The basal ganglia (BG) are a group of brain nuclei situated deep in the cerebral hemispheres. While BG were primarily associated with motor functions, in recent years there has been an increasing evidence that BG are also significantly involved in a wide range of non-motor functions. This work focused on some of the non-motor symptoms associated with two typical basal ganglia disorders: Parkinson's disease (PD) and Huntington's disease (HD). The first study concerned spatial navigation impairment in patients with HD. Their spatial navigation skills were tested using the Blue Velvet Arena, technique evaluating spatial navigation in real space, capable to selectively differentiate between two components of spatial navigation - allocentric (environment-oriented) and egocentric (self-oriented). Allocentric navigation is linked to hippocampal function, whereas egocentric navigation is usually associated with striatum, a structure predominantly affected in HD. We found that spatial navigation is not significantly affected in the early stages of HD and that in more advanced stages, when spatial navigation is already impaired, there is no significant difference between allocentric and egocentric navigation impairment. We speculate that the striatal involvement does not contribute to the impairment of the...

現在有許多對於眼動軌跡與人在認知方面的研究，包括理解狀態以及感興趣的程度；其中，閱讀文章時的眼動軌跡是最常被討論及研究的題材。而本研究的目的就是希望探討讀者在閱讀時的眼動軌跡，與其感興趣程度之間是否存在關係。 / 本研究的特色在於，我們不用一般分析眼動時關心每個AOI（area of interest）上的眼動資料，而是希望將眼動資料以序列的方式分析，並且運用資料探勘的方法，找出眼動序列中區分感興趣程度的眼動軌跡特徵的片段。 / 透過對於眼動軌跡的分析，我們希望研究的結果，在未來可以運用在資訊檢索的領域上，成為一種有效的「隱含式回饋（implicit feedback）」的方式，以改善現有資訊檢索效能。 / Much research has been performed on the relationship between eye movements and human cognition, including comprehension and interesting degree. The purpose of our research is to find out if there are relationships between eye movements of reading and interesting degree. / Instead of analyzing the eye movements on each area of interest, the characteristic of our research is to transform eye movements to sequence data, and to determine the eye movement patterns which discriminate whether user is interesting or not by using the method of data mining. / Through the analysis of the eye movements, our research result can be used as one way of implicit feedback of information retrieval to improve the effectiveness of the search engine.

La maladie de Parkinson (MP) est une maladie neurodégénérative qui se caractérise principalement par la présence de symptômes moteurs. Cependant, d’autres symptômes, dits non moteurs, sont fréquents dans la MP et assombrissent le pronostic; ceux ci incluent notamment les désordres du sommeil et les troubles cognitifs. De fait, sur une période de plus de 10 ans, jusqu’à 90 % des patients avec la MP développeraient une démence. L’identification de marqueurs de la démence dans la MP est donc primordiale pour permettre le diagnostic précoce et favoriser le développement d’approches thérapeutiques préventives. Plusieurs études ont mis en évidence la contribution du sommeil dans les processus de plasticité cérébrale, d’apprentissage et de consolidation mnésique, notamment l’importance des ondes lentes (OL) et des fuseaux de sommeil (FS). Très peu de travaux se sont intéressés aux liens entre les modifications de la microarchitecture du sommeil et le déclin cognitif dans la MP. L’objectif de cette thèse est de déterminer, sur le plan longitudinal, si certains marqueurs électroencéphalographiques (EEG) en sommeil peuvent prédire la progression vers la démence chez des patients atteints de la MP. La première étude a évalué les caractéristiques des OL et des FS durant le sommeil lent chez les patients avec la MP selon qu’ils ont développé ou non une démence (MP démence vs MP sans démence) lors du suivi longitudinal, ainsi que chez des sujets contrôles en santé. Comparativement aux patients MP sans démence et aux sujets contrôles, les patients MP démence présentaient au temps de base une diminution de la densité, de l’amplitude et de la fréquence des FS. La diminution de l’amplitude des FS dans les régions postérieures était associée à de moins bonnes performances aux tâches visuospatiales chez les patients MP démence. Bien que l’amplitude des OL soit diminuée chez les deux groupes de patients avec la MP, celle ci n’était pas associée au statut cognitif lors du suivi. La deuxième étude a évalué les marqueurs spectraux du développement de la démence dans la MP à l’aide de l’analyse quantifiée de l’EEG en sommeil lent, en sommeil