Thèses sur le sujet « Memoria verbale »

Si sono studiati i correlati neurali dei sistemi di memoria verbale in pazienti con glioma cerebrale. Si tratta di pazienti sottoposti ad asportazione di lesioni cerebrali dell’emisfero dominante, in cui le funzioni mnestiche sono state valutate mediante prove specifiche prima e dopo l’intervento chirurgico, per verificare l’impatto funzionale dell’espanso e della rimozione della lesione. L’indagine anatomo-funzionale si è inoltre avvalsa delle tecniche di mappaggio cerebrale in awake surgery laddove l’intervento è stato eseguito in anestesia asleep-awake per la rimozione dei tumori estesi alle aree del linguaggio. Nel primo studio si esamina l’impatto della crescita tumorale sulla memoria verbale: le valutazioni neuropsicologiche effettuate pre-trattamento hanno permesso di identificare difficoltà conclamate o lievi compromissioni, che variano in funzione delle aree di infiltrazione tumorale; la prospettiva anatomo-clinica ha fornito una conferma dell’esistenza di sistemi di memoria verbale in distretti anatomo-funzionali differenti. Il secondo studio esamina i correlati neurali della memoria verbale a breve termine in un gruppo di pazienti sottoposti a mappaggio cerebrale in awake surgery: la stimolazione corticale e sottocorticale diretta ha permesso di identificare un circuito fronto-parietale coinvolto nei processi di MBT; l’analisi degli errori registrati durante i test intraoperatori ha permesso inoltre di distinguere il substrato neurale delle due componenti del circuito fonologico. Il terzo studio valuta gli effetti della lobectomia temporale sulla memoria a lungo termine; le prove mnestiche somministrate ad una settimana dall’intervento e dopo tre mesi hanno evidenziato prestazioni patologiche che non vanno incontro ad un rapido recupero nei pazienti che hanno subito la rimozione di un circuito cortico-sottocorticale esteso dalle regioni temporo-polari a quelle temporali mesiali; lo studio anatomico mediante voxel-based lesion-symptom mapping delle aree asportate ha permesso di verificare i correlati neurali di memoria semantica e apprendimento verbale. Questi risultati confermano che i pazienti con tumore cerebrali possono fornire dati interessanti nello studio dei deficit neuropsicologici.

This thesis addressed two key issues. The first was the extent to which verbal short-term memory (STM) for item and order information can be differentiated in terms of their underlying neural mechanisms. The second was to analyze the relative contributions of item and order STM to vocabulary learning in bilingual (BL) and monolingual (ML) children and ML adults. The first issue was addressed with four studies. Three used electroencephalography (EEG) with ML adults, BL adults and ML children. The aim was to determine whether there is any evidence that the two types of verbal STM have different neural signatures. The fourth study used transcranial magnetic stimulation (TMS) in ML adults to test the hypothesis that the right intraparietal sulcus (IPS) is involved in order STM but not item STM. The second issue was addressed by two behavioural studies. The first was a large-scale longitudinal study testing item and order STM in relation to natural vocabulary acquisition in 7 to 10 year old BL and ML children. The children were tested once in the beginning and once in the end of the school year. In addition, ML children learning a second language were examined in the end of the school year. The second behavioural study explored therelationship of item and order STM with new-word-learning in ML adults using artificially-created nonwords. Some evidence was found to support the view that the distinction of item and order STM is a useful one. Results of the EEG data suggested differences in patterns of neuro-electrical activity for ML and BL adults and ML children when they are performing item STM and order STM tasks. The results suggest that order STM is important for new word learning in one´s native language learning, where there has already been some exposure to this language, but not in complete novice language learners.

Selon la théorie du replay, le sommeil améliore la consolidation mnésique des apprentissages récents à travers leur réactivation. Pour tester cette hypothèse, nous avons utilisé le modèle de la somniloquie : les paroles nocturnes reflétant le contenu mental du dormeur et les informations qu’il est en train de traiter. La somniloquie survient fréquemment dans le cadre de parasomnies de sommeil lent (somnambulisme) ou de sommeil paradoxal (TCSP). Nous avons d’abord montré comment ces deux parasomnies correspondaient à la mise en gestes et en paroles du contenu mental du dormeur, avec une prédominance en sommeil lent de rêves de catastrophes que les somnambules fuyaient et en sommeil paradoxal, de rêves d’agressions d’animaux ou de personnes que les patients contre-attaquaient. Ceci soutient le concept de la fonction évolutionniste des rêves comme un entraînement virtuel à « fuir ou combattre » les menaces. Ensuite, nous avons utilisé les somniloquies pour tester si un apprentissage verbal récent était consolidé pendant le sommeil mais aussi si certains mots étaient répétés en dormant. Nous avons d’abord montré que la consolidation mnésique verbale liée au sommeil était bien conservée chez les somnambules comme chez les patients atteints de TCSP, même déments, comparée aux sujets normaux. Ensuite, nous n’avons pas identifié de réexécution de phrases apprises la veille lors des somniloquies de sommeil lent, mais avons identifié chez un patient avec TCSP, un élément sémantique évoquant une réutilisation du contexte de l’histoire. Enfin, nous avons collecté 883 verbatim nocturnes et décrit les aspects acoustico-phonétiques, prosodiques et sémantiques du langage nocturne
According to the replay theory, sleep improves memory consolidation of recent learning through their reactivation. To test this hypothesis, we used the model of sleep-talking: the words uttered reflecting the mental content of the sleeper and the information he is proceeding. Sleep-talking occur frequently within the context of slow wave sleep (sleepwalking) or REM sleep parasomnias (RBD). We first showed how these two parasomnias corresponded to the setting gestures and words of the mental content of the sleeper, with predominance during slow wave sleep of dreams featuring disasters that sleepwalkers fleeing, and during REM sleep of dreams of attacks by animals or people that subjects counterattack. This supports the concept of evolutionary function of dreams as a virtual drive to “fight or flight” threats. Then, we used sleep-talking to test if a recent verbal was not only consolidated during sleep but also if some words were repeated while sleeping. We first showed that verbal memory consolidation related to sleep was preserved in sleepwalkers as in patients with RBD, even with dementia, compared with normal subjects. Then, we haven’t identified rehearsed sentences of the material learned the day before during slow wave sleep parasomnias, but we identified in a subject with RBD, a semantic component evoking a rehearse of the context of the learned history. Finally, we collected 883 verbatim during sleep and describes the acoustic-phonetic, prosodic and semantic aspects of sleep-talking

The understanding of information encoding and retrieval processes in working memory is one of the fundamental problems of cognitive psychology. Information monitoring tasks, in which the current status of changing information is tracked, are claimed to require the use of updating processes in working memory. This thesis examines updating in the running ' memory span task (Pollack, Johnson, & Knaff, 1959), a task requiring the reporting of the most recent items from a continuous stream of spoken information. The aim is to better understand updating of working memory in terms of the processes that are employed during encoding and the memory structures associated with recall. Empirical data and ACT-R . cognitive models are used to compare one theory ~laiming that verbal information . is stored in the phonological loop, and updated via associated positional information under the control of a supervisory central executive (Morris & Jones, 1990), with a recency-based account, in which updating arises from storage of items in episodic memory (Ruiz, Elosua, & Lechuga, 2005). This research argues against a unitary account of updating. Examining the impact of a range of different rehearsal strategies on recall revealed significant improvements in running memory span when participants were trained to use active rehearsal strategies compared with recall following the passive encoding of items. Further increases in span were observed with increasing organisation in rehearsal. Six major strategies were identified by self-report, when varying presentation rate and memory load. These included shadowing of the current item, updating rehearsal of a list ofrecently presented items and rehearsing adhoc lists when memory load restricted the use o~task specific strategies. The key finding is that the selection ofrehearsal strategies depends systematically on task conditions. ACT-R models of encoding and retrieval supported empirical findings demonstrating that key rehearsal strategies were associated with complex patterns of recall, requiring encoding of items into both a phonological loop and episodic memory. These findings reveal a varied and diverse account of memory updating processes, based around the use of rehearsal strategies and the availability of working memory structures for tracking and updating of verbal working memory.

