Background. Although a growing market, most of the commercially available gamestoday that features eye tracking support is rendered in a 3D perspective. Games ren-dered in 2D have seen little support for eye trackers from developers. By comparing the differences in player performance and experience between an eye tracker and acomputer mouse when playing a classic 2D genre: space shooter, this thesis aim tomake an argument for the implementation of eye tracking in 2D video games. Objectives. Create a 2D space shooter video game where movement will be handledthrough a keyboard but the input method for aiming will alter between a computermouse and an eye tracker. Methods. Using a Tobii EyeX eye tracker, an experiment was conducted with fif-teen participants. To measure their performance, three variables was used: accuracy,completion time and collisions. The participants played two modes of a 2D spaceshooter video game in a controlled environment. Depending on which mode wasplayed, the input method for aiming was either an eye tracker or a computer mouse.The movement was handled using a keyboard for both modes. When the modes hadbeen completed, a questionnaire was presented where the participants would ratetheir experience playing the game with each input method. Results. The computer mouse had a better performance in two out of three per-formance variables. On average the computer mouse had a better accuracy andcompletion time but more collisions. However, the data gathered from the question-naire shows that the participants had on average a better experience when playingwith an eye tracker Conclusions. The results from the experiment shows a better performance for par-ticipants using the computer mouse, but participants felt more immersed with the eyetracker and giving it a better score on all experience categories. With these results,this study hope to encourage developers to implement eye tracking as an interactionmethod for 2D video games. However, future work is necessary to determine if theexperience and performance increase or decrease as the playtime gets longer.

The electrocardiogram (ECG) is a graphical representation of the electrical activity of the heart. The 12-lead ECG shows this activity in 12 "views" called "leads", relative to the location of sensors attached to the body surface. The ECG is a routinely applied cost effective diagnostic medical test, utilised in healthcare settings around the world. Although more than three hundred million ECGs are recorded each year, correctly interpreting them is considered a complex task. Failure to make correct interpretations can lead to injury or death and costs vast sums in litigation payments. Many automated attempts at interpreting ECGs have been implemented and continue to be developed and improved. Despite this, automated methods are still considered to be less reliable than expert human interpretation. As ECG interpretation is both a cognitive and visual task, eye-tracking holds great potential as an investigative methodology. This thesis aims to identify any cues in visual behaviour that may indicate differences in subsequent ECG interpretation accuracy. This is the first work that uses eye-tracking to analyse how practitioners interpret ECGs as a function of accuracy. In order to investigate these phenomenon, several experiments were carried out using eye-movements captured from clinical practitioners that interpret ECGs as part of their usual clinical role. The findings presented in this thesis have advanced research in the understanding of ECG interpretation. Specifically: Clinical history makes a difference to how people look at ECGs; different gaze patterns are often found in accurate and inaccurate interpretation groups. Grouping data to account for within ECG lead behaviour (eye-movement patterns within a lead) is more revealing than analysis at the level of the lead (eye-movements between leads). Findings suggest analysing visual behaviour at this level is crucial in order to detect behaviour in ECG interpretation. Further to this the thesis presents eye-tracking techniques that can be applied to wider areas of task performance. These methods work over complex stimuli, are able to deal post hoc with differently sized groups and generate appropriate areas of interest on a stimulus. These methods detect important differences in eye-movement behaviour between groups that are missed when applying standard inferential statistical techniques.

Comme la consommation de médias numériques a explosé ces dernières années, faire des photos esthétiques, avec ou sans expertise artistique, est plus que jamais un sujet de recherche. Plusieurs axes peuvent être explorés: la haute définition, la luminance ou contraste étendue, les gamut couleur étendus. En plus de ces propriétés intrinsèques de l'image, des connaissances perceptuelles et/ou artistiques seraient de grande valeur pour tout utilisateur manipulant le contenu des images. Cette thèse propose d'aborder le thème de l'harmonie des couleurs. La littérature en lien avec ce sujet se retrouve à travers diverses disciplines : la science des couleurs, le traitement d'image, la psychologie… Ces expériences menées en science des couleurs privilégient la mesure de patchs combinant deux ou trois couleurs, rendant l'extrapolation à des images naturelles impossibles. D'autres approches ont défini des lois empiriques dictant l'arrangement des couleurs sur la roue des teintes. Le cadre applicatif de ces modèles géométriques manque de rigueur quant à leur utilisation. Malgré cela, des algorithmes en traitement d'image employant ces modèles ont vus le jour. Si les résultats semblent qualitativement agréables, ces algorithmes méritent une validation plus quantitative et objective, faisant intervenir une base de données appropriée. Dans cette thèse, deux approches sont mises en perspective: un travail expérimental et une partie algorithmique. Une expérience a été menée à l'aide d'un oculomètre avec une tâche dédiée à l'analyse de l'harmonie des couleurs, permettant de mesurer des effets dans le déploiement de l'attention visuelle. A partir de ces données, une vérité terrain a été extrapolée, permettant la validation des méthodes algorithmiques ensuite proposées. En premier, nous avons amélioré l'état de l'art sur l'harmonisation automatique des images au travers de diverses contributions et avons démontré de façon exhaustive le gain de notre approche. En deuxième contribution algorithmique, nous avons introduit une nouvelle sorte de métrique de qualité qui combine les concepts de masquage visuel et d'harmonie des couleurs. Ainsi, nous pouvons prédire quelles zones de l'image seront perçues harmonieuses, au vue de leur voisinage et donc des effets de masquages potentiels. Enfin, une dernière contribution, nous a amené à dériver deux outils d'édition incorporant les deux techniques précédentes, permettant de rendre accessible les concepts d'harmonie des couleurs à travers une formulation cachée et intuitive. / Since the consumption of digital media exploded in the last decade, making aesthetic pictures quickly - with or without artistic expertise - is more than ever a research topic. Different axis of investigations remain possible: high resolution, high dynamic range or wide color gamut. Additionally to these objective image properties, more perceptual and artistic insights could be of benefit to any user manipulating pictures. In such context, this thesis deals with the topic of Color Harmony. The literature related to this topic is limited, but involves many different scientific areas: color science, image processing and psychology and so on. The validity of collected data is questionable due to their limitation to two- or three-colors patches. The models fitted from these data remain non-exploitable on natural pictures. Other models depicting rules or areas on color wheel lack scientific guidelines for their utilization. Nonetheless, some algorithms employing color harmony theory and models as a core concept showed up in the literature, but suffered from being quantitatively tested and validated. In this thesis, two views are put in perspective in order to respond to the previous statements: an experimental and a computational approaches. The conducted experiment allowed observing some effects with an eye-tracking protocol, never applied before with a task on color harmony assessment. From the collected data of our experimental work, we designed a method to generate a ground truth, which would serve to the validation of the two proposed computational methods. First, we improved an existing architecture for automatic color harmonization and demonstrated exhaustively the benefit of our approach. As a second computational contribution, a novel quality metric is introduced that integrates the concepts of visual masking and color harmony. Thus, we may predict which areas would be perceived harmonious regarding its neighborhood and then the potential masking effects. As a last contribution, two editing tools made accessible the color harmony theory through a hidden formulation of it and a user-friendly and intuitive interface.

Eyes are an ideal tool for investigating social attention, as their physiological composition with the iris and pupil highly-distinguishable against the white sclera, combined with our foveated vision, mean that gaze cues are both a means of understanding where attention is being allocated and a method for non-verbal communication. Previous attention research using gaze cues has focused on Posner-type paradigms that have supported a model of reflexive orienting of attention in response to gaze cues. However, the ecological validity of this type of paradigm has been called into question given more recent real world research, which has produced findings that cannot be explained by laboratory-based Posner-type paradigms. Therefore, the aim of this thesis was to develop and test a novel, more ecologically-valid paradigm that could investigate observers’ responses to gaze cues in a realistic, but controlled, manner. Based on past research, an initial goal of this research was to develop an early iteration of a realistic visual search paradigm in which a single non-predictive gaze cue is presented. This was built on in later chapters by adding manipulations of task instruction. These chapters presented some evidence that supported a reflexive orienting model of gaze, with clear facilitation to performance as a result of person presence. The second goal of this research was to explore observers’ responses when presented with the same task and search arrays, but with the inclusion of a second gaze cue. This is some of the first research to address multiple gaze cues within a realistic visual search paradigm. These chapters showed multiple gaze cues result in quite considerably different observer eye movement behaviour. Benefits of people presence were stronger and far more congruency effects were apparent. There were also clear effects of instruction, with the suggestion that gaze cues provided may be helpful to the task resulting in significantly greater proportions of overt gaze-seeking than in other instruction conditions. The introduction of multiple gaze cues created a new gaze cue condition – the conflicting condition in which each person cued separate spatial areas within the scene. In order to explore the effects of gaze cue sender reliability on observers’ eye movements, a third version of the study was tested where the gaze cues presented were spatially informative, cuing the target in 70% of trials. Results showed similar benefits of people presence to the previous multiple-cue chapters, but there were minimal reliability effects. Methodological adaptations were suggested based on previous research that has explored reliability effects that may more successfully elicit reliability effects in future research. The final chapter presents a summary of the findings of the research contained within this thesis. The results showed that in a more complex and realistic visual search task employing a single gaze cue, results are somewhat consistent with the reflexive orienting model of gaze due to the clear facilitation as a result of person presence and the lack of instruction effects. The findings presented also demonstrate that once multiple gaze cues are introduced, the reflexive orienting model cannot account for observers’ gaze behaviour. Instead, findings are more consistent with recent real world research. This would suggest that a new model of gaze processing is required when more than one gaze cue is presented, and the final chapter offers some suggestions of what this new model would need to take into account. It is suggested that subsequent research using this novel paradigm should explore the use of dynamic cues and the effects on eye movement behaviour in special populations, and that the research presented in this thesis provides a solid foundation upon which these new directions for research can be built.

Individuals with Autistic Spectrum Disorders (ASD) often perform better than typically developing (TD) individuals in simple, albeit difficult, visual search tasks. This ability is often attributed to a lack of drive for coherence or superior local processing. We compare thirty adults with ASD with forty-nine TD individuals and twenty-seven adults with anxiety (ANX) across two real-world visual search tasks. Individuals had to find either a number superimposed over a real-world scene ("œno context" condition) or an object located in a contextually relevant location ("œcontext" condition). Each participant completed forty-one trials in each condition, each with a unique scene. Eye movements were recorded using an SR Research EyeLink 1000 eyetracker. All groups performed better in the context condition. However, the ASD group was less accurate than both groups, across conditions. All groups were quicker to find the target in the context condition but the ASD group was slower than the TD group. Furthermore, the ASD group took longer to initiate their search, fixate on the target, and decide that they had found the target than the TD group. These results suggest that individuals with ASD are able to integrate contextual information to aid the search but that their previously seen visual search advantage may not transfer to visual searches of real-world scenes.

To find if video enjoyment was deeper for people with ADHD (attention deficit/hyperactive disorder) than for their non-ADHD peers, subjects with ADHD, and without, had their eye movement tracked during video exposure to determine average saccade rates. I interviewed subjects using pre-tested statements to establish periods of flow state (a measure of enjoyment). Results indicate that there is a deeper sense of enjoyment for people with ADHD, as subjects with ADHD passed a greater average time in flow state during video consumption (27% compared to 21%). Furthermore, the effects of flow state on the eye movement of those with ADHD was much greater than the effects of flow state on the eye movement of the non-ADHD control group. Average saccade rates jumped up 0.15 saccades per second when comparing out-of-flow to in-flow states for the ADHD group, while the average saccade rate for the non-ADHD group increased only 0.03 saccades per second when comparing out-of-flow to in-flow states. This helps further understanding of why people with ADHD consume more screen time than their non-ADHD peers; they may be more inclined to choose video consumption as an activity since the enjoyment they receive from video consumption is deeper and more frequent.

Crew coordination in the context of aviation is a specifically choreographed set of tasks performed by each pilot, defined for each phase of flight. Based on the constructs of effective Crew Resource Management and SOPs for each phase of flight, a shared understanding of crew workload and task responsibility is considered representative of well-coordinated crews. Nominal behavior is therefore defined by SOPs and CRM theory, detectable through pilot eye-scan. This research investigates the relationship between the eye-scan exhibited by each pilot and the level of coordination between crewmembers. Crew coordination was evaluated based on each pilot's understanding of the other crewmember's workload. By contrasting each pilot's workload-understanding, crew coordination was measured as the summed absolute difference of each pilot's understanding of the other crewmember's reported workload, resulting in a crew coordination index. The crew coordination index rates crew coordination on a scale ranging across Excellent, Good, Fair and Poor. Eye-scan behavior metrics were found to reliably identify a reduction in crew coordination. Additionally, crew coordination was successfully characterized by eye-scan behavior data using machine learning classification methods. Identifying eye-scan behaviors on the flight deck indicative of reduced crew coordination can be used to inform training programs and design enhanced avionics that improve the overall coordination between the crewmembers and the flight deck interface. Additionally, characterization of crew coordination can be used to develop methods to increase shared situation awareness and crew coordination to reduce operational and flight technical errors. Ultimately, the ability to reduce operational and flight technical errors made by pilot crews improves the safety of aviation.

Since the late 20th century, nature-based tourism, an alternative to mass tourism with a focus on natural environments, has steadily grown in popularity. Nature-based tourism areas are considered a platform for informal education and exemplify principles of environmental stewardship and conservation. Iceland, an island nation in the North Atlantic, is one area of the world that has seen dramatic growth in its nature-based tourism industry in recent years; tourists are drawn to Iceland in numbers five times the total population of the Country. The pressures of economic development have resulted in the continued promotion of Icelandic tourism, and, subsequently, the rapid, sometimes detrimental, development of tourist destinations. This study used a triangulated mixed methods approach including post-visitation assessments, mobile eye-tracking (MET), GPS footpath collection, and observational analysis to assess visitor experience and behavior in two popular Icelandic tourist destinations: Sólheimajökull and Þingvellir. Through the use of MET, a greater understanding of visitor behavior was developed in these areas. Results suggest that the infrastructure development which has occurred at Þingvellir is effective at managing tourist behavior; however, the less developed and more authentic environment of Sólheimajökull appeals more to visitor expectations of Icelandic tourism. Observing the strengths and weaknesses of the study sites revealed ways to guide the future development of the sites in ways that promote both education and conservation. Furthermore, the critical evaluation of the original methodology developed for this study also presents a technique by which the development of other nature-based tourism destinations can be assessed.

The phenomenon of attentional bias to alcohol, where drinkers demonstrate a preference in allocating visual attention towards alcohol-related stimuli rather than neutral stimuli, is well-established. Studies detecting this phenomenon typically utilize computer-administered stimulus presentation tasks such as the visual dot probe task. Despite their frequency of use, these tasks do not represent the ways in which individuals typically encounter alcohol outside of the laboratory. Typical environments where alcohol is present allow individuals to move about freely and encounter alcohol while also being exposed to many other stimuli. This dissertation sought to implement a novel approach to assessing attentional bias in vivo, and identify how alcohol consumption might influence such in vivo attentional bias. This two-study dissertation utilized an in vivo task where participants looked freely around a room representing a recreational setting containing numerous objects while portable eye-tracking glasses monitored what an individual looked at and for how long. Target items of alcohol and neutral beverages were placed throughout the environment and fixation time spent on these objects was recorded. The first study of this dissertation examined attentional bias to alcohol-related objects across two identical testing sessions to understand the impact of novelty on allocation of in vivo attention. The second study tested individuals using the same in vivo assessment following a 0.30 g/kg dose of alcohol, a 0.65 g/kg dose of alcohol and a placebo. Participants also completed the visual dot probe task in order to measure and compare their attentional bias in a more traditionally implemented task to the novel in vivo approach. Results from the first study indicate that as the novelty of stimuli begins to wane and habituation to neutral stimuli occurs, attentional bias to alcohol-related objects emerges. This attentional bias was shown to be related to drinking habits, where heavier drinkers demonstrated increased attentional bias. The second study in this research found no discernible effect of alcohol consumption on in vivo attentional bias, but did identify a satiating effect of consumption on bias as measured by the visual dot probe task. Additional visual dot probe findings suggest the specificity of the effect of alcohol consumption on attentional bias. Together, these findings help inform whether there is benefit in utilizing an ecological model of measuring attentional bias and how the phenomenon might be measured in laboratory settings in the future.

Les spécificités de la dépression chez la personne âgée, tant sur le plan cognitif qu'émotionnel, peuvent rendre difficile son diagnostic. La dépression du sujet jeune se caractérise notamment par la présence d'un biais dirigé vers les informations négatives. Aucune étude n'a encore évalué les biais attentionnels chez le sujet âgé déprimé bien que le vieillissement modifie le traitement de l'information à valence émotionnelle. L'objectif de cette thèse était d'identifier le caractéristiques du traitement de l'information émotionnelle chez les sujets dépressifs âgés par l'étude des performances des systèmes saccadiques et des stratégies d'explorations visuelles en ayant recours aux techniques d'eye-tracking. Les résultats montrent chez ces patients une augmentation du temps de réaction aux tâches de prosaccades et d'antisaccades ainsi que du taux d'erreur comparativement aux sujets contrôles. Par ailleurs, l'augmentation du taux d'erreur et du coût temporel (différence entre le temps de réaction d'antisaccades et le temps de réaction des prosaccades) suggère que ces processus ne sont pas uniquement liés à un ralentissement global, mais qu'ils pourraient être aussi expliqués par une altération spécifique des mécanismes d'inhibition. Cette altération est corrélée à la sévérité de l'épisode dépressif. L'analyse des performances oculomotrices lors de la présentation de paires d'images à connotation émotionnelle a mis ei évidence un biais de positivité chez les sujets dépressifs âgés en comparaison à un groupe contrôle. L'utilisation des techniques d'eye-tracking a donc permis de préciser la nature des interactions entre le vieillissement et la dépression au niveau neurophysiologique et émotionnel. Les anomalies oculomotrices objectivées par ces tâches pourraient constituer des marqueurs de la dépression du sujet âgé. Les limites méthodologiques liées à l'utilisation de ces techniques ainsi que les applications cliniques potentielles comme par exemple l'aide au diagnostic différentiel entre la dépression et la maladie d'Alzheimer, entre le trouble unipolaire et bipolaire et comme facteur d'évaluation de la réponse aux traitements sont discutées. / The specificities of dépression in thé elderly, on both thé cognition and emotional level, may render its diagnosis difficult. Dépression in young patients is characterized by thé présence of bias directed toward négative information. No study has assessed thé attentional bias in thé elderly depressed although aging changes thé emotional information processing. The aûn of this thesis was to identify thé characteristics of thé emotional information processing in depressed elderly subjects by studying thé performance of saccadic Systems and visual explorations stratégies through thé use of eye-tracking techniques. Our results showed that depressed patients had a higher reaction time in prosaccade and antisaccade tasks as well as higher error rates than controls. Moreover, thé higher time cost of inhibition (i.e. antisaccade reaction time minus prosaccade reaction time) suggests that thèse processes may imply a spécifie impairment of inhibition processes. This altération was found to be linked to dépression severity. The analysis of oculomotor performance on thé présentation of emotional picture pairs has highlighted a positivity bias in elderly depressed patients compared to healthy controls. The use of eye-tracking technologies has been found to be useful to specify thé link between ageing and dépression on neurophysiological and emotional levels. In this thesis, we also discuss thé methodological limits related to thé use of thèse techniques as well as thé potential clinical applications in thé differential diagnosis between dépression and Alzheimer's disease, or between unipolar and bipolar dépression, as well as in thé prédiction of treatment response.