Le trouble de la théorie de l’esprit (ToM) observé dans la schizophrénie et la schizotypie pourrait résulter d’anomalies élémentaires de traitement du contexte. La compréhension de l’ironie, en tant qu’exercice de ToM contexte-dépendant, constitue un moyen privilégié de tester cette hypothèse. À l’aide de mesures comportementales et électrophysiologiques, l’objectif principal de ce travail était de préciser la place des anomalies des processus de contextualisation dans le trouble de la ToM dans la schizotypie-schizophrénie en utilisant le paradigme de l’ironie. Le second objectif était d’identifier les conditions dans lesquelles ces anomalies de la ToM se manifestent et celles dans lesquelles elles peuvent être compensées. Nos résultats suggèrent (i) que les difficultés de ToM dans la schizotypie-schizophrénie résultent d’anomalies de traitement du contexte, (ii) que ces difficultés concernent spécifiquement la mise à jour de la représentation des états mentaux en fonction du contexte, soit un processus sous-tendu par des stratégies contextuelles rétroactives connues pour être altérées dans la schizotypie-schizophrénie et (iii) que la structuration du contexte sémantique permet d’améliorer les capacités de ToM dans le spectre de la schizophrénie, tandis que la présence d’un co-acteur inconnu semble inhiber ces capacités. Nos résultats soulignent par ailleurs un lien entre l’altération de la ToM et les difficultés sociales des participants. En conclusion, ce travail désigne les processus de contextualisation comme une cible cruciale des programmes de remédiation de la cognition sociale dans les troubles du spectre de la schizophrénie. / Theory of mind disturbances are a core manifestation of schizophrenia spectrum disorders. They contribute to the social handicap associated with the pathology, leading to disruption in autonomy, professional achievement, and interpersonal relationships. According to several authors, these disturbances may be due to a contextual impairment. Irony comprehension as a context-dependent ToM exercise is an ideal way to test this hypothesis. The first aim of this work was to clarify the contextual impairment’s role in ToM disturbances in schizotypy-schizophrenia using the paradigm of irony through behavioral and electrophysiological measures. The second aim was to identify the conditions in which these ToM disturbances occur and the conditions in which they can be compensated. Our results suggest that (i) ToM difficulties in schizotypy-schizophrenia result from abnormalities in context processing, (ii) these difficulties relate specifically to the updating of the mental states’ representation according to the context, e.g. a mentalizing process underlayed by retroactive contextual strategies known to be altered in schizotypy-schizophrenia, and (iii) structuring the semantic context can improve ToM's abilities in the schizophrenia’s spectrum, while the presence of an unknown co-actor seems to inhibit these abilities. Our results also highlight a link between the participant’s ToM disturbances and their social difficulties. In conclusion, this work indicates the relevance of cognitive remediation programs that target contextual processing in schizophrenia spectrum disorders.

No description available.

Syntactic anomalies reliably elicit P600 effects in natural language processing. A survey of previous work converged on a conclusion that the mean amplitude of the P600 seems to be associated with the goodness of fit of a target word with expectation generated based on already unfolded materials. Based on this characteristic of the P600 effects, the current study aimed to look for evidence indicating the influence of input statistics in shaping grammatical knowledge/representations, and as a result leading to probabilistically-based competition/expectation generation processes of online sentence processing. An artificial grammar learning (AGL) task with 4 different conditions varying in probabilities were used to test this hypothesis. Results from this task indicated graded mean amplitude of the P600 effects across conditions, and the pattern of gradience is consistent with the variation of the input statistics. The use of the artificial language to simulate natural language learning process was further justified with statistically undistinguishable P600 effects elicited in a natural language sentence processing (NLSP) task. Together, the results indicate that the same neural mechanisms are recruited for both syntactic processing of natural language stimuli and sentence strings in an artificial language.

