No description available.

The aim of this study was to investigate how young adults who stutterer allocate attentional resources during two linguistic stages in picture naming, specifically lemma and lexeme retrieval. This study reports on behavioral and brain electrophysiological data collected during a simple auditory oddball task and a Dual Picture-Word Interference/Tone Monitoring Task.

In the study of language production in aging, an important question relates to the relationship between lexical retrieval and syntactic production. Studies have reported changes in syntactic production across the lifespan, but their underlying cause remains unclear. In younger adults, it has been suggested that lexical factors, such as an item‟s semantic or phonological representation influence syntactic production; however, the full nature of this influence remains unclear. Studies investigating the type of sentence produced have found semantic facilitation and phonological interference (e.g., Bock, 1986, 1987), but studies investigating response time (e.g., Meyer, 1996) have found the opposite effects. This investigation sought to examine the influence of lexical level information on sentence production in younger and older adults. This was accomplished by concurrently examining reaction time and sentence type effects. In Experiment 1, 61 adults (mean age: 21.8 years) were presented with pictures and distractor words (unrelated, or semantically or phonologically related). Three stimulus onset asynchronies (SOA) were used (-1000ms, -150ms and 150ms). Participants were required to describe each picture. Using an analysis of variance, response time was compared across the different conditions and using generalized estimating equations, the type of sentence produced and the position of the primed word were compared. In Experiment 2, phonological distractors were excluded, and one SOA (-150ms) was used. Testing involved 83 younger adults (mean age: 22.9 years) and 56 older adults (mean age: 74.7 years). In Experiment 1, semantic distractors resulted in related nouns being produced more often in the subject position. This effect was observed in the analysis of the position of the target noun, but not in the analysis of the type of sentence produced. There were no effects of phonological distractors. In Experiment 2, semantic distractors influenced the type of sentence produced for both age groups. The groups differed only in error production. No reaction time effects were observed in either experiment. This investigation successfully demonstrated an influence of lexical level information on the syntactic productions of younger and older adults. The two groups were similar in their productions, suggesting that aspects of syntactic production are preserved in older adults.

In the study of language production in aging, an important question relates to the relationship between lexical retrieval and syntactic production. Studies have reported changes in syntactic production across the lifespan, but their underlying cause remains unclear. In younger adults, it has been suggested that lexical factors, such as an item‟s semantic or phonological representation influence syntactic production; however, the full nature of this influence remains unclear. Studies investigating the type of sentence produced have found semantic facilitation and phonological interference (e.g., Bock, 1986, 1987), but studies investigating response time (e.g., Meyer, 1996) have found the opposite effects. This investigation sought to examine the influence of lexical level information on sentence production in younger and older adults. This was accomplished by concurrently examining reaction time and sentence type effects. In Experiment 1, 61 adults (mean age: 21.8 years) were presented with pictures and distractor words (unrelated, or semantically or phonologically related). Three stimulus onset asynchronies (SOA) were used (-1000ms, -150ms and 150ms). Participants were required to describe each picture. Using an analysis of variance, response time was compared across the different conditions and using generalized estimating equations, the type of sentence produced and the position of the primed word were compared. In Experiment 2, phonological distractors were excluded, and one SOA (-150ms) was used. Testing involved 83 younger adults (mean age: 22.9 years) and 56 older adults (mean age: 74.7 years). In Experiment 1, semantic distractors resulted in related nouns being produced more often in the subject position. This effect was observed in the analysis of the position of the target noun, but not in the analysis of the type of sentence produced. There were no effects of phonological distractors. In Experiment 2, semantic distractors influenced the type of sentence produced for both age groups. The groups differed only in error production. No reaction time effects were observed in either experiment. This investigation successfully demonstrated an influence of lexical level information on the syntactic productions of younger and older adults. The two groups were similar in their productions, suggesting that aspects of syntactic production are preserved in older adults.

No description available.

The thesis focuses on lexical retrieval in bilinguals' first language. The aim of the work is to follow up on the research conducted abroad which has shown that lexical retrieval in the first language of bilinguals is slower than lexical retrieval in matched monolinguals. The present thesis is based on an experiment consisting of a verbal fluency task and a picture naming task; the participants were 152+120 students of the Faculty of Arts of Charles University with varying levels of their L2 (ranging from speakers with low proficiency in L2 to almost balanced bilinguals). In contrast to the previous research, this project thus views L2 proficiency as differentiated along a scale. The results of both tasks suggest that lexical retrieval in native speakers of Czech with high proficiency in L2 is not slower than in matched speakers with low proficiency in L2. Analysis of reaction times in the picture naming task also indicates the involvement of frequency and cognate effects.

This thesis investigated lexical representations of children who stutter (CWS) and children who do not stutter (CWNS) using a duration-blocked gating task. This thesis tested the hypothesis that children who stutter have underspecified phonological representations for words, are less sensitive to incremental and segmental information for lexical items, and therefore require more acoustic-phonetic information to activate words in their lexicon. Pilot data collected from fourteen children (ages 5;6 to 10;1): 7 CWS and 7 CWNS matched on age were included in this thesis. Results showed that children in both talker groups required relatively equal amounts of acoustic-phonetic information to identify target words. A regression model revealed that age in months predicted performance on the gating task for CWNS, but that age in months did not predict performance on the gating task for CWS suggesting a difference in the developmental maturity of lexical representations in CWS. Possible conclusions from these pilot data are presented along with recommendations for future research. / text

La production de mots intéresse un vaste réseau cérébral principalement localisé dans l'hémisphère gauche, synthétisé dans une revue de littérature traitant des études de production de mots en enregistrements intracérébraux. Nous nous sommes principalement focalisés sur l'implication du réseau cérébral lors de l'accès lexical en utilisant deux protocoles de dénomination d'images manipulant l'interférence sémantique, connue pour moduler les liens entre les étapes sémantiques et lexicales. Nous avons comparé la dynamique spatiotemporelle de ces protocoles utilisés de façon interchangeable dans la littérature, mais qui diffèrent dans l'implication de paramètres méthodologiques pouvant faire intervenir des mécanismes mnésiques tels que la familiarisation et la répétition. Notre hypothèse étant que ces paramètres étant si divergents, le réseau neuronal sous-jacent devrait au moins être modulé selon le protocole étudié. Notre étude EEG révèle deux patterns d'activité électrophysiologique distincts entre les protocoles attribuables à l'effet de familiarisation. Nous avons étudié l'implication de la structure hippocampique dans la production de mot via des enregistrements intracérébraux. Les analyses en temps-fréquence et en champs locaux montrent que l'hippocampe est impliqué dans l'apprentissage progressif des liens sémantico-lexicaux, mais aussi dans leur maintien en mémoire durant une courte période et dans leur récupération. Ce travail de thèse a permis de révéler que la dynamique spatiotemporelle de la dénomination d'images est modulée par différents facteurs, ce qui va à l'encontre de l'implication d'un réseau partagé par ces deux protocoles de dénomination d'images. / Words production involves a vast brain network mainly localized in the left hemisphere, summarized in a review of literature based on studies of word production in intracranial recordings.We focused principally on the involvement of the cerebral network during lexical access by using two picture naming protocols manipulating the semantic interference effect, known to modulate the links between semantic and lexical processes. We compare the spatiotemporal dynamics of these protocols interchangeably used in the literature, but which differ in the involvement of methodological parameters that may involve mnemonic mechanisms such as familiarity and repetition. Our hypothesis was that these parameters are so divergent that the underlying neural network should at least be modulated by the protocol investigated. Our EEG study reveals two distinct patterns of electrophysiological activity between the protocols due to the familiarization effect. We studied the involvement of the hippocampal structure in the production of word through intracranial recordings. The time-frequency and the local field analyses show that the hippocampus is involved in the progressive learning links between semantic and lexicon, but also in keeping them in memory for a short period and in their recovery. This work revealed that the spatiotemporal dynamics of picture naming is modulated by various factors, which goes against the involvement of a common network shared by these two picture naming protocols.

No description available.