User behavior analysis in web applications is currently mainly performed by analysis of statistical measurements based on user interactions or by creation of personas to better understand users. Both of these methods give great insights in how the users utilize a web site, but do not give any additional information about what they are actually doing. This thesis attempts to use eye tracking data for analysis of user activities in web applications. Eye tracking data has been recorded, labeled and analyzed for 25 test participants. No data source except eye tracking data has been used and two different approaches are attempted where the first relies on a gaze map representation of the data and the second relies on sequences of features. The results indicate that it is possible to distinguish user activities in web applications, but only at a high error-rate. Improvement are possible by implementing a less subjective labeling process and by including features from other data sources. / I nuläget utförs analys av användarbeteende i webbapplikationer primärt med hjälp av statistiska mått över användares beteenden på hemsidor tillsammans med personas förökad förståelse av olika typer av användare. Dessa metoder ger stor insikt i hur användare använder hemsidor men ger ingen information om vilka typer av aktiviteter användare har utfört på hemsidan. Denna rapport försöker skapa metoder för analys av användaraktiviter på hemsidor endast baserat på blickdata fångade med eye trackers. Blick data från 25 personer har samlats in under tiden de utför olika uppgifter på olika hemsidor. Två olika tekniker har utvärderats där den ena analyserar blick kartor som fångat ögonens rörelser under 10 sekunder och den andra tekniken använder sig av sekvenser av händelser för att klassificera aktiviteter. Resultaten indikerar att det går att urskilja olika typer av vanligt förekommande användaraktiviteter genom analys av blick data. Resultatet visar också att det är stor osäkerhet i prediktionerna och ytterligare arbete är nödvändigt för att finna användbara modeller.

One way of increasing 3D rendering performance is the use of foveated rendering. In this thesis a novel foveated rendering technique called gaze contingent depth of field tessellation (GC DOF tessellation) is proposed. Tessellation is the process of subdividing geometry to increase detail. The technique works by applying tessellation to all objects within the focal plane, gradually decreasing tessellation levels as applied blur increases. As the user moves their gaze the focal plane shifts and objects go from blurry to sharp at the same time as the fidelity of the object increases. This can help hide the pops that occur as objects change shape. The technique was evaluated in a user study with 32 participants. For the evaluated scene the technique helped reduce the number of primitives rendered by around 70 % and frame time by around 9 % compared to using full adaptive tessellation. The user study showed that as the level of blur increased the detection rate for pops decreased, suggesting that the technique could be used to hide pops that occur due to tessellation. However, further research is needed to solidify these findings. / Ett sätt att öka renderingsprestanda i 3D applikationer är att använda foveated rendering. I denna uppsats presenteras en ny foveated rendering-teknik som kallas gaze contingent depth of field tessellering (GC DOF tessellering). Tessellering är när geometri delas i mindre delar för att öka detaljrikedom. Tekniken fungerar genom att applicera tessellering på alla objekt i fokalplanet och gradvis minska tesselleringsnivåer när oskärpan ökar. När användaren flyttar sin blick så flyttas fokalplanet och suddiga objekt blir skarpa samtidigt som detaljrikedomen i objektet ökar. Det kan hjälpa till att dölja de ’pops’ som uppstår när objekt ändrar form. Tekniken utvärderades i en användarstudie med 32 del- tagare. I den utvärderade scenen visade sig tekniken minska antalet renderade primitiver med ca 70 % och minska renderingstiden med ca 9 % jämfört med att använda full adaptiv tessellering. Användarstudien visade att när oskärpa ökade så minskade antalet som sa sig se ’pops’, vilket tyder på att tekniken kan användas för att dölja de ’pops’ som uppstår på grund av tessellering. Det behövs dock ytterligare forskning för att säkerställa dessa fynd.

There is a distinction between participants and observers; the former performs an activity, whereas the latter spectates. The idea of observers who can influence activities is largely unexplored and could contain potential use-cases for eye-trackers and improve social presence in digital settings. This thesis adds to existing research by investigating whether higher degrees of observer influence correspond to increased social presence perception in digital co-located settings. It also provides designers with a tool that helps design and evaluate interactions accounting for observers' influences. The thesis presents five gaze implementations across two games that allow observers to influence them to investigate the hypothesised link between social presence perception and an observer's degree of influence. The results indicate that the link exists, although more tests are necessary to determine whether there is a noticeable difference between observers who impact activities directly and indirectly.

A complete understanding of the functional and structural impairments driving persistent post-concussive symptom (PCS) expression in approximately one-third of those who suffer from mild traumatic brain injury (mTBI) is essential for the development of effective treatment strategies and improving quality of life. While traditional outcome measures, such as neuropsychological testing and structural magnetic resonance imaging, are sensitive to the severe functional impairments and widespread tissue damage frequently seen after moderate-to-severe injuries, more advanced measures that are sensitive to the subtle changes in cognitive function and tissue microstructure that may underlie persistent PCS are necessary for the assessment of recovery from mTBI. Toward this end, the current study investigates the utility of eye-tracking analysis and high-definition fiber tractography (HDFT) as advanced measures of functional and microstructural outcome in 11 adults with chronic mTBI and varying levels of PCS (ages 20-60; mean time post-injury = 9.53 ± 6.74 years) in comparison to 10 healthy adults (ages 20-54). Performance on neuropsychological and eye-tracking tasks of processing speed, attention, and working memory, and HDFT-derived quantitative measures of the microstructural integrity of the forceps major, inferior fronto-occipital fasciculus, middle longitudinal fasciculus, and superior longitudinal fasciculus were compared between groups, and the results were used to define discriminatory functions for mTBI classification. The relationships between neuropsychological and eye-tracking measures of cognitive function and HDFT-derived measures of tract integrity were explored, as was the utility of these functional and structural measures for predicting persistent PCS in chronic mTBI. The results suggest that eye-tracking analysis may be more specific to cognitive impairments resulting from mTBI than neuropsychological testing, and HDFT is highly sensitive and specific to the subtle microstructural changes that persist chronically in this population. Furthermore, white matter integrity assessed using HDFT is more strongly associated with impairments in processing speed, attention, and memory indicated through eye-tracking analysis relative to performance on neuropsychological tests. Finally, although the predictive utility of eye-tracking and HDFT for the experience of persistent PCS was not demonstrated in the present sample, the possibility that these data are confounded by symptom exaggeration, comorbid mental health impairment, or lack of self-awareness for functional deficits cannot be ruled out, and future research using large, homogenous sample of mTBI is necessary to validate the present findings.

Studies indicate an attentional bias towards food in binge-eating disorder (BED), however, more evidence on attentional engagement and disengagement and processing of multiple attention-competing stimuli is needed. This study aimed to examine visual attention to food and non-food stimuli in BED. In n = 23 participants with full-syndrome and subsyndromal BED and n = 23 individually matched healthy controls, eye-tracking was used to assess attention to food and non-food stimuli during a free exploration paradigm and a visual search task. In the free exploration paradigm, groups did not differ in initial fixation position. While both groups fixated non-food stimuli significantly longer than food stimuli, the BED group allocated significantly more attention towards food than controls. In the visual search task, groups did not differ in detection times. However, a significant detection bias for food was found in full-syndrome BED, but not in controls. An increased initial attention towards food was related to greater BED symptomatology and lower body mass index (BMI) only in full-syndrome BED, while greater maintained attention to food was associated with lower BMI in controls. The results suggest food-biased visual attentional processing in adults with BED. Further studies should clarify the implications of attentional processes for the etiology and maintenance of BED.

Many games are set in 3D worlds and have shifting camera viewpoints. In this study, we attempt to create and evaluate a Proof-of-Concept Worldspace Heatmap System that accounts for the shifting camera views in 3D game worlds, in an attempt to improve user testing processes. We test the system by conducting a stimulated recall user study, in which we examine the areas in a game that drew the attention of the participants, with the help of heatmaps placed in the game world. Our results include observations of several behavior patterns and participant evaluations of the Worldspace Heatmap System. We observed multiple indications in the data we gathered, that such a system can be useful for obtaining player behavior insights and for enhancing user testing processes, especially if some of the limitations are overcome.

The video game and esports industry has grown exponentially over the past few years.“During recent years, esports have become one of the most rapidly growing forms ofnew media driven by the growing provenance of online games and onlinebroadcasting technologies” (Hamari and Sjöblom, 2017). Sponsors have identifiedmarketing opportunities in this rapidly growing advertising medium. Brand placementin esports is gaining momentum as a means to target audiences in an indirect andengaging way. In our study we have defined embedded brand placement in the contextof video games and esports as the practice of including a brand name, signage or otherforms of trademark merchandise integrated naturally within the game and in return,visibly featured in the esport broadcast. The aim of this study was to examine howembedded brand placement performed during different spectating scenarios whichpossess different distraction levels and in-game dynamics (audio and visual). Ourstudy explores the effectiveness of embedded brand placement within esports byemploying an eye tracking methodology as well as a brand recall exercise inconnection to participant's prior involvement with the video game, League of Legendsand the respective esports scene. The practical implications from the results of thisstudy hope to assist advertisers in making a better informed decision aboutcollaborating with esport events and uncover a better perception in regards to howthey might expect their advertising messages to perform. Through our study, we havesuccessfully contributed to the foundation of research surrounding embedded brandplacements within esports through our investigation of practical factors affecting towhich extent viewers are able to consume these advertising messages. These factorsbeing prior involvement, how differing spectating scenarios, distractions and in-gamedynamics affect fixations on advertising messages and finally how the above factorscontribute to overall brand recall as well as long-term versus short-term brandrecollection.

