Es natural que la lengua materna de un bilingüe cambie. Sin embargo, si un individuo vive en un contexto donde se habla su segunda lengua como lengua mayoritaria, si usa constantemente su segunda lengua y si el uso de su lengua materna ha disminuido, es muy probable que se vea afectado por la atrición de las habilidades lingüísticas. Esta investigación se concentra en el estudio de la atrición léxica del español como lengua materna. Los participantes son mexicanos adultos con educación universitaria entre los 25 y los 35 años de edad, los participantes del grupo experimental (n=10) inmigraron a los Estados Unidos después de los 17 años de edad, y han vivido en este país entre 5 y 16 años. Los participantes del grupo de control (n=10) residen en México y nunca han vivido en un país de habla inglesa. Tres medidas se obtuvieron y analizaron estadísticamente para determinar si el grupo experimental está siendo afectado por la atrición de la lengua: en las medidas de diversidad y la sofisticación léxica los resultados de la investigación revelaron una diferencia estadísticamente significativa entre ambos grupos. Estos resultados resultan similares a los de Keijzer (2017), Schmid y Dusseldrop (2011); y Yilmaz y Schmid (2012). No hubo diferencia en la prueba de fluidez verbal. Los resultados no revelaron significancia de la edad, el tiempo de arribo y el sexo en la media de los resultados, y de la misma manera no se encontró una correlación de los resultados de las pruebas léxicas con el uso del idioma, debido quizá al tamaño de la muestra.

Lexical retrieval models illustrate both activation and inhibition between concepts, words, and phonemes. When semantic activation spreads from one concept to its related concepts, inhibition is recruited so that competition between related concepts can be overcome and a target production achieved. Persons with aphasia often exhibit difficulty with producing the desired response, which could be the result of inadequate inhibitory processes to overcome response competition. Inhibitory processing is typically measured using a negative priming task. Twenty participants with aphasia, twenty-five young participants, and twenty age-matched aphasia group controls were recruited for this study. Participants with aphasia completed a picture-naming task, two written lexical decision tasks, subtests of an aphasia assessment, and the negative priming lexical decision task. Control groups completed only the negative priming task. This task consisted of 4 blocks of 72 trials each in which target words were related associates (RA), related distractors (RD), or unrelated (UN), or pseudowords. Results indicate that no groups showed predicted decreased reaction times to the RA condition. Instead of showing the fastest reaction times, the average RTs in the RA condition were between those in the RD and the UN conditions. Error rates were higher in the aphasia group, with significantly more errors for related conditions. In the young control group, significant negative priming was achieved. However, in the aphasia and aphasia-control groups, there was no significant negative priming. Multiple regression analysis determined that time post onset, age, education, type of fluency, and classification of anomia were not significant predictors of these results in the aphasia group. It is argued that these results are not strategically induced secondary to expectancy or a semantic expectancy or a semantic-matching process. Using a prospective or a retrospective strategy would be useless since only a small portion of the prime-probe pairs are directly related. The results of the aphasia group and the aphasia-control group are similar to those found in the aging negative priming literature, but it is unclear if this should be interpreted as degraded inhibitory processes. Future studies to further explore negative priming in aphasia are discussed.

This study examined the effects of bilingualism on speech recognition in noise performance of young normal-hearing Spanish-English bilinguals across several signal-to-noise ratios (SNR). The estimated signal-to-noise ratio needed for 50% correct recognition performance obtained for bilingual listeners was compared to young normal-hearing monolingual listeners of both English and Spanish. The estimated mean SNR needed for 50% correct recognition was significantly higher (i.e., poorer) for the bilingual than for the monolingual English listeners. The Spanish language performance of the bilingual listeners did not significantly differ from that of the monolingual Spanish listeners. The bilinguals were then divided into subgroups based on age of acquisition of the second language. Bilinguals were subdivided into early and later learners of English and further comparisons were made. The average estimated SNR needed for 50% correct recognition for the early bilinguals did not differ statistically from that of monolingual listeners in either the English or the Spanish language testing. The SNR obtained for 50% correct recognition of English words was significantly higher for the late bilinguals than for the monolingual English listeners. For Spanish words, the mean SNRs obtained for 50% correct recognition for the later bilinguals and the monolingual Spanish speakers did not differ statistically from one another. These results suggest that caution should be used when assessing speech-in-noise performance in the second language of bilingual patients because separate norms may be needed for this population. Age of acquisition of the second language should be considered as a confounding factor in speech-in-noise performance of bilingual listeners.