<p>Event-related potentials (ERPs) have been used extensively in the scientific research of cognitive processing such as language comprehension. Specific responses, such as the negativity called N400 (Kutas & Hillyard, 1980), have in the literature typically been associated with semantic violations in sentences. Another electrophysiological response, the positive P600 waveform, has mostly been associated with syntactic and morphological violations. However, recently, the P600 has been reported also in connection with semantic violations (Kuperberg et al, 2003; van Herten, 2004; Osterhout, 2004). The present research further explores the neurophysiological correlates of processing sentences with semantic and morpho-syntactic violations. It tests the functional interpretations of the P600 component, which has been proposed to reflect syntactic error detection, context updating, or syntactic reanalysis or repair. I contrasted semantic and syntactic possessive violations. The semantic violation conditions (i.e. <em>The mother borrowed the <strong>car’s daughter</strong> for work yesterday</em>), morphosyntactic violations (i.e. <em>The mother borrowed the <strong>daughter car</strong> for work yesterday) </em>and double violation sentences (i.e. <em>The mother borrowed the <strong>car daughter</strong> for work yesterday) </em>were derived from the control condition, (i.e. <em>The mother borrowed the <strong>daughter’s car</strong> for work yesterday). </em>I explored whether the P600 component may index more general processes than ones related to syntactic error detection. An N400 was seen to our semantic manipulation, i.e. <em>The mother borrowed the <strong>car’s daughter</strong> for work yesterday.</em> However, none of the conditions produced a P600.</p> / Master of Science (MSc)

Yes / The processing of notes and chords which are harmonically incongruous with their context has been shown to elicit two distinct late ERP effects. These effects strongly resemble two effects associated with the processing of linguistic incongruities: a P600, resembling a typical response to syntactic incongruities in language, and an N500, evocative of the N400, which is typically elicited in response to semantic incongruities in language. Despite the robustness of these two patterns in the musical incongruity literature, no consensus has yet been reached as to the reasons for the existence of two distinct responses to harmonic incongruities. This study was the first to use behavioural and ERP data to test two possible explanations for the existence of these two patterns: the musicianship of listeners, and the resolved or unresolved nature of the harmonic incongruities. Results showed that harmonically incongruous notes and chords elicited a late positivity similar to the P600 when they were embedded within sequences which started and ended in the same key (harmonically resolved). The notes and chords which indicated that there would be no return to the original key (leaving the piece harmonically unresolved) were associated with a further P600 in musicians, but with a negativity resembling the N500 in non-musicians. We suggest that the late positivity reflects the conscious perception of a specific element as being incongruous with its context and the efforts of musicians to integrate the harmonic incongruity into its local context as a result of their analytic listening style, while the late negativity reflects the detection of the absence of resolution in non-musicians as a result of their holistic listening style.

Music's effect on non-musical domains has been an area of intense research. Musical training has been shown to positively affect the processing of phonology, lexical tone, and syntax. While music also has positive effects in second language phonology acquisition, its effect on grammar acquisition is contested. This thesis aimed to study the under-researched topic of music and second language grammar acquisition using electroencephalography (EEG), thereby studying the electrical responses of the brain. Beginning level Spanish students were trained on a new grammatical principle prior to performing a grammaticality judgment task, and their behavioral and neural results were analyzed. Those students with a stronger musical aptitude did not perform better than the other students in the grammaticality judgement task, nor was there any difference in their neural responses to critical syntactic violations.

The purpose of this study was to compare event-related potential (ERP) effects of speech processing and effects in sentence reading elicited by sentences containing gapping structures, or a "missing" verb. N400 and P600 waveforms were collected in 20 adults between 18 and 30 years of age. Two experiments were conducted with each participant. In the two experiments ERP recordings were collected as sentences, some containing gapping structures, were presented to the subjects. In one experiment sentences were presented through headphones in sentences spoken at normal rate and with normal intonation. In the second experiment sentences with the same gapping structures were presented on a computer screen word by word at a rate of four words per second. Results suggest that all gapping structures are processed at approximately the same time. Amplitude and topography differences were seen between stimuli types and modalities.

Many questions remain unanswered regarding the intricacies of the human brain, especially with regard to the complexities of language processing. One essential component of human sentence processing is the ability to detect, decipher, and recover from errors in the interpretation of both verbal and written language. This process of repair of ungrammatical sentences and revision or reinterpretation of ambiguous sentences has been studied extensively in recent years. A variety of tools have been developed, including the use of event-related potentials (ERPs) in order to assess how language is processed and developed, and to help better identify the nature of these processes. The purpose of this study was to compare event-related potential effects of speech processing of spoken and written sentences containing both incorrect and correct semantic and syntactic information. Specifically, sentences containing correct and incorrect gapping structures, each with a "missing" verb, were presented along with other grammatical and ungrammatical sentences in order to elicit and measure the P300, N400, and P600 amplitudes and latencies. The aim was to determine some of the commonalities and differences in these electrophysiological responses via the auditory and visual modalities. Two experiments were conducted with each participant, one in the auditory modality, and one within the visual using two sets of stimuli. Amplitude and topography differences were noted within and between modalities for each of the components (P300, N400, and P600), as well as between stimulus types. Significant findings suggest that in the adolescent population, incorrect gapping structures are generally processed as semantic errors, as evidenced by the N400 response, followed by the P600 response in both the auditory and visual modalities. The exact nature of the P600 component within gapping structures remains unclear. Of particular interest was the involvement of the occipital area of the brain for the processing of gapping structures. Minimal differences were noted overall between adolescents and the adult populations.

Studying language development through event-related potentials provides specific information regarding how the brain processes specific aspects of language over time. In this study, the P600 component, a positive wave occurring approximately 600 ms post-stimulus and known for detecting syntactic errors, was specifically analyzed. Thirty children between the ages of 5 and 12 years listened to linguistically correct, syntactically incorrect, and semantically incorrect sentences in three ear conditions: monaurally to the right ear, monaurally to the left ear, and binaurally. The participants were instructed to judge the sentences to be correct or incorrect. Comparisons were then made of the latency and amplitude of the P600 between the age groups, sentence types, and ear conditions. The results of this study indicate that younger children exhibit later latencies and higher amplitudes than do adults. The study also suggests that syntactic processing becomes fully established around the age of 8 to 9 years. In reference to ear condition, this study found that ear condition may be a factor in a child's ability to recognize syntax. This was the first study that investigated developmental ERPs and ear condition. Therefore, this finding is a result of interest that needs to be further explored in future studies. The current study also suggests that the right ear advantage (REA) phenomenon may exist neurologically in older ages with monotic sentences. This is another area that would benefit from additional research as this phenomenon has not been previously described.

Event related potentials (ERPs) may provide specific information about how particular aspects of language are processed by the brain over time. This study investigated the electrophysiology of language processing in two children with language impairment (LI) when compared to five typically developing children. The N400, P600, and the early left anterior negativity (ELAN) were analyzed after participants listened to linguistically correct, syntactically incorrect, and semantically incorrect sentences. Participants were instructed to indicate whether the sentences were correct or incorrect. Latency and amplitude of the ERP components were compared between the two groups of participants and sentence types. Results from the current study concerning the typically developing children suggest that, at least by eight years of age, typically developing children may process linguistic information similarly to adults with regard to the areas of the brain that are activated during the processing of linguistic stimuli. When comparing results from participants with LI and their typically developing counterparts, results indicate that children with LI exhibit slower real-time language processing than typically developing children. Results also indicate that children with LI require more effort than typically developing children in processing linguistic information as indicated by the amplitude of the N400 and the ELAN. In analyzing the P600 in both groups of participants, results indicate that syntactic processing may be intact in children with LI as well as typical children. Results concerning the N400 and the ELAN were variable between the two participants with LI indicating that children with LI may be heterogeneous even in the presence of similar tasks. Results obtained from the ELAN may also indicate that the ELAN is not fully mature at eight years of age.