paradoxal et à l’éveil. Les patients MP démence présentaient une diminution de la puissance spectrale sigma durant le sommeil lent dans les régions pariétales comparativement aux patients MP sans démence et aux contrôles. Durant le sommeil paradoxal, l’augmentation de la puissance spectrale en delta et en thêta, de même qu’un plus grand ratio de ralentissement de l’EEG, caractérisé par un rapport plus élevé des basses fréquences sur les hautes fréquences, était associée au développement de la démence chez les patients avec la MP. D’ailleurs, dans la cohorte de patients, un plus grand ralentissement de l’EEG en sommeil paradoxal dans les régions temporo occipitales était associé à des performances cognitives moindres aux épreuves visuospatiales. Enfin, durant l’éveil, les patients MP démence présentaient au temps de base une augmentation de la puissance spectrale delta, un plus grand ratio de ralentissement de l’EEG ainsi qu’une diminution de la fréquence dominante occipitale alpha comparativement aux patients MP sans démence et aux contrôles. Cette thèse suggère que des anomalies EEG spécifiques durant le sommeil et l’éveil peuvent identifier les patients avec la MP qui vont développer une démence quelques années plus tard. L’activité des FS, ainsi que le ralentissement de l’EEG en sommeil paradoxal et à l’éveil, pourraient donc servir de marqueurs potentiels du développement de la démence dans la MP. / Parkinson’s disease (PD) is a neurodegenerative disorder characterized principally by its motor symptoms. However, non motor symptoms are frequent in PD and are associated with a poorer prognosis; these include sleep disorders and cognitive impairments. Indeed, prospective studies have shown that over a 10 year period, up to 90% of PD patients will develop dementia. Therefore, identifying clinical risk factors or markers of dementia in PD is essential, notably for early diagnosis, but also to facilitate the development of preventive therapeutic approaches. There is increasing evidence for a relationship between sleep and cognition in normal and pathological aging. Electroencephalographic (EEG) events during non rapid eye movement (N REM), including sleep spindles and slow waves (SW), may contribute to brain plasticity, learning, and memory processes. However, very few studies have investigated the relationships between sleep changes and cognitive decline in PD. The objective of this thesis is to examine whether specific sleep EEG markers are associated with increased likelihood of developing dementia on prospective follow up assessment in PD patients. The first study evaluated baseline N REM sleep SW and spindle characteristics in PD patients according to their cognitive status (presence or absence of dementia) at follow up (mean 4,5 years), along with a group of healthy controls. Compared to PD patients who remained dementia free and controls, PD patients who developed dementia at follow up showed lower baseline spindle density, amplitude, and frequency. Lower spindle amplitude in posterior cortical regions was associated with poorer visuospatial abilities in demented PD patients. SW amplitude was lower in both PD groups at baseline, regardless of dementia status at follow up. The second study examined EEG spectral markers of dementia across three states of consciousness (N REM sleep, REM sleep, and wakefulness) in PD using power spectral analysis. PD patients who developed dementia at follow up showed lower N REM sleep sigma power in parietal areas compared to both PD patients who remained dementia free and controls. During REM sleep, PD patients who converted to dementia showed, at baseline, higher power in delta and theta bands and a higher EEG slowing ratio (increased slow to fast frequencies ratio) compared to PD patients who remained dementia free and controls. In both PD groups, higher slowing ratios in temporal and occipital regions during REM sleep were associated with poor performance on visuospatial tests. Finally, PD patients who later developed dementia showed lower dominant occipital frequency as well as higher delta and slowing ratio during wakefulness compared to PD patients who remained dementia free and controls. This thesis suggests that specific EEG alterations during sleep and wakefulness, mainly in posterior cortical regions, can identify PD patients who will later develop dementia. Sleep spindle activity, as well as REM sleep and wake EEG slowing, could thus serve as additional markers of cognitive decline in PD.

