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Darbe analizuojama Blackfin procesorių sparta vaizdo apdorojime akių žvilgsnio sekimui. / New Blackfin media processors perfomance was analyzed for video preprocessing in eye gaze tracking.

The human visual system has learned to assume that light originates from above, most likely because of the persistent natural overhead light source – the sun (Ramachandran, 1988). Asymmetries of perception in neurologically normal individuals, like assuming light is coming from above, in part result from efficiency measures of the visual system. Not only is light assumed to come from above, but light from above and to the left has been found to decrease reaction times in target finding as well as increase aesthetic preference (Sun & Perona, 1998; Smith & Elias, 2013). The underlying cause of the bias towards upper-left lighting is debated, and may have a relationship with another peculiar phenomenon in neurologically normal individuals where greater attention is paid to leftward space, called pseudoneglect (Bowers & Heilman, 1980). Alternatively, an explanation suggesting that directional reading influences lighting preferences has been proposed, as Smith and Elias (2013) found native right-to-left readers to be significantly different from leftward biased left-to-right readers. The current set of experiments used eye-tracking and a target finding paradigm to assess differences between left-to-right and right-to-left readers. Manipulating the position of the light illuminating a field of spheres generated targets, creating either 1 convex bubble among 15 concave depressions, or vice-versa. Results from these studies are mixed, and highlight differences between both upper and lower and lateral visual space. Light originating from above facilitated shorter average duration times for both groups, whereas left-to-right readers tended to prefer light from the upper-left, while right-to-left readers preferred light from the upper-right. No one target location in the array facilitated shorter average duration times for right-to-left readers, although left-to-right readers tended to exhibit shorter durations when identifying targets in the upper-left quadrant. Participants spent the greatest amount of time examining the upper quadrants of the array, tending to focus more on the side of the image that their native reading direction begins on. The influence of directional reading on light source perception, and the potential problems of using exclusively Western participant samples are discussed.

Building on Message Framing Theory and the Elaboration Likelihood Model (ELM), this study examined how message frame impacts viewer attention to and cognitive processing of osteoporosis prevention print ads. Attention was measured with eye tracking technology, which calculated participants’ number of fixations and dwell time. Cognitive processing was assessed through a textual masked-recall exercise. Sixty women, with a mean age of 21.25+/-2.61 years, viewed the same 36 ads; however, the message frame changed on a randomized, rotating basis, resulting in each group viewing 12 gain-, 12 loss-, and 12 neutrally-framed ads. One-way repeated measures analyses of variance revealed that message frame significantly impacted viewers’ number of fixations, F(2,118)=8.18, p<.01, η2= .12 dwell time, F(2,118)=9.84, p<.01, η2= .14 and masked-recall results, F(2,118)=22.28, p<.01, η2 = .27. Viewers’ number of fixations, dwell time and recall of gain-framed osteoporosis prevention ads was significantly higher than to loss- or neutrally-framed ads, p<.01. Message frame was also positively correlated with number of fixations, r=.29, p<.02 and dwell time, r=.42, p<.01. Findings may help expand theory related to message framing and the ELM, while contributing to advancements in eye tracking literature and health communications practice. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2009-08-27 16:13:32.848

