Web pages are typically comprised of different kinds of visual elements such as menus, headers and footers. To improve user experience, eye tracking has been widely used to investigate how users interact with such elements. In particular, eye movement sequences, called scanpaths, have been analysed to understand the path that people follow in terms of these elements. However, individual scanpaths are typically complicated and they are related to specific users, and therefore any processing done with those scanpaths will be specific to individuals and will not be representative of multiple users. Therefore, those scanpaths should be clustered to provide a general direction followed by users. This direction will allow researchers to better understand user interactions with web pages, and then improve the design of the pages accordingly. Existing research tends to provide a very short scanpath which is not representative for understanding user behaviours. This thesis introduces a new algorithm for clustering scanpaths, called Scanpath Trend Analysis (STA). In contrast to existing research, in STA, if a particular element is not shared by all users but it gets at least the same attention as the fully shared elements, it is included in the resulting scanpath. Thus, this algorithm provides a richer understanding of how users interact with web pages. The STA algorithm was evaluated with a series of eye tracking studies where the web pages used were automatically segmented into their visual elements by using different approaches. The results show that the outputs of the STA algorithm are significantly more similar to the inputted scanpaths in comparison with the outputs of other existing work, and this is not limited to a particular segmentation approach. The effects of the number of users were also investigated on the STA algorithm as the number of users required for scanpath analysis has not been studied in depth in the literature. The results show the possibility to reach the same results with a smaller group of users. The research presented in this thesis should be of value to eye tracking researchers, to whom the STA algorithm has been made available to analyse scanpaths, and to behaviour analysis researchers, who can use the algorithm to understand user behaviours on web pages, and then design, develop and present the pages accordingly.

Driving is a complex visuomotor task, and the study of eye movements can provide interesting and detailed insights into driving behaviour. The aim of this thesis was to understand (a) what methods are useful to assess driving behaviour, (b) the reasons we observe differences in eye movements when driving, and (c) offer a possible visual training method. The first experiment compared drivers' eye movements and hazard perception performance in an active simulated driving task and a passive video driving task. A number of differences were found, including an extended horizontal and vertical visual search and faster response to the hazards in the video task. It was concluded that when measuring driving behaviour in an active task, vision, attention and action interact in a complex manner that is reflected in a specific pattern of eye movements that is different to when driving behaviour is measured using typical video paradigms. The second experiment investigated how cognitive functioning may influence eye movement behaviour when driving. It was found that those with better cognitive functioning exhibited more efficient eye movement behaviour than those with poorer cognitive functioning. The third experiment compared the eye movement and driving behaviour of an older adult population and a younger adult population. There were no differences in the eye movement behaviour. However, the older adults drove significantly slower, suggesting attentional compensation. The final experiment investigated the efficacy of using eye movement videos as a visual training tool for novice drivers. It was found that novice drivers improved their visual search strategy when driving after viewing videos of an expert driver's eye movements. The results of this thesis helps to provide insights into how the visual system is used for a complex behaviour such as driving. It also furthers the understanding of what may contribute to, and what may prevent, road accidents.

The aim of the present thesis was to investigate the relationship between individuals' allocation of overt visual attention during action observation and their consequent pickup of information. Four interrelated studies were conducted to achieve this. In Study 1 we examined the effects of visual guidance - colour highlighting of relevant aspects of the action - on observational learning of the golf swing. The results showed that the visual guides facilitated novices' intake of information pertaining to the model's posture, which was reflected in faster learning. In the remaining studies, transcranial magnetic stimulation and eye tracking data were acquired concurrently to measure the interaction between gaze behaviour and motor resonance - a neurophysiological index of the motor system's engagement with a viewed action, and thus a correlate of information extraction. In Study 2, we directed observers' gaze to distinct locations of the display while they viewed thumb adduction/abduction movements. The results showed that, by directing gaze to a location that maximised the amount of thumb motion across the fovea, motor resonance was maximised relative to a free viewing condition. In Study 3 we examined the link between gaze and motor resonance during the observation of transitive actions. Participants viewed reach-to-grasp actions with natural gaze, or while looking at a target- or an effector- based visual guide. The results showed that the effector-based guide disrupted natural gaze behaviour, and this was associated with a reversal of the motor resonance response. In Study 4 we showed novice and skilled golfers videos of the golf swing and of a reach-grasp-lift action. The results revealed that, for both actions, the extent of motor resonance was related to the location of participants' fixations. The present work provides the first evidence of a relationship between gaze and motor resonance and highlights the importance of appropriate gaze behaviour for observational learning.