The thesis investigates methods of examining corneal biomechanics using non-contact tonometry and introduces novel techniques to investigate corneal material properties in vivo. A comprehensive systems analysis of the CorvisST (CST) and Ocular Response Analyser (ORA) was performed. Pressure sensors were used to characterisation the airflow produced by the CST and the ORA. Distinct differences were observed between the central airflow pressures between the two devices: the CST pressure was higher and of shorter duration. Scheimpflug high-speed imaging via the CST allowed components of the corneal deformation to be investigated and the development of a 3D deformation matrix (time, depth and spatial resolution) through tracing of the anterior and posterior corneal surface. Measures of whole eye movement (WEM) with CST were found to be robust. WEM demonstrated an asymmetric profile and a correction method was developed to address the corneal deformation matrix for this asymmetry. Novel methods for characterisation of intrinsic material characteristics of the cornea were developed using numerical and graphical analytical procedures. Application of these parameters was tested on enucleated porcine eyes across a wide range of manometry internal ocular pressure (MIOP). The dynamic E-Modulus was found to be most affected by MIOP change. To investigate the in vivo distribution and heterogeneity of the corneal biomechanics, a novel set-up allowed the mapping of corneal biomechanics across the cornea using the CST (central, paracentral, peripheral) and ORA (central, peripheral). Biometric and demographic grouping of subjects allowed detection of discriminating factors between individuals. The results suggest that the in vivo cornea of healthy human adults can be characterised as a viscoelastic, damped system for longitudinal strain and a highly oscillating system for lateral strain. The cornea is approximately homogenous for measures of rigidity and dynamic E-Modulus but other corneal material characteristics (longitudinal and lateral strain, hysteresis, damping and compressibility) demonstrated regional differences. The experimental design employed allowed for strict control of biometric and biomechanical intersubject variables, based on gold-standard techniques as well as newly-developed methods, thereby creating a normative database for future use.

nÃo hà / Investiga o custo de processamento de sentenÃas coordenadas e de sentenÃas subordinadas em um grupo de estudantes do 9 ano do Ensino Fundamental (EF). Em Engelkamp e Rummer (2002) e Rummer, Engelkamp e Konieczny (2003), observou-se que o processamento de sentenÃas subordinadas à menos custoso do que o de sentenÃas coordenadas em tarefas de memorizaÃÃo. Os resultados de Rummer, Engelkamp e Konieczny (2003) tambÃm sugeriram que o deslocamento da sentenÃa subordinada interfere nos custos de processamento. Tais achados entram em confronto com impressÃes do autor derivadas do exercÃcio da prÃtica docente de ensino de conjunÃÃes subordinadas ao 9 ano do EF, o que culminou para a proposiÃÃo desta pesquisa. Foram elaborados experimentos cuja previsÃo era a de que os estudantes teriam mais dificuldade de ler sentenÃas subordinadas, uma dificuldade decorrente do pouco conhecimento da relaÃÃo lÃgica veiculada pelas conjunÃÃes. Dada a variabilidade das relaÃÃes lÃgicas e o escasso tempo de execuÃÃo desta pesquisa, foram investigadas aqui apenas as relaÃÃes de oposiÃÃo e concessÃo. Para tanto, foram propostos trÃs experimentos de rastreamento ocular. O primeiro investigou o custo de processamento de leitura da estrutura subordinada deslocada; o segundo comparou o custo de processamento de leitura de sentenÃas coordenadas e subordinadas; e o terceiro observou o peso de quatro diferentes conjunÃÃes em oraÃÃes coordenadas. Foram produzidos 24 itens experimentais, compostos de condiÃÃes, que contemplavam em conjunto os trÃs experimentos supracitados: quatro oraÃÃes subordinadas, sendo duas sem e duas com deslocamento, que faziam uso das conjunÃÃes âemboraâ e âainda queâ; quatro oraÃÃes coordenadas, que faziam uso das conjunÃÃes âentretantoâ, âmasâ, âno entantoâ e âeâ. Seguia-se a todas as frases uma pergunta de controle de atenÃÃo. Participaram dos experimentos 42 estudantes do 9 ano do EF e 40 adultos leitores proficientes. As medidas observadas foram o tempo total de leitura nas sentenÃas completas e o tempo de primeira leitura na sentenÃa/perÃodo completo. Para o experimento 1 (deslocamento da subordinada), na medida de primeira leitura, encontrou-se uma interaÃÃo entre grupo e deslocamento (F = 4,06, p = 0.04), alÃm de efeito principal para deslocamento (p < 0.001), mas nÃo houve efeito de grupo. Para a medida de tempo total, foi encontrado apenas efeito principal