Acute exposure to light within the blue wavelengths has been shown to enhance alertness and vigilance, and lead to improved speed on reaction time tasks, possibly due to activation of the noradrenergic system. It remains unclear, however, whether the effects of blue light extend beyond simple alertness processes to also enhance other aspects of cognition, such as memory performance. The aim of this study was to investigate the effects of a thirty minute pulse of blue light versus placebo (amber light) exposure in healthy normally rested individuals in the morning during verbal memory consolidation (i.e., 1.5 hours after memory acquisition) using an abbreviated version of the California Verbal Learning Test (CVLT-II). At delayed recall, individuals who received blue light (n = 12) during the consolidation period showed significantly better long-delay verbal recall than individuals who received amber light exposure (n = 18), while controlling for the effects of general intelligence, depressive symptoms and habitual wake time. These findings extend previous work demonstrating the effect of blue light on brain activation and alertness to further demonstrate its effectiveness at facilitating better memory consolidation and subsequent retention of verbal material. Although preliminary, these findings point to a potential application of blue wavelength light to optimize memory performance in healthy populations. It remains to be determined whether blue light exposure may also enhance performance in clinical populations with memory deficits.

Introducción: El lenguaje es una habilidad esencial para el ser humano ya que es la base de la comunicación. Dentro de las funciones cerebrales superiores la memoria y el lenguaje están sujetos a sufrir alteraciones como las que pueden evidenciarse en un cuadro de afasia, en donde existen problemas en la comprensión auditiva, memoria de trabajo verbal y lenguaje en general. Objetivos: Este estudio pretende evaluar, relacionar y comparar el déficit de la memoria de trabajo y las alteraciones en la compresión auditiva en sujetos afásicos fluentes y no fluentes. Metodología: La muestra está compuesta por 10 individuos con afasia fluente y 7 no fluente con diagnóstico neurológico de accidente cerebro vascular isquémico o hemorrágico de arteria cerebral media izquierda, sin alteraciones sensoriales o cognitivas. La recolección de datos fue realizada mediante la utilización de la ficha clínica, la aplicación del Token Test y del Spam de dígitos directos de la Escala de Memoria de Wechsler. Resultados: No se evidenciaron diferencias estadísticamente significativas en los desempeños en memoria de trabajo y comprensión auditiva entre afásicos fluentes y no fluentes, junto con esto no existe una relación significativa entre el desempeño en la memoria de trabajo y el déficit de comprensión auditiva. Discusión: Un análisis descriptivo evidencia variaciones en los desempeños de ambos grupos de afásicos tanto en memoria de trabajo como en comprensión auditiva, lo que se explica por la localización anatómica de las funciones antes evaluadas en relación al sitio de la lesión de los tipos de afasia estudiados.
Introduction: Language is an essential skill for the humans because it is the basis of communication. Within the higher brain functions, memory and language are subject to be altered as may be evidenced in aphasia, in this can exist problems with listening comprehension, verbal working memory and language in general. Objectives: This study aims to evaluate, relate and compare the deficit of working memory and alterations in the listening comprehension in fluent and non-fluent aphasic subjects. Methodology: The sample consists of 10 subjects with fluent aphasia and 6 non-fluent with neurologic diagnosis of ischemic or hemorrhagic cerebrovascular accident of middle left cerebral artery, without sensory or cognitive impairments. Data collection was performed using the clinical record, the implementation of the Token Test and Spam direct digits of the Wechsler's Memory Scale. Results: Not exist statistically significant differences in the results in working memory and listening comprehension between fluent and non-fluent aphasic, also not exist a significant relationship between performance in working memory and auditive comprehension deficits. Discussion: A qualitative analysis indicates variations in the performances of the two groups of aphasic in working memory and listening comprehension, this is explained for the anatomical localization of function before evaluated and the lesion sites of the different types of aphasia.

This study investigated the verbal credibility of incarcerated offenders’ memory reports of perpetrated violent crime through the use of Criteria Based Content Analysis (CBCA) and Reality Monitoring (RM). For a previous study, which examined memory in violent offenders, 150 male incarcerated violent crime perpetrators recalled up to five different types of memories: an act of perpetrated instrumental violence, an act of perpetrated reactive violence, a subjectively disturbing (traumatic) event, a positively valenced event, and a perpetrated act of violence for which the offender had poor memory (Cooper, 2005). The present study applied CBCA and RM to each of the memory reports of violence. In particular, this study compared the credibility of reports of instrumental violence to reports of reactive violence, compared credibility ratings with consistency with file information (whether details from memory reports were corroborated by correctional file information), compared the utility of CBCA and RM as credibility assessment tools, and compared the credibility ratings of psychopaths to nonpsychopaths. The results showed that the vast majority (96%) of the memories were judged to be credible according to CBCA. CBCA proved to be somewhat effective at discriminating memories based on consistency with file information, as every memory partially confirmed by correctional file information was found credible according to CBCA, and every memory found noncredible according to CBCA was not confirmed or was partially contradicted by correctional file information. RM, as measured by the Memory Characteristics Questionnaire, showed limited effectiveness in discriminating memories based on consistency with file information. Further, CBCA and RM were not similarly effective at discriminating memories based on the known truth of the memories. RM differentiated memories according to type of violence, but CBCA did not, suggesting that while memories for acts of instrumental violence are more vivid and detailed than memories for acts of reactive violence, they are not more likely to appear credible. Neither RM nor CBCA differentiated memory reports according to whether the participant met the diagnostic criteria for psychopathy. These results are discussed in terms of how they support existing research and theory. Their implications to the criminal justice system are discussed.

This dissertation attempts to provide a comprehensive view of the role of verbal processing in face recognition memory by examining some of the neglected issues in two streams of cognitive research, face recognition and verbal overshadowing. Traditionally, research in face recognition focuses on visual and semantic aspects of familiar and unfamiliar face processing, with little acknowledgement of any verbal aspect. By contrast, the verbal overshadowing literature examines the effect of verbal retrieval of unfamiliar face memory on subsequent recognition, with little attention to actual mechanisms underlying processing of these faces. Although both are concerned with our ability to recognise faces, they have proceeded independently as their research focus is diverse. It therefore remains uncertain whether or not face encoding entails verbal processing, and whether or not verbal processing is always detrimental to face recognition. To address these issues, some experimental techniques used in face recognition research were combined with methods from verbal overshadowing research. The first strand of experiments examined configural-visual and featural-verbal processing associations in change recognition tasks. The second strand systematically examined the role of verbal processing in recognition memory by manipulating the degree of verbal involvement during and after encoding. The third strand examined the ‘perceptual expertise’ account of verbal overshadowing in picture recognition memory tasks, involving pictures of familiar and unfamiliar people. The fourth strand directly tested a tentative hypothesis ‘verbal code interference’ to explain verbal overshadowing by manipulating the frequency and time of face verbalisation in line-up identification tasks. The concluding experiment looked at the relation between intentional learning and verbal overshadowing in a recognition memory task using more naturalistic stimuli. The main findings indicate first, that mechanisms underlying face processing appear to be complex, and simple processing associations (configural-visual and featural-verbal processing) cannot be made. Second, face encoding seems to involve some sort of verbal processing which may actually be necessary for successful recognition. Third, post-encoding verbalisation per se does not seem to be the key determiner for recognition impairment. Rather, the interference between verbal representations formed under different contexts seems to harm recognition. Fourth, verbal overshadowing was found only for unfamiliar face picture recognition, but not for familiar face picture recognition, casting a doubt on ‘perceptual expertise account’. Finally, although no clear evidence linking intentional learning and verbal overshadowing was found, intentional learning and verbalisation in combination affected a response pattern. These results were discussed in relation to ongoing debate over causes of the verbal overshadowing effect, which raises an important ecological question as to whether the phenomenon might reflect natural human memory interference.

Closed head injury (CHI) typically results in diffuse damage to the brain with particular damage to the frontal and temporal regions. Individuals who have suffered a CHI often exhibit impaired verbal learning and memory. It has been noted that CHI individuals do not use semantic organizational encoding strategies to the same degree as non-CHI individuals. This failure is presumed to contribute to the observed verbal learning and memory impairment and is likely associated with frontal region damage and related frontal system dysfunction. The purposes of this study were to (a) investigate the effect of providing CHI subjects with guided semantic encoding and (b) describe the nature of the relationship between frontal system functioning and ability to benefit from guided semantic encoding. Twenty-four closed head injured subjects and 24 demographically matched control subjects participated in this study. Verbal learning and memory was measured using the California Verbal Learning Test (CVLT; Delis, Kramer, Kaplan, & Ober, 1987). The CVLT involves learning a sixteen word list containing four words from four categories. The CVLT was administered in both standard and non-standard, guided semantic encoding formats. Frontal system functioning was measured with the Wisconsin Card Sorting Test (Grant & Berg, 1948) and FAS Generative Naming (Borkowski, Benton & Spreen, 1967). Results from this study indicate that verbal learning and memory performance improves following guided semantic encoding. CHI subjects benefit to relatively the same degree as control subjects. This suggests that, with external guidance, CHI subjects have the ability to benefit from organizational cuing in a qualitatively similar manner to control subjects. However, performance of CHI subjects did not reach that of controls, even with guided semantic encoding, indicating additional processing deficits. Guided semantic encoding facilitates performance for both low and high frontal system functioning subjects on free and cued recall tests. Guided semantic encoding particularly helps low frontal system functioning CHI subjects in long delay recall and recognition discriminability. The finding that CHI subjects take advantage of semantic encoding strategies, when encouraged to do so, is similar to that reported for Korsakoff's syndrome and focal frontal lesion patients.

This thesis uses visual imagery tasks (mental rotation and mental subtraction) to examine verbal interference and verbal facilitation in visual memory. It demonstrates how task demands can mediate the verbal interference and verbal facilitation effects in visual imagery. Using the mental rotation paradigm, this thesis places a focus upon the method of stimulus presentation during the learning phase and the test. It demonstrates how a presentation method that emphasizes serial order (the temporal presentation method) can elicit positive effects of covert spontaneous naming during both encoding and retrieval. In contrast, a presentation method that emphasizes spatial information does not show a significant role for covert spontaneous naming during encoding or retrieval. Further, under temporal presentation conditions, explicit labelling during encoding (via the use of either self-generated or experimenter-generated labels) is found to show an interfering effect compared to covert spontaneous naming. Using experimenter-generated labels, it is found that re-presenting the explicit verbal labels as cues at retrieval removes the interfering effects of explicit labelling during encoding and enhances performance. In addition, reducing exposure to explicit verbal labels during encoding is found to be a possible method for removing the negative effect of explicit verbal labels during encoding. Finally, the positive effect of covert spontaneous naming and the negative effect of explicit labelling are replicated using a different mental subtraction paradigm. Overall, the findings indicate that task demands determine the role of the verbal code in visual imagery. Hence, there is no unified theory to account for the role of the verbal code in visual memory, but different theories can be applied under different conditions.

Die vorliegende Arbeit widmet sich der Repräsentation und Verarbeitung arithmetischer Fakten. Dieser Bereich semantischen Wissens eignet sich unter anderem deshalb besonders gut als Forschungsgegenstand, weil nicht nur seine einzelne Bestandteile, sondern auch die Beziehungen dieser Bestandteile untereinander außergewöhnlich gut definierbar sind. Kognitive Modelle können also mit einem Grad an Präzision entwickelt werden, der in anderen Bereichen kaum je zu erreichen sein wird. Die meisten aktuellen Modelle stimmen darin überein, die Repräsentation arithmetischer Fakten als eine assoziative, netzwerkartig organisierte Struktur im deklarativen Gedächtnis zu beschreiben. Trotz dieser grundsätzlichen Übereinstimmung bleibt eine Reihe von Fragen offen. In den hier vorgestellten Untersuchungen werden solche offene Fragen in Hinsicht auf drei verschiedene Themenbereiche angegangen: 1) die neuroanatomischen Korrelate 2) Nachbarschaftskonsistenzeffekte bei der verbalen Produktion sowie 3) die automatische Aktivierung arithmetischer Fakten. In einer kombinierten fMRT- und Verhaltensstudie wurde beispielsweise der Frage nachgegangen, welche neurofunktionalen Entsprechungen es für den Erwerb arithmetischer Fakten bei Erwachsenen gibt. Den Ausgangspunkt für diese Untersuchung bildete das Triple-Code-Modell von Dehaene und Cohen, da es als einziges auch Aussagen über neuroanatomische Korrelate numerischer Leistungen macht. Das Triple-Code-Modell geht davon aus, dass zum Abruf arithmetischer Fakten eine „perisylvische“ Region der linken Hemisphäre unter Einbeziehung der Stammganglien sowie des Gyrus angularis nötig ist (Dehaene & Cohen, 1995; Dehaene & Cohen, 1997; Dehaene, Piazza, Pinel, & Cohen, 2003). In der aktuellen Studie sollten gesunde Erwachsene komplexe Multiplikationsaufgaben etwa eine Woche lang intensiv üben, so dass ihre Beantwortung immer mehr automatisiert erfolgt. Die Lösung dieser geübten Aufgaben sollte somit – im Gegensatz zu vergleichbaren ungeübten Aufgaben – immer stärker auf Faktenabruf als auf der Anwendung von Prozeduren und Strategien beruhen. Hingegen sollten ungeübte Aufgaben im Vergleich zu geübten höhere Anforderungen an exekutive Funktionen einschließlich des Arbeitsgedächtnisses stellen. Nach dem Training konnten die Teilnehmer – wie erwartet – geübte Aufgaben deutlich schneller und sicherer beantworten als ungeübte. Zusätzlich wurden sie auch im Magnetresonanztomografen untersucht. Dabei konnte zunächst bestätigt werden, dass das Lösen von Multiplikationsaufgaben allgemein von einem vorwiegend linkshemisphärischen Netzwerk frontaler und parietaler Areale unterstützt wird. Das wohl wichtigste Ergebnis ist jedoch eine Verschiebung der Hirnaktivierungen von eher frontalen Aktivierungsmustern zu einer eher parietalen Aktivierung und innerhalb des Parietallappens vom Sulcus intraparietalis zum Gyrus angularis bei den geübten im Vergleich zu den ungeübten Aufgaben. So wurde die zentrale Bedeutung von Arbeitsgedächtnis- und Planungsleistungen für komplexe ungeübte Rechenaufgaben erneut herausgestellt. Im Sinne des Triple-Code-Modells könnte die Verschiebung innerhalb des Parietallappens auf einen Wechsel von quantitätsbasierten Rechenleistungen (Sulcus intraparietalis) zu automatisiertem Faktenabruf (linker Gyrus angularis) hindeuten. Gibt es bei der verbalen Produktion arithmetischer Fakten Nachbarschaftskonsistenzeffekte ähnlich zu denen, wie sie auch in der Sprachverarbeitung beschrieben werden? Solche Effekte sind nach dem aktuellen „Dreiecksmodell“ von Verguts & Fias (2004) zur Repräsentation von Multiplikationsfakten erwartbar. Demzufolge sollten richtige Antworten leichter gegeben werden können, wenn sie Ziffern mit möglichst vielen semantisch nahen falschen Antworten gemeinsam haben. Möglicherweise sollten demnach aber auch falsche Antworten dann mit größerer Wahrscheinlichkeit produziert werden, wenn sie eine Ziffer mit der richtigen Antwort teilen. Nach dem Dreiecksmodell wäre darüber hinaus sogar der klassische Aufgabengrößeneffekt bei einfachen Multiplikationsaufgaben (Zbrodoff & Logan, 2004) auf die Konsistenzverhältnisse der richtigen Antwort mit semantisch benachbarten falschen Antworten zurückzuführen. In einer Reanalyse der Fehlerdaten von gesunden Probanden (Campbell, 1997) und einem Patienten (Domahs, Bartha, & Delazer, 2003) wurden tatsächlich Belege für das Vorhandensein von Zehnerkonsistenzeffekten beim Lösen einfacher Multiplikationsaufgaben gefunden. Die Versuchspersonen bzw. der Patient hatten solche falschen Antworten signifikant häufiger produziert, welche die gleiche Zehnerziffer wie das richtigen Ergebnisses aufwiesen, als ansonsten vergleichbare andere Fehler. Damit wird die Annahme unterstützt, dass die Zehner- und die Einerziffern zweistelliger Zahlen separate Repräsentationen aufweisen – bei der Multiplikation (Verguts & Fias, 2004) wie auch allgemein bei numerischer Verarbeitung (Nuerk, Weger, & Willmes, 2001; Nuerk & Willmes, 2005). Zusätzlich dazu wurde in einer Regressionsanalyse über die Fehlerzahlen auch erstmalig empirische Evidenz für die Hypothese vorgelegt, dass der klassische Aufgabengrößeneffekt beim Abruf von Multiplikationsfakten auf Zehnerkonsistenzeffekte zurückführbar ist: Obwohl die Aufgabengröße als erster Prädiktor in das Modell einging, wurde diese Variable wieder verworfen, sobald ein Maß für die Nachbarschaftskonsistenz der richtigen Antwort in das Modell aufgenommen wurde. Schließlich wurde in einer weiteren Studie die automatische Aktivierung von Multiplikationsfakten bei gesunden Probanden mit einer Zahlenidentifikationsaufgabe (Galfano, Rusconi, & Umilta, 2003; Lefevre, Bisanz, & Mrkonjic, 1988; Thibodeau, Lefevre, & Bisanz, 1996) untersucht. Dabei sollte erstmals die Frage beantwortet werden, wie sich die automatische Aktivierung der eigentlichen Multiplikationsergebnisse (Thibodeau et al., 1996) zur Aktivierung benachbarter falscher Antworten (Galfano et al., 2003) verhält. Ferner sollte durch die Präsentation mit verschiedenen SOAs der zeitliche Verlauf dieser Aktivierungen aufgeklärt werden. Die Ergebnisse dieser Studie können insgesamt als Evidenz für das Vorhandensein und die automatische, obligatorische Aktivierung eines Netzwerkes arithmetischer Fakten bei gesunden, gebildeten Erwachsenen gewertet werden, in dem die richtigen Produkte stärker mit den Faktoren assoziiert sind als benachbarte Produkte (Operandenfehler). Dabei führen Produkte kleiner Aufgaben zu einer stärkeren Interferenz als Produkte großer Aufgaben und Operandenfehler großer Aufgaben zu einer stärkeren Interferenz als Operandenfehler kleiner Aufgaben. Ein solches Aktivierungsmuster passt gut zu den Vorhersagen des Assoziationsverteilungsmodells von Siegler (Lemaire & Siegler, 1995; Siegler, 1988), bei dem kleine Aufgaben eine schmalgipflige Verteilung der Assoziationen um das richtige Ergebnis herum aufweisen, große Aufgaben jedoch eine breitgipflige Verteilung. Somit sollte die vorliegende Arbeit etwas mehr Licht in bislang weitgehend vernachlässigte Aspekte der Repräsentation und des Abrufs arithmetischer Fakten gebracht haben: Die neuronalen Korrelate ihres Erwerbs, die Konsequenzen ihrer Einbindung in das Stellenwertsystem mit der Basis 10 sowie die spezifischen Auswirkungen ihrer assoziativen semantischen Repräsentation auf ihre automatische Aktivierbarkeit. Literatur Campbell, J. I. (1997). 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Neighborhood Effects in Mental Arithmetic. Psychology Science. Zbrodoff, N. J. & Logan, G. D. (2004). What everyone finds: The problem-size effect. In J. I. D. Campbell (Hrsg.), Handbook of Mathematical Cognition (pp.331-345). New York, NY: Psychology Press.
The present thesis deals with the representation and processing of arithmetic facts. This domain of semantic knowledge has gained a substantial amount of interest as its components as well as their interrelations are well specified. Thus, cognitive models can be developed with a degree of precision, which cannot be reached in many other domains. Most recent models agree that arithmetic facts are represented in an associative, network-like structure in declarative memory. Despite this general agreement a lot of issues still remain unresolved. The open questions tackled in the present work address three different aspects of arithmetic facts: 1) their neuro-anatomical correlates, 2) neighbourhood consistency effects in their verbal production and 3) their automatic activation. In a combined behavioural and fMRI study the neurofunctional correlates of the acquisition of arithmetic facts in adults were examined. This research was based on the Triple-Code-Model of Dehaene and Cohen, the only recent model which makes explicit assumptions on neuroanatomical correlates of numerical abilities. The Triple-Code-Model assumes that a “perisylvian” region in the left hemisphere including the basal ganglia and the Angular Gyrus is involved in the retrieval of arithmetic facts (Dehaene & Cohen, 1995; Dehaene & Cohen, 1997; Dehaene, Piazza, Pinel, & Cohen, 2003). In the present study healthy adults were asked to train complex multiplication problems extensively during one week. Thus, these problems could be solved more and more automatically. It was reasoned that answering these trained problems should more and more rely on the retrieval of facts from declarative memory, whereas answering untrained problems should rely on the application of strategies and procedures, which impose high demands on executive functions including working memory. After the training was finished, participants – as expected – could solve trained problems faster and more accurately than non-trained problems. Participants were also submitted to a functional magnetic resonance imaging examination. In general, this examination added to the evidence for a mainly left hemispheric fronto-parietal network being involved in mental multiplication. Crucially, comparing trained with non-trained problems a shift of activation from frontal to more parietal regions was observed. Thus, the central role of central executive and working memory for complex calculation was highlighted. Moreover, a shift of activation from the Intraparietal Sulcus to the Angular Gyrus took place within the parietal lobe. According to the Triple-Code-Model, this shift may be interpreted to indicate a strategy change from quantity based calculation, relying on the Intraparietal Sulcus, to fact retrieval, relying on the left Angular Gyrus. Are there neighbourhood consistency effects in the verbal production of arithmetic facts similar to what has been described for language production? According to the “Triangle Model” of simple multiplication, proposed by Verguts & Fias (2004), such effects can be expected. According to this model corrects answers can be given more easily if they share digits with many semantically close wrong answers. Moreover, it can be assumed that wrong answers, too, are more likely to be produced if they share a digit with the correct result. In addition to this, the Triangle Model also states that the classical problem size effect in simple multiplication (Zbrodoff & Logan, 2004) can be drawn back to neighbourhood consistency between the correct result and semantically close wrong answers. In fact, a re-analysis of error data from a sample of healthy young adults (Campbell, 1997) and a patient with acalculia (Domahs, Bartha, & Delazer, 2003) provided evidence for the existence of decade consistency effects in the verbal production of multiplication results. Healthy participants and the patient produced significantly more wrong answers which shared the decade digit with the correct result than otherwise comparable wrong answers. This result supports the assumption of separate representations of decade and unit digits in two-digit numbers in multiplication (Verguts & Fias, 2004) and in number processing in general (Nuerk, Weger, & Willmes, 2001; Nuerk & Willmes, 2005). Moreover, an additional regression analysis on the error rates provided first empirical evidence for the hypothesis that the classical problem size effect in the retrieval of multiplication facts may be an artefact of neighbourhood consistency: Although problem size was the first variable to enter the model, it was excluded from the model once a measure for neighbourhood consistency was included. Finally, in a further study the automatic activation of multiplication facts was examined in a number matching task (Galfano, Rusconi, & Umilta, 2003; Lefevre, Bisanz, & Mrkonjic, 1988; Thibodeau, Lefevre, & Bisanz, 1996). This experiment addressed the question how the automatic activation of actual multiplication results (Thibodeau et al., 1996) relates to the activation of semantically close wrong answers (Galfano et al., 2003). Furthermore, using different SOAs the temporal properties of these activations should be disclosed. In general, the results of this study provide evidence for an obligatory and automatic activation of a network of arithmetic facts in healthy educated adults in which correct results are stronger associated with the operands than semantically related wrong answers. Crucially, products of small problems lead to stronger interference effects than products of larger problems while operand errors of large problems lead to stronger interference effects than operand errors of small problems. Such a pattern of activation is in line with predictions of Siegler’s Distribution of Associations Model (Lemaire & Siegler, 1995; Siegler, 1988) which assumes a more peaked distribution of associations between operands and potential results for small compared to large multiplication problems. In sum, the present thesis should shed some light into largely ignored aspects of arithmetic fact retrieval: The neural correlates of its acquisition, the consequences of its implementation in the base 10 place value system, as well as the specific effects of its semantic representation for automatic activation of correct multiplication facts and related results. References Campbell, J. I. (1997). On the relation between skilled performance of simple division and multiplication. Journal of Experimental Psychology: Learning, Memory, and Cognition, 23, 1140-1159. Dehaene, S. & Cohen, L. (1995). Towards an anatomical and functional model of number processing. Mathematical Cognition, 1, 83-120. Dehaene, S. & Cohen, L. (1997). Cerebral pathways for calculation: double dissociation between rote verbal and quantitative knowledge of arithmetic. Cortex, 33, 219-250. Dehaene, S., Piazza, M., Pinel, P., & Cohen, L. (2003). Three parietal circuits for number processing. Cognitive Neuropsychology, 20, 487-506. Domahs, F., Bartha, L., & Delazer, M. (2003). Rehabilitation of arithmetic abilities: Different intervention strategies for multiplication. Brain and Language, 87, 165-166. Galfano, G., Rusconi, E., & Umilta, C. (2003). Automatic activation of multiplication facts: evidence from the nodes adjacent to the product. Quarterly Journal of Experimental Psychology A, 56, 31-61. Lefevre, J. A., Bisanz, J., & Mrkonjic, L. (1988). Cognitive arithmetic: evidence for obligatory activation of arithmetic facts. Memory and Cognition, 16, 45-53. Lemaire, P. & Siegler, R. S. (1995). Four aspects of strategic change: contributions to children's learning of multiplication. Journal of Experimental Psychology: General, 124, 83-97. Nuerk, H. C., Weger, U., & Willmes, K. (2001). Decade breaks in the mental number line? Putting the tens and units back in different bins. Cognition, 82, B25-B33. Nuerk, H. C. & Willmes, K. (2005). On the magnitude representations of two-digit numbers. Psychology Science, 47, 52-72. Siegler, R. S. (1988). Strategy choice procedures and the development of multiplication skill. Journal of Experimental Psychology: General, 117, 258-275. Thibodeau, M. H., Lefevre, J. A., & Bisanz, J. (1996). The extension of the interference effect to multiplication. Canadian Journal of Experimental Psychology, 50, 393-396. Verguts, T. & Fias, W. (2004). Neighborhood Effects in Mental Arithmetic. Psychology Science. Zbrodoff, N. J. & Logan, G. D. (2004). What everyone finds: The problem-size effect. In J. I. D. Campbell (Ed.), Handbook of Mathematical Cognition (pp.331-345). New York, NY: Psychology Press.

At the beginning of this work, recent studies had evidenced a tight link between serial order in verbal working memory and space processing. In a first study, we investigated the nature of this link. By discarding the possibility that it results from conceptual associations, our results favoured the idea that the representation of serial order is intrinsically of a spatial nature. This led us to hypothesize that a deficit of space processing should be accompanied by a deficit of serial order. To test this hypothesis, we investigated verbal working memory abilities in a group of brain-damaged patients with hemispatial neglect, a syndrome characterized by a deficit of spatial attention. We showed that these patients have a specific deficit for serial order, as they showed difficulties when judging the ordinal relations between memorized items, whereas they were able to judge the identity of these items. This deficit of serial order was related to hemispatial neglect severity and to posterior parietal lesions. We formulated the hypothesis that the link between serial order and space results from the overlap of brain networks subtending these cognitive processes, at the level of the posterior parietal cortex. To test this hypothesis, we used transcranial magnetic stimulation (TMS) to temporarily disrupt this area in healthy participants, with the prediction that TMS would induce a similar bias when judging the position of a landmark on horizontal lines (spatial task), and when judging the position of an item in memorized sequences (ordinal task). In line with previous studies, TMS induced a bias in the spatial task. However, contrary to our prediction, TMS over the same area in the same participants did not induce a similar bias in the ordinal task.
Doctorat en Sciences psychologiques et de l'éducation
info:eu-repo/semantics/nonPublished

This thesis considers the contribution of semantic cognition to verbal short-term memory (STM) in three groups of brain damaged patients. It directly compares patient groups that are typically studied separately. Patients with semantic dementia (SD) suffer a loss of core semantic representations and make phonological errors in STM tasks, suggesting that semantic knowledge binds phonological information.

Remembering the sound of a new word when it is first encountered is an important skill which plays a critical role in the development of vocabulary (Gathercole & Baddeley, 1989), yet the mechanisms underlying this form of verbal short-term memory are not well understood. Errors in the repetition and serial recall of nonwords indicate that structural properties of the syllable are represented in short-term memory, but existing accounts of serial learning and recall do not incorporate any representation of linguistic structure. Models of speech production implicate syllable structure in the representation of phonological form, but do not explain how such representations are acquired. This thesis draws together theories of speech production and serial memory to develop a computational model of nonword repetition based on the novel idea that short-term memory for the serial order of a sequence of speech sounds is constrained by a syllabic template. The results of simulations using the model are presented and compared with experimental findings concerning short-term memory for nonwords. The interaction of short- and long-term phonological memory systems and the aquisition of vocabulary are discussed in terms of the model. The model is evaluated in comparison with other contemporary theories.

Subvocal rehearsal, the use of inner speech for the maintenance of phonological material, is thought to play an important role verbal short-term memory (STM). The importance of rehearsal is based largely on indirect measures, as it is difficult to detect and quantify. To address this issue and investigate rehearsal timing, a novel ‘rehearsal-probe’ task was developed. Individuals silently rehearsed an auditory-verbal sequence, responding after an unpredictable probe (tone) by indicating the item currently being rehearsed. The presentation of probes after variable and repeated delays provides item response proportions over time. The data were analysed using a theory-neutral measure of temporal precision; the circular standard deviations of response distributions. The methods were established across seven experiments designed to explore whether timing precision is fixed or resource-limited. Experiment 3 showed that timing precision decreases with increased in memory load. Temporal precision was negatively correlated with auditory-verbal STM span in six experiments, including one designed specifically to examine individual differences. Experiments 6 and 7 investigated timing in developmental language disorders, which are characterized by serial ordering deficits. Adults with dyslexia and children with language impairments showed more temporal imprecision compared to matched controls. These results suggest that temporal precision is limited by shared resources and may play a role in language development. A computational model was also developed to describe the data with four separable temporal properties. The model captured the main characteristics of the data and provided quantitative estimates of each property. In an EEG experiment, event-related responses to item probes were modulated by the contents of rehearsal, and there was increased spectral power at the item rate during sequence presentation and rehearsal, but not baseline, periods. The findings suggest an important role for fine-grained timing information in serial order STM and have broader implications for debates about models of serial order.

The present study explored the possibility of implicit memory for verbal information presented during sleep. Nineteen subjects in the experimental condition each spent one adaptation and two experimental nights in the sleep laboratory. On one experimental night they were presented with two lists of cued homophones (e.g. tortoise-hare) over earphones during REM or Stage 2 sleep and tested immediately afterward. On the other experimental night they were presented with two lists of category-instance pairs (e.g. bird-cardinal). In most cases, the lists were presented five times. For comparison, 12 control subjects came to the laboratory during the day and while awake underwent the same procedures as the sleeping subjects. All subjects were eliminated from the data analysis who had not been presented with two cued-homophone and two category-instance lists. The final data analysis included 10 sleeping subjects and 12 waking controls. For these subjects, all items were eliminated for which the subject had shown arousal or was in an inappropriate sleep stage before, during, or in the fifteen seconds immediately after stimulus presentation. A repeated measures ANOVA followed by a posteriori comparisons indicated that, contrary to what had been predicted, subjects in the experimental condition showed no sleep learning effects on either the homophone or the category-instance tests, although control subjects did. Consistent with earlier studies, recall for words presented during sleep was found in a few cases, but only when presentation was soon followed by arousal. These findings strongly suggest that semantic priming does not occur for verbal material presented during REM or Stage 2 sleep. The possibility of structural priming during sleep is also discussed. Past sleep learning studies are critically reviewed, and recommendations are made regarding the topics and methodology of future sleep learning experiments. In particular, a recommendation is made for additional research on quasi sleep learning, that is, learning for information presented immediately prior to arousal.

There is agreement in the learning disability (LD) literature that reading problems in children can be attributed to difficulties in coding linguistic information. One explanation for this is that students with LD have impaired verbal memory ability. However, the specific mechanisms underlying these memory impairments are not well understood, especially in adolescents. The purpose of the current study was to compare the memory performance of adolescent students with specific reading disabilities (RD) to normal adolescent readers on a newly developed verbal learning test. The Bergen-Tucson Verbal Learning Test (BTVLT), English version, modeled after the California Verbal Learning Test (CVLT), is a multiple trial test designed to measure memory acquisition, retention, retrieval, and forgetting rates, as well as the ability to organize and retrieve the information from memory according to the phonological (surface) and semantic (lexical) features of words. Twenty subjects with RD and 20 control subjects with a mean age of 15.2 years, matched for age, gender, and ethnicity, participated in the study. Results indicated that the RD group learned significantly fewer list items and did so at a slower rate than the controls. Although the RD group was equally able to retain information once learned, they did demonstrate inefficient elaborative rehearsal strategies. The RD group also recalled fewer words in both the semantic and phonetic cued recall conditions, but the effect size was significantly greater in the phonetic cued recall condition. Taken together, the data suggest that students with RD have less efficient rehearsal and encoding mechanisms but normal retention. Retrieval also appears normal except under conditions that require information to be recalled based on phonetic codes.

In this dissertation an attempt was made to uncover the source of verbal associations. The investigation focused on establishing the locus of representation for associative relationships in the cognitive system and whether this locus is different from that for semantic relationships. A picture naming task and an object decision task were used within the standard priming paradigm, in which the target is preceded by a prime. A dual-level model was proposed in which associative relatedness is represented at a lemma level that connects the lexical form representation of a word to its semantic information. According to this model an interaction between associative and categorical relatedness should occur in picture naming, but not in object decision, when primes and targets share both relationships, and this is what was observed. To investigate the mechanisms of associative priming, asymmetrically associated prime-target pairs were used to create two situations. In the forward priming condition the target was an associate of the prime (e.g., brick-house), and in the backward priming condition the prime was an associate of the target (e.g., babyrattle). Unexpectedly, facilitation was observed for backward priming at the short SOA in picture naming. Because no effect was observed for this condition in the object decision task, and given that forward priming produced facilitation in both tasks spreading activation was upheld as the mechanism for associative priming. In order to investigate whether the source of the relationship between associates might be in their latent semantic content, the impact of instrument relationships (e.g., grinder-coffee), script relationships (e.g., zoo-tiger), and proximity in multidimensional semantic space were also investigated in the picture naming task. Items that were close in semantic space, but did not share any semantic relationships, produced the same priming pattern as category co-ordinates in picture naming (i.e., interference), while instrumental and script relationships did not produce a priming pattern that matched either that observed for associative or categorical relatedness. These results were taken to indicate that the source of associative relationships is in the co-occurrence of words in the language, which further supported the main claim of a dual-level model where information about verbal associations is stored outside semantic memory.

L'etude, basee sur la distinction signifiant / signifie, porte sur la nature du stockage des representations en memoire semantique et leurs relations avec les modalites d'acces (verbales et imagee). L'objectif est de determiner si les reseaux semantiques actives par les images sont similaires a ceux actives par les mots. L'approche qui est utilisee est l'approche multidisciplinaire des sciences cognitives faisant intervenir des donnees de psychologie cognitive - domaine dominant de la these -, des donnees neurophysiologiques d'imagerie cerebrale et des donnees issues d'etudes de neuropsychologie. L'aspect connexionnisme est aborde pour son apport aux modelisations envisagees a partir des donnees experimentales ou pour conforter celles-ci. Les experiences relatees ici utilisent le paradigme d'amorcage semantique automatique avec une tache de decision lexicale ou une tache de decision d'objets. L'absence d'amorcage semantique automatique d'un mot par une image lorsque les associations semantiques sont issues de tables d'associations verbales conduisent a envisager que le reseau associatif des images est different de celui des mots. C'est ce qui a ete teste dans l'experience consistant a etablir une table d'associations pour les images et a la comparer avec une table d'associations pour les mots. Une typologie des liens associatifs a revele que les images evoquaient preferentiellement des associes replacant l'entite presentee dans un contexte (spatial, temporel), alors que les mots suscitaient des associes de type descriptif. Une validation de la differenciation des reseaux associatifs est obtenue par l'utilisation de ces tables d'associations pour realiser des experiences d'amorcage reiteree en y adjoignant des conditions ou la cible elle-meme pouvait etre une image. Des experiences complementaires ont permis de tester le role de la nature de l'image (en la remplacant par une icone), de l'intervalle inter-stimulus, de la denomination implicite de l'image et de l'effet syllabique de sa denomination. Au total, sept experiences de psychologie cognitive ont ete realisees et entrent dans le cadre de la discussion sur les modeles unitaire ou modulaire de la memoire semantique et de sa nature modale ou amodale.

