Symmetry suppression was conducted for five subjects who demonstrated a tendency to derive equivalence relations based on conditional discrimination training in a match-to-sample procedure. Symmetry suppression was applied in three consecutive sessions in which symmetrical responses were suppressed for one stimulus class in the first condition, two stimulus classes in the second condition, and all three stimulus classes in the final condition. Symmetry suppression slowed the emergence of transitivity for two subjects and prevented it for the other three. Results indicated that unplanned features of stimulus configurations emerged as discriminative variables that controlled selection responses and altered the function of consequent stimuli. Disruption of cognitive development by conflicting contingencies in natural learning environments is discussed.

Stimulus preference assessments have been shown to identify stimuli that are likely to function as reinforcers for individuals with disabilities. It is important to identify these stimuli to increase the effectiveness of interventions. The ability to conduct a stimulus preference assessment is a skill that parents and caregivers should have. Research on training preference assessments is limited to staff, teachers, and students. The following study evaluated the effectiveness of video modeling to teach caregivers to conduct paired stimulus preference assessments. The results showed that video modeling was effective and that the results maintained during a one week follow up.

No description available.

Abstract Visual world is naturally correlated both spatially and temporally. The correlations are used in vision to enhance performance of neurons. For gaining maximal neural performance of the visual neurons, the experiments, from stimulus to the analysis, should be designed to take advantage of the correlations. In this thesis methods for generating and analyzing natural stimuli were examined by using computations and algorithms. For analyzing responses to natural stimuli in visual neurons, a method with only a few assumptions was developed for estimating information rate in long responses. The novel method gave a good agreement with Shannon information rate with linear system and Gaussian input but was able to handle also nonlinear processing and non-Gaussian data. Secondly, a computer controlled 3D virtual environment with a spherical screen was developed, with a large visual field. The image of the world was projected to the screen with a DLP projector, giving good enough temporal performance for insect vision research. A track-ball was used in closed loop experiments. Thirdly, properties of single photon (“bump”) information transfer at various light levels were investigated in cockroach photoreceptor with a coarse computational model. At dim light (< 10 ph/s), where single bump responses were visible, shot noise was dominant. At higher light levels latency distribution of the bump decreased the information rate, but amplitude distribution of bump did not have an effect. Fourthly, the contribution of K⁺ channels to information rate and energy consumption was investigated by creating a database of computation models with varying channel compositions. The information rate has a maximum as a function of mean conductance, which was a sum of the average K⁺ conductance and the leak conductance. This maximum was fine-tuned by the K⁺ channel composition, which had high so-called novel contribution and relatively low amount of other conductances.

Cette thèse traite de deux projets en rapport avec la microfluidique. Le premier est consacré à la réalisation d'actionneurs à base d'hydrogel thermosensible. Avec une approche technologique basée sur le greffage et la structuration d'un hydrogel thermosensible sur des surfaces en verre, nous montrons comment un matériau capable de subir de fortes variations de volume peut être utilisé comme actionneur microfluidique dans les milieux aqueux. D'abord, en tant que vanne, nous démontrons que la stratégie de greffage des structures permet d'obtenir des actionneurs robustes et durables capables de réguler la circulation de fluides en micro-canaux avec une réponse rapide en miniaturisant la stimulation thermique. Ensuite, une autre configuration, dite de compartimentation libre, est mise en oeuvre et appliquée en biologies moléculaire et cellulaire. Le second est quant à lui dédié à l'étude du glissement par nanovélocimétrie en utilisant la technique de microscopie de fluorescence par réflexion totale interne. Cette technique permet de suivre les écoulement de nanoparticules à proximité immédiate de la paroi d'un micro-canal (dans les premiers 800nm de fluide). En utilisant les modèles de Langevin, nous avons été en mesure de prendre en compte différents artéfacts expérimentaux et les corriger. Nous confirmons l'absence de glissement de l'eau pure sur surface hydrophile et l'existence du glissement sur surface hydrophobe. Cette partie est traitée sous la forme d'une brève introduction, suivie d'un article publié dans Journal of Fluid Mechanics. / In this work, we have addressed two projects related to microfluidics.The first one is dedicated to the integration of hydrogel-based actuators in microsystems. Thanks toa technological approach based on the grafting and patterning of a thermosensitive hydrogel on glasssubstrates, we show how a material that can undergo large volume changes can be embedded as anactuator for aqueous solutions. First as a valve, we prove that the strategy consisting in grafting patternsof hydrogel enables us to obtain robust actuators able to regulate flows in micro-channels, and with afast response by miniaturising the thermal stimulation. Then we report another configuration called freecompartmentalization, applied to molecular and cellular biology. The second part of this manuscript deals with the study of slippage by nanovelocimetry using the totalinternal reflection fluorescence microscopy technique. This method enables us to follow fluorescent nanoparticlesflowing near the wall of a microchannel (within the first 800nm ). Using Langevin simulations,we have been able to take several experimental biases into account and correct them. We can confirmthe no-slip condition of water on hydrophilic surfaces and the actual slippage over hydrophobic surfaces.This part is made of a brief introduction followed by an publication in Journal of Fluid Mechanics.