L’utopie est la suivante : elle débute par l’injonction amoureuse de Pablo Neruda, ‘‘je veux faire avec toi ce que le printemps fait avec les cerisiers’’, à la suite de laquelle, j’entame une petite collection dépareillée qui met en scène et met ensemble : pièces détachées, éléments brillants, particules rougissantes ou ternies et corps inconnus, qu’il me faudra déployer et marier dans les moindres détails, de novembre 2010 à novembre 2015 pour constituer ce que j’appelle : ‘‘la plastique du corps amoureux’’. J’observerai les effets des images, des corps, de l’œil de l’artiste et celui du regardeur, sous la contrainte du rougissement. Il ne sera pas nécessaire de chercher l’unité mais de bien faire le dessein d’hypothèses amoureuses éparses. Car si la plastique a le pouvoir de faire émerger une forme, celle d’un corps amoureux, ne serait-elle pas une tentative de s’exiler de la forme et de sa propre chair ? Faut-il parler d’informité quand on en vient au couple tant la limite est fragile lorsqu’on s’attaque aux contours ? Que fait-on une fois qu’il n’y a plus d’amour ? Que fait-on, une fois que l’on ne s’y voit plus ? L’engagement s’inscrivant sur une courte durée, il sera de bon augure de le situer dans une temporalité de l’instantané et de ce fait, il sera préférable de ne pas négliger ce que l’on nomme communément ‘‘cliché’’ comme une expérience vécue et recevable par tous, pour amorcer une pensée fleurissante qui croit et décroit suivant la saison. / Here is the utopia: it will all start with the loving injunction of Pablo Neruda “I want to do with you what spring does with the cherry trees.” Then comes a little mismatched collection which will put on a performance and put together: spares parts, blushy or faded particles and shiny elements, which, from November 2010 until November 2015, I will open out and combine down to the smallest detail to constitute what I will call “The plasticity of the loving body”. I will observe images, bodies, the artist’s vision and the spectator vision when they are placed under the effects of blushing. I do not aim at achieving any form of unity but instead, at intending to make numerous assumptions of “loving designs”. Assuming that plasticity has the power of arising shapes, would not the plasticity of loving body be the attempt to get extracted from its own shape and its own flesh. .Should we define the couple as something shapeless: its limits are becoming more and more fragile as deconstruct its outlines. What should we do when love is nowhere to be found ? What should we do once all hopes are gone ? The implication, in the field of love, is timewise very short. It is characterized by its instantaneous dimension. Therefore, I will explore what is generally defined as a “cliché” as actually anybody could very easily experience it. I should be then carried away by a blooming thinking that would blossom and wither with the seasons.