Previous studies on the acquisition of verb inflection in normally developing children have revealed an astonishing pattern: children use correctly inflected verbs in their own speech but fail to make use of verb inflections when comprehending sentences uttered by others. Thus, a three-year old might well be able to say something like ‘The cat sleeps on the bed’, but fails to understand that the same sentence, when uttered by another person, refers to only one sleeping cat but not more than one. The previous studies that have examined children's comprehension of verb inflections have employed a variant of a picture selection task in which the child was asked to explicitly indicate (via pointing) what semantic meaning she had inferred from the test sentence. Recent research on other linguistic structures, such as pronouns or focus particles, has indicated that earlier comprehension abilities can be found when methods are used that do not require an explicit reaction, like preferential looking tasks. This dissertation aimed to examine whether children are truly not able to understand the connection the the verb form and the meaning of the sentence subject until the age of five years or whether earlier comprehension can be found when a different measure, preferential looking, is used. Additionally, children's processing of subject-verb agreement violations was examined. The three experiments of this thesis that examined children's comprehension of verb inflections revealed the following: German-speaking three- to four-year old children looked more to a picture showing one actor when hearing a sentence with a singular inflected verb but only when their eye gaze was tracked and they did not have to perform a picture selection task. When they were asked to point to the matching picture, they performed at chance-level. This pattern indicates asymmetries in children's language performance even within the receptive modality. The fourth experiment examined sensitivity to subject-verb agreement violations and did not reveal evidence for sensitivity toward agreement violations in three- and four-year old children, but only found that children's looking patterns were influenced by the grammatical violations at the age of five. The results from these experiments are discussed in relation to the existence of a production-comprehension asymmetry in the use of verb inflections and children's underlying grammatical knowledge. / Experimentelle Studien zum Erwerb der Verbflexion bei sprachunauffälligen Kindern haben ein überraschendes Muster aufgezeigt. Kinder im Alter von drei und vier Jahren verwenden Verbflexionsendungen anscheinend korrekt in ihrer eigenen Sprachproduktion, aber sie scheinen unfähig zu sein, Verbflexionen in den Äußerungen anderer zu verstehen. Ein Kind ist also problemlos in der Lage “Sie schläft auf dem Bett.” zu sagen, wenn es die Position von z. B. einer Katze beschreiben möchte. Gleichzeitig scheint es nicht zu verstehen, dass sich ein Satz wie “Sie schläft auf dem Bett” auf nur eine schlafende Katze und nicht mehrere bezieht. Das Verständnis von Sätzen, in denen der einzige Hinweis auf die Anzahl der Handelnden (den Numerus des Subjekts) die Verbflexion ist, wurde bislang nur mit ‘Zeige-Experimenten’ untersucht. In solchen Sprachtests soll das Kind durch eine Zeigegeste auf eines von zwei vorgegebenen Bildern explizit anzeigen wie es den vorgegebenen Satz verstanden hat. Aktuelle Studien, die das Verständnis von sprachlichen Elementen wie Pronomen und Fokuspartikeln bei Kindern untersucht haben, lassen erkennen, dass die Testmethodik einen erheblichen Einfluss auf die kindlichen Sprachverständnisfähigkeiten zu haben scheint. Wenn man Methoden verwendet, die keine explizite Reaktion von Seiten der Kinder verlangen, findet man korrektes Verständnis schon bei jüngeren Kindern. Das Ziel dieser Dissertation war es zu untersuchen, ob drei- und vierjährige Kinder tatsächlich nicht in der Lage sind die Beziehung zwischen Verbform (Art der Verbflexion) und Subjektbedeutung (Numerus des Subjekts) zu verstehen oder ob man korrektes Sprachverständnis in jüngeren Populationen finden kann, wenn eine alternative Testmethode, die Messung der Augenbewegungen, verwendet wird. Zusätzlich wurde untersucht ob Kinder im gleichen Alter Verletzungen der Subjekt-Verb-Kongruenz in auditiv präsentierten Sätzen entdecken. Drei Experimente dieser Dissertation, die das kindliche Sprachverständnis in Bezug auf Verbflexion untersucht haben bringen folgendes Muster zum Vorschein: Deutsch-sprachige Kinder im Alter von drei bis vier Jahren schauten mehr zu einem Bild, auf dem nur ein Akteur zu sehen war, wenn sie einen Satz mit einem singular flektierten Verb hörten (Sie streichelt eine Katze). Andererseits schauten sie mehr zu einem Bild, auf dem zwei Akteure zu sehen waren, wenn sie einen Satz mit einem plural flektierten Verb hörten (Sie streicheln eine Katze). Wenn sie hingegen gebeten wurden, auf das korrekte Bild zu zeigen, reagierten sie nicht besser als es der Zufall erwartet hätte, d.h.~sie waren nicht in der Lage einen Satz einem entsprechenden Bild zuzuordnen. Dieses Ergebnismuster deutet auf die Existenz von (methoden-abhängigen) Asymmetrien innerhalb einer sprachlichen Modalität, dem Sprach-verständnis, hin. Das vierte Experiment untersuchte die kindliche Sensitivität gegenüber der Verletzung von Subjekt-Verb-Kongruenz. Hier zeigte sich, dass das Blickverhalten von fünfjährigen Kindern von der Grammatikalität der Testsätze beeinflusst war, während keine Evidenz für das Erkennen von Grammatikalitätsverletzungen bei jüngeren Kindern gefunden werden konnte. Das asymmetrische Performanzmuster innerhalb der rezeptiven Modalität, das in dieser Arbeit gefunden wurde, erlaubt Rückschlüsse auf die Annahme einer Produktions-Verständnis-Aymmetrie und somit auch auf Theorien zur grammatischen Entwicklung bei Kindern.