Three children between the ages of 3 and 3 1/2 were asked to choose a colored object from an array of 5 colors in a baseline condition. After color preferences were established, stickers, small toys and praise were made contingent on choosing the least preferred color. After the first experimental condition resulted in consistent choosing of the least preferred color, a second experimental condition was implemented. At the beginning of each session a contingency-specifying stimulus (CSS) was presented, each CSS specifying a different color to be selected. Both contingency-shaping and CSS presentation resulted in stimulus control over responding. However, CSS presentation resulted in immediate redistributions of behavioral units across CSS sessions.

Ce travail de thèse concerne l’étude de la variabilité inter-individuelle du transcriptome soumis à un stimulus. Cette variabilité n’est pas homogène au sein même du transcriptome et varie suite aux perturbations extérieures.Nous avons mis en place une stratégie d’analyse de la variabilité inter-individuelle sur la base des indices de diversité. Nous avons sélectionné trois jeux de données ayant des caractéristiques particulières (stimulus fort, faible, cinétique, données appariées, …). Ces indices nous permettent de mettre en évidence les différences entre les individus; certains ayant des transcriptomes plus divers que d’autre. Ces différences s’attenues après l’application d’un stimulus au système : La variabilité de la diversité diminue. Nous mesurons cette diminution à l’aide d’une mesure de la similarité. Les résultats indiquent un phénomène global. Nous avons par la suite analysé les données sous le regard d’un indice de spécialisation. Les différences entre groupes témoins et groupes sous l’action d’un stimulus indiquent que la spécialisation diminue de manière significative après l’action du stimulus.Les informations obtenues sont différentes de celles obtenues par les stratégies d’analyses statistiques classiques. Nos travaux montrent enfin que ces outils permettent d’établir de nouvelles hypothèses. Ces indices, utilisés pour la première fois pour ce type d’analyse, ouvrent ainsi la voie à un nouvel arsenal d’outils d’analyse pour la compréhension des modifications transcriptomiques globales mais aussi individuelles et s’inscrit donc parfaitement dans le mouvement de la médecine personnalisée. / This thesis concern the study of the interindividual variability of transcriptome after stimulation. This variability is not homogenous within the same transcriptome and varies with external stimulus.We designed an analysis strategy of the interindividual variability based on diversity indices. We selected three transcriptome datasets based on particular characteristics (strong stimulus, kinetic, paired data…). The indices highlight differences across the samples, some being more diverse than the others. The differences decrease after applying a stimulation to the samples. We measure this modification with a measure of similarity. The results depict a global effect of the stimulation.We analysed the data using specialisation measure. The samples’ specialisation significantly decrease after stimulation, meaning the interindividual variability decreases when the system is on the pressure of a stimulus.Noteworthy, these information are different from those obtained with classical analyses. Our work describe also that this strategy leads to new hyptotheses. These indices are used for these analyses for the first time and can be added to the statistical and mathematical tools already available for transcriptome analysis. They show their capability for highlighting global but also individual modifications and therefore fits perfectly into the field of personalized medicine.

Many children are exposed to excessively technology. Such use of technology may lead to health issues including obesity, attention deficits, and sleep disorders. Research has shown that parameters of reinforcement, such as quality and delay, may influence how children allocate their preferences. One way to drive preference away from high-tech toys may be to arrange delays to reinforcement following such selections and immediate reinforcement for an alternative response. In Experiment 1, four subjects who preferred high-tech leisure items over low-tech leisure items were identified through the pair-stimulus preference assessments. The results of Experiment 2 indicated that all subjects were sensitive to delay to reinforcement. When delays were implemented following selection of high-tech items, preference shifted from high-tech to low-tech leisure items at different delays.