Background: Software is an integral part of today's world with an outlook of ever-increasing importance. Maintaining all of these software artifacts is a major challenge for software engineering. A future with robust software primarily relies on programmers' ability to understand existing source code, because they spend most of their time on it. Program comprehension is the cognitive process of understanding source code. Since program comprehension is an internal cognitive process, it is inherently difficult to observe and measure reliably. Decades of research have developed fundamental models of program comprehension, but there still are substantial knowledge gaps in our understanding of program comprehension. Novel psycho-physiological and neuroimaging measures provide an additional perspective on program comprehension which promise new insights to program comprehension. Recently, these measures have been permeating software engineering research. The measures include eye tracking and physiological sensors, but also neuroimaging measures, such as functional magnetic resonance imaging (fMRI), which allow researchers to more objectively observe cognitive processes. Aims: This dissertation aims to advance software engineering by better understanding program comprehension. We apply and refine the use of psycho-physiological and neuroimaging measures. The goals are twofold: First, we develop a framework for studying program comprehension with neuroimaging, psycho-physiological, eye tracking, and behavioral methods. For neuroimaging, we focus on functional magnetic resonance imaging (fMRI), as it allows researchers to unravel cognitive processes in high detail. Our framework offers a detailed, multi-modal view on program comprehension that allows us to examine even small effects. Second, we shed light on the underlying cognitive process of program comprehension by applying our experiment framework. One major focus is to understand experienced programmers' efficient top-down comprehension. We also link programmers' cognition to common code complexity metrics. Method and Results: To fulfill our goals, we conduct a series of empirical studies on program comprehension. In these studies, we use and combine fMRI, psycho-physiological, and eye-tracking measures. Throughout the experiments, we develop and refine a multi-modal experiment framework to shed light onto program comprehension with a neuro-cognitive perspective. We demonstrate that the framework provides a reliable approach to quantify and to investigate programmers' cognitive processes. We explore the neuro-cognitive perspective of program comprehension to validate and extend established program-comprehension models. We show that programmers using top-down comprehension require less cognitive effort, but use the same network of brain areas. We also demonstrate how our developed experiment framework and fMRI as a measure can be used in software engineering to provide objective data in long-standing debates. For example, we show that commonly used, but criticized code complexity metrics indeed only have a limited predictive power on the required cognitive effort to understand source code. Conclusion: In our interdisciplinary research, we show how neuroimaging methods, such as fMRI, in combination with psycho-physiological, eye tracking and behavioral measures, is beneficial to software-engineering research. This dissertation provides a foundation to further investigate the neuro-cognitive perspective to programmers' brains, which is a critical contribution to the future of software engineering. / Hintergrund: Software ist ein fester Bestandteil der heutigen Welt mit einer immer wichtiger werdenden Bedeutung. Das moderne Leben ist infolgedessen zunehmend von funktionierender und möglichst fehlerfreier Software abhängig. Deshalb ist die Pflege aller Software-Artefakte eine wichtige und große Herausforderung für das Software-Engineering. Eine Zukunft mit robuster Software hängt in erster Linie von der Fähigkeit ab, den vorhandenen Quellcode zu verstehen, da damit die meiste Zeit verbracht wird. Programmverständnis ist der kognitive Prozess des Verstehens von Quellcode. Da dieser kognitive Prozess intern abläuft, ist ein zuverlässiges Beobachten und ein genaues Messen mit erheblichen Schwierigkeiten verbunden. Jahrzehntelange Forschung hat zwar grundlegende Modelle des Programmverständnisses entwickelt, aber das Bild von Programmverständnis weist noch immer erhebliche Wissenslücken auf. Neuartige psychophysiologische und nicht-invasive human-bildgebende Verfahren bieten zusätzliche Perspektiven auf das Programmverständnis, die neue Erkenntnisse versprechen. In den letzten Jahren haben diese Erfassungsmöglichkeiten die Software-Engineering-Forschung durchdrungen. Zu den Messverfahren gehören Eyetracking und physiologische Sensoren, aber auch nicht-invasive Human-Bildgebung, wie die funktionelle Magnetresonanztomographie (fMRT). Diese innovativen Messverfahren ermöglichen es Forschenden, kognitive Prozesse objektiver und genauer zu verfolgen und auszuwerten. Ziele: Diese Dissertation zielt darauf ab, Software-Engineering durch ein besseres Erfassen des Programmverständnisses voranzubringen. Dafür werden psychophysiologische und nicht-invasive human-bildgebende Verfahren angewendet und verfeinert. Es werden zwei Ziele verfolgt: Zum einen wird ein Framework für Experimente zum Programmverständnis, die mit Human-Bildgebung, Psychophysiologie, Eyetracking und Verhaltensmethoden durchgeführt werden, entwickelt. Bei der Human-Bildgebung erfolgt die Konzentration auf die funktionelle Magnetresonanztomographie (fMRT), da sie kognitive Prozesse mit hoher Detailschärfe entschlüsseln kann. Das entwickelte Framework bietet eine detaillierte, multimodale Sicht auf das Programmverständnis, die es ermöglicht, auch kleine Effekte zu untersuchen. Zum anderen wird der zugrunde liegende kognitive Prozess des Programmverständnisses durch den Einsatz des aufgestellten Frameworks analysiert. Ein Hauptaugenmerk liegt dabei auf dem Erfassen des effizienten Top-Down-Verstehens von Quellcode. Zusätzlich wird die Kognition beim Programmieren mit gängigen Komplexitätsmetriken von Quellcode verknüpft und im Zusammenhang ausgewertet. Methodik und Ergebnisse: Um die Ziele zu erreichen, werden eine Reihe empirischer Studien zum Programmverständnis durchgeführt. In diesen Studien werden fMRT, Psychophysiologie sowie Eyetracking verwendet und miteinander kombiniert. Während der Experimente erfolgt eine Entwicklung und Verfeinerung eines multimodalen Experimentframework, um das Programmverständnis mit einer neurokognitiven Perspektive zu beleuchten. Es wird dokumentiert, dass das entwickelte Framework einen zuverlässigen Ansatz bietet, um kognitive Prozesse beim Programmieren zu quantifizieren und zu untersuchen. Weiterhin wird die neurokognitive Perspektive des Programmverständnisses erforscht, um etablierte Programmverständnismodelle zu validieren und zu erweitern. Im Kontext dessen wird belegt, dass das Top-Down-Verständnis das gleiche Netzwerk von Gehirnbereichen aktiviert, aber zu geringerer kognitiver Last führt. Es wird demonstriert, wie das entwickelte Experimentframework und fMRT als Messverfahren im Software-Engineering verwendet werden können, um in langjährigen Debatten objektive Daten zu bieten. Dabei wird insbesondere gezeigt, weshalb gängige, aber in Frage gestellte Komplexitätsmetriken von Quellcode tatsächlich nur eine begrenzte Vorhersagekraft auf die erforderliche kognitive Last beim Verstehen von Quellcode haben. Schlussfolgerung: In interdisziplinärer Forschung wird nachgewiesen, dass nicht-invasive human-bildgebende Verfahren wie die fMRT, kombiniert mit Psychophysiologie, Eyetracking sowie Verhaltensmethoden für die Software-Engineering-Forschung von erheblichem Vorteil sind. Diese Dissertation bietet eine belastbare Grundlage für die weitere Untersuchung der neurokognitiven Perspektive auf das Gehirn von Programmierern. Damit wird ein entscheidender Beitrag für ein erfolgreiches Software-Engineering geleistet.