eSeeTrack, an eye-tracking visualization, facilitates exploration and comparison of sequential gaze orderings in a static or a dynamic scene. It extends current eyetracking data visualizations by extracting patterns of sequential gaze orderings, displaying these patterns in a way that does not depend on the number of fixations on a scene, and enabling users to compare patterns from two or more sets of eye-gaze data. Extracting such patterns was difficult, if not impossible, with previous visualization techniques. eSeeTrack combines a timeline and a tree-structured visual representation to embody three aspects of eye-tracking data that users are interested in: duration, frequency and orderings of fixations. eSeeTrack allows ordering of fixations to be rapidly queried, explored and compared. Two case studies on surgical simulation and retail store chain to assert the capabilities of eSeeTrack are discussed in this thesis. Furthermore, eSeeTrack provides an effective and efficient mechanism to determine the pattern outliers. This approach can be effective for behavior analysis in a variety of domains that are also described.

Considerable research has examined strategies involved in spatial navigation, and what factors determine which strategy an individual will use. The little research that has examined strategy adoption has produced conflicting results. The present study investigated the relative rate of adoption of allocentric and egocentric strategies in an environment that allowed individuals to adopt one or the other, or switch between them. Results indicated that by the end of testing nearly all participants had adopted one strategy or the other. Also, more participants were using an allocentric strategy than an egocentric strategy. However, strategy selection was not related to gender, or the relative efficiency of the two strategies. Analysis of gaze position at the start of trials showed that those who adopted an allocentric strategy tended to focus their attention on the distal (landscape) features of the environment whereas those who adopted an egocentric strategy tended to focus their attention on the proximal object features. However, vertical gaze position could not be used to reveal the rate of adoption of an egocentric strategy, because this did not vary over trials. Analysis of gaze position using “regions of interest” overcame this problem and showed that both strategies are adopted at a similar rate early in trials. Comparison of strategy by gaze position and strategy by navigation probe indicated that these two metrics were measuring two different stages of navigation. Finally, analysis of the navigational efficiency of different strategies indicated that the best navigators were those who used both strategies. These findings indicate allocentric and egocentric strategies are adopted at a similar rate and that within the space of a few seconds, individuals may use different strategies for orientation and navigation. / Graduate

This study aims to explore how novices learn computer games. In order to observe the characteristics of learning a novel computer game, an eye tracking method was integrated with usability studies&amp / #8217 / methods. Data was collected from 16 undergraduate university students. Every student played the game for 10 minutes. Their eye movements were recorded with an eye tracker. Subjects&amp / #8217 / behaviors were also videotaped while playing the game. Results showed that eye tracking can be used as measure to study learning experience of games. Theoretical implications and applicability of the findings to the use of computer games for educational purposes were discussed.

La présente thèse s’intéresse à l’efficacité de la description verbale d’un suspectpour le détecter parmi d’autres personnes dans le cadre de délits de fuite oude flagrants délits. Cette approche permet de connaître l’identité du suspect recherchélorsque les enquêteurs ne détiennent aucun autre indice à leur disposition.La description constitue la technique la plus couramment utilisée sur le terrainpar les professionnels, il semble donc nécessaire de comprendre son usage et sonimpact sur le terrain lors de la détection des suspects. