Tesis por compendio / En esta tesis, el objetivo principal fue diseñar y desarrollar una nueva tarea que combinara interfaces de usuario naturales (NUI) y dispositivos inteligentes para evaluar la memoria espacial utilizando estímulos auditivos, y su validación tanto en niños como en adultos. La nueva tarea evalúa la capacidad de los participantes para detectar y localizar estímulos auditivos que se emiten en diferentes posiciones del área de trabajo. La tarea reconoce los movimientos de los brazos del usuario, utilizando para ello Kinect. Los dispositivos inteligentes (conejos Karotz) se utilizan para emitir estímulos auditivos y también como señales visuales. Por lo tanto, la tarea combina estímulos auditivos con claves visuales reales para la evaluación de la memoria espacial. La tarea incluye un total de 45 estímulos acústicos, repartidos en 5 niveles y cada nivel consta de 3 ensayos. Nuestra tarea es el primer trabajo que combina NUI y dispositivos inteligentes para la evaluación de la memoria espacial. Del mismo modo, nuestra tarea es el primer trabajo que utiliza estímulos auditivos para evaluar la memoria espacial. Para la validación, se llevaron a cabo 3 estudios. El rendimiento de nuestra tarea se comparó con métodos tradicionales. El primer estudio involucró niños con y sin síntomas de falta de atención. Un total de 34 niños participaron (17 niños con falta de atención). Los resultados demostraron que los niños con falta de atención mostraron un rendimiento estadísticamente peor en la tarea. Estos niños con falta de atención también mostraron un rendimiento estadísticamente peor con el método tradicional para evaluar el aprendizaje de sonidos verbales. No se encontraron diferencias estadísticamente significativas en el tiempo dedicado por cada grupo para completar la tarea. Los resultados sugieren que la tarea es una buena herramienta para distinguir las dificultades de memoria espacial en niños con falta de atención. El segundo estudio comparó el rendimiento en la tarea entre niños mayores y adultos (32 niños y 38 adultos sanos). Los resultados de rendimiento con la tarea fueron significativamente más bajos para los niños mayores. Se encontraron correlaciones entre nuestra tarea y los métodos tradicionales, lo que indica que nuestra tarea ha demostrado ser una herramienta válida para evaluar la memoria espacial mediante el uso de estímulos auditivos tanto para niños mayores como para adultos. A partir del análisis, podemos concluir que la satisfacción con la tarea de los niños mayores fue significativamente mayor que la de los adultos. El tercer estudio incluyó un total de 148 participantes (niños más pequeños, niños mayores y adultos). Los resultados están en línea con el segundo estudio. El rendimiento de la tarea se relacionó significativamente, de forma incremental y directa con el grupo de edad (niños más pequeños <niños mayores <adultos). Los resultados fueron mejores para adultos y niños mayores; resultado que es consistente con la idea de que los adultos pueden almacenar más elementos en la memoria a corto plazo que los niños. Las siguientes conclusiones generales se han extraído del desarrollo y los tres estudios: * Las interfaces de usuario naturales y los dispositivos inteligentes son apropiados para desarrollar tareas para la evaluación de la memoria espacial. * Como juego de ordenador, nuestra tarea facilita el control de la presentación de estímulos y el almacenamiento de las respuestas. * Nuestra tarea y tareas similares podrían usarse para la evaluación y el entrenamiento de la memoria espacial en niños y adultos. * La tarea podría ser una herramienta alternativa para evaluar la memoria espacial en niños con síntomas de falta de atención. * La tarea promueve interés y permite la evaluación de una manera ecológica. * La tarea podría ayudar a identificar alteraciones en la memoria espacial tanto en niños como en adultos. / In this thesis, the main objective was to design and develop a new task that combine Natural User Interfaces (NUI) and smart devices for assessing spatial memory using auditory stimuli, and its validation in both children and adults. The new task tests the ability of participants to detect and localize auditory stimuli that are emitted in different positions of the task area. The task recognizes the movements of the arms of the user using Kinect. Smart devices (Karotz rabbits) are used for emitting auditory stimuli and also as visual cues. Therefore, the task combines auditory stimuli with real visual cues for the assessment of spatial memory. The task includes a total of 45 acoustic stimuli, which should be randomly emitted in different locations. The task is composed of five different levels. Each level consists of 3 trials. The difference between levels lies in the number of sounds to be used in each trial. To our knowledge, our task is the first work that combines NUI and smart devices for the assessment of spatial memory. Similarly, our task is the first work that uses auditory stimuli to assess the spatial memory. For the validation, three studies were carried out to determine the efficacy and utility of our task with regard to the performance outcomes, usability, fun, perception and overall satisfaction. The performance of our task was compared with traditional methods. The first study involved children with and without symptoms of inattention. A total of 34 children participated (17 children with inattention). The results showed that the children with inattention showed statistically worse performance in the task. These children with inattention also showed statistically worse performance in the traditional method for testing the learning of verbal sounds. There were no statistically significant differences in the time spent by each group to complete the task. The results suggest that the task is a good tool for distinguishing spatial memory difficulties in children with inattention. The second study compared the performance in the task between older children and adults. A total of 70 participants were involved in this study. There were 32 healthy children from 9 to 10 years old, and 38 healthy adults from 18 to 28 years old. The performance outcomes with the task were significantly lower for the older children. Correlations were found between our task and traditional methods, indicating that our task has proven to be a valid tool for assessing spatial memory by using auditory stimuli for both older children and adults. From the analysis, we can conclude that the older children were significantly more satisfied with the task than the adults. In the third study, a total of 148 participants were involved. They were distributed in three groups (younger children, older children and adults). A total of 100 children and 48 adults participated in this study. The results are in line with the second study. The task performance was significantly incrementally and directly related to the age group (younger children <older children <adults). The results were better for adults and older children; this is consistent with the idea that adults can store more elements in short-term memory than children. The following general conclusions were extracted from the development and the studies: * Natural user interfaces and smart devices are appropriated for developing tasks for the assessment of spatial memory. * As a computer-based game, our task facilitates the control of the presentation of stimuli and the recording of responses. * Our task and similar tasks could be used for assessment and training of spatial memory in children and adults. * The task could be an alternative tool to assess spatial memory in children with symptoms of inattention. * The task promotes engagement and allows the assessment in an ecological way. * The task could help in the identification of alterations in spatial memory in both children and adults. / En aquesta tesi, l'objectiu principal va ser dissenyar i desenvolupar una nova tasca que combinés NUI i dispositius intel·ligents per a avaluar la memòria espacial utilitzant estímuls auditius, i la seua validació tant en xiquets, com en adults. La nova tasca avalua la capacitat dels participants per a detectar i localitzar estímuls auditius que s'emeten en diferents posicions de l'àrea de treball. La tasca reconeix els moviments dels braços de l'usuari, utilitzant per a açò Kinect. Els dispositius intel·ligents (conills Karotz) s'utilitzen per a emetre estímuls auditius i, també, com a senyals visuals. Per tant, la tasca combina estímuls auditius amb claus visuals reals per a l'avaluació de la memòria espacial. La tasca inclou un total de 45 estímuls acústics, repartits en 5 nivells diferents i cada nivell consta de 3 assajos. La nostra tasca és el primer treball que combina NUI i dispositius intel·ligents per a l'avaluació de la memòria espacial. De la mateixa manera, la nostra tasca és el primer treball que utilitza estímuls auditius per a avaluar la memòria espacial. Per a la validació, es van dur a terme tres estudis. El rendiment de la nostra tasca es va comparar amb mètodes tradicionals. El primer estudi va involucrar 34 xiquets (17 xiquets amb inatenció). Els resultats van demostrar que els xiquets amb inatenció van mostrar un rendiment estadísticament pitjor en la tasca. Aquests xiquets amb inatenció també van mostrar un rendiment estadísticament pitjor amb el mètode tradicional per a avaluar l'aprenentatge de sons verbals. No es van trobar diferències estadísticament significatives en el temps dedicat per cada grup per a completar la tasca. Els resultats suggereixen que la tasca és una bona ferramenta per a distingir les dificultats de memòria espacial en xiquets amb dificultats d'atenció. El segon estudi va comparar el rendiment en la tasca entre xiquets majors i adults. Un total de 70 participants van estar involucrats en aquest estudi. Van participar 32 xiquets i 38 adults sans. Els resultats de rendiment amb la tasca van ser significativament més baixos per als xiquets majors. Es van trobar correlacions entre la nostra tasca i els mètodes tradicionals, la qual cosa indica que la nostra tasca ha demostrat ser una ferramenta vàlida per a avaluar la memòria espacial mitjançant l'ús d'estímuls auditius tant per a xiquets majors, com per a adults. A partir de l'anàlisi, podem concloure que la satisfacció amb la tasca dels xiquets majors va ser significativament major que la dels adults. El tercer estudi va incloure un total de 148 participants (100 xiquets i 48 adults). Es van distribuir en tres grups (xiquets més xicotets, xiquets majors i adults). Els resultats estan en línia amb el segon estudi. El rendiment de la tasca es va relacionar significativament, de forma incremental i directa amb el grup d'edat (xiquets més xicotets <xiquets majors <adults). Els resultats van ser millors per a adults i xiquets majors; resultat que és consistent amb la idea que els adults poden emmagatzemar més elements en la memòria a curt termini que els xiquets. Las següents conclusions generals s'han extret del desenvolupament i els tres estudis: * Les NUI i els dispositius intel·ligents són apropiats per a desenvolupar tasques per a l'avaluació de la memòria espacial. * Com a joc d'ordinador, la nostra tasca facilita el control de la presentació d'estímuls i l'emmagatzematge de les respostes. * La nostra tasca, i tasques similars, podrien usar-se per a l'avaluació i l'entrenament de la memòria espacial en xiquets i adults. * La tasca podria ser una ferramenta alternativa per a avaluar la memòria espacial en xiquets amb problemes de inatenció. * La tasca promou interès i permet l'avaluació d'una manera ecològica. * La tasca podria ajudar a identificar alteracions en la memòria espacial tant en xiquets, com en adults. / Loachamín Valencia, MR. (2018). Natural user interfaces and smart devices for the assessment of spatial memory using auditory stimuli [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/107955 / Compendio

Human motion analysis (HMA) can play a crucial role in sports and healthcare by providing unique insights on movement mechanics in the form of objective measurements and quantitative data. Traditional, state of the art, marker-based techniques, despite their accuracy, come with financial and logistical barriers, and are restricted to laboratory settings. Markerless systems offer much improved affordability and portability, and can potentially be used outside of laboratories. However, these advantages come with a significant cost in accuracy. This thesis attempts to address the challenge of democratizing HMA by leveraging recent advances in smartphone technology and machine learning.\newline\newlineThis thesis evaluates two modalities of performing markerless HMA: Single smartphone using Apple Arkit, and multiple smartphone setup using OpenCap, and compares both to a state of the art multiple-camera marker-based system from Vicon. Additionally, this thesis presents and evaluates two approaches to improving the single smartphone modality: Employing a Gaussian Process Model (GPR), and a Long-short-term-memory (LSTM) neural network to refine the single smartphone data to align with the marker-based result. Specific movements were recorded simultaneously with all three modalities on 13 subjects to build a dataset. From this, GPR and LSTM models were trained and applied to refine the single camera modality data. Lower limb joint angles, and joint centers were evaluated across the different modalities, and analyzed for potential use in real-world applications. While the findings of this thesis are promising, as both the GPR and LSTM models improve the accuracy of Apple Arkit, and OpenCap providing accurate and consistent results. It is important to acknowledge limitations regarding demographic diversity and how real-world environmental factors may influence its application. This thesis contributes to the efforts in narrowing the gap between marker-based HMA methods, and more accessible solutions. / Rörelseanalys av människokroppen (HMA) kan spela en betydelsefull roll i både idrott och hälso- och sjukvården. Genom objektiv och kvantitativ data ger den unik insikt i mekaniken bakom rörelser. Traditionella, toppmoderna, markör-baserade tekniker är mycket precisa, men medför finansiella och logistikbaserade barriärer, och finns endast tillgängliga i laboratorier. Markör-fria system erbjuder mycket bättre pris, portabilitet och kan potentiellt användas utanför laboratorier. Dessa fördelar går dock hand i hand med en betydande minskning av nogrannhet. Denna avhandling försöker ta itu med utmaningen att demokratisera HMA genom att utnyttja de senaste framstegen inom smartphoneteknik och maskininlärning. Denna avhandling utvärderar två sätt att utföra markör-fri HMA: Genom att använda en smartphone som kör Apple Arkit, och en uppsättning med flera smartphones som kör OpenCap. Båda modaliteter jämförs med ett markör-baserat system som använder flera kameror, från Vicon. Dessutom presenteras och utvärderas två metoder för att förbättra modaliteten med endast en smartphone: Användning av en Gaussisk Process modell för Regression (GPR) och ett Long-short-term-memory (LSTM) neuronnät för att förbättra data från en smartphone modalititeten, så att det bättre överenstämmer med det markör-baserade resultatet. Specifika rörelser spelades in samtidigt med alla tre modaliteter på 13 försökspersoner för att bygga upp ett dataset. Utifrån detta tränades GPR- och LSTM-modeller och användas för att förbättra data från en kamera modaliteten (Apple Arkit). Ledvinklar och ledcentra för de nedre extremiteterna utvärderades i de olika modaliteterna och analyserades för potentiell använding i verkliga tillämpningar. Även om resultaten av denna avhandling är lovande, då både GPR- och LSTM-modellerna förbättrar nogrannheten hos Apple Arkit, och OpenCap ger korrekta och konsekventa resultat, så är det viktigt att erkänna begränsningarna när det gäller demografisk mångfald och hur miljöfaktorer i verkligheten kan påverka tillämpningen.