de grupo (p < 0.001). Para o estudo do processamento da coordenaÃÃo e subordinaÃÃo (experimento 2), foram encontrados efeitos principais de grupo para a primeira leitura e o tempo total de leitura (p = 0.04 e p < 0.001). E no estudo das conjunÃÃes coordenativas, observou-se diferenÃa significativa para cada conjunÃÃo na primeira leitura (p = 0.006), mas nÃo no tempo total de leitura. Houve diferenÃa significativa no tempo total de leitura para o grupo (p < 0.001). Os resultados sugerem que o grupo de estudantes là de modo diferente e mais lentamente do que o grupo de adultos, mas essa medida nÃo à sensÃvel Ãs sentenÃas coordenadas e subordinadas. Jà o deslocamento da subordinada para a posiÃÃo inicial da sentenÃa gera maior custo de processamento para os estudantes, sugerindo que a aprendizagem escolar deste tema tem relevÃncia para o encapsulamento da informaÃÃo do perÃodo subordinado. Para o estudo das conjunÃÃes, observou-se que a primeira leitura à sensÃvel ao tamanho da conjunÃÃo, pois a conjunÃÃo âeâ tem um tempo de processamento mais rÃpido no tempo total de leitura, diferenciando-se da conjunÃÃo âmasâ, que apresenta relaÃÃo adversativa explÃcita dada sua frequÃncia de uso. / Investigates if the cost of the processing of coordinate clauses is higher than the cost of the processing of subordinate clauses in a group of 9th grade students. In Engelkamp and Rummer (2002) and Rummer, Engelkamp and Konieczny (2003), it was observed that the processing of subordinate clauses is less costly than the coordinate ones in tasks of memorization, as suggested that the displacement of the subordinate clause influences the costs of the processing. Such results were confronted with the exercise of teaching subordinate conjunctions to 9th graders, which ended up with the proposal of this research. The expectation is that the students would have more difficulties in reading subordinate clauses due to the lack of knowledge of the logical relation served by the conjunction. Given the variability of the logical relations and the lack of time for the execution of this research, we could investigate only the relations of opposition and concession. To do so, three experiments of eye tracking were developed: (i) the first one investigated the cost of reading processing of subordinate clause displacement; (ii) the second one compared the reading process of coordinate and subordinate clauses; (iii) and the third one observed the importance of four different conjunctions in coordinate clauses. Twenty-four experimental items, made up of conditions, were created, which contemplated, all together, the three experiments listed above: four subordinate clauses, two without and two with displacement, which used the conjunctions âemboraâ (although) and âainda queâ (even if); four coordinate clauses, which used the conjunctions âentretantoâ (however), âmasâ (but), âno entantoâ (yet) and âeâ (and). A question of control of attention followed all clauses. Forty-two 9th graders and forty proficient adult readers participated in the experiment. The observed measurements were the total time of reading of the complete clauses, and the time of the first reading in the complete sentence/clause. For experiment one (subordinate displacement), measuring the first reading, an interaction between group and displacement was found (F=4,06, p = 0.04), besides the main effect for displacement (p<0.001), but group effect was not observed. For total time measurement, only main group effect was found (p<0.001). For the study of the processing of the coordinate and subordinate clauses (experiment two), main group effects were found for the first reading and the total reading time (p=0.04 e p<0.001). In the study of coordinate conjunctions, we observed an important difference for each conjunction in the first reading (p=0.006), but not in the total time of reading. There was significant difference in the total time of reading for the group (p<0.001). The results suggest that the group of students read in a different way and more slowly than the adult group, but this measurement is nor sensitive to coordinate and subordinate clauses. However, the displacement of the subordinate clause to the front position of the sentence generates a higher cost of processing for the students, suggesting that the school learning of this topic is relevant for the coating of the information in the subordinate clause. For the study of the conjunctions, it was observed that the first reading is sensitive to the length of the conjunction, because the conjunction âeâ (and) has a time of processing faster in the total time of the reading, which is quite different from the conjunction âmasâ (but), which shows clear adversative relationship given its frequency of use.

