed national-level memorial sites (Kigali, Murambi, and Bisesero) and a spontaneous place of memory – Nyabarongo River. The research on these heterogeneous spaces assembled as places of memory is based on fieldwork conducted in Rwanda in 2011 and 2014.

No description available.

L’objectif de ce travail de thèse est d’évaluer le potentiel de la musique comme support mnémotechnique pour l’acquisition de nouvelles informations chez des personnes âgées saines et atteintes de la maladie d’Alzheimer (MA). Les bénéfices de la musique sur la cognition ont souvent été mis en évidence, y compris chez des populations âgées ou atteintes de démence. Parallèlement, chez des sujets jeunes, l’idée que la musique peut servir de support pour la mémoire a été largement débattue. Pourtant, très peu d’études ont posé cette question auprès de populations âgées ou dans la démence, malgré le besoin persistant de stratégies d’intervention dans ce domaine. Dans le présent travail, deux études sont menées dans une cohorte de 8 participants atteints d’un stade léger de la maladie d’Alzheimer, et 7 participants âgés sains appariés en âge et niveau de scolarité. La première étude porte sur la mémoire verbale, et compare l’apprentissage et la rétention de paroles (textes inconnus) présentées de manière récitée ou chantée. Lorsque les paroles sont chantées, différents degrés de familiarité de la mélodie sont contrastés. Aussi, l’action motrice étant intimement liée à l’écoute musicale, nous contrastons deux procédures d’apprentissage impliquant (ou non) la production synchronisée des paroles à mémoriser pendant l’encodage : le participant est invité à chanter à l’unisson avec un modèle (ou à écouter simplement sans chanter). Les résultats de cette étude sont présentés et discutés dans les deux premiers articles de la partie expérimentale. Ils suggèrent globalement que la musique n’aide pas l’apprentissage en rappel immédiat ; un effet délétère est même observé lorsque la mélodie utilisée est non familière. Par contre, la musique favorise la rétention à long terme des paroles, principalement pour les participants MA. Elle ne semble cependant pas interagir avec la procédure d’apprentissage impliquant le chant à l’unisson. La seconde étude porte sur l’apprentissage de séquences de gestes. Suivant la même logique que dans la première étude, nous explorons l’influence d’un accompagnement musical (versus apprentissage en silence) et d’une procédure d’apprentissage avec production synchronisée (versus observation) des gestes durant l’encodage. Les résultats (article 3) ne montrent pas non plus d’interaction entre l’accompagnement et la procédure d’apprentissage, mais différents effets de chaque composante sur les deux groupes de participants. Effectuer les gestes en synchronie avec un modèle lors de l’encodage est bénéfique pour les sujets Contrôles, mais plutôt délétère pour les participants MA. Par contre, l’accompagnement musical favorise davantage l’apprentissage chez les sujet MA que chez les Contrôles. En discussion générale, nous discutons les implications de ces résultats pour la neuropsychologie fondamentale et clinique, et proposons notamment différentes recommandations visant à maximiser ces effets et à les rendre pertinents pour l’usage thérapeutique en stimulation cognitive. / This thesis research aims to test the potential of music as a mnemonic support for new learning in normal elderly and Alzheimer’s disease (AD) participants. Several studies have highlighted the beneficial effects of music on cognition in aging and dementia. At the same time, in young adults, the idea that music could serve as a mnemonic support is highly debated. Yet, very few studies addressed this question in aging or dementia. In the present work, we conduct two studies in a cohort of 8 mild Alzheimer’s disease and 7 matched control participants. The first study concerns verbal memory, and compares learning and different retention delays of lyrics (unknown texts) that are either spoken or sung. When lyrics are sung, different degrees of melody familiarity are contrasted. Moreover, as motor activity is strongly related to music, we compare two learning procedures that are either synchronized or not with the production of these lyrics during encoding: 1) participants sing in unison with the model or 2) participants hear the model without singing. Results of this study are presented and discussed in the first two articles of the experimental section. Globally, music does not show aid for learning measured in immediate recall; we even observed a harmful effect when lyrics are sung on a non-familiar melody. But music helps long-term retention of lyrics, particularly for AD participants. Nevertheless, music does not clearly interact with learning procedure involving unison singing. The second study of the thesis investigates the learning of gesture sequences. Similarly to the first study, we explore influence of music versus silence as background accompaniment, and synchronized production versus observation of gestures during encoding. Results (article 3) showed again no interaction between background accompaniment and learning procedure, but different effects of each variable on both groups. Learning gestures with synchronized production is beneficial for normal controls, but harmful for AD participants. On the other hand, musical accompaniment led to greater benefit for AD participants than for controls. In the general discussion, we present the implications of these results for fundamental and clinical neuropsychology. We propose some recommendations to maximize these effects and make them relevant for therapeutic care.

No description available.