Il lavoro di tesi si è focalizzato sullo studio dell’arousal come indice psicofisiologico di attivazione e sull’applicazione della metodica di stimolazione elettrica transcranica (tES) non invasiva con lo scopo di modulare tale indice. L’obiettivo è stato quello di indagare se, applicando la tES, fosse possibile migliorare la performance di soggetti giovani sani in compiti di tipo cognitivo. Il progetto di ricerca si è sviluppato in 2 studi principali per un totale di 4 esperimenti. Tali studi hanno previsto l’acquisizione e la successiva analisi sia di dati comportamentali (tempi di reazione, accuratezza), che di indici psicofisiologici (conduttanza cutanea, diametro pupillare). I risultati hanno evidenziato che è possibile modulare l’arousal con dei “bursts” di stimolazione elettrica transcranica, somministrati in concomitanza di stimoli salienti per il soggetto. Tale modulazione si è manifestata con una riduzione dei tempi di reazione ed un contemporaneo aumento della risposta di conduttanza cutanea. Questi dati supportano la possibilità di utilizzare questo protocollo in pazienti con difficoltà di attenzione o altri problemi cognitivi per aumentare l’efficacia di interventi di riabilitazione. / The thesis analyzed the role of the arousal as a psychophysiological index of activation, and the application of non-invasive transcranial electrical stimulation (tES) technique with the aim to modulate this index. In this work we investigated if the application of tES could increase the performance of healthy young subjects during cognitive tasks. The thesis is based on 2 main studies for a total of 4 experiments with the recording of behavioural (reaction times, accuracy) and psychophysiological (skin conductance, pupil diameter) indeces. The results showed that it is possible to modulate arousal with bursts of tES, administered during the presentation of salient stimuli for the subject. This modulation resulted in a reduction of reaction times and an increase of the skin conductance response. These data support the possibility to use this protocol of stimulation with patients with attentional and other cognitive deficits in a rehabilitative context.

Summaries in Afrikaans and English / Text in Afrikaans / Two opposing approaches to beginning reading are used, namely the phonological and global approach, under which the whole word, whole sentence and whole language methods are classed. The whole crux of the controversy is situated in beginning reading as an explicit, intensive and systematic method of teaching phonics, as opposed to implicit beginning reading through discrimination of global configurations, augmented by psycholinguistic guesses within reading context. Arguments about the advantages and disadvantages of the opposing methods have been hurdled to and fro for decades without any discernible gain. The question emerged whether research on brain physiology with respect to language and reading, a relatively new field of study, could shed light on the foundation of an accountable method for beginning reading. Renewed insights to the controversial differences were gained, and brain physiologically accountable parameters as a base for a beginning reading method were framed from these insights. / Twee opponerende aanvangsleesbenaderings word in die skole gebruik, naamlik die fonologiese benadering en die geheelbenadering, waaronder die geheelwoord-, geheelsinen die geheeltaalmetode ressorteer. Die kern van die verskil tussen die aanvangsleesbenaderings le in aanvangslees as eksplisiete, intensiewe en sistematiese foneemonderrig, teenoor implisiete aanvangslees wat die waarneming van globale konfigurasies, aangevul deur psigolinguistiese raaiskote binne die leeskonteks, aanmoedig. In die polemiek om die beste leesmetode word argumente oor die voor- en nadele ten opsigte van die begronding van hierdie opponerende metodes reeds dekades heen en weer geslinger. Navorsingsresultate word eindeloos, sonder duidelike winste, met mekaar vergelyk. Dit het die vraag laat onstaan of navorsing ten opsigte van die breinfisiologie met betrekking tot taal en lees, 'n relatief nuwe studieveld, moontlik lig sou kon werp op die begronding van 'n verantwoordbare aanvangsleesmetode. Die literatuurstudie ten opsigte van breinfisiologie het vernuwende insigte oor die polemiese begrondingsverskille na vore gebring, en breinfisiologies-verantwoordbare parameters as basis vir 'n aanvangsleesmetode is uit hierdie insigte opgestel. / Psychology of Education / M. Ed. (Psychology of Education)

本研究旨在探討「以常用詞根輔以圖像構詞式詞彙教學法」、「常用詞根無圖像構詞式詞彙教學法」及傳統的「詞義說明式詞彙教學法」在學生的詞彙記憶上的差異；本研究亦探討學生的英文詞彙量、構詞察覺度、短期記憶、長期記憶及拼詞能力之間的相關。 本研究的主要發現如下：接受「以常用詞根輔以圖像構詞式詞彙教學法」的學生比接受「常用詞根無圖像構詞式詞彙教學法」及傳統的「詞義說明式詞彙教學法」的學生表現出更好的構詞察覺度、短期記憶、長期記憶及拼詞能力。在這三組中，構詞察覺度較高的學生對生詞有較佳的短期記憶與長期記憶能力，反之亦然；在詞彙記憶方面，短期記憶力較佳則長期記憶力也是較佳，反之亦然；並且，一星期後的後測分數比較高的學生在一個月後的後後測分數也會比較高；再者，詞彙的短期記憶與學生英文詞彙量的差異無關，因為學生所記住的生詞都可以持續短暫的時間，但不一定能長久記憶。 / This study aims to investigate the discrepancy in the use of the iconic-morphological approach via commonly-used roots, the non-iconic morphological approach via commonly-used roots, and the traditional definition-based teaching method in vocabulary memorization. It also explores the correlation between English vocabulary size, awareness of morphology, short-term memory for words, long-term memory for words, and vocabulary spelling abilities. The subjects of this study are 91 third-year students studying at the National Overseas Chinese Experimental Senior High School in Taipei County. They received instruction in the iconic-morphological approach via commonly-used roots, the non-iconic morphological approach via commonly-used roots, and the traditional definition-based teaching method, respectively. In the beginning, the three groups took the same pre-test to examine their vocabulary size. Then, subjects were immediately asked to take post-test 1 to examine their awareness of morphology after receiving different instructions. Later, subjects were asked to memorize forty unknown words within twenty minutes and then to take post-test 2 to investigate their short-term memory for words. A week later, post-test 3 was held to check their long-term memory for words. A month later, they sat for post-test 4, used to explore their longer-term memory for the forty words. In conclusion, the study summarizes the main findings pertinent to the proposed research questions. The students who receive instruction in the iconic-morphological approach via commonly-used roots finally develop higher awareness of morphology, better short-term memory for words, better long-term memory for words, and better spelling ability than those who learn in the traditional definition-based approach or in the non-iconic morphological approach via commonly-used roots. Among the three groups, the students who display higher awareness of morphology have better short-term memory and long-term memory for words, and vice versa. Moreover, those who have better short-term memory have better long-term memory, and vice versa; those who have better one-week long-term memory for words definitely have better one-month long-term memory for words. Interestingly, students can learn words by rote for a short period of time regardless of their vocabulary size. That is, one person’s short-term memory for words is not correlated with his vocabulary size.

Une variété d’opérations cognitives dépend de la capacité de retenir de l’information auditive pour une courte période de temps. Notamment l’information auditive prend son sens avec le temps; la rétention d’un son disparu permet donc de mieux comprendre sa signification dans le contexte auditif et mène ultimement à une interaction réussite avec l’environnement. L’objectif de cette thèse était d’étudier l’activité cérébrale reliée à la rétention des sons et, ce faisant, parvenir à une meilleure compréhension des mécanismes de bas niveau de la mémoire à court-terme auditive. Trois études empiriques se sont penchées sur différents aspects de la rétention des sons. Le premier article avait pour but d’étudier les corrélats électrophysiologiques de la rétention des sons variant en timbre en utilisant la technique des potentiels reliés aux événements. Une composante fronto-centrale variant avec la charge mnésique a été ainsi révélée. Dans le deuxième article, le patron électro-oscillatoire de la rétention a été exploré. Cette étude a dévoilé une augmentation de l’amplitude variant avec la charge mnésique dans la bande alpha pendant la rétention des sons ainsi qu’une dissociation entre l’activité oscillatoire observée pendant la rétention et celle observée pendant la présentation des sons test. En démontrant des différentes modulations des amplitudes dans la bande alpha et la bande beta, cette étude a pu révéler des processus distincts mais interdépendants de la mémoire à court-terme auditive. Le troisième article a davantage visé à mieux connaître les structures cérébrales soutenant la rétention de sons. L’activité cérébrale a été mesurée avec la magnétoencéphalographie, et des localisations des sources ont été effectuées à partir de ces données. Les résultats ont dévoilé l’implication d’un réseau cérébral contenant des structures temporales, frontales, et pariétales qui était plus important dans l’hémisphère droit que dans l’hémisphère gauche. Les résultats des études empiriques ont permis de souligner l’aspect sensoriel de la mémoire à court-terme auditive et de montrer des similarités dans la rétention de différentes caractéristiques tonales. Dans leur ensemble, les études ont contribué à l’identification des processus neuronaux reliés à la rétention des sons en étudiant l’activité électromagnétique et l’implication des structures cérébrales correspondantes sur une échelle temporelle fine. / The capacity to retain auditory information for a short period of time is fundamental for a variety of cognitive operations. Sounds, in particular, often do not reveal their meaning before being integrated in their temporal context; the retention of tones that are no longer present in the environment is thus necessary for understanding the significance of auditory information. Retaining tones ultimately leads to a successful interaction with the environment. The goal of this thesis was to study brain activity related to the retention of tones, thereby providing a better understanding of low-level mechanisms related to auditory short-term memory. Three empirical studies have been conducted, each of them focusing on a different aspect of the retention of tones. The first article investigated electrophysiological correlates of the retention of tones differing in timbre using the event-related potential technique. The electrophysiological results revealed a fronto-central component that varied with memory load. In the second article, the oscillatory pattern of electric brain activity was explored using electroencephalography. The results revealed that alpha band amplitudes were modulated by memory load during retention. Furthermore, a dissociation of oscillatory activity between the retention of tones and the comparison of test tones against retained tone representations was observed. This study also revealed distinct but interrelated processes taking place at the same time by showing specific amplitude modulations in the alpha and beta bands. The third article focused more on brain areas underpinning the retention of tones. Brain activity was measured with magnetoencephalography and subsequent source localisations were performed. The results suggested the implication of a network of temporal, frontal, and parietal brain areas which was more pronounced in the right hemisphere than in the left hemisphere. The results of the empirical studies emphasized the sensory aspect of auditory short-term memory. In addition, they revealed similarities between the retention of tones differing in fundamental sound characteristics such as timbre and pitch. Considered as a whole, the studies of this thesis contributed to the identification of neural processing underlying the retention of tones by studying electromagnetic brain activity and the implication of corresponding brain areas on a fine temporal scale.

