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Research suggests that novel word learning tasks engage both verbal short-term memory (STM) and lexical processing, and may serve as a potential treatment for word processing and functional language in aphasia (e.g., Gupta, Martin, Abbs, Schwartz, Lipinski, 2006; Tuomiranta, Grönroos, Martin, & Laine, 2014). The purpose of this study was to gain support for the hypotheses that novel word learning engages verbal STM and lexical access processes and can be used to promote improvements in these abilities in treatment of aphasia. We used a novel word learning task as a treatment with three participants: KT, UP, and CN, presenting with different types and severities of aphasia and predicted that treatment would result in (1) acquisition of trained novel words (2) improved verbal STM capacity and (3) improved access to and retrieval of real words. Twenty novel words were trained for 1 hour x 2 days/week x 4 weeks. Language and learning measures were administered pre- and post-treatment. All three participants showed receptive learning and some improvement on span tasks, while UP and CN demonstrated some expressive learning. KT also improved in performance on the Peabody Picture Vocabulary Test and the Philadelphia Naming Test. UP showed significant improvement on proportion Correct Information Units (CIUs) in discourse. CN showed some minimal improvement in narrative production for proportion CIUs and proportion of closed class words. These findings support that novel word learning treatment, which engages verbal STM processes and lexical retrieval pathways, can improve input lexical processing. Theoretically, this study provides further evidence for models that propose common mechanisms supporting novel word learning, short-term memory, and lexical processing. / Communication Sciences

L’objectif de cette thèse est d’étudier l’apprentissage tardif de nouvelles catégories vocaliques, en particulier l’influence de la langue première sur les processus d’acquisition tels qu’ils sont décrits dans les modèles du traitement des phonèmes non natifs. Dans cette étude, deux approches expérimentales ont été adoptées. En premier lieu, les techniques comportementales et électrophysiologiques ont permis d’examiner la perception de contrastes de l’anglais-américain chez des francophones natifs, aux niveaux acoustique, phonologique et lexical, en fonction de l’expérience linguistique. En second lieu, des analyses acoustiques ont été menées sur la perception et la production des voyelles du français et de l’anglais chez des Californiens durant une année d’immersion linguistique en France pour comprendre a) comment ces deux processus évoluent et sont liés aux premiers stades de l’apprentissage en L2 et b) l’influence de la L1 sur la production de mots homophoniques entre les deux langues. Les résultats montrent que la formation tardive de nouvelles catégories vocaliques est possible et que cette distinction est maintenue au niveau lexical. L’expérience linguistique participe à ce changement perceptif mais ne garanti pas un traitement cognitif aussi automatique que pour les auditeurs natifs de la langue. Dans la partie phonétique, les résultats montrent que les distinctions phonétiques peuvent être perçues et produites en fonction des patrons d’assimilation décrits dans les modèles en acquisition et du recouvrement phonologique sur les items lexicaux. Enfin, les distinctions réalisées en perception précèderaient leur réalisation articulatoire comme le postule Flege (1995). / This thesis investigates the formation of L2 vowel category in late learners, regarding particularly the influence of the first language on the acquisition process as described in the theoretical predictions of models of L2 speech sound processing. In this study, two different experimental approaches were conducted. At first, we examined, with electrophysiological and behavioral techniques, the perception of American-English contrasts by French late learners of English at the acoustical, phonological and lexical level as a function of linguistic experience. Second, fine grained acoustical analysis have been run on the perception and production of French vowels by American English late learners with a specific dialect: that from California, in order to a) understand how both processes evolve and are linked during the first stages of learning an L2 in immersion and b) examine the effect of the L1 on the production of L2 speech sounds due to possible lexical competition with homophonic words in French and English. The results show that new L2 vowel categories can be learned and the differences maintained at the lexical level even in late learners. Linguistic experience enables perceptive changes but does not guarantee a cognitive processing as automatic as for native speakers. In the phonetic part of the study, the results show that phonetic differences can be perceived and produced as a function of the pattern of assimilation described in models of L2 acquisition and phonological overlap between French and English words. Finally, it seems that the evolution of perception skills precede production one’s in line with SLM predictions (Flege, 1995).

