This thesis examines the way in which meaningful facial signals (i.e., eye gaze and emotional facial expressions) influence the allocation of visual attention. These signals convey information about the likely imminent behaviour of the sender and are, in turn, potentially relevant to the behaviour of the viewer. It is already well established that different signals influence the allocation of attention in different ways that are consistent with their meaning. For example, direct gaze (i.e., gaze directed at the viewer) is considered both to draw attention to its location and hold attention when it arrives, whereas observing averted gaze is known to create corresponding shifts in the observer’s attention. However, the circumstances under which these effects occur are not yet understood fully. The first two sets of experiments in this thesis tested directly whether direct gaze is particularly difficult to ignore when the task is to ignore it, and whether averted gaze will shift attention when it is not relevant to the task. Results suggest that direct gaze is no more difficult to ignore than closed eyes, and the shifts in attention associated with viewing averted gaze are not evident when the gaze cues are task-irrelevant. This challenges the existing understanding of these effects. The remaining set of experiments investigated the role of gaze direction in the allocation of attention to emotional facial expressions. Without exception, previous work looking at this issue has measured the allocation of attention to such expressions when gaze is directed at the viewer. Results suggest that while the type of emotional expression (i.e., angry or happy) does influence the allocation of attention, the associated gaze direction does not, even when the participants are divided in terms of anxiety level (a variable known to influence the allocation of attention to emotional expressions). These findings are discussed in terms of how the social meaning of the stimulus can influence preattentive processing. This work also serves to highlight the need for general theories of visual attention to incorporate such data. Not to do so fundamentally risks misrepresenting the nature of attention as it operates out-with the laboratory setting.

<p>This dissertation consists of two independent musical compositions and an article detailing the process of the design and assembly of an electric guitar with particular emphasis on the carefully curated suite of embedded effects. </p><p>The first piece, 'Phase Locked Loop and Modulo Games' is scored for electric guitar and a single echo of equal volume less than a beat away. One could think of the piece as a 15 minute canon at the unison at the dotted eighth note (or at times the quarter or triplet-quarter), however the compositional motivation is more about weaving a composite texture between the guitar and its echo that is, while in theory extremely contrapuntal, in actuality is simply a single [superhuman] melodic line.</p><p>The second piece, 'The Dogma Loops' picks up a few compositional threads left by ‘Phase Locked Loop’ and weaves them into an entirely new tapestry. 'Phase Locked Loop' is motivated by the creation of a complex musical composite that is for the most part electronically transparent. 'The Dogma Loops' questions that same notion of composite electronic complexity by essentially asking a question: "what are the inputs to an interactive electronic system that create the most complex outputs via the simplest musical means possible?"</p><p>'The Dogma Loops' is scored for Electric Guitar (doubling on Ukulele), Violin and Violoncello. All of the principal instruments require an electronic pickup (except the Uke). The work is in three sections played attacca; [Automation Games], [Point of Origin] and [Cloning Vectors]. </p><p>The third and final component of the document is the article 'Finding Ibrida.' This article details the process of the design and assembly of an electric guitar with integrated effects, while also providing the deeper context (conceptual and technical) which motivated the efforts and informed the challenges to hybridize the various technologies (tubes, transistors, digital effects and a microcontroller subsystem). The project was motivated by a desire for rigorous technical and hands-on engagement with analog signal processing as applied to the electric guitar. ‘Finding Ibrida’ explores sound, some myths and lore of guitar tech and the history of electric guitar distortion and its culture of sonic exploration.</p> / Dissertation

Across species, the face and more specifically the mouth, serves as an essential facet of everyday life. Amongst humans the mouth serves as a tool for the ingestion of food, a marker for facial recognition and a medium for communication. In order for the mouth to properly form, a series of precise growth and fusion events are needed. In order to insure that these events are orchestrated properly is a wide array of signals, transcription factors and epigenetic regulators. Due to the needed precision of these events, congenital birth defects of the face such as cleft lip and cleft palate are some of the most common worldwide. In order to support existing and identify new developmental processes involved in mouth formation, we have utilized the effective model, Danio to study the molecules and events implicated in orofacial development. This was accomplished by developing a novel confocal imaging technique that allows for visualization of the forward facing zebrafish. Using this imaging technique we were able to establish when the embryonic mouth first forms in zebrafish. Additionally, we recapitulated cleft-palate phenotypes shown in previous literature with the imaging method. Utilizing this technique, we then sought to further establish the role of Ca2+ signaling in proper orofacial morphogenesis and determine if the serine/threonine protein kinase, Ca2+/calmodulin-dependent protein kinase type-II (CaMK-II), has a role in proper orofacial developmental.

L'objectif de ce mémoire est de fournir une nouvelle preuve pour la "Non-leaving face property" dans le cas An à l'aide de l'approximation dans les catégories amassées. Cette preuve ouvre la porte pour une généralisation pour d'autres cas.

