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.

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.

No description available.

The use of eye movements to interact with computers offers opportunities for people with impaired motor ability to overcome the difficulties they often face using hand-held input devices. Computer games have become a major form of entertainment, and also provide opportunities for social interaction in multi-player environments. Games are also being used increasingly in education to motivate and engage young people. It is important that young people with motor impairments are able to benefit from, and enjoy, them. This thesis describes a program of research conducted over a 20-year period starting in the early 1990's that has investigated interaction techniques based on gaze position intended for use by people with motor impairments. The work investigates how to make standard software applications accessible by gaze, so that no particular modification to the application is needed. The work divides into 3 phases. In the first phase, ways of using gaze to interact with the graphical user interfaces of office applications were investigated, designed around the limitations of gaze interaction. Of these, overcoming the inherent inaccuracies of pointing by gaze at on-screen targets was particularly important. In the second phase, the focus shifted from office applications towards immersive games and on-line virtual worlds. Different means of using gaze position and patterns of eye movements, or gaze gestures, to issue commands were studied. Most of the testing and evaluation studies in this, like the first, used participants without motor-impairments. The third phase of the work then studied the applicability of the research findings thus far to groups of people with motor impairments, and in particular,the means of adapting the interaction techniques to individual abilities. In summary, the research has shown that collections of specialised gaze-based interaction techniques can be built as an effective means of completing the tasks in specific types of games and how these can be adapted to the differing abilities of individuals with motor impairments.

With the spread of virtual reality, eye tracker embedded VR headset gradually becomes a trend. A company such as Fove has already released its eye-tracking VR headset. However, the relatively low frame rate of eye tracker in VR HMD (e.g. 90 fps) makes tracking unstable with consumption of computing power. Understanding relations between gaze direction and head direction would be helpful, for example, to predict and compensate eye tracking with head tracking. In this research, a unity project consisted of a moving object with variable parameters was created to examine if there’s correlation exists between players’ head direction and gaze direction in eye’s smooth pursuit movement. Furthermore, object parameters, shape, color, distance, speed and horizontal moving degree were tested to explore whether they can elicit statistically significant differences in gaze prediction. Results revealed that while smoothly pursuing a moving object with the gaze, people’s horizontal and vertical component of head direction and gaze direction are separately linearly correlated. Moreover, formulas were calculated via linear regression to express their relations. As for object parameters, significant impacts were detected for all five parameters and interaction effect of speed and horizontal moving degree with various effect size, partial eta squared. / Med spridningen av den virtuella verkligheten blir Eye Tracking-inbyggd VR-headset gradvis en trend. Ett företag som Fove har redan släppt sitt Eye Tracking VR-headset. Emellertid gör den relativt låga bildhastigheten för ögonspårare i VR HMD (t.ex. 90 fps) spårning ostabil med förbrukning av datorkraft. Att förstå relationer mellan blickriktning och huvudriktning skulle vara till hjälp, till exempel för att förutsäga och kompensera ögonspårning med huvudspårning. I den här undersökningen, var ett Unity-projekt bestående av ett rörligt objekt med varierande parametrar skapad för att undersöka om det finns korrelation mellan spelarens huvudriktning och blickriktning i ögonens följerörelse. Dessutom testades objektparametrar; form, färg, avstånd, hastighet och horisontell rörelsegrad för att undersöka huruvida de kan framkalla statistiskt signifikanta skillnader i blickprediktionen. Resultaten avslöjade att medan man rör sig smidigt med ett rörligt föremål med blicken, är människornas horisontella och vertikala komponent i huvudriktning och blickriktning separat linjärt korrelerad. Dessutom beräknades formler via linjär regression för att uttrycka deras relationer. När det gäller objektparametrar detekterades signifikanta effekter för alla fem parametrarna och interaktionseffekten av hastighets-och horisontell rörelsegrad med olika effektstorlek, partiell Eta-kvadrat.

This thesis proposes a novel approach for efficiently estimating gaze points in dual camera transportation datasets. Traditional methods for gaze point estimation are dependent on large amounts of labeled data, which can be both expensive and time-consuming to collect. Additionally, alignment and calibration of the two camera views present significant challenges. To overcome these limitations, this thesis investigates the use of self-learning techniques such as semi-supervised learning and self-training, which can reduce the need for labeled data while maintaining high accuracy. The proposed method is evaluated on the DGAZE dataset and achieves a 57.2\% improvement in performance compared to the previous methods. This approach can prove to be a valuable tool for studying visual attention in transportation research, leading to more cost-effective and efficient research in this field. / Master of Science / This thesis presents a new method for efficiently estimating the gaze point of drivers while driving, which is crucial for understanding driver behavior and improving transportation safety. Traditional methods require a lot of labeled data, which can be time-consuming and expensive to obtain. This thesis proposes a self-learning approach that can learn from both labeled and unlabeled data, reducing the need for labeled data while maintaining high accuracy. By training the model on labeled data and using its own estimations on unlabeled data to improve its performance, the proposed approach can adapt to new scenarios and improve its accuracy over time. The proposed method is evaluated on the DGAZE dataset and achieves a 57.2\% improvement in performance compared to the previous methods. Overall, this approach offers a more efficient and cost-effective solution that can potentially help improve transportation safety by providing a better understanding of driver behavior. This approach can prove to be a valuable tool for studying visual attention in transportation research, leading to more cost-effective and efficient research in this field.

This studie investigates the phenomenon of remedation within the #Booktok community, focusing on the content shared and the prevalent gender dynmics. Through a combination of qualitive and quantitive content analysis, the study aims to uncover the themes and dynamics present in these digital spaces. By examining the visual, textual, and auditory elements of 120 film clips, this study illuminates the reasons behind #Booktok´s emergence as a preffered platform for literary engagement. Furthermore, the research also investigates the portrayal of “The female gaze”, which is a theory based on "The male gaze" by Laura Mulvey. To explore how gender perspectives shape the discourse within this digital space.   The result uncovers that #Booktok serves as a chosen digital arena for diverse reasons, evolving into a alternative form of public discourse. These reasons include shorter, accessible videos that are easier to engage with, as well as a community fostering interacitivity. Morover, the research highlights a notable emphasis on erotic literature within the community. It is predominatly men who criticize these erotic books, often labeling them as pornography. In contrast, women defend these works, arguing that such criticism stems from misogyny. Notably, the analysis underscores the predominant self-presentation of women on the platform, influencing content creation throught the lens of “The female gaze”. This study enhances our comprehension of how remedation, gender dynamics, and content intertwine within the #Booktok community, offering insights into the shifting landcape of digital literay interaction.

Yes / Recently we demonstrated how changes in gaze angle can be determined without an eye-tracker. The approach uses 3D motion-capture, to track the viewed target in the head’s reference frame and assumes head or target movement causes a gaze-angle change. This study determined the validity of this “assumed-gaze” method. Participants read information presented on a smartphone whilst walking. Changes in gaze angles were simultaneously assessed with an eye-tracker and our assumed-gaze method. The spatial and temporal agreement of the assumed-gaze approach with the eye-tracker were ~1deg and ~0.02s, respectively, and spatial congruence indicated the direction of changes in the assumed-gaze angle were in accordance with those determined with the eye tracker for ~81% of the time. Findings indicate that when the head is moving and gaze is continually directed to a small target, our assumed-gaze approach can determine changes in gaze angle with comparable precision to a wearable eye-tracker / Alejandro Rubio Baranano ˜ was funded by a UK College of Optometrists PhD studentship

This thesis presents a novel system that estimates the point-of-gaze (where a person is looking at) remotely while allowing for free head movements and minimizing personal calibration requirements. The point-of-gaze is estimated from the pupil and corneal reflections (virtual images of infrared light sources that are formed by reflection on the front corneal surface, which acts as a convex mirror) extracted from eye images captured by video cameras. Based on the laws of geometrical optics, a detailed general mathematical model for point-of-gaze estimation using the pupil and corneal reflections is developed. Using this model, the full range of possible system configurations (from one camera and one light source to multiple cameras and light sources) is analyzed. This analysis shows that two cameras and two light sources is the simplest system configuration that can be used to reconstruct the optic axis of the eye in 3-D space, and therefore measure eye movements, without the need for personal calibration. To estimate the point-of-gaze, a simple single-point personal calibration procedure is needed. The performance of the point-of-gaze estimation depends on the geometrical arrangement of the cameras and light sources and the method used to reconstruct the optic axis of the eye. Using a comprehensive simulation framework developed from the mathematical model, the performance of several gaze estimation methods of varied complexity is investigated for different geometrical system setups in the presence of noise in the extracted eye features, deviation of the corneal shape from the ideal spherical shape and errors in system parameters. The results of this investigation indicate the method(s) and geometrical setup(s) that are optimal for different sets of conditions, thereby providing guidelines for system implementation. Experimental results with adults, obtained with a system that follows those guidelines, exhibit RMS point-of-gaze estimation errors of 0.4-0.6º of visual angle (comparable to the best commercially available systems, which require multiple-point personal calibration procedures). Preliminary results with infants demonstrate the ability of the proposed system to record infants' visual scanning patterns, enabling applications that are very difficult or impossible to carry out with previously existing technologies (e.g., study of infants' visual and oculomotor systems).

This thesis presents a novel system that estimates the point-of-gaze (where a person is looking at) remotely while allowing for free head movements and minimizing personal calibration requirements. The point-of-gaze is estimated from the pupil and corneal reflections (virtual images of infrared light sources that are formed by reflection on the front corneal surface, which acts as a convex mirror) extracted from eye images captured by video cameras. Based on the laws of geometrical optics, a detailed general mathematical model for point-of-gaze estimation using the pupil and corneal reflections is developed. Using this model, the full range of possible system configurations (from one camera and one light source to multiple cameras and light sources) is analyzed. This analysis shows that two cameras and two light sources is the simplest system configuration that can be used to reconstruct the optic axis of the eye in 3-D space, and therefore measure eye movements, without the need for personal calibration. To estimate the point-of-gaze, a simple single-point personal calibration procedure is needed. The performance of the point-of-gaze estimation depends on the geometrical arrangement of the cameras and light sources and the method used to reconstruct the optic axis of the eye. Using a comprehensive simulation framework developed from the mathematical model, the performance of several gaze estimation methods of varied complexity is investigated for different geometrical system setups in the presence of noise in the extracted eye features, deviation of the corneal shape from the ideal spherical shape and errors in system parameters. The results of this investigation indicate the method(s) and geometrical setup(s) that are optimal for different sets of conditions, thereby providing guidelines for system implementation. Experimental results with adults, obtained with a system that follows those guidelines, exhibit RMS point-of-gaze estimation errors of 0.4-0.6º of visual angle (comparable to the best commercially available systems, which require multiple-point personal calibration procedures). Preliminary results with infants demonstrate the ability of the proposed system to record infants' visual scanning patterns, enabling applications that are very difficult or impossible to carry out with previously existing technologies (e.g., study of infants' visual and oculomotor systems).