The electro-oculogram (EOG) is the most widely used technique for recording eye movements in clinical settings. It is inexpensive, practical, and non-invasive. Use of EOG is usually restricted to horizontal recordings as vertical EOG contains eyelid artefact (Oster & Stern, 1980) and blinks. The ability to analyse two dimensional (2D) eye movements may provide additional diagnostic information on pathologies, and further insights into the nature of brain functioning. Simultaneous recording of both horizontal and vertical EOG also introduces other difficulties into calibration of the eye movements, such as different gains in the two signals, and misalignment of electrodes producing crosstalk. These transformations of the signals create problems in relating the two dimensional EOG to actual rotations of the eyes. The application of an artificial neural network (ANN) that could map 2D recordings into 2D eye positions would overcome this problem and improve the utility of EOG. To determine whether ANNs are capable of correctly calibrating the saccadic eye movement data from 2D EOG (i.e. performing the necessary inverse transformation), the ANNs were first tested on data generated from mathematical models of saccadic eye movements. Multi-layer perceptrons (MLPs) with non-linear activation functions and trained with back propagation proved to be capable of calibrating simulated EOG data to a mean accuracy of 0.33° of visual angle (SE = 0.01). Linear perceptrons (LPs) were only nearly half as accurate. For five subjects performing a saccadic eye movement task in the upper right quadrant of the visual field, the mean accuracy provided by the MLPs was 1.07° of visual angle (SE = 0.01) for EOG data, and 0.95° of visual angle (SE = 0.03) for infrared limbus reflection (IRIS®) data. MLPs enabled calibration of 2D saccadic EOG to an accuracy not significantly different to that obtained with the infrared limbus tracking data.

本文以兩個眼動閱讀實驗探討語意訊息 (semantic cues) 和句法訊息 (syntactic cues) 如何在中文關係子句的處理中運作及交互作用。實驗一旨在研究兩種動詞與論元之間的合理性關係 (plausibility) 是否會影響讀者理解不同結構的關係子句。結果顯示，當兩個論元都是合理施事者 (agent) 時，論旨角色的指派 (thematic roles) 有歧義，較難理解；而當只有一個論元是合理的施事者時，讀者趨向指派正確的論旨角色，且較快整合句法上的困難。此外，因中文句法結構特殊，讀者在關係詞之前就處理主語關係子句 (subject relative clauses) 的歧義，在主要動詞上則會遇到賓語關係子句 (object relative clauses) 的理解困難。此發現解決了Hsiao & Gibson (2003) 和 Lin (2006) 的歧見，證明中文讀者在不同位置會遇到不一樣的困難。實驗二所關注的語意訊息為論元的生命性 (animacy)，關係子句中的兩個論元分屬有生命的 (animate) 及無生命的 (inanimate) 名詞。結果發現論旨角色的指派和生命性相互關聯，有生命性的論元較傾向當施事者，而無生命的論元傾向當受事者。讀者仍在關係詞之前遇到主語關係子句的理解困難，但在主要動詞，讀者主要依循生命性的引導來指派論旨角色，句法訊息的影響並不顯著。因此語意訊息在中文的語句處理扮演重要的角色，結果大致上與Traxler (2002)的研究相符。讀者同時受到當下的句法訊息以及語意訊息影響，在不同的位置會遇到不一樣的歧義性，而產生花園路徑效果 (garden-path effect)。 / Two eye movement experiments were conducted to investigate how semantic cues and syntactic structural cues function and interact in Mandarin Chinese relative clause (RC) processing. Mandarin Chinese is unique in combining head-final RCs with a VO basic order (Dryer, 1992, 2003) and also in relying solely on word order as structural cues, without case marking or agreement. However, Mandarin Chinese still preserves flexibility in word order that is motivated by pragmatics. Semantic cues, including the plausibility of the argument-verb relation and argument animacy within RCs, may be crucial to sentence processing in Mandarin Chinese. Experiment 1 aims to examine whether the meaning of the verb allowing only one of the two animate arguments to be a plausible agent may lead to reduction of ORC difficulty (cf. Traxler, 2002). The results showed that the plausibility effects were robust at the head noun and the main verb. A bias of thematic role assignment in the irreversible relation leads readers to correct interpretations, while the reversible relation does not elicit such a bias. The results also solved the discrepancy between the two previous studies (Hsiao and Gibson, 2003 & Lin, 2006) by unveiling a dynamic process in which readers encounter diverse ambiguities at different positions for different structures. Chinese readers disambiguate SRCs earlier due to their non-canonical word order and have trouble integrating the main verb in ORCs owing to perspective shifting. The interaction between plausibility and RC type on re-reading rate suggested that plausibility cues were used to solve syntactic ambiguity. Experiment 2 manipulated contrastive argument animacy in order to investigate whether thematic role assignment correlates with animacy. The results confirmed the hypothesis that while animate entities bias towards agent roles, inanimate ones incline towards patient roles (c.f., Valin & LaPolla, 1997). Besides, inanimate entities are conceptually less accessible than animate ones. Contrastive animacy shows its impact on syntactic processing with robust interactions at different positions. The findings of interactions between semantic cues and RC types in two experiments suggest that semantic cues play an important role in Chinese relative clause processing. Semantic plausibility and argument animacy can influence the process of thematic role assignment. The semantic cues that accord with the biases of thematic role assignment then would ease the syntactic ambiguities. Not only syntactic cues but also semantic cues are utilized by readers in sentence comprehension. In this thesis, the eye movement data provide clear evidence indicating that readers solve various temporary ambiguities syntactically and semantically at different positions of the sentence with relative clauses.