Let’s imagine a typical word-learning scenario. A toddler sits in her highchair in the kitchen and waits for her lunch. Her mother says: “Use a spoon to eat your meal”. Several objects are placed in front of the child. She can see a dish with her lunch, a spoon, a cup, a sugar bowl, a milk jar, her mother’s plate and a second cup. All these objects, present in the visual array, must be identified by the toddler; she must also parse the auditory stream into segments and determine which words are familiar and which ones are potentially new. If the child does not know the word “spoon”, she will need to use the event of naming of this referent by her mother to adjust her attention to the relevant referent. She also needs to update her representation of this word upon hearing it in different contexts with different speakers and, perhaps, different types of spoons. Efficient attention allocation in this word-learning situation will clearly contribute to the success of mapping; the degree of encoding of the word-form and of its meaning will certainly influence whether this word enters the child’s vocabulary.The complexity of such a typical scenario seems very challenging for a toddler whose cognitive resources are still far from being fully mature. Unsurprisingly, several accounts of how toddlers manage to solve this task are currently on the market. The problem of ambiguity associated with meaning-to-referent mapping (several objects co-presented in the visual scene) and with word form-to-meaning mapping (the correct word is to be singled out among phonological competitors) might be even more challenging for children who present an atypical developmental trajectory.Children with Autism Spectrum Disorder and toddlers at risk for the disorder were found to acquire their vocabularies at a slower rate than their typically developing peers. In the contemporary literature, this delay in lexical knowledge acquisition is associated with poor socio-pragmatic understanding that presumably limits children’s capacity to establish referents for words in social contexts. Since impaired understanding of social interaction is a core characteristic of the cognitive profile of individuals with ASD, such an explanation of the delay in language development seems very plausible. However, several other theoretical accounts hold that in typical development socio-pragmatic skills emerge, bottom-up, through more domain-general processing of interactional experiences. In line with the latter views, it can be hypothesized that delays in lexical acquisition in ASD are not directly linked to poor socio-pragmatic understanding but are caused by low-level deficits and atypical attention allocation during word learning.Research programs on lexical learning and processing in ASD thus face the existence of different, contradictory theories of first language acquisition in typical development. Deciding a priori to build one’s experimental study against this or that theoretical background carries the risk of a limited interpretation of experimental results. A more promising way to deal with the variety of available theories of language acquisition is rather to directly confront the existing paradigms and to plan the study design in accordance. This is the approach that I privilege here. In the studies presented within this thesis, I question how social cues are used to resolve ambiguity in meaning during word-learning tasks (chapter 1) and during referential processing in typically developing children (chapter 2) and in children with ASD (chapter 3). Not only do I attempt to compare the use of social cues in word-learning and of perspectival information in referential processing in children with and without ASD, but I also try to link these results with two opposing theoretical views: the one that postulates early reliance on socio-pragmatic understanding and the other that conceives of word-learning as not being necessarily grounded in social understanding. In Chapter 1, I present evidence that children with ASD, children with SLI and typically developing children learn novel words in a flexible way by selectively attending to mappings offered by previously accurate speakers. However, I also show that such learning is likely to be supported by a surface trait attribution mechanism, rather than by genuine socio-pragmatic understanding: children in both clinical groups fail to learn selectively, when learning requires genuinely building a model of the speakers’ epistemic states. Chapters 2 and 3 are devoted to referential communication. I adopt several analytical and methodological modifications to existing methods, which allows me to compare two different aspects of partner-dependent processing of referential precedents. Typically developing children can be expected to recognize precedents previously established with the same partner faster, because of an automatic priming mechanism. However, potential faster processing of broken precedents with a new partner could not be explained by a low-level memory mechanism and would strongly suggest that lexical processing is influenced by expectations about the child’s partner perspective. I present evidence that children with and without ASD do not spontaneously rely on common ground during referential processing and that partner-specific effects in processing are associated with low-level priming. In chapter 3, I report evidence of impaired ability to switch between different conceptual perspectives in children with ASD, which may lead to maladaptive behavior in communication. In the last chapter of this thesis, I explore how word form-to-meaning ambiguity is resolved in children with ASD and whether these children exhibit difficulty in correctly mapping similar-sounding novel words. The results of this study suggest that lexical activation in children with ASD may be impaired and they display deficits in suppressing phonological competitors. Taken together, the results presented in this doctoral dissertation suggest that delays in word acquisition in ASD are likely to be driven by deficits in domain-general cognitive development. Even though impaired socio-cognitive understanding may lead to difficulties in discourse and pragmatics in older children, delayed access to lexical meaning in young children with ASD is likely to be associated with disruptions in domain-general mechanisms of perception, attention and memory. / Doctorat en Langues, lettres et traductologie / info:eu-repo/semantics/nonPublished

Second language (L2) reading fluency has not received sufficient attention in the field of second language acquisition (SLA) and applied linguistics, especially regarding the types of treatments that promote reading fluency (Grabe, 2009). Hence, this study was a longitudinal, quasi-experimental investigation of the effects of timed reading, repeated oral reading, and extensive reading on the development of reading fluency among Japanese university students. The eight purposes of this study were to: (a) better understand how timed reading, repeated oral reading, and extensive reading treatments contribute to reading fluency in terms of reading rate and comprehension over one academic year; (b) distinguish how extensive reading, timed reading, and repeated oral reading treatments differentially promote reading fluency; (c) elucidate on how timed reading, repeated oral reading, and extensive reading treatments affect the automatization of word recognition sub-processes over time; (d) investigate differences between the reading fluency treatment groups in terms of their word recognition sub-processes; (e) further understand how reading fluency treatments contribute to oral reading fluency; (f) examine differences in oral reading fluency between the reading fluency treatment groups; (g) determine how reading fluency training affects learners’ perception of their L2 reading self-efficacy; and (h) shed light on differences in L2 reading self-efficacy between reading fluency treatment groups. This study was conducted in a private university in western Japan. The participants (N = 101) were first- and second-year Japanese university students. These participants formed four quasi-experimental groups: (a) Group 1, labeled as the oral reading group, received a reading fluency treatment consisting of extensive reading, timed reading, and repeated oral reading; (b) Group 2, the timed reading group, participated in extensive reading and timed reading; (c) Group 3, the extensive reading group, did extensive reading only; and (d) Group 4, the comparison group, practiced speaking and communication activities. Data for this study were obtained using the following instruments: a vocabulary size test, timed reading tests, timed reading practice passages used throughout the treatment period, an extensive reading test, a lexical decision task, an antonym semantic decision task, a pseudoword homophone judgment task, an oral reading task, and an L2 reading self-efficacy questionnaire, a utility of the reading fluency treatments questionnaire, as well as individual interviews with 20 of the participants. Excluding the vocabulary size test, the timed reading treatment passages, the utility of the reading fluency treatments questionnaire, and the interviews, the other measures were administered three times over the course of one academic year—once prior, once in the middle, and once at the end of the reading fluency treatment period. Prior to conducting quantitative analyses on the data gathered with the instruments mentioned above, the L2 reading self-efficacy questionnaire data were analyzed using the Rasch rating-scale model in order to confirm the validity and reliability of the instrument as well as to transform the raw scores into equal interval measures. In addition, the Rasch model was used to check for interrater reliability and rater severity of the scores of the oral reading task. Data cleaning procedures were also applied to the reaction time and reading rate data. The data were then analyzed using repeated-measures ANOVAs and MAN(C)OVAs in order to ascertain differences in within-subjects and between-subjects measures. The results showed that the three reading fluency treatment groups made significant within-subjects increases in their reading fluency with the oral reading group making the most reading rate gains, followed by the timed reading group, and the extensive reading group. Moreover, the oral reading group generally outperformed the other groups on reading rate measures. However, the extensive reading group did not significantly outperform the comparison group. In addition, while the timed reading group had the fastest word recognition reaction times, the oral reading group made the most gains in orthographic, semantic, and phonological processing. Furthermore, no significant differences were found between the groups on orthographic processing, but the oral reading group, timed reading group had significantly faster semantic and phonological processing reaction times compared to the comparison group. With regards to oral reading fluency, the oral reading group made the most gains and achieved the highest scores, but the timed reading group also made significant gains. Finally, the oral reading groups’ L2 reading self-efficacy increased the most. The results of the study underscore the importance of using a multifaceted approach of extensive reading, timed reading, and repeated oral reading in the development of L2 reading fluency. Through this reading fluency training, the learners not only became more proficient readers in both silent and oral modes, but they also became more self-efficacious in L2 reading tasks. Ultimately, these learners became more empowered to achieve success in their L2 learning endeavors. / Teaching & Learning

Dans le cadre de cette thèse, nous investiguons la capacité de chaque hémisphère cérébral à utiliser l’information visuelle disponible lors de la reconnaissance de mots. Il est généralement convenu que l’hémisphère gauche (HG) est mieux outillé pour la lecture que l’hémisphère droit (HD). De fait, les mécanismes visuoperceptifs utilisés en reconnaissance de mots se situent principalement dans l’HG (Cohen, Martinaud, Lemer et al., 2003). Puisque les lecteurs normaux utilisent optimalement des fréquences spatiales moyennes (environ 2,5 - 3 cycles par degré d’angle visuel) pour reconnaître les lettres, il est possible que l’HG les traite mieux que l’HD (Fiset, Gosselin, Blais et Arguin, 2006). Par ailleurs, les études portant sur la latéralisation hémisphérique utilisent habituellement un paradigme de présentation en périphérie visuelle. Il a été proposé que l’effet de l’excentricité visuelle sur la reconnaissance de mots soit inégal entre les hémichamps. Notamment, la première lettre est celle qui porte habituellement le plus d’information pour l’identification d’un mot. C’est aussi la plus excentrique lorsque le mot est présenté à l’hémichamp visuel gauche (HVG), ce qui peut nuire à son identification indépendamment des capacités de lecture de l’HD. L’objectif de la première étude est de déterminer le spectre de fréquences spatiales utilisé par l’HG et l’HD en reconnaissance de mots. Celui de la deuxième étude est d’explorer les biais créés par l’excentricité et la valeur informative des lettres lors de présentation en champs divisés. Premièrement, nous découvrons que le spectre de fréquences spatiales utilisé par les deux hémisphères en reconnaissance de mots est globalement similaire, même si l’HG requière moins d’information visuelle que l’HD pour atteindre le même niveau de performance. Étonnament toutefois, l’HD utilise de plus hautes fréquences spatiales pour identifier des mots plus longs. Deuxièmement, lors de présentation à l’HVG, nous trouvons que la 1re lettre, c’est à dire la plus excentrique, est parmi les mieux identifiées même lorsqu’elle a une plus grande valeur informative. Ceci est à l’encontre de l’hypothèse voulant que l’excentricité des lettres exerce un biais négatif pour les mots présentés à l’HVG. De façon intéressante, nos résultats suggèrent la présence d’une stratégie de traitement spécifique au lexique. / In this thesis, we investigate the cerebral hemispheres’ ability to use the available visual information for word recognition in lateral periphery. It is generally acknowledged that the left hemisphere (LH) is more able at reading than the right (RH). Accordingly, the visuoperceptual mechanisms of the brain for word recognition are primarily localized in the LH (Cohen, Martinaud, Lemer et al., 2003). As normal readers use medium spatial frequencies (about 2,5 – 3 cycles per degree of visual angle) to recognize words, it is possible that the LH is better tuned for processing these spatial frequencies than the RH (Fiset, Gosselin, Blais et Arguin, 2006). Furthermore, studies concerned with reading abilities in the cerebral hemispheres commonly present words in visual periphery. However, the effect of visual eccentricity on word recognition is thought to be unequal between hemifields, notably because the first letter in a word usually carries the most information for its accurate identification. It is also the most eccentric letter when a word is presented in the LVF, which may cause a negative bias for the identification of words presented to the LVF regardless of the actual reading capacities of the RH. The main objective of the first study is to determine the spatial frequency tuning functions of the LH and RH for word recognition. The goal of our second study is to explore letter identification biases for words presented to the left and right visual fields as a function of eccentricity by varying the information value of letter positions. Firstly, we discover that the spatial frequency tuning of both hemispheres is globally similar, even though the LH requires less visual information than the RH to reach the same level of performance. Surprisingly however, the RH requires higher spatial frequencies to identify longer words. Secondly, we find that for LVF displays, the first letter, i.e. the most eccentric, is among the most accurately identified, even when it has a greater information value. This argues against the hypothesis that letter eccentricity exerts a negative bias for words presented to the LVF. Interestingly, our findings also suggest a lexical-specific processing strategy.

Dans le cadre de cette thèse, nous investiguons la capacité de chaque hémisphère cérébral à utiliser l’information visuelle disponible lors de la reconnaissance de mots. Il est généralement convenu que l’hémisphère gauche (HG) est mieux outillé pour la lecture que l’hémisphère droit (HD). De fait, les mécanismes visuoperceptifs utilisés en reconnaissance de mots se situent principalement dans l’HG (Cohen, Martinaud, Lemer et al., 2003). Puisque les lecteurs normaux utilisent optimalement des fréquences spatiales moyennes (environ 2,5 - 3 cycles par degré d’angle visuel) pour reconnaître les lettres, il est possible que l’HG les traite mieux que l’HD (Fiset, Gosselin, Blais et Arguin, 2006). Par ailleurs, les études portant sur la latéralisation hémisphérique utilisent habituellement un paradigme de présentation en périphérie visuelle. Il a été proposé que l’effet de l’excentricité visuelle sur la reconnaissance de mots soit inégal entre les hémichamps. Notamment, la première lettre est celle qui porte habituellement le plus d’information pour l’identification d’un mot. C’est aussi la plus excentrique lorsque le mot est présenté à l’hémichamp visuel gauche (HVG), ce qui peut nuire à son identification indépendamment des capacités de lecture de l’HD. L’objectif de la première étude est de déterminer le spectre de fréquences spatiales utilisé par l’HG et l’HD en reconnaissance de mots. Celui de la deuxième étude est d’explorer les biais créés par l’excentricité et la valeur informative des lettres lors de présentation en champs divisés. Premièrement, nous découvrons que le spectre de fréquences spatiales utilisé par les deux hémisphères en reconnaissance de mots est globalement similaire, même si l’HG requière moins d’information visuelle que l’HD pour atteindre le même niveau de performance. Étonnament toutefois, l’HD utilise de plus hautes fréquences spatiales pour identifier des mots plus longs. Deuxièmement, lors de présentation à l’HVG, nous trouvons que la 1re lettre, c’est à dire la plus excentrique, est parmi les mieux identifiées même lorsqu’elle a une plus grande valeur informative. Ceci est à l’encontre de l’hypothèse voulant que l’excentricité des lettres exerce un biais négatif pour les mots présentés à l’HVG. De façon intéressante, nos résultats suggèrent la présence d’une stratégie de traitement spécifique au lexique. / In this thesis, we investigate the cerebral hemispheres’ ability to use the available visual information for word recognition in lateral periphery. It is generally acknowledged that the left hemisphere (LH) is more able at reading than the right (RH). Accordingly, the visuoperceptual mechanisms of the brain for word recognition are primarily localized in the LH (Cohen, Martinaud, Lemer et al., 2003). As normal readers use medium spatial frequencies (about 2,5 – 3 cycles per degree of visual angle) to recognize words, it is possible that the LH is better tuned for processing these spatial frequencies than the RH (Fiset, Gosselin, Blais et Arguin, 2006). Furthermore, studies concerned with reading abilities in the cerebral hemispheres commonly present words in visual periphery. However, the effect of visual eccentricity on word recognition is thought to be unequal between hemifields, notably because the first letter in a word usually carries the most information for its accurate identification. It is also the most eccentric letter when a word is presented in the LVF, which may cause a negative bias for the identification of words presented to the LVF regardless of the actual reading capacities of the RH. The main objective of the first study is to determine the spatial frequency tuning functions of the LH and RH for word recognition. The goal of our second study is to explore letter identification biases for words presented to the left and right visual fields as a function of eccentricity by varying the information value of letter positions. Firstly, we discover that the spatial frequency tuning of both hemispheres is globally similar, even though the LH requires less visual information than the RH to reach the same level of performance. Surprisingly however, the RH requires higher spatial frequencies to identify longer words. Secondly, we find that for LVF displays, the first letter, i.e. the most eccentric, is among the most accurately identified, even when it has a greater information value. This argues against the hypothesis that letter eccentricity exerts a negative bias for words presented to the LVF. Interestingly, our findings also suggest a lexical-specific processing strategy.

<p><b>Purpose:</b> Children with speech sound disorder (SSD) mispronounce more speech sounds than is typical for their age and a growing body of research suggests that a deficit in speech perception abilities contributes to development of the disorder. However, little work has been done to characterize the neurophysiological processes indexing speech perception deficits in SSD. The primary aim of the current study was to compare the neural activity underlying speech perception in young children with SSD and typical development (TD).</p><p><b>Method</b>: Twenty-eight children ages 4;1-6;0 participated in the current study. Event-related potentials (ERPs) were recorded while children completed a speech perception task which included phonetic (speech sound) and lexical (meaning) matches and mismatches. Groups were compared on their judgment accuracy for matches and mismatches as well as the mean amplitude of the Phonological Mapping Negativity (PMN) and N400 ERP components.</p><p><b>Results</b>: Children with SSD demonstrated lower judgment accuracy across the phonetic and lexical conditions compared to peers with TD. The ERPs elicited by lexical matches and mismatches did not distinguish the groups. However, in the phonetic condition, the SSD group exhibited a more consistent left lateralized PMN effect and a delayed N400 effect over frontal sites compared to the TD group.</p><p><b>Conclusions</b>: These findings provide some of the first evidence of a delay in the neurophysiological processing of phonological information for young children with SSD compared to their peers with TD. This delay was not present for the processing of lexical information, indicating a unique difference between children with SSD and TD related to speech perception of phonetic errors.</p>

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