How do bi/multilinguals switch between languages so effectively that there is no obvious intrusion from the alternatives? One can examine this by comparing language selection with task selection, or language switching with task switching. This is the approach adopted in the first of two strands of research presented in this thesis. In task switching, providing advance warning of the task typically leads to a reduction in the performance ‘switch cost’, suggesting top-down biasing of task selection. It is not clear whether the language switch cost also reduces with preparation, partly because there have been very few attempts to examine preparation for a language switch, and partly because these attempts suffered from non-trivial methodological drawbacks. In Experiments 1-3 I used an optimised picture naming paradigm in which language changed unpredictably and was specified by a language cue presented at different intervals before the picture. Experiment 1, conducted on ‘unbalanced’ bilinguals, revealed some evidence of reduction in the language switch cost for naming times with preparation, but only when cue duration was short. In an attempt to further optimise the paradigm, in Experiment 2 the cue-stimulus interval (which was varied from trial to trial in Experiment 1), was varied over blocks instead. Visual cues were replaced with auditory cues – the latter also enabled a comparison between semantically transparent word cues (the spoken names of the languages) and less transparent cues (fragments of national anthems). Experiment 2 revealed a reduction in switch cost with preparation for naming latencies, but only in the second language; the first language showed the reverse. To examine whether the increase in switch cost with preparation in the first language could be due to unbalanced bilinguals biasing processing towards L2, balanced bilinguals were tested in Experiment 3. This revealed a robust reduction in switch cost in naming latencies for both languages, which was driven primarily by the trials with the anthem cues. However, in the error rates the switch cost increased with preparation interval, thus complicating the interpretation of the reduction observed for response times. Experiment 4 investigated whether preparation for a language switch elicits the electrophysiological patterns commonly found during preparation for a task switch – a switch-induced positive polarity Event-Related Potential (ERP) with a posterior scalp distribution. Contrary to a recent report of the absence of the posterior positivity in language switching, it was clearly present in the present EEG data. As in task switching, the amplitude of the posterior positivity predicted performance. The electrophysiological data suggest that preparation for a language switch and preparation for a task switch rely on highly overlapping control mechanisms. The behavioural data suggest that advance control can be effective in language switching, but perhaps not as effective as in task switching. Experiments 1-3 also examined the effect of stimulus associative history – whether the language used on the previous encounter with a given stimulus influenced performance on the current trial). Having previously named a given picture in the same language benefited overall performance, but did not do so more for switches than repeats. Thus, stimulus associative history does not seem to contribute to the language switch cost. The second strand of my research asked whether bilinguals can set themselves independently for speech vs. comprehension. Previous research has examined the cost of switching the language in output tasks and in input tasks. But, it is not clear whether one can apply separate control settings for input and output selection. To investigate this, I used a paradigm that combined switching languages for speech production and comprehension. My reasoning was that, if there is cross-talk between the control settings for input vs. output, performance in one pathway should benefit if the language selected for the other pathway is the same relative to when it is different: a ‘language match effect’. Conversely, if there is no cross-talk, there should not be a language match effect. In Experiment 5 bilinguals alternated predictably between naming numbers in their first and second language (in runs of 3 trials), whilst also having to semantically categorise spoken words which occasionally (and unpredictably) replaced the numbers. The language of the categorisation ‘probes’ varied over blocks of ~17 naming runs, but was constant within a block. The results showed a clear match effect in the input task (categorisation), but not the output task (naming). To examine the potential role of proficiency, Experiment 6 used the same paradigm to test unbalanced and balanced bilinguals. The pattern of results was qualitatively similar in both groups to that observed in Experiment 5: a language match effect confined to the input task. These results suggest ‘leakage’ from the output control settings into the input control settings.

La LPC ou Cued Speech est un augment manuel qui permet au sourd de désambiguïser l'information phonologique visible sur le visage. L'efficacité de ce système pour l'acquisition de la phonologie de la langue est bien établie. Mais la production du code LPC n'avait jamais été étudiée, et nous l'avons fait par une technique de suivi des mouvements labiaux et manuels de quatre codeuses professionnelles. Notre résultat comportemental majeur est que le geste de la main - contre toute attente - précède le geste des lèvres. Cette anticipation donne un rôle inattendu à la parole visible: celui de venir désambiguïser le geste manuel, conçu au départ pour désambiguïser la parole... Notre hypothèse est que le système de Cornett a été recodé en termes neuralement compatibles pourle contrôle des gestes des voyelles et des consonnes dans la LPC et la parole. Ainsi le contrôle des contavts vocaliques manuels va se trouver en phase avec celui des contacts consonantiques visibles. Ce phasage est assez précis pour que, quelles que soient les variations de la durée de l aproduction de la syllabe CV, l'aboutissement de la détente (stroke) du système main-bras se produise dans la phase de tenue de l'attaque consonantique. L'icorporation de la main et de la face dans un espace de contrôle neural commun peut être ainsi pleinement réalisée dans la LPC.