Orientador: Prof. Dr. Amer Cavalheiro Hamdan
Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Programa de Pós-Graduação em Psicologia. Defesa: Curitiba, 16/12/2016
Inclui referências : f. 43-59
Linha de pesquisa: Avaliação e reabilitação neuropsicológica
Resumo: A Memória de Trabalho é a ação combinada entre atenção e memória que regula o fluxo de informações sustentadas para a realização de uma atividade, possibilitando reter e manipular informações por um curto período de tempo. O Teste Dígitos, da Escala Wechesler de Inteligência para Adultos, é indicado para avaliar a capacidade de memória de trabalho verbal, enquanto que o Teste dos Cubos de Corsi (TCC) é tido como avaliador da memória de trabalho visuoespacial. Esta pesquisa teve como objetivo avaliar a relação entre estas duas estruturas cognitivas em 107 adultos jovens saudáveis divididos em 2 grupos etários. Além dos testes supracitados, foram utilizados um questionário estruturado e a Escala Wechsler de Inteligência Abreviada. Os resultados indicam que os testes de memória de trabalho verbal e visuoespacial apresentam níveis de dificuldades diferentes na ordem inversa, sendo o TCC mais fácil do que o Dígitos. Estes achados corroboram pesquisa anteriores que questionam a analogia não verbal do TCC ao Dígitos. Palavras-chave: Avaliação Neuropsicológica; Memória de Trabalho; Cubos de Corsi; Saúde Mental.
Abstract: Working Memory is the combined action of attention and memory that regulates the flow of sustained information to perform an activity, allowing to retain and manipulate information for a short period of time. The Digit Span, from the Wechesler Adult Intelligence Scale, is a test indicated to evaluate verbal work memory capacity, while the Corsi Block Test (CBT) is considered as a visual space memory assessor. This study aimed to evaluate the relationship between these two cognitive structures in 107 healthy young adults divided into 2 age groups. In addition to the aforementioned tests, a structured questionnaire and the Wechsler Scale of Abbreviated Intelligence were used. The results indicate that verbal and visuospatial work memory tests have different difficulty levels in the reverse order, with CBT being easier than Digits. These findings corroborate previous research that questions the nonverbal analogy of CBT to Digit Span. Keywords: Neuropsychological Assessment; Working Memory; Corsi Blocks Tapping Task; Mental Health.

[Truncated abstract] Various capabilities such as the ability to read or conduct a conversation rely on our ability to maintain and recall information in the correct order. Research spanning more than a century has been devoted to understanding how units of information are retained in order in short-term memory. The nature of the mechanisms that code the positions of items in serial short-term verbal recall can be investigated by examining a set of phenomena that can be termed temporal grouping effects. Inserting extended pauses to break a list of verbal items into sub-lists (e.g. SHD-QNR-BJF, where the dashes represents the pauses) improves the accuracy of serial recall relative to performance observed without this temporal grouping. In addition, two other effects are linked to temporal grouping. One of these effects is a shift in the shape of the serial position function, which changes from a single bowed function to a multiple-bowed function. That is, the serial position curve for ungrouped sequences is typically characterized by better performance for the beginning and ending items compared to the mid-list items. For grouped lists, the multiple-bowed function comprises better recall for the beginning and ending items within each group. Another effect associated with temporal grouping is a change in the patterns of order errors. For ungrouped sequences (e.g. SHDQNRBJF), order errors often involve the swapping of items in neighbouring positions, such as exchanging D for Q or R for B. By contrast, grouped sequences (such as SHD-QNR-BJF) show a reduction in order errors that cross group boundaries such as exchanging items D and Q or R and B; instead, there tend to be an increased incidence of exchanging items that share similar within-group positions such as swapping H and N or Q and B. According to several current models of short-term memory, items are retained by associating them with extra-list information such as contextual information. ... This was done by unconfounding temporal position (time from group onset) and ordinal position (number of items from group onset) for certain key items in sequences comprising two groups of four consonants. The critical manipulation was to vary the SOAs within and across the two groups. Errors that involve items migrating across groups should preserve within-group temporal position according to oscillator models, but should preserve within-group ordinal position according to non-oscillator models. Results from the intergroup errors strongly favored preservation of ordinal rather than temporal position. Finally, the Appendix reports an unpublished experiment that examined patterns of errors in recalling sequences of nine visually presented letters, where the letters were grouped into threes using temporal gaps. A critical manipulation was the insertion of a tobe- ignored item (an asterisk) between the first and second letters of selected groups. Inclusion of this item failed to alter the patterns of errors observed, indicating that the coding of serial position is based on only those events represented for recall. The central conclusion based on all the studies is that serial order for verbal items is retained using contextual positional codes that change with each presentation of a tobe- remembered item, are influenced by large temporal gaps that lead to grouping, but otherwise are not dependent on the timing of events.

Children with ADHD diagnosis often display working memory deficits, as well as reading and mathematical disabilities. Previous studies have demonstrated that computerized working memory training (WMT) is a promising intervention. The present study aimed at exploring the effects of WMT on working memory, scholastic skills and behavioral symptoms in children with ADHD. Thirty-two children, aged 6 to 11, were randomized to WMT or a control condition. WMT consisted of nine tasks taxing working memory with adaptive difficulty level. All children trained in their homes, with their parents acting as supervisors. Children who completed more than 20 days of training in 5-8 weeks (8 in the WMT condition and 13 in the control condition) were considered compliers. Assessments were conducted before and after intervention. Results indicated that WMT lead to significant gains of verbal working memory and arithmetic skills. More research is needed to further investigate the effects of WMT.

This study investigated the relationship between working memory and language in typically developing young children. The aim was to gain a better understanding of language development, in particular, the involvement of visual and verbal short-term memory in language acquisition and its influence on vocabulary size. It explored possible underlying causes of why some children have problems in the process of learning to talk, whereas other children acquire language easily. A total of 51 New Zealand English speaking children aged two to five completed a battery of assessments measuring receptive and expressive vocabulary and visual and verbal short-term memory. The standardized tests administered included the Receptive One Word Picture Vocabulary Test (Brownell, 2000b), the Expressive One Word Picture Vocabulary Test (Brownell, 2000a), the Visual Patterns Test (Stokes, Klee, Cruickshank, & Pleass, 2009), and the Test of Early Nonword Repetition (Stokes & Klee, 2009a). Receptive vocabulary knowledge was strongly associated with visual (r = .75) and verbal (r = .60) short-term memory performance and age (r = .72). The relationship of expressive vocabulary to visual short-term memory (r = .80) was stronger than to verbal short-term memory (r = .62) but significant for both and also for age (r= .83). Significant unique predictors for expressive vocabulary were age (R2 change = .60) as well as visual (R2 change = .04) and verbal (R2 change = .04) short-term memory. However, age appeared to be the only unique predictor for receptive vocabulary (R2 change = .54). In addition, the findings suggested that visual and verbal short-term memory increases as children get older. Hence, the Visual Patterns Test and Test of Early Nonword Repetition seem to be good predictors, over and above age, of expressive vocabulary knowledge.

Thesis (Ph. D.)--University of Oregon, 2003.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 135-145). Also available for download via the World Wide Web; free to University of Oregon users.

Even though Broca's area has been associated with speech and language processing since the 19th century, the exact role that it plays is still a matter of debate. Recent models on the neuroanatomical substrates of language have assigned Broca's area to different processes: syllabification (Indefrey and Levelt 2004), articulatory code storage (Hickok and Poeppel 2004) and verbal working memory (Chein and Fiez 2001; Chein et al. 2002). The subject of this doctoral dissertation, is to examine language production and disambiguate the role of Broca's area. This issue was addressed in a series of functional magnetic resonance imaging studies (fMRI) involving speech production, where the phonological properties of pseudowords were manipulated in a way that differentiated between syllabification and articulatory code generation. The load on verbal working memory was also changed. The behaviour of Broca's area was then examined in response to these manipulations to determine the dependence of the observed results on the different levels of processing and verbal working memory. The results from the present studies suggest that the dorsal premotor cortex has a consistent role in articulatory code generation irrespective of verbal working memory demands. In contrast, Broca's area, specifically Brodmann area 44, showed a main effect of phonetic encoding only during delayed response tasks. Interestingly, area BA44 was also found to be functionally segregated between the dorsal and ventral part. The dorsal part was sensitive to articulatory and phonological load, such as stimulus length. The ventral part on the other hand was sensitive to sub-lexical stimulus properties, but only during delayed response trials. These findings suggest that BA44 is not a homogeneous region, but it is divided into a dorsal premotor and a ventral prefrontal part. These results add another dimension of complexity to the study of Broca's area, its functional segregation and its role in language production.