The focus of this dissertation is a methodology that enables computer systems to classify different up-front images of human faces as belonging to one of the individuals to which the system has been exposed previously. The images can present variance in size, location of the face, orientation, facial expressions, and overall illumination. The approach to the problem taken in this dissertation can be classified as analytic as the shapes of individual features of human faces are examined separately, as opposed to holistic approaches to face recognition. The outline of the features is used to construct signature functions. These functions are then magnitude-, period-, and phase-normalized to form a translation-, size-, and rotation-invariant representation of the features. Vectors of a limited number of the Fourier decomposition coefficients of these functions are taken to form the feature vectors representing the features in the corresponding vector space. With this approach no computation is necessary to enforce the translational, size, and rotational invariance at the stage of recognition thus reducing the problem of recognition to the k-dimensional clustering problem. A recognizer is specified that can reliably classify the vectors of the feature space into object classes. The recognizer made use of the following principle: a trial vector is classified into a class with the greatest number of closest vectors (in the sense of the Euclidean distance) among all vectors representing the same feature in the database of known individuals. A system based on this methodology is implemented and tried on a set of 50 pictures of 10 individuals (5 pictures per individual). The recognition rate is comparable to that of most recent results in the area of face recognition. The methodology presented in this dissertation is also applicable to any problem of pattern recognition where patterns can be represented as a collection of black shapes on the white background.

This study investigated the interactions of facially deformed infants (FD) with their mothers compared to a facially nondeformed control group (FND). All mother-infant dyads were videotaped for 10 minutes during a free play period. Mothers were instructed to spend time with their baby as they normally would. The videotaped interactions of 14 FD dyads and 14 FND dyads were rated by five raters for quality of interactions, amount of vocalization, touch, and face-to-face gaze. The infants were rated on their level of attractiveness from polaroid pictures and videotapes. Mothers also completed a questionnaire which assessed their infants' temperament. Three of the studies' four hypotheses were confirmed. First, the more attractive an infant was, the better his/her interactions with the mother were judged to be. Second, FD infant dyads were rated as significantly poorer in quality of interaction than FND dyads, although FD* dyads did not spend significantly less time vocalizing, touching, or in face-to-face gaze as predicted. A significantly higher percentage of FD infants were judged as having difficult temperament relative to FND infants. Finally, as predicted it was found that infants with difficult temperaments were more likely to exhibit poorer quality interactions than infants with less difficult temperaments. These results have important implications for providing anticipatory guidance to caregivers of FD infants. Without intervention, FD infants appear at risk for subsequent developmental problems stemming from disrupted early mother-infant interactions. Future research should focus on these interactions soon after the infant's birth, attempt to determine if FD infants' emotions can be reliably understood from their facial expressions (as has been found in normal infants) and extend the current research paradigm to include fathers of FD infants.

Co-auteurs de l'article: Karine Morin, Jacalyn Guy, Claudine Habak, Hugh, R. Wilson, Linda S.Pagani, Laurent Mottron, Armando Bertone / La perception faciale est la mesure visuelle la plus commune pour mesurer les habiletés sociales chez les personnes autistes. Lorsque cette habileté est atypique, la nature de son origine est souvent contentieuse. Une hypothèse suggère qu’une analyse visuelle orientée localement dans l’autisme affecterait leur performance sur les tâches faciales lorsque l’analyse configurale est nécessaire. Objectif. Évaluer cette hypothèse en mesurant la discrimination de l’identité faciale avec des visages synthétiques présentés avec ou sans changement de point de vue, afin de minimiser ou non l’accès aux attributs locaux. Méthodes. Cinquante-huit participants, autistes et neurotypiques, appariés selon leur quotient intellectuel, genre et âge, ont accompli une tâche de discrimination de l’identité faciale similaire à celle de Habak, Wilkinson et Wilson (2008). Les stimuli étaient des visages synthétiques, présentés de face ou de profil, simplifiés et écologiquement validés. Les seuils de discrimination de l’identité faciale, pourcentage minimum de changement dans la géométrie faciale à 75 % de réponses correctes, ont été obtenus en utilisant un système à deux choix alternatifs. Résultats. Les analyses montraient une interaction significative entre les groupes et conditions, avec une différence significative entre les groupes pour la condition avec changement de point de vue, où la performance du groupe autiste était inférieure comparativement au groupe neurotypique. Discussion. La performance inférieure pour la condition avec changement de point de vue suggère que la discrimination de l’identité des visages est plus difficile chez les individus autistes lorsque l’accès aux éléments locaux est minimisé et lorsqu’une analyse globale des informations est nécessaire. / Face perception is the most commonly used visual metric of social abilities in autism. When found to be atypical, the nature of its origin is often contentious. One hypothesis proposes that locally-oriented visual analysis, which characterizes persons with autism, influences performance on most face tasks where configural analysis is optimal. Objective. We evaluate this hypothesis by assessing face identity discrimination with synthetic faces presented with and without changes in viewpoint, with the former condition minimizing access to local face attributes used for identity discrimination. Methods. Fifty eight participants, with and without autism, matched for global intellectual quotient, age, and gender, were asked to perform a face identity discrimination task similar to that of Habak, Wilkinson, and Wilson (2008). Stimuli were frontal and side viewpoint of simplified and ecologically validated synthetic faces. Face identity discrimination thresholds, defined by the minimum percentage of change in face geometry at 75% correct performance, were obtained using a two-alternative, temporal forced choice match-to-sample paradigm. Results. Analyses revealed a significant interaction effect between groups and conditions, with significant group differences found only for the viewpoint change condition, where performance of the autism group was significantly decreased compared to that of neurotypical participants. Discussion. The selective decrease in autism performance for the viewpoint change condition suggests that face identity discrimination in autism is more difficult when (i) access to local cues are minimized, and (ii) an increased dependence on integrative analysis is introduced to the face task used.

Facial motion provides an abundance of information necessary for mediating social communication. Emotional expressions, head rotations and eye-gaze patterns allow us to extract categorical and qualitative information from others (Blake & Shiffrar, 2007). Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterised by a severe impairment in social cognition. One of the causes may be related to a fundamental deficit in perceiving human movement (Herrington et al., 2007). This hypothesis was investigated more closely within the current thesis. In neurotypical controls, the visual processing of facial motion was analysed via EEG alpha waves. Participants were tested on their ability to discriminate between successive animations (exhibiting rigid and nonrigid motion). The appearance of the stimuli remained constant over trials, meaning decisions were based solely on differential movement patterns. The parieto-occipital region was specifically selective to upright facial motion while the occipital cortex responded similarly to natural and manipulated faces. Over both regions, a distinct pattern of activity in response to upright faces was characterised by a transient decrease and subsequent increase in neural processing (Girges et al., 2014). These results were further supported by an fMRI study which showed sensitivity of the superior temporal sulcus (STS) to perceived facial movements relative to inanimate and animate stimuli. The ability to process information from dynamic faces was assessed in ASD. Participants were asked to recognise different sequences, unfamiliar identities and genders from facial motion captures. Stimuli were presented upright and inverted in order to assess configural processing. Relative to the controls, participants with ASD were significantly impaired on all three tasks and failed to show an inversion effect (O'Brien et al., 2014). Functional neuroimaging revealed atypical activities in the visual cortex, STS and fronto-parietal regions thought to contain mirror neurons in participants with ASD. These results point to a deficit in the visual processing of facial motion, which in turn may partly cause social communicative impairments in ASD.

La présente recherche décrit et examine le cheminement émotionnel d’ex-contrevenants engagés dans un processus de justice réparatrice. Le cheminement émotionnel est appréhendé sous l’angle de l’analyse des « trajectoires de vie ». Nous avons rencontré quatre anciens contrevenants condamnés à une peine d’incarcération, et vivant dans la communauté au moment de nos entretiens. Afin d’établir leur trajectoire de vie émotionnelle, les entretiens ont été menés en profondeur et selon une approche non-directive. Les participants ont réalisé soit une expérience de Rencontre-Détenus-Victimes (RDV), soit une expérience de face-à-face avec une victime, ou une réparation directe avec leur victime. L’analyse de nos données empiriques met en évidence deux périodes émotionnelles distinctes chez les ex-contrevenants. Leur cheminement est d’abord caractérisé par un état de fermeture puis d’ouverture émotionnelle. Pour chaque état émotionnel, nous présentons les différentes composantes émotionnelles qui les constituent ainsi que les changements émotionnels qui en résultent. La transition entre le passage d’un état de fermeture à un état d’ouverture émotionnelle, ainsi que l’expérience de justice réparatrice, ont été minutieusement étudiées. De ces analyses a émergé le concept de « point tournant émotionnel », apparaissant comme la clé de voûte du cheminement réparateur des anciens contrevenants. Il ressort en effet qu’un point tournant émotionnel est considéré comme un préalable nécessaire à la participation à un programme réparateur, mais aussi comme le baromètre de l’effet réparateur des expériences. / This research describes and discusses the emotional path of ex-offenders involved in a process of restorative justice. The emotional path is tackled from the perspective of "lifecourse" analysis. We met four former offenders sentenced to a prison term, and living in the community at the moment of our interviews. In order to interpret their emotional life course, the interviews were conducted in depth and in a non-directive approach. Participants performed either a Victim-Offender-Encounter (VOE), a face-to-face experience with a victim, or direct atonement with their victim. The analysis of our empirical data shows two distinct emotional periods in ex-offenders. Their path is characterized first by a closed state, then by an emotional opening. For each emotional state, we present its various emotional components and the resulting emotional changes. The transition, that is the passage between a closed state to a state of emotional openness, and the restorative justice experience, have been thoroughly studied. From these analysis emerged the concept of "emotional turning points," appearing as the keystone of the restorative pathway of former offenders. It is clear that an emotional turning point is considered a prerequisite for taking part in a restorative program, but also as a barometer of the restorative effects of the experiences.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.