Although research on children's play is abundant and considerable advances have been made in young children's play, the majority of these studies have been based in western developed countries and written from adults' perspectives rather than with children. Additionally, very little research has been done on children's play with active participants from smaller developing countries. The voices of society's youngest members have been lost or are only marginally represented. The purpose of this qualitative research is to explore, understand, and describe young Jamaican children's lived play experiences as related through their eyes. The theoretical frameworks used to guide this study are sociocultural theory and narrative case study. Narrative case study focuses on a particular phenomenon and, through rich description, each participant's story relates the complexities of this phenomenon. Sociocultural theory is related to the social, cultural, and historical theory of a people and is constructed as they participate in culturally pertinent activities. The examined literature, which draws on diverse theoretical frameworks, including Vygotsky and Rogoff's sociocultural theory and Bronfenbrenner's work on socioecological theory, discusses types of play, the relationship between play and children's development, indoor and outdoor play at school, and play as perceived by children. A key theme in this literature is children's beliefs and values observed through a cultural filter. The three 5-year-old children, their teacher, and parents were purposefully selected for this single-bounded case study. The methods of data collection include video-cued interviews (VCI), a researcher's journal, and observation and field-notes. An understanding of the history of Jamaican education and its people is essential to the successful implementation of the play-based curriculum. The importance of knowing how children view their play and its manifestations and meanings is compelling to the Jamaican people and will help inform teachers, teacher education programs, parents, national and international funders, and other stakeholders as they try to fuse Jamaican culture with global elements of young children education.

Le champ socio-professionnel circonscrit par la prise en compte éducative et sociale des surdités sévères et profondes congénitales est structuré par un clivage entre les courants gestualistes et oralistes apparu à la fin du XVIIIè siècle. Depuis la fin des années mille neuf-cent soixante-dix, sous les impulsions de la militance pour la « cause sourde » d'une part et des progrès technico-médicaux de l'autre, ce clivage s'est trouvé refondé dans celui distinguant une conception du sujet sourd, héritant du structuralisme en linguistique et en psychanalyse, d'une approche de l'individu déficient auditif marqué du positivisme des modèles biologiques appliqués à l'humain.Si l’indigence de la prise en compte de la complexité de la rationalité humaine par ce second paradigme fait l'objet de critiques tout aussi sévères qu'argumentées de la part du premier, la passion pour la langue des signes qui infiltre celui-ci l'inscrit aussi, par là même, dans la tendance sociale repérable comme celle d'un effacement de la spécificité de l'enfant.Bien au-delà d'ailleurs du contexte du handicap, on peut identifier que la langue des signes produit dans notre contemporanéité des effets de fascination amplement redevables aux échos qu'elle trouve dans la négativité – au sens de Jean Gagnepain – constitutive de la condition de l'Homme.Dans l'investissement de la langue des signes, ordonné par la militance pour la « cause sourde » et l'orientation se présentant comme oeuvrant à un bilinguisme, la question de l'imprégnation de la langue audio-orale communautaire et de son outillage par l’écrit figure enfin un point d’achoppement dont se démarquent les approches oralistes notamment renouvelées par la Langue française Parlée Complétée (LPC). / The socio-professional area is delimited by the social and educative ways of regarding the severe congenital deafnesses. It is structured by the split between the oralism and gestualism branches which appeared at the end of XVIIIth century. Since the end of the seventies, driven by parental and cultural militancies as well as technical and medical progress, this division has been refounded in a new one which sets apart two ways of seeing the deaf person. One derives from structuralism in linguistic and psychoanalyse and the other one from positivism of biological models applied to Human.The paucity of the second paradigm regarding the human rationality complexity is the target of serious as well as documented criticisms by the first one. However, the passion for the sign language which comes in the latter one puts it also, by the fact, in the social trend which erases the child specificity. Besides, far beyond the handicap context, the fascination for the sign language observed in our contemporaneity is fully indebted to echoes found in the human constitutive negativity – in the Jean Gagnepain's meaning.Finally the issues of impregnation by audio-oral community language and of its equipment by writing are sticking points in the sign language approach, ordered by campaigners for the deaf cause and considered as working for bilingualism. Conversely, oralism, especially when renewed by the Cued Speech adapted to French, gets free from these pitfalls.