Este trabalho apresenta uma metodologia de cálculo para a obtenção de doses em estruturas do olho humano, como: esclera, coróide, retina, nervo óptico, corpo vítreo, câmara anterior, lente, além do tumor devido ao tratamento com placas oftálmicas. Construiu-se um modelo de olho humano com suas principais estruturas e dimensões fieis, além de um modelo matemático para uma placa de Co-60 e uma placa de sementes de I-125, levando-se em conta tamanho e disposição geométrica das fontes reais, com o código de Monte Carlo MCNP-4C. Esse modelo é capaz de calcular as distribuições de dose axiais e radiais para qualquer ponto do olho e para cada uma de suas estruturas. Construiu-se, também, um simulador de acrílico para o olho. Esse simulador é formado por uma esfera de acrílico fatiada em lâminas de 1 mm de espessura para simular as mesmas condições de simulação realizada pelos código MCNP-4C, fornecendo as doses axiais e radiais em filmes radiográficos. O simulador foi utilizado para validar os cálculos realizados com o código MCNP-4C. Os dados obtidos desse modelo matemático servirão para montar um banco de dados de doses para todas as estruturas do olho, posições e tamanhos de tumores e quaisquer placas oftálmicas utilizadas para tratamento. Esse banco de dados será a parte principal para a construção de um “software” nacional para cálculos de dose, que poderá fazer parte de um sistema de planejamento confiável para ser utilizado em radioterapia/braquiterapia. / This work presents a calculational methodology for dose determination in human eye structures, such as: sclera, choroid, retina, lens, vitreous body, optic nerve and disc, and cornea, as well as tumor due to treatment to the eye plaques. A human eye model was constructed taking into consideration its main structural and dimension characteristics. Beyond that a mathematical model for the Co-60 and I-125 plaques with all geometric details were built employing the MCNP-4C code. This model is able to calculate the axial and radial doses in any point of the eye and for each of its structures. An acrylic eye simulator was also built with the aim to obtain experimental results for the both model validations. This simulator is made of an acrylic sphere split into foils of 1 mm thickness which allow the introduction a radiographic film to measure the axial and radial doses. The experimental data were used to validate the MCNP-4C results. The data from the mathematical model will serve as the basis to build a data bank for all the eye structures allowing different position and sizes of tumor as well as the replacement of all ophthalmic plaques used in the treatment. This data bank will be the principal part for the construction of a national software for the dose calculation and can be of great help for a reliable treatment system planning in radiotherapy/brachytherapy.

During collaboration, people communicate using verbal and non-verbal cues, including gaze cues. Spoken language is usually the primary medium of communication in these interactions, yet despite this co-occurrence of speech and gaze cueing, most experiments have used paradigms without language. Furthermore, previous research has shown that myriad social factors influence behaviour during interactions, yet most studies investigating responses to gaze have been conducted in a lab, far removed from any natural interaction. It was the aim of this thesis to investigate the relationship between language and gaze cue utilisation in natural collaborations. For this reason, the initial study was largely observational, allowing for spontaneous natural language and gaze. Participants were found to rarely look at their partners, but to do so strategically, with listeners looking more at speakers when the latter were of higher social status. Eye movement behaviour also varied with the type of language used in instructions, so in a second study, a more controlled (but still real-world) paradigm was used to investigate the effect of language type on gaze utilisation. Participants used gaze cues flexibly, by seeking and following gaze more when the cues were accompanied by distinct featural verbal information compared to overlapping spatial verbal information. The remaining three studies built on these findings to investigate the relationship between language and gaze using a much more controlled paradigm. Gaze and language cues were reduced to equivalent artificial stimuli and the reliability of each cue was manipulated. Even in this artificial paradigm, language was preferred when cues were equally reliable, supporting the idea that gaze cues are supportive to language. Typical gaze cueing effects were still found, however the size of these effects was modulated by gaze cue reliability. Combined, the studies in this thesis show that although gaze cues may automatically and quickly affect attention, their use in natural communication is mediated by the form and content of concurrent spoken language.