The current push from the industry for Head-Mounted Display based wearable computers to the masses for everyday use suggests that academia's goals of a tight human and computer integration is achievable. Although promising, many interaction challenges remain to achieve a deep integration. Primarily that of active cognitive support in the form of focusing user attention. This thesis investigates to what degree a system can unobtrusively, perhaps even subliminally, guide attention of a user by directing their gaze from a current point to a selected point in a virtual environment. A subjective evaluation is made regarding the characteristics of visual sensory stimuli in order to possibly achieve an unobtrusive (or even subliminal) gaze guidance. The attention guidance system developed is deployed in a controlled experiment with 30 participants. Participants are asked to fire a longbow at targets in a virtual reality environment while their point of gaze is monitored with an eye-tracker. The experiment produced interesting results, but no conclusive evidence that the system was able actively guide a user's attention nor influence their choice could be observed. The conclusion of this thesis is that further development is needed towards a system that is capable of objectively calibrating the stimuli characteristics for each individual participant.

The main topic of this thesis are map skills, and the key point of interest are strategies used for map analysis. General reference map was found as a suitable map given its frequent use in the school atlases. The main goal of this study is evaluation of the general reference map analysis strategies in terms of their dimensions, i. e. their repertoire, distribution, efficiency, and adaptability. 20 upper secondary school students participated in an eye-tracking experiment that consisted of the test and the follow-up questionnaire. The eye-tracking data were analyzed qualitatively and quantitatively to obtain information about the strategy dimensions. Results showed that students used broad repertoire of strategies when analyzing the general reference map and they pointed to the most chosen strategies as well. In some cases, students used more than one strategy to solve the task and thus the most frequent strategy combinations were detected. The efficiency of strategies was evaluated based on the students' success rate and the length of the solving cycle which was affected by the type of elements, respectively map content, used for solving the task. The ability to adapt to specific task demand was proven by addition of elements needed into the strategy or using entirely different strategy type. The...