A long standing debate surrounds the issue of whether there is overlap in the cognitive processing of language and music. This thesis examined the extent to which there are similarities in the immediate serial recall (ISR) of verbal and tonal pitch sequences using the working memory model as the empirical framework. The thesis had three aims. The first was to develop an ISR task that would allow individuals of any level of musical training to report back sequences of tones and letters. The second aim was to compare letter and tone sequence recall performance under various conditions known to affect ISR for auditory-verbal materials. The third aim was to examine performance as a function of musical expertise. Nine experiments were conducted in total. The first six experiments tested, refined and validated the new ISR tone paradigm. The final three experiments compared musicians and nonmusicians letter and tone sequence recall using manipulations known to affect ISR for auditory-verbal items; phonological similarity (pitch proximity used for tone recall), articulatory suppression and irrelevant sound. Similarities across the results included comparable sequence length effects for letter and tone conditions, an effect of pitch proximity and phonological similarity for nonmusicians, and effects of articulatory suppression on recall of both sequence types for both groups. However, there were also a number of differences in tone recall compared to letter recall including a lack of recency and no effect of irrelevant sound. Therefore, a complete theoretical overlap between language and music processing in short-term memory was not supported by the evidence. The problems of equivalent testing across the language and music domain, and across populations of varying musical expertise were discussed. It was suggested that increased understanding of how cognitive resources are shared to process language and music in the brain would come from future research combining behavioural experiments with functional models and neuroimaging studies.

The purpose of the present research program was to investigate IA children's language abilities during school age in order to see whether the difficulties reported in this population at younger ages persist (e.g., Gauthier & Genesee, 2011) or if they decrease with more exposure to the adopted language. Another goal was to investigate if IA children have verbal memory difficulties in addition to their language lags. Note that these studies all compared IA children to non-adopted monolingual French-speaking children matched on age, gender, and socio-economic status.Study 1 evaluated the language abilities of IA children from China adopted into French-speaking families as well as their non-verbal cognitive abilities, their socio-emotional development, and their health status. The children were between 7-8 years of age at the time of testing. The IA children's age at the time of adoption ranged between 6-21 months. The results showed that the IA children performed significantly lower than the control children on expressive vocabulary, knowledge of word definitions, receptive grammar, and sentence recall.Study 2 was conducted to investigate IA children's mastery of object clitics during school age. The goal of this study was to determine whether, with sufficient amount of language exposure, IA children are able to master this aspect of French. The IA children were assessed using a Clitic Elicitation task. The participants in Study 2 were the same as those in Study 1. The results indicated that the IA children omitted significantly more accusative object clitics and made significantly more agreement errors in gender and/or numberusing clitics than the non-adopted children.Study 3 was undertaken in order to examine IA children's memory abilities. Children's verbal short-term memory (STM), verbal working memory (WM), verbal long-term memory (LTM), non-verbal STM, non-verbal WM, non-verbal cognitive development, socio-emotional development, and language abilities were assessed. The children were between 9-12 years of age at the time of testing and the IA children's age at the time of adoption ranged between 6 and 24 months of age. The results of this study showed that, although the groups did not differ on measures of non-verbal cognitive ability and socio-emotional development, the IA children performed significantly lower than the controls on expressive and receptive vocabulary, receptive grammar, a word association test, and on measures of verbal STM, verbal WM, and verbal LTM. The groups did not differ on non-verbal memory ability, suggesting language-specific memory difficulties. Regression analyses suggested that the IA children's language abilities were best predicted by their verbal memory abilities, verbal STM in particular, while the CTL children's performance on language measures was best predicted by their length of exposure to French. Overall, the findings suggest that, while IA children exhibit normal general development, their verbal memory abilities and aspects of their language abilities are below those of control children matched on age, gender, and SES. These difficulties suggest very early age of acquisition effects on language and verbal memory abilities, but also that the IA children's verbal memory lags might account for their lags in language, at least proximally.
L'objectif du présent programme de recherche était d'évaluer, à l'âge scolaire, les habiletés langagières d'enfants adoptés internationalement (AI) afin de déterminer si les difficultés rapportées chez des enfants AI d'âge préscolaire persistent (e.g., Gauthier & Genesee, 2011) ou si elles diminuent avec plus d'exposition à la langue d'adoption. Un autre objectif était de déterminer si les enfants AI ont des difficultés de mémoire verbale en plus de leurs retards de langage. Notez que ces études ont toutes comparées les enfants AI à des enfants non-adoptés, monolingues francophones et appariés sur l'âge, le sexe et le statut socioéconomique. L'étude 1 a évalué les habiletés langagières d'enfants AI de Chine par des familles francophones, ainsi que leurs habiletés cognitives non-verbales, leur développement socio-émotionnel et leur santé. Les enfants étaient âgés de 7-8 ans au moment de l'étude. Les enfants AI étaient âgés de 6-21 mois lors de leur adoption. Les résultats ont démontré que la performance des enfants AI aux tests de vocabulaire expressif, de définition de mots, de grammaire réceptive et de répétition de phrases sont significativement plus faibles que celle des contrôles. L'étude 2 a été réalisée dans le but d'évaluer la maitrise des clitiques objets par les enfants AI d'âge scolaire. Le but de cette étude était de déterminer si, avec une exposition suffisante à leur langue d'adoption, les enfants AI sont capables de maitriser cet aspect du français. Les enfants AI ont été évalués à l'aide d'un test d'élicitation de clitiques. Les participants de l'étude 2 étaient les mêmes que ceux de l'étude 1. Les résultats ont indiqués que les enfants AI omettent significativement plus de clitiques objets et produisent significativement plus de clitiques objets contenant des erreurs en genre et/ou nombre que les enfants non-adoptés. L'étude 3 a été entreprise dans le but d'examiner la mémoire chez les enfants AI. La mémoire verbale à court-terme, la mémoire verbale de travail, la mémoire verbale à long-terme, la mémoire non-verbale à court-terme, la mémoire de travail non-verbale,le développement cognitif non-verbal, le développement socio-émotionnel et les habiletés langagières des enfants ont été évalués. Les enfants étaient âges de 9-12 ans au moment de l'étude. Les enfants AI étaient âgés de 6-24 mois au moment de leur adoption. Les résultats de cette étude ont démontré que, malgré le fait que la performance des groupes aux tests de développement cognitif non-verbal et de développement socio-émotionnel soit similaire, les enfants AI performent significativement plus faiblement que les enfants contrôles aux test de vocabulaire expressif et réceptif, de grammaire réceptive, d'association de mots ainsi qu'aux tests de mémoire verbale à court-terme, de mémoire verbale de travail et de mémoire verbale à long-terme. Les groupes ont toutefois performé de façon similaire aux tests de mémoire non-verbale à court-terme et de mémoire de travail non-verbale, suggérant des difficultés spécifiques au langage. Des analyses de régressions ont démontré que les habiletés langagières des enfants AI sont mieux prédites par leur mémoire verbale, la mémoire verbale à court-terme en particulier, alors que, pour les contrôles, le meilleur prédicteur de leur performance aux tests de langage est la durée de leur exposition au français. De façon générale, les résultats suggèrent que, bien que le développement général des enfants AI est normal, leur mémoire verbale et certains aspects de leurs habiletés langagières sont en-deçà de celles des enfants contrôles appariés pour l'âge, le sexe et le statut-socioéconomique. Ces difficultés suggèrent des effets très précoces de « l'âge d'acquisition » sur le langage et sur la mémoire verbale, mais également que les délais de mémoire verbale des enfants AI pourraient expliquer leurs retards de langage, au moins de façon proximale.