L’approche psycholinguistique suggère que la rétention à court terme verbale et le langage dépendent de mécanismes communs. Elle prédit que les caractéristiques linguistiques des items verbaux (e.g. phonologiques, lexicales, sémantiques) influencent le rappel immédiat (1) et que la contribution des niveaux de représentations linguistiques dépend du contexte de rappel, certaines conditions expérimentales (e.g. format des stimuli) favorisant l’utilisation de codes spécifiques (2). Ces prédictions sont évaluées par le biais de deux études empiriques réalisées auprès d’une patiente cérébrolésée qui présente une atteinte du traitement phonologique (I.R.) et de participants contrôles. Une première étude (Article 1) teste l’impact des modes de présentation et de rappel sur les effets de similarité phonologique et de catégorie sémantique de listes de mots. Une seconde étude (Article 2) évalue la contribution du code orthographique en mémoire à court terme (MCT) verbale en testant l’effet de la densité du voisinage orthographique des mots sur le rappel sériel immédiat de mots présentés visuellement. Compte tenu du rôle déterminant du code phonologique en MCT et du type d’atteinte de I.R., des effets linguistiques distincts étaient attendus chez elle et chez les contrôles. Selon le contexte de rappel, des effets sémantiques (Article 1) et orthographiques (Article 2) plus importants étaient prédits chez I.R. et des effets phonologiques plus marqués étaient attendus chez les participants contrôles. Chez I.R., le rappel est influencé par les caractéristiques sémantiques et orthographiques des mots, mais peu par leurs caractéristiques phonologiques et le contexte de rappel module l’utilisation de différents niveaux de représentations linguistiques. Chez les contrôles, une contribution relativement plus stable des représentations phonologiques est observée. Les données appuient une approche psycholinguistique qui postule que des mécanismes communs régissent la rétention à court terme verbale et le langage. Les implications théoriques et cliniques des résultats sont discutées en regard de modèles psycholinguistiques actuels. / The psycholinguistic view of verbal short-term retention suggests that verbal short-term retention and language processing rely on common mechanisms. It predicts that all linguistic characteristics of verbal items (e.g. phonological, lexical, semantic) influence their immediate recall (1). It also predicts that the relative contribution of the different linguistic representational levels is a function of the recall context (2). In this view, some experimental conditions (e.g. modes of presentation of stimuli) are thought to promote the use of specific coding. Two studies assess these predictions in a brain-damaged patient (I.R.) who shows a phonological deficit as well as in control participants. In a first article, the impact of presentation and recall modes on phonological and semantic similarity effects of words is tested. In a second article, the contribution of orthographic coding in verbal short-term memory (STM) is assessed by testing the effect of orthographic Neighborhood (N) density of words on immediate serial recall (ISR) of written words. Due to her phonological deficit and because phonological representations play a predominant role in STM, distinct linguistic effects were expected in I.R. and in controls. Overall, (and) depending on the recall context, larger semantic and orthographic effects were predicted in I.R. and larger phonological effects were predicted in controls. In I.R., the data indicate that recall is influenced by semantic and orthographic characteristics of items but less by their phonological properties. The results also indicate that the impact of representations depends of recall conditions. In controls, a different pattern of results is obtained, suggesting an overall predominant contribution of phonological representations. Results support the psycholinguistic view of verbal short-term retention and are discussed in regard to current interactive activation psycholinguistic models of verbal STM and language processing.