A recent model of Parkinson’s disease (PD) suggests that the neuropathological, behavioural and cognitive symptoms progress in stages. There is substantial evidence for a prodromal stage of PD, during which time pre-motor symptoms develop. Rapid eye movement (REM) sleep behaviour disorder (RBD) is a risk factor for developing PD and may be part of the pre-motor stage. In both disorders, neuropathological α-synuclein aggregates are thought to be a direct cause of the resulting symptoms. One model has shown that in rats, proteasome inhibition produced by systemic exposure to environmental toxins results in α-synuclein pathology and motor behaviour dysfunction that mimics the progression of PD in humans. The present study examined the hypothesis that the systemic proteasome inhibition model would produce pre-Parkinsonian RBD-like pathology in rats. It was expected that sleep disturbances would be seen prior to behavioural disturbances in rats treated systemically with PSI (a proteasome inhibitor). Following baseline sleep recording and training on the inclined beam-traverse task, rats were injected with PSI (a proteasome inhibitor) or ethanol (control), 6 times over 2 wk. Sleep recording over 8 wk and behavioural testing over 16 wk provided no evidence of sleep disturbances or motor dysfunction. Post-mortem immunohistochemical analyses of brain tissue provided no evidence of PSI-associated α-synuclein aggregates in the locus coeruleus, subcoeruleus (dorsal part), or substantia nigra (areas involved in RBD and/or PD). These results did not provide support for RBD as a prodromal phase of PD within the systemic proteasome inhibitor-based model and add to a growing body of research reporting inconsistent findings using this model. We suggest that systemic PSI exposure in rats does not produce a viable model of RBD or PD. Whether RBD is an early symptom in the progression of PD remains to be established. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2010-04-28 12:04:50.613

兩種語句處理模型曾被提出以解釋閱讀句子時語法及語意資訊的互動。句法優先模型(syntax-first models)認為詞性判斷必定先於語意分析，而制約滿足模型(constraint-satisfaction models)則認為不同的資訊在語句理解的過程中會同時被處理。本研究檢驗兩種語句處理模型能否解釋語句中的詞彙歧義解困(lexical ambiguity resolution)。 許多眼動研究曾發現詞彙歧義詞的次要語義偏向效應(subordinate bias effect)，顯示語意偏向次要語義的語境能加速激發歧義詞的次要語義並且產生語義競爭。然而，語境的語法在詞彙歧義解困中扮演的角色並不清楚。因而，不同語義分屬不同詞性的詞性歧義詞便提供我們一個媒介以檢驗詞彙歧義解困中詞性及語意限制的互動。 本研究的目的有二：(一) 檢驗詞性限制能否決定中文詞性歧義詞的語義解困；(二) 檢驗中文歧義詞語義的詞性是否會影響次要語義偏向效應。實驗一我們將四種不同類型的中文非均勢同形異義詞置於語法及語意皆為次要語義偏向的句子裡；實驗二則將四種不同類型的中文非均勢同形異義詞置於語法為次要語義偏向但語意中立的句子裡。受試者閱讀句子時的眼動表現會即時被記錄。 實驗一的結果發現：(一) 四類型歧義詞的次要語義偏向效應只反映在目標詞後區域的二次閱讀指標上；(二) 就效果量而言，NV歧義詞的次要語義偏向效應在目標詞及目標詞後兩個區域都比VN歧義詞來得大。實驗二的結果則發現：(一) VN歧義詞的次要語義偏向效應從目標詞區的首次閱讀指標就出現，並且持續至目標詞及目標詞後兩個區域的二次閱讀指標；(二) 另外三類型歧義詞的次要語義偏向效應直到所有分析區域的二次閱讀指標才反映出來；(三) NV歧義詞的次要語義偏向效應比VN歧義詞出現得更晚也更不明顯。整體而言，本研究的結果顯示詞性限制並不是影響中文詞性歧義詞語義解困的唯一因素。此結果支持制約滿足模型，並反對句法優先模型的預測。 / Two primary sentence processing models have been proposed to account for the interaction between syntactic and semantic information in reading sentences: Syntax-first models assume that syntactic-category assignment must precede semantic analysis, while constraint-satisfaction models propose that information from different sources is processed and weighed at the same time during sentence comprehension. The present study examined whether these sentence processing models, which assume different contribution of syntactic category and semantic context, can explain the resolution of lexical ambiguity in sentences. Several eye movement studies have demonstrated the subordinate bias effect (SBE) for lexical-semantic ambiguous words (i.e., NN/VV homographs), indicating that a subordinate-biased semantic context can boost the activation of the subordinate meaning of ambiguous words and causes meaning competition (Duffy, Morris, & Rayner, 1988). However, the role of syntactic context in lexical ambiguity resolution is less clear. Syntactic category ambiguous words (i.e., SCA words; VN/NV homographs), whose alternative meanings differ in syntactic category (e.g., watch in English), serve