Lexical access is the process in which basic components of meaning in language, the lexical entries (words) are activated. This activation is based on the organization and representational structure of the lexical entries. Semantic features of words, which are the prominent semantic characteristics of a word concept, provide important information because they mediate semantic access to words. An experiment was conducted to examine the importance of semantic feature distinctiveness and feature frequency in accessing the lexical representations of young and older adults in an off-line task using features of animals. The McRae, Cree, Seidenberg, and McNorgan (2005) feature norm corpus is the basis for the selection of stimuli for the current research project. Semantic features were utilized to explore the structure of the lexicon. Stimuli varied in feature distinctiveness based on the study by McRae, et al. (2005) in 3 broad stimulus groups: Distinctive (D), Low Frequency Non-Distinctive (LFND), and Non-Distinctive High Frequency (NDHF). Participants were asked to list all of the concepts that came to mind for a given feature in an untimed task. Distinctiveness was examined between stimulus groups for the number of concepts and variety of first concepts given to the presented feature. It was found that fewer concepts were given and there was less variety in first concepts given for the distinctive features and the most concepts and greater variety of first concepts were given for the high-frequency non-distinctive features. Distinctiveness appears to vary along a continuum, supporting theories of lexical access based on activation and competition between concept words. Additionally, participant age groups were compared for the number of concepts given and the variety of first concepts given. The older adult group produced more concepts and more variety of first concepts than the younger group, in all three feature categories. These results indicate that greater (lifetime) language experience of the participants in the older group was reflected in their performance. A continued interest in semantic features is important to our understanding of the influence of features on the retrieval of semantic concepts and the changes in those retrieval processes over the lifespan.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

The research reported in this thesis examines the relative contributions of top-down and bottom-up information during lexical access. I evaluate the Cohort Model of lexical access (Marslen-Wilson and Welsh, 1978; Marslen-Wilson and Tyler, 1980; and Marslen-Wilson, 1987) which specifies that the first stage in lexical access is fully autonomous and that during this stage all processing proceeds in terms of analysis of the acoustic-phonetic input. Implicit in this model is the assumption that bottom-up processing is immune to any effects of contextual or top-down information. I examine the extent to which listeners ever rely exclusively on bottom-up information during lexical access and investigate this issue empirically, by measuring effects of context on both the production and the perception of words in various contexts. I test the hypothesis that a word uttered in a constraining context will be acoustically indistinguishable from its competitors by, first, measuring one acoustic parameter (VOT) across constraining and non-constraining contexts and, then, examining the intelligibility of tokens of that parameter taken from the varyingly constraining contexts. The data from these experiments suggest that the realization of VOT is not an aspect of bottom-up information which would create problems for a bottom-up processor in terms of providing ambiguous acoustic-phonetic information. I then investigate whether bottom-up processing during lexical access is immune to effects of context. Following Grosjean (1980) and Tyler (1984), I utilize the Gating Paradigm. Using incongruous contexts, I argue that direct assessment of the contributions made by different information sources during lexical access can be made. By presenting bottom-up information which is inappropriate to the contextual (topdown) information, I evaluate the extent to which one information source is given priority over the other. I vary both the contextual constraints available to the listener and the acoustic clarity of bottom-up information. The observed pattern of listeners' identifications of the words suggested that whilst bottomup information was given priority, top-down information was available and was utilized during lexical access. I present data which support the working structure of the Cohort Model of lexical access. I conclude, however, that the model places disproportionate emphasis on initial bottom-up processing. It appears that top-down information is not prohibited from contributing to processing during the initial stage of lexical access.

The research on bilingual language processing explores two main avenues of relevance to the present study: lexico-semantic access and cognitive control. Lexico-semantic access research investigates the manner in which bilingual individuals retrieve single words from their lexical system. Healthy bilingual individuals can manipulate their lexico-semantic access to accommodate settings in which code- or language-switching is expected. Alternatively, they can manipulate their lexico-semantic access to speak only their first (L1) or second (L2) languages. Cognitive control, also known as executive functioning, is closely related to lexico-semantic access. Specifically, bilingual individuals maintain and switch between their languages through a mechanism known as cognitive control. Both cognitive control and lexico-semantic access are important for language processing in healthy bilingual individuals as well as bilingual persons with aphasia (BPWA). However, the extent to which BPWA utilize each of these processes in the production of single words is still unknown. The present study used a method of verbal fluency in the form of a novel modified category generation task to assess the relative contributions of lexico-semantic access and cognitive control in bilingual healthy controls and BPWA.

Os estudos nas áreas da neuropsicologia e da afasiologia sempre demonstraram uma preocupação em analisar o processamento da linguagem de afásicos. Porém, ainda existe a necessidade de se analisar a produção oral desses indivíduos, com o objetivo de melhor descrever os distúrbios apresentados pelos mesmos com vistas a contribuir com os possíveis tratamentos dedicados a essas pessoas. Por essa razão, esta dissertação investigou a dificuldade de acesso lexical, tanto na produção de fala espontânea, através de uma Entrevista de Memória Autobiográfica, como na fala semi espontânea, através da Tarefa do Roubo dos Biscoitos, em dois indivíduos afásicos, caracterizando dois fenômenos linguísticos decorrentes da afasia – anomia e parafasia – bem como elencando os tipos de estratégias comunicativas empregadas por esses indivíduos com vistas a superar dificuldades linguísticas no momento da comunicação. Os resultados encontrados mostram que ambos os indivíduos apresentaram casos de anomia, principalmente relacionados aos substantivos concretos, à subcategoria dos nomes próprios e aos numerais. Foi possível verificar também que, quando apresentavam casos de anomia, os dois participantes utilizaram-se com frequência de estratégias comunicativas. No que tange aos casos de parafasia, foi possível observar que na produção oral de ambos os participantes, os casos de parafasia morfêmica relacionados aos verbos e às palavras funcionais foram mais frequentes, se comparados com os outros tipos de parafasia. Nos casos de parafasia morfêmica dos verbos, observou-se uma dificuldade de referência de tempo ao passado, ao passo que, em relação às palavras funcionais, houve uma dificuldade de flexão de gênero. / A large number of studies in Neuropsychology and Aphasiology have analyzed language processing of individuals with aphasia. However, there is still the necessity of analyzing the oral production, with the purpose of improving the description of language disorders common to these aphasic patients and analyzing appropriate treatment for these individuals. Within this context, the present study aimed to investigate lexical access in two aphasic patients in spontaneous versus semi-spontaneous speech production through two distinct tasks: an Autobiographical Memory Interview as well as The Cookie Theft Picture Description Task with the focus on the linguistic phenomena that result of aphasia - anomia and paraphasia. In addition to that, we also looked at the types of communication strategies employed by these aphasic individuals in order to overcome language difficulties when communicating. The results show that both subjects presented cases of anomia, mainly related to concrete nouns, the subcategory of proper names and numerals. It was also verified that, when presenting anomia, the two participants used communication clues in order to overcome their language impairments. With regard to the cases of paraphasia, it was also observed that, in the oral production of both participants, cases of morphemic paraphasia related to verbs and function words were more frequent when compared with other types of paraphasia. When the cases of morphemic paraphasia were related to verbs, there was a difficulty associated with time reference to the past, whereas in relation to functional words there was a difficulty of bending genre.