Text in English / Abstracts in Afrikaans and English / Ekspressiewe skryfwerk (ES) – as ‘n metode van intervensie gemik op fisiese en geesteswelstand van deelnemers – word reeds vir ongeveer drie dekades ondersoek. Klein en Boals beweer met hul 2001-studie dat ES ook ‘n positiewe invloed uitoefen op die werkende geheue van individue. Met die huidige studie word die vraag of hierdie bevinding ook van toepassing is op adolessente en jong volwassenes van Suidelike Afrika ondersoek. Dié projek betrek aanvanklik skoolleerders (N = 44) en eerstejaar universiteitstudente (N = 83) in die Suid-Kaap en met die skryfoefeninge word ‘n komponent bygevoeg by een van die eksperimentele groepe waar kognitiewe insette saam met die emosionele onthulling verlang word. Die studie-resultate toon heelwat teenstrydighede, dog die positiewe invloed van ES op die werkspan word by ‘n goeie aantal eksperimentele groep deelnemers waargeneem. Vorige navorsing dui op ‘n verlaging in die voorkoms van indringer- en vermydingsgedagtes na ES tesame met verbeterde werkspan en hierdie verband word van nader beskou deur die huidige studie. Die moontlikheid dat woordtelling per minuut as informele meting van werkspan aanvaar kan word, sowel as die moontlike verband tussen gemoedsvlak en skryfkondisie word ook met die projek ondersoek. / During the past three decades expressive writing has been in the research spotlight as an effective method of intervention in the improvement of human well-being. In 2001 a study done by Klein and Boals claimed that expressive writing also has a positive influence on the working memory of the student participants. The current study investigates the influence of expressive writing on adolescents and young adults in the Southern Africa context. Solution-focused exercises, together with emotional expression during the writing sessions, add a cognitive component to the intervention which strive to create greater impact on working memory capacity (WMC). Previous research indicate that improvement in WMC goes hand in hand with the reduction in the prevalence of intrusive and avoidant thoughts. During the current project the relationship between working memory and these thoughts is investigated. Additionally the possibility of word count as informal measure for WMC are looked at as well as a possible association between mood level and writing condition. / Psychology / M.A. (Psychology)

In dieser Arbeit werden zwei wesentliche neue Ergebnisse vorgestellt. Das erste bezieht sich auf die olfaktorische Kodierung und das zweite auf das sensorische Gedaechtnis. Beide Phaenomene werden am Beispiel des Gehirns der Honigbiene untersucht. In Bezug auf die olfaktorische Kodierung zeige ich, dass die neuronale Dynamik waehrend der Stimulation im Antennallobus duftspezifische Trajektorien beschreibt, die in duftspezifischen Attraktoren enden. Das Zeitinterval, in dem diese Attraktoren erreicht werden, betraegt unabhaengig von der Identitaet und der Konzentration des Duftes ungefaehr 800 ms. Darueber hinaus zeige ich, dass Support-Vektor Maschinen, und insbesondere Perzeptronen, ein realistisches und biologisches Model der Wechselwirkung zwischen dem Antennallobus (dem kodierenden Netwerk) und dem Pilzkoerper (dem dekodierenden Netzwerk) darstellen. Dieses Model kann sowohl Reaktionszeiten von ca. 300 ms als auch die Invarianz der Duftwahrnehmung gegenueber der Duftkonzentration erklaeren. In Bezug auf das sensorische Gedaechtnis zeige ich, dass eine einzige Stimulation ohne Belohnung dem Hebbschen Postulat folgend Veraenderungen der paarweisen Korrelationen zwischen Glomeruli induziert. Ich zeige, dass diese Veranderungen der Korrelationen bei 2/3 der Bienen ausreichen, um den letzten Stimulus zu bestimmen. In der zweiten Minute nach der Stimulation ist eine erfolgreiche Bestimmung des Stimulus nur bei 1/3 der Bienen moeglich. Eine Hauptkomponentenanalyse der spontanen Aktivitaet laesst erkennen, dass das dominante Muster des Netzwerks waehrend der spontanen Aktivitaet nach, aber nicht vor der Stimulation das duftinduzierte Aktivitaetsmuster bei 2/3 der Bienen nachbildet. Man kann deshalb die duftinduzierten (Veraenderungen der) Korrelationen als Spuren eines Kurzzeitgedaechtnisses bzw. als Hebbsche "Reverberationen" betrachtet werden. / Two major novel results are reported in this work. The first concerns olfactory coding and the second concerns sensory memory. Both phenomena are investigated in the brain of the honeybee as a model system. Considering olfactory coding I demonstrate that the neural dynamics in the antennal lobe describe odor-specific trajectories during stimulation that converge to odor-specific attractors. The time interval to reach these attractors is, regardless of odor identity and concentration, approximately 800 ms. I show that support-vector machines and, in particular perceptrons provide a realistic and biological model of the interaction between the antennal lobe (coding network) and the mushroom body (decoding network). This model can also account for reaction-times of about 300 ms and for concentration invariance of odor perception. Regarding sensory memory I show that a single stimulation without reward induces changes of pairwise correlation between glomeruli in a Hebbian-like manner. I demonstrate that those changes of correlation suffice to retrieve the last stimulus presented in 2/3 of the bees studied. Succesful retrieval decays to 1/3 of the bees within the second minute after stimulation. In addition, a principal-component analysis of the spontaneous activity reveals that the dominant pattern of the network during the spontaneous activity after, but not before stimulation, reproduces the odor-induced activity pattern in 2/3 of the bees studied. One can therefore consider the odor-induced (changes of) correlation as traces of a short-term memory or as Hebbian reverberations.

O estabelecimento das memórias de longo prazo requer uma efetiva comunicação do hipocampo com o neocortex. Um mecanismo plausível envolvido na comunicação neuronal e na plasticidade sináptica é a sincronização da atividade elétrica cerebral na frequência teta. Estudos recentes mostraram que a sincronização entre os ritmos teta do hipocampo e do córtex pré-frontal aumenta durante a evocação das memórias aversivas e diminui após a extinção do aprendizado. Entretanto, outros ritmos cerebrais, como as ondas delta, também estão envolvidos nas respostas comportamentais do medo e nos processos de memória. Desta forma, o ritmo teta, que já foi bastante estudado pelo seu papel no aprendizado e na memória, e o ritmo delta, por seu envolvimento no ciclo sono-vigília, foram investigados considerando a relação causal entre eles. Ainda não está bem estabelecido como os ritmos delta e teta podem juntos contribuir nos processos cognitivos ou como os ritmos do hipocampo podem influenciar ou receber influencias da atividade cortical. Neste trabalho foi investigada a contribuição dos ritmos delta e teta em função do estado comportamental (vigília ativa ou congelamento) e do tipo de memória evocada (recente ou remota). Além disso, foi realizada uma análise de sincronia de fase para inferir a dinâmica da atividade elétrica entre o córtex pré-frontal medial, o hipocampo e o córtex visual durante a evocação das memórias de medo. Para tanto, os animais foram treinados e testados numa tarefa de condicionamento de medo ao contexto. Neste tipo de condicionamento, o animal aprende a estabelecer uma associação entre um determinado contexto (caixa de condicionamento) e um evento aversivo (choque elétrico nas patas) que ocorreu neste contexto. Quando o animal foi reintroduzido na caixa de condicionamento, o mesmo exibiu uma série de respostas condicionadas incluindo a reação de congelamento. Os resultados mostraram que os ritmos delta e teta estão relacionados de forma específica às respostas comportamentais de medo e de evocação das memórias recente e remota. Observou-se no espectro de potências uma maior contribuição do ritmo teta durante a vigília exploratória, diminuindo durante o congelamento. Neste último, os ratos apresentaram um robusto aumento da contribuição do ritmo delta. Além disso, a medida de causalidade mostrou ser dependente do estado comportamental do animal. Finalmente, um aumento da sincronia entre o hipocampo e o córtex pré-frontal foi evidenciado durante a evocação de memória recente, contraposta à diminuição durante a evocação da memória remota. Estes resultados indicam que a sincronização da atividade elétrica cerebral pode refletir uma facilitação na comunicação neuronal / The establishment of long-term memories requires effective communication of the hippocampus to the neocortex. Electrophysiological activities between hippocampus and prefrontal cortex have shown higher theta synchronization during retrieval of aversive memories and lower during extinction learning. While theta activity is more differently related to learning and memory, delta waves have been more discussed in the context of sleep or \"offline\" states. Few studies have investigated delta waves during \"on-line\" states (such as task-relevant situations) and the contribution of these rhythms to memory storage remains unclear. We recorded electrophysiological data to study the contributions of delta and theta waves in cortico-hippocampal system of rats underwent to contextual fear conditioning. Our experiment consisted of environmental pre-exposition, training with electrical footshocks, and recent/remote memory tests. Two groups of rats were tested one or eighteen days post training for recent or remote memory, respectively. Local field potential time series of two behavioral states were sampled: active exploration and freezing. The results showed that theta and delta rhythms play an important role in behavioral responses and memory processing. They are related to fear recall and their contribution depend on the recent or remote memory. Additionally, using an order parameter we show that theta contribution is strongly pronounced in active exploration, decreasing during freezing. In the latter, the rats presented pronounced delta waves in freezing. Moreover, a behavioral-dependent causality measure showed an increase of theta influence in delta rhythms, resulting in a theta slowing in aversive memory retrieval. Finally, we show an increased synchrony between hippocampus and prefrontal cortex during recall of recent memory, but a decreased synchrony in remote memory. We proposed that synchronized activity may facilitate the communication of information and once the memories are established in the neocortex, the synchronization decreases, and recalling them becomes more independent of the hippocampus. We proposed that delta-theta oscillations of the hippocampus over neocortical areas reflect information processing during aversive memory retrieval