as a means of examining the interaction between syntactic category and semantic constraints during lexical ambiguity resolution. The purpose of the present study was twofold: (a) to examine whether the syntactic category constraint can determine the semantic resolution of Chinese SCA words, and (b) to investigate whether syntactic category of alternative meanings of Chinese homographs can influence the SBE during lexical ambiguity resolution. Four types of Chinese biased homographs (NN, VV, VN, and NV) were embedded into syntactically and semantically subordinate-biased sentences (Experiment 1) and into syntactically subordinate-biased but semantically neutral sentences (Experiment 2). Participants’ eye movements were recorded as they read each sentence. In Experiment 1, the results showed: (1) The SBE for the four types of homographs was significant only in the second-pass reading on the post-target words. (2) Numerically, the NV homographs revealed a larger effect size of SBE than VN homographs on both target and post-target words. In Experiment 2, the results showed: (1) The SBE for VN appeared from the first-pass reading on the target words and lasted to the second-pass reading on the target and post-target words. (2) The SBE for the other types of homographs did not occur until the second-pass reading in all analyzed regions. (3) The SBE for NV occurred much later and less obviously than that for VN. In general, our findings support the constraint-satisfaction models and reject the prediction of the syntax-first models, suggesting that the syntactic category constraint is not the only factor influencing the semantic resolution of SCA words.

Le présent travail de thèse s’inscrit dans le domaine de recherche sur la perception audio-visuelle (AV) de la parole. Son objectif est de répondre aux questions suivantes : (i) Quelle est la nature du traitement de l’input visuel (holistique vs analytique) dans la perception AV de la parole ? (ii) Quelle est l’implication des régions faciales extra-buccales dans la perception AV de la parole ? (iii) Quel est le comportement oculaire des sujets lors de la perception AV de la parole ? (iv) Quelle est l’évolution de la perception AV de la parole dans les aspects (i), (ii) et (iii) au cours du développement. Le paradigme de dégradation de l’information auditive par le bruit a été utilisé dans deux expériences qui ont été menées avec des participants de quatre groupes d’âge, enfants, préadolescents, adolescents, adultes (16 participants par groupe). La tâche des participants consistait à répéter les syllabes de type consonne-voyelle /a/, faiblement et fortement dégradées par le bruit rose, présentées dans quatre conditions différentes. Ces conditions étaient les suivantes : une auditive (AU) et trois audio-visuelles (AV) (AV visage (AVV)), AV « bouche extraction » (AVB-E) (format bouche sans contrastes lumineux), AV « bouche-masquage » (AVB-M) (format bouche avec contrastes lumineux) pour l’expérience 1, et AVV, AV « bouche active » (AVV-BA) (format « visage » avec un contexte facial statique), AV « régions extra-buccales actives » (AVV-EBA) (format « visage » sans bouche) pour l’expérience 2. Le nombre total des répétitions correctes par condition (performance totale), la différence dans ce score entre chaque condition AV et la condition auditive (gain AV) et la durée totale des fixations oculaires dans la région buccale et les autres régions faciales (pour les formats AVV) ont été analysés. Les principaux résultats montrent que les mécanismes de traitement AV de la parole atteignent leur maturité avant l’enfance tardive. La vision du visage entier de l’orateur n’est pas avantageuse pour ce type de traitement. Elle semble même désavantageuse pour les adultes possiblement car elle déclenche le traitement d’autres aspects du visage (identité, expressions faciales) qui pourrait interférer avec le traitement des indices acoustiques relatifs à la parole. Pour les quatre groupes d’âge, la contribution des mouvements articulatoires