Emotions are among the most pervasive aspects of human experience. They have long been of interest to social and behavioural sciences. Recently, emotions have attracted the attention of researchers in computer science and particularly in computational linguistics. Computational approaches to emotion analysis have also focused on various emotion modalities, but there is less effort in the direction of automatic recognition of the emotion expressed. Although some past work has addressed detecting emotions, detecting why an emotion arises is ignored. In this work, we explore the task of classifying texts automatically by the emotions expressed, as well as detecting the reason why a particular emotion is felt. We believe there is still a large gap between the theoretical research on emotions in psychology and emotion studies in computational linguistics. In our research, we try to fill this gap by considering both theoretical and computational aspects of emotions. Starting with a general explanation of emotion and emotion causes from the psychological and cognitive perspective, we clarify the definition that we base our work on. We explain what is feasible in the scope of text and what is practically doable based on the current NLP techniques and tools. This work is organized in two parts: first part on Emotion Expression and the second part on Emotion Stimulus. In emotion expression detection, we start with shallow methodologies, such as corpus-based and lexical-based, followed by deeper methods considering syntactic and semantic relations in text. First, we demonstrate the usefulness of external knowledge resources, such as polarity and emotion lexicons, in automatic emotion detection. Next, we provide a description of the more advanced features chosen for characterizing emotional content based on the syntactic structure of sentences, as well as the machine learning techniques adopted for emotion classification. The main novelty of our learning methodology is that it breaks down a problem into hierarchical steps. It starts from a simpler problem to solve, and uses what is learnt to extend the solution to solve harder problems. Here, we are learning emotion of sentences with one emotion word and we are extending the solution to sentences with more than one emotion word. Next, we frame the detection of causes of emotions as finding a stimulus frame element as defined for the emotion frame in FrameNet – a lexical database of English based on the theory of meaning called Frame Semantics, which was built by manually annotating examples of how words are used in actual texts. According to FrameNet, an emotion stimulus is the person, event, or state of affairs that evokes the emotional response in the Experiencer. We believe it is the closest definition to emotion cause in order to answer why the experiencer feels that emotion. We create the first ever dataset annotated with both emotion stimulus and emotion class; it can be used for evaluation or training purposes. We applied sequential learning methods to the dataset. We explored syntactic and semantic features in addition to corpus-based features. We built a model which outperforms all our carefully-built baselines. To show the robustness of our model and to study the problem more thoroughly, we apply those models to another dataset (that we used for the first part as well) to go deeper than detecting the emotion expressed and also detect the stimulus span which explains why the emotion was felt. Although we first address emotion expression and emotion stimulus independently, we believe that an emotion stimulus and the emotion itself are not mutually independent. In the last part, we address the relation of emotion expression and emotion stimulus by building four cases: both emotion expression and emotion stimulus occur at the same time, none of them appear in the text, there is only emotion expression, or only the emotion stimulus exists while there is no explicit mention of the emotion expressed. We found the last case the most challenging, so we study it in more detail. Finally, we showcase how a clinical psychology application can benefit from our research. We also conclude our work and explain the future directions of this research. Note: see http://www.eecs.uottawa.ca/~diana/resources/emotion_stimulus_data/ for all the data built for this thesis and discussed in it.

The aim of this study was to investigate the intra- and intermodal impact of different kinds of early sensory experience on the development of specific neural/perceptual systems. The manipulations of the rats' early experience involved a combination of early binocular deprivation through dark-rearing, somatosensory restriction through cauterization of mystacial vibrissae, and multimodal enrichment through rearing in a complex environment. Specific lesions to somatosensory (Parl) and visual (Oc2M) cortex in differentially reared animals were included in an attempt to gain further insight into the plasticity surrounding manipulations of early stimulation history. Five tasks were used to assess these effects of early rearing condition in combination with later cortical lesions. Behavioral assessment focused on the ability of the animals to encode, abstract, and remember specific relationships between stimuli within the deprived modality itself, their ability to do so with information presented in other modalities, and on the basic species specific behavior. The only effect found was a main effect for rearing condition. Basically, complex-reared rats were more competent on several of the behavioral tasks than were dark-reared rats. However, this result provided little behavioral support for ideas of modality interdependence. Dendritic proliferation is considered to be a general mechanism supporting behavioral change. The subsequent neuroanatomical assessment focused on dendritic branching of neurons in specific cortical areas thought to be most affected by early environmental manipulations. Animals that were raised in a complex environment, but had experienced early tactile restriction through cauterization of vibrissae, showed significantly more dendritic branching than animals from all other rearing conditions in all cortical areas measured. This finding is consistent with ideas of both intra- and intermodal compensation following damage to an early developing modality, as well as behavioral demand acting as a significant factor in determining the impact of early somatosensory restriction. It is reasonable to assume that anatomical changes should be manifested behaviorally. Suggestions for smaller, more restricted studies, that would be more effective in describing the behavioral impact of early manipulations of the environment, were outlined. / Arts, Faculty of / Psychology, Department of / Graduate