Nicotine has been shown to enhance multiple forms of learning and memory. However the substrates through which these effects occur are not well understood. To examine the specific substrates of nicotine's acute effects on trace fear conditioning, I infused nicotine into areas thought to support trace fear conditioning, the dorsal hippocampus, ventral hippocampus and medial prefrontal cortex. Additionally, we investigated the contributions of nicotinic acetylcholinergic signaling to trace fear conditioning by infusing the nicotinic antagonists dihydro-beta-erythroidine (DHbE) and methyllycaconitine (MLA) into these areas. Nicotine had different effects on both trace and contextual fear conditioning depending on dose and brain region, as did the nicotinic antagonists. In the dorsal hippocampus nicotine infusion enhanced both trace and contextual conditioning, although these effects were dissociable by dose and training protocol. Additionally, the high-affinity nicotinic antagonist DHbE produced selective deficits in trace conditioning, suggesting that while enhancement of nicotinic signaling can affect both contextual and trace learning, nicotinic activity in the dorsal hippocampus is critically involved in trace but not contextual conditioning. In the ventral hippocampus nicotine infusion produced deficits in both trace and contextual fear conditioning, without affecting delay conditioning, while the antagonists had no effect. This finding suggests that altered nicotinic signaling in the ventral hippocampus can suppress hippocampus dependent learning. In the mPFC nicotine selectively enhanced trace conditioning though both antagonists also enhanced trace fear conditioning. Unlike in the mPFC or dorsal hippocampus, where nicotine and antagonist induced effects occurred during training, effects in the ventral hippocampus occurred at both training and testing, suggesting that the ventral hippocampus may be able to modulate acquisition as well as expression of hippocampus dependent learning. Additionally, antagonist infusion into the mPFC during testing produced deficits in expression, suggesting that this area can modulate fear expression. Thus, the substrates of nicotinic acetylcholinergic contributions to trace and contextual fear conditioning are diverse. I put forth a multi-component model of these contributions, where trace fear conditioning is supported by dorsal hippocampus dependent maintenance of the CS during the trace interval, long-term storage in the mPFC and ventral hippocampal mediated acquisition and expression. / Psychology

This study explored the effects of lecture speech rate and duration on L1 Chinese listeners' listening comprehension of online L2 English lectures on free-recall and cued-recall questions. There are many factors that may affect a Chinese listener's listening comprehension of online English lectures. The current study focused specifically on the effects of speech rate and duration, and explored the possibility of identifying tools that listeners might use to control these factors during online lectures in order to achieve better learning experiences. Using an exploratory quasi-experimental approach, this study explored the research questions in three phases: 1) An initial quasi-experiment was conducted via Qualtrics and applied as a pilot study; 2) The quasi-experiment was revised, with a new link sent out to potential participants from both the United States and China; and 3) Quasi-experiment responses were collected and analyzed. Based on 28 participant responses, the findings from the current study suggest that the interaction between speech rate and duration impacted L1 Chinese listener's comprehension of online L2 English lectures. The findings also suggest that study participants' responses on various types of questions were affected differently by the speech rate and duration of the lectures. / Doctor of Philosophy / It is assumed that the slower and the shorter the listening material is, the better the foreign language learner's listening comprehension will be. Is this true? This study explored how a lecture's speech rate and duration may affect L1 Chinese listeners' listening comprehension of online L2 English lectures on free-recall and cued-recall questions. It discusses the possibility of identifying tools for listeners to control the speech rate and duration of online lectures in order to help listeners achieve better learning experiences. Using an exploratory quasi-experimental approach, this study explored the research questions in three phases: 1) An initial quasi-experiment was conducted via Qualtrics and applied as a pilot study; 2) The quasi-experiment was revised, with a new link sent out to potential participants from both the United States and China; and 3) Quasi-experiment responses were collected and analyzed. Based on 28 participant responses, the findings from the current study suggest that speech rate and duration worked together to impact L1 Chinese listeners' comprehension of online L2 English lectures. The findings also suggest that study participants' responses on various types of questions were affected differently by the speech rate and duration of the lectures.

Visual attention improves sensory processing, as well as perceptual readout and behavior. Over the last decades, many proposals have been put forth to explain how attention affects visual neural processing. These include the modulation of neural firing rates and synchrony, neural tuning properties, and rhythmic, subthreshold activity. Despite the wealth of knowledge provided by previous studies, the way attention shapes interactions between cortical layers within and between visual sensory areas is only just emerging. To investigate this, we studied neural signals from macaque V1 and V4 visual areas, while monkeys performed a covert, feature-based spatial attention task. The data were simultaneously recorded from laminar electrodes disposed normal to cortical surface in both areas (16 contacts, 150 μm inter-contact spacing). Stimuli presentation was based on the overlap of the receptive fields (RFs) of V1 and V4. Channel depths alignment was referenced to laminar layer IV, based on spatial current source density and temporal latency analyses. Our analyses mainly focused on the study of Local Field Potential (LFP) signals, for which we applied local (bipolar) re-referencing offline. We investigated the effects of attention on LFP spectral power and laminar interactions between LFP signals at different depths, both at the local level within V1 and V4, and at the inter-areal level across V1 and V4. Inspired by current progress from literature, we were interested in the characterization of frequency-specific laminar interactions, which we investigated both in terms of rhythmic synchronization by computing spectral coherence, and in terms of directed causal influence, by computing Granger causalities (GCs). The spectral power of LFPs in different frequency bands showed relatively small differences along cortical depths both in V1 and in V4. However, we found attentional effects on LFP spectral power consistent with previous literature. For V1 LFPs, attention to stimuli in RF location mainly resulted in a shift of the low-gamma (∼30-50 Hz) spectral power peak towards (∼3-4 Hz) higher frequencies and increases in power for frequency bands above low-gamma peak frequencies, as well as decreases in power below these frequencies. For V4 LFPs, attention towards stimuli in RF locations caused a decrease in power for frequencies < 20 Hz and a broad band increase for frequencies > 20 Hz. Attention affected spectral coherence within V1 and within V4 layers in similar way as the spectral power modulation described above. Spectral coherence between V1 and V4 channel pairs was increased by attention mainly in the beta band (∼ 15-30 Hz) and the low-gamma range (∼ 30-50 Hz). Attention affected GC interactions in a layer and frequency dependent manner in complex ways, not always compliant with predictions made by the canonical models of laminar feed-forward and feed-back interactions. Within V1, attention increased feed-forward efficacy across almost all low-frequency bands (∼ 2-50 Hz). Within V4, attention mostly increased GCs in the low and high gamma frequency in a 'downwards' direction within the column, i.e. from supragranular to granular and to infragranular layers. Increases were also evident in an ‘upwards’ direction from granular to supragranular layers. For inter-areal GCs, the dominant changes were an increase in the gamma frequency range from V1 granular and infragranular layers to V4 supragranular and granular layers, as well as an increase from V4 supragranular layers to all V1 layers.

De nombreuses études longitudinales ont montré un lien causal entre habiletés phonologiques précoces et plus tard le développement de la lecture et de l’écriture chez l’enfant entendant (Bryant, MacLean, Bradley & Crossland, 1990). Pour apporter une contribution aux connaissances concernant ce lien chez les enfants sourds, nous avons réalisé une étude longitudinale qui s’échelonne de la troisième maternelle à la seconde primaire. Les performances d’enfants sourds sévères et profonds prélinguaux exposés (précocement vs tardivement) ou non au Langage Parlé Complété (« LPC », code manuel destiné à lever l’ambiguïté de la lecture labiale seule) sont comparées à celles d’enfants entendants de même âge chronologique. Diverses épreuves phonologiques, de lecture et d’écriture ont été proposées. Les résultats ont montré que les habiletés phonologiques précoces prédisaient le niveau de reconnaissance de mots écrits en première primaire chez les enfants sourds comme chez les enfants entendants. Cependant, un effet plus important de l’apprentissage de la lecture est observé sur le niveau d’habiletés phonologiques, de lecture et d’écriture lors des deux premières primaires chez les enfants sourds. De plus, les performances des enfants sourds exposés précocement au LPC ne diffèrent pas de celles des enfants entendants et sont plus élevées que celles des autres enfants sourds, en particulier en première et seconde primaire. L’exposition précoce au LPC permettrait donc le développement de représentations phonologiques précises et par conséquent l’utilisation d’un décodage phonologique efficace en lecture et en écriture au début de l’apprentissage de la lecture. / Longitudinal studies have shown a causal connection between early phonological skills and later literacy development in hearing children (Bryant, MacLean, Bradley & Crossland, 1990). The aim of our study is to investigate whether early phonological skills predict later literacy performance in deaf children either exposed (early versus late) or not exposed to Cued Speech (“CS”, a manual system delivering phonetically augmented speechreading through the visual modality). Different phonological and literacy tasks were administered from kindergarten to seconde grade. The results show that the early phonological skills in kindergarten predict written word recognition in first grade in the deaf as well as in the hearing groups. However, an effect of learning to read seems to be more important on the level of phonological and literacy skills during the first and seconde grade in deaf children. In addition, the performances of early CS users do not differ from those of hearing children and are higher than those of the other deaf children, especially in first and second grade. Early exposure to Cued Speech may permit the development of accurate phonological representations and, consequently, the use of accurate phonological decoding to recognize written words and to spell at an early stage in learning to read.

L’ambition de la thèse est de contribuer à une meilleure compréhension des difficultés cognitives rencontrées par les enfants sourds munis d’un implant cochléaire (IC). Elle présente une recension de travaux et une étude originale concernant la mémoire à court-terme/mémoire de travail.Est évalué l’apport recommandé de la lecture labiale et des clés de la LPC (Langue Parlée Complétée) sur le rappel.Une série d’épreuves originales de rappel immédiat a été conçue sur support informatique. Elle comprend des tâches contrastées du point de vue de la nature de l’information à mémoriser (spatiale vs verbale) et des modalités de présentation de l’information. Les épreuves ont été validées auprès d’une population d’enfants normo-entendants (NE)(âgés de 6 à 8 ans, N=42). Les réponses d’enfants IC(N=14) ont été comparées à celles d’enfants NE, sur la base de la constitution de deux groupes appareillés selon les critères d’âge, de sexe et d’aptitude intellectuelle.Pour les deux groupes, le rappel immédiat est meilleur pour les informations visuo-spatiales. Les informations verbales sont moins bien retenues par les enfants IC. Contrairement aux attentes, l’apport de la LPC, spécifiquement dans la modalité verbale, ne conduit pas à une augmentation des performances des enfants sourds. L’analyse de l’ordre de rappel des items ne fait pas apparaître de difficultés spécifiques. En revanche, la longueur des listes est préjudiciable en verbal. L’analyse des erreurs atteste de leurs difficultés au plan des connaissances langagières. Une analyse fine des performances individuelles montre des profils différenciés attestant de la singularité des modes d’adaptation des enfants sourds IC. / The aim of the thesis is to contribute to a better understanding of cognitive difficulties in deaf children with a cochlear implant (CI). Firstly, this thesis presents a comparative analysis of previous research work. Secondly, it presents an original study addressing short-term memory (STM)/working memory (WM) issues, in which the contribution of cued speech (CS) is assessed on memorization performances. To do so, a novel STM/WM task series was developed and used to investigate whether the use of verbal stimuli versus spatial stimuli differentially affects immediate memory processes and to examine whether the presentation of items in an enriched context has a benefit on the immediate memory capacity. The developed tasks were validated on normal-hearing (NH) children (6- and 8-year-old, N=42) and the capacities of CI deaf children(N=14) were compared to those of their NH peers matched for age, sex and reasoning ability. For both groups, the immediate recall proves to be better for visuo-spatial information. Also, CI deaf children appear as memorizing less verbal information. Surprisingly, CS, appears to be ineffective to improve the CI deaf children performances, especially in the verbal modality case; if the analysis of the order of recall of items does not reveal any specific difficulty, the length of the items lists is harmful in the verbal modality. The analysis of the recall errors confirms difficulties in linguistic knowledge. Individual performances of CI deaf children show diverse patterns.

Children with autism typically exhibit deficits in behavior and also in visual processing. Development and implementation of visually-cued instructional procedures, combined with electronic technology, have been used successfully to teach children with autism complex behavior chains. This study used photographic activity schedules on computer slideshow software to teach two children with autism to follow computer-mediated cues and engage in four play activities, and to transition between each activity in their homes without the presence of a trained behavior therapist. Results of this study demonstrated that these technologies can be utilized in children's homes to promote computer-mediated play behavior while eliminating the necessary cost of a home behavior therapist to prompt and supervise such activities.