dans les régions extra-buccales à la perception AV de la parole s’est avérée faible et limitée aux conditions de haute incertitude quant à l’information auditive. Pour les stimuli respectant les caractéristiques écologiques de l’information faciale, les patterns du comportement oculaire dans la perception bimodale de la parole varient en fonction du degré de dégradation de l’information auditive, mais semblent relativement stables durant la période allant de l’enfance à l’âge adulte. Finalement, les modalités de présentation de l’information visuelle localisée à la bouche ont affecté le comportement oculaire chez les adultes, les pré-adolescents et les enfants. Ceci suggère que le traitement visuo-attentionnel dans le cadre de la perception AV de la parle est sensible aux caractéristiques de bas niveau des stimuli visuels chez ces populations. Les variations au niveau du traitement visuo-attentionnel s’accompagnent, dans une certaine mesure, de variations dans la perception AV de la parole. / The present thesis work fits into the domain/is incorporated within the framework of research on audio-visual (AV) speech perception. Its objective is to answer the following questions: (i) What is the nature of visual input processing (holistic vs analytic) in AV speech perception? (ii) What is the implication of extra-oral facial movement in AV speech perception? (iii) What are the oculomotor patterns in AV speech perception? (iv) What are the developmental changes in the above-mentioned aspects (i), (ii) and (iii)? The classic noise degradation paradigm was applied in two experiments conducted in the framework of the present thesis. Each experiment were conducted on participants of 4 age groups, adults, adolescents, pre-adolescents and children. Each group consisted of 16 participants. Participants’ task was to repeat consonant-vowel (/a/) syllables. The syllables were both mildly and strongly degraded by pink noise and were presented in four audio(-visual) conditions, one purely auditory (AO) and three audio-visual conditions. The AV conditions were the following: (i) AV face (AVF), (ii) AV « mouth extraction » (AVM-E ; mouth format without visual contrasts), (iii) AV « mouth window » (AVM-W ; mouth format with high visual contrasts) in experiment 1, and (i) AVF, (ii) AVF « mouth active (and facial frame static) » (AVF-MA), (iii) AVF « extra-oral regions active (and mouth absent) » (AVF-EOA) in experiment 2. The data relative to (i) the total number of correct repetitions (total performance), (ii) the difference in the correct repetitions score between each AV and the AO condition (AV gain), and (iii) the total fixations duration in the oral area and other facial areas (for the AV formats) were analyzed. The main results showed that the mechanisms involved in AV speech perception reach their maturity before late childhood. The vision of the talker’s full face does not seem to be advantageous in this context. It seems that the vision of the talker’s full face might perturb AV speech processing in adults, possibly because it triggers processing of other types of information (identity, facial expressions) which could in terms interfere with the processing of acoustic aspects of speech. The contribution of the extra-oral articulatory movement to AV speech perception was poor and limited to the condition of highly degraded auditory information. For ecologically presented facial information, the oculomotor patterns in AV speech perception varied as a function of the level of auditory information degradation, but appeared rather stable across the 4 groups. Finally, the modalities of the featural (mouth) facial information presentation affected the oculomotor behavior patterns in adults, pre-adolescents and children, thus suggesting a certain sensitivity of visuo-attentional processing to low-level visual stimuli characteristics in AV speech perception. The variations in visuo-attentional processing seemed to be associated to a certain extent with variations in AV speech perception.