Yim, Nga Kin Edward. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 46-53). / Abstracts in English and Chinese. / Table Captions --- p.v / Figure Captions --- p.vi / Abstract --- p.vii / Chapter Chapter 1: --- Introduction --- p.1 / "The ""Awareness"" Approach to Tapping Influence of Morphemes" --- p.2 / "Inadequacies of the ""Awareness"" Approach" --- p.6 / "The ""Processing"" Approach to Tapping Influence of Morphemes" --- p.7 / Measuring Eye Movements in Linguistic Research --- p.10 / The Present Study --- p.13 / Chapter Chapter 2: --- Method --- p.15 / Participants --- p.15 / Stimuli and Apparatus --- p.16 / Design and Procedure --- p.19 / Data Analyses --- p.20 / Chapter Chapter 3: --- Results --- p.22 / Literacy Tasks --- p.22 / Experimental Session 1 (Picture) --- p.23 / Experimental Session 2 (Printed Words) --- p.28 / Comparison between Picture and Printed Word session --- p.32 / Chapter Chapter 4: --- Discussion --- p.34 / Reliability and Validity of the Measure --- p.34 / Grade Differences in Morphemic Processing --- p.35 / Mechanisms of Morphemic Ambiguity Resolution and Speech Processing in Children --- p.38 / Stimulus Differences --- p.41 / Chapter Chapter 5: --- Conclusion --- p.43 / Theoretical and Methodological Contributions --- p.43 / Limitations and Future Directions --- p.44 / References --- p.46 / Appendix --- p.54

The growth of a child’s early vocabulary is one of the most salient indicators of progress in language development, but measuring a young child’s comprehension of words is non-trivial. Parental checklists are prone to underestimation of a child’s vocabulary (Houston-Price et al., 2007; Brady et al. 2014), so it may be that more direct measures, such as measuring a child’s eye movements during comprehension, may provide a better assessment of children’s vocabulary. Prior research has found relationships between gaze patterns and vocabulary development (Fernald et al. 2006), and the present exploratory study investigates these relationships with verbs, along with a number of methodological considerations. In addition, recent research supports the idea that verbs may differ in difficulty of acquisition based on word class, with manner verbs being easier to learn than result verbs (Horvath et al. 2015). The present study has two aims: 1) investigate the effect of dynamic stimuli on correlations with vocabulary scores and 2) experimentally investigate the notion that manner verbs are easier to learn than result verbs. Forty children (Mean age = 22.97 months) were recruited for participation and shown a vocabulary test. While no significant correlations were found between vocabulary measures and accuracy and latency, several experimental measures proved to be related to vocabulary development, including fixation density and length of first fixation to the non-target. Additionally, results indicate that children knew the same number of manner and result verbs. Finally, these results could inform vocabulary tests using eye-tracking measures that specifically target verb knowledge.

To date, invasive brain-computer interface (BCI) research has largely focused on replacing lost limb functions using signals from hand/arm areas of motor cortex. However, the oculomotor system may be better suited to BCI applications involving rapid serial selection from spatial targets, such as choosing from a set of possible words displayed on a computer screen in an augmentative and alternative communication application. First, we develop an intracortical oculomotor BCI based on the delayed saccade paradigm and demonstrate its feasibility to decode intended saccadic eye movement direction in primates. Using activity from three frontal cortical areas implicated in oculomotor production – dorsolateral prefrontal cortex, supplementary eye field, and frontal eye field – we could decode intended saccade direction in real time with high accuracy, particularly at contralateral locations. In a number of analyses in the decoding context, we investigated the amount of saccade-related information contained in different implant regions and in different neural measures. A novel neural measure using power in the 80-500 Hz band is proposed as the optimal signal for this BCI purpose. In the second part of this thesis, we characterize the interactions between the neural signals recorded from electrodes in these three implant areas. We employ a number of techniques to quantify the spectrotemporal dynamics in this complex network, and we describe the resulting functional connectivity patterns between the three implant regions in the context of eye-movement production. In addition, we compare and contrast the amount of saccade-related information present in the coupling strengths in the network, on both an electrode-to-electrode scale and an area-to-area scale. Different frequency bands stand out during different epochs of the task, and their information contents are distinct between implant regions. For example, the 13-30 Hz band stands out during the delay epoch, and the 8-12 Hz band is relevant during target and response epochs. This work extends the boundary of BCI research into the oculomotor domain, and invites potential applications by showing its feasibility. Furthermore, it elucidates the complex dynamics of the functional coupling underlying oculomotor production across multiple areas of frontal cortex.

Tese de mestrado. Multimédia. Faculdade de Engenharia. Universidade do Porto. 2009