Os estudos nas áreas da neuropsicologia e da afasiologia sempre demonstraram uma preocupação em analisar o processamento da linguagem de afásicos. Porém, ainda existe a necessidade de se analisar a produção oral desses indivíduos, com o objetivo de melhor descrever os distúrbios apresentados pelos mesmos com vistas a contribuir com os possíveis tratamentos dedicados a essas pessoas. Por essa razão, esta dissertação investigou a dificuldade de acesso lexical, tanto na produção de fala espontânea, através de uma Entrevista de Memória Autobiográfica, como na fala semi espontânea, através da Tarefa do Roubo dos Biscoitos, em dois indivíduos afásicos, caracterizando dois fenômenos linguísticos decorrentes da afasia – anomia e parafasia – bem como elencando os tipos de estratégias comunicativas empregadas por esses indivíduos com vistas a superar dificuldades linguísticas no momento da comunicação. Os resultados encontrados mostram que ambos os indivíduos apresentaram casos de anomia, principalmente relacionados aos substantivos concretos, à subcategoria dos nomes próprios e aos numerais. Foi possível verificar também que, quando apresentavam casos de anomia, os dois participantes utilizaram-se com frequência de estratégias comunicativas. No que tange aos casos de parafasia, foi possível observar que na produção oral de ambos os participantes, os casos de parafasia morfêmica relacionados aos verbos e às palavras funcionais foram mais frequentes, se comparados com os outros tipos de parafasia. Nos casos de parafasia morfêmica dos verbos, observou-se uma dificuldade de referência de tempo ao passado, ao passo que, em relação às palavras funcionais, houve uma dificuldade de flexão de gênero. / A large number of studies in Neuropsychology and Aphasiology have analyzed language processing of individuals with aphasia. However, there is still the necessity of analyzing the oral production, with the purpose of improving the description of language disorders common to these aphasic patients and analyzing appropriate treatment for these individuals. Within this context, the present study aimed to investigate lexical access in two aphasic patients in spontaneous versus semi-spontaneous speech production through two distinct tasks: an Autobiographical Memory Interview as well as The Cookie Theft Picture Description Task with the focus on the linguistic phenomena that result of aphasia - anomia and paraphasia. In addition to that, we also looked at the types of communication strategies employed by these aphasic individuals in order to overcome language difficulties when communicating. The results show that both subjects presented cases of anomia, mainly related to concrete nouns, the subcategory of proper names and numerals. It was also verified that, when presenting anomia, the two participants used communication clues in order to overcome their language impairments. With regard to the cases of paraphasia, it was also observed that, in the oral production of both participants, cases of morphemic paraphasia related to verbs and function words were more frequent when compared with other types of paraphasia. When the cases of morphemic paraphasia were related to verbs, there was a difficulty associated with time reference to the past, whereas in relation to functional words there was a difficulty of bending genre.

Os estudos nas áreas da neuropsicologia e da afasiologia sempre demonstraram uma preocupação em analisar o processamento da linguagem de afásicos. Porém, ainda existe a necessidade de se analisar a produção oral desses indivíduos, com o objetivo de melhor descrever os distúrbios apresentados pelos mesmos com vistas a contribuir com os possíveis tratamentos dedicados a essas pessoas. Por essa razão, esta dissertação investigou a dificuldade de acesso lexical, tanto na produção de fala espontânea, através de uma Entrevista de Memória Autobiográfica, como na fala semi espontânea, através da Tarefa do Roubo dos Biscoitos, em dois indivíduos afásicos, caracterizando dois fenômenos linguísticos decorrentes da afasia – anomia e parafasia – bem como elencando os tipos de estratégias comunicativas empregadas por esses indivíduos com vistas a superar dificuldades linguísticas no momento da comunicação. Os resultados encontrados mostram que ambos os indivíduos apresentaram casos de anomia, principalmente relacionados aos substantivos concretos, à subcategoria dos nomes próprios e aos numerais. Foi possível verificar também que, quando apresentavam casos de anomia, os dois participantes utilizaram-se com frequência de estratégias comunicativas. No que tange aos casos de parafasia, foi possível observar que na produção oral de ambos os participantes, os casos de parafasia morfêmica relacionados aos verbos e às palavras funcionais foram mais frequentes, se comparados com os outros tipos de parafasia. Nos casos de parafasia morfêmica dos verbos, observou-se uma dificuldade de referência de tempo ao passado, ao passo que, em relação às palavras funcionais, houve uma dificuldade de flexão de gênero. / A large number of studies in Neuropsychology and Aphasiology have analyzed language processing of individuals with aphasia. However, there is still the necessity of analyzing the oral production, with the purpose of improving the description of language disorders common to these aphasic patients and analyzing appropriate treatment for these individuals. Within this context, the present study aimed to investigate lexical access in two aphasic patients in spontaneous versus semi-spontaneous speech production through two distinct tasks: an Autobiographical Memory Interview as well as The Cookie Theft Picture Description Task with the focus on the linguistic phenomena that result of aphasia - anomia and paraphasia. In addition to that, we also looked at the types of communication strategies employed by these aphasic individuals in order to overcome language difficulties when communicating. The results show that both subjects presented cases of anomia, mainly related to concrete nouns, the subcategory of proper names and numerals. It was also verified that, when presenting anomia, the two participants used communication clues in order to overcome their language impairments. With regard to the cases of paraphasia, it was also observed that, in the oral production of both participants, cases of morphemic paraphasia related to verbs and function words were more frequent when compared with other types of paraphasia. When the cases of morphemic paraphasia were related to verbs, there was a difficulty associated with time reference to the past, whereas in relation to functional words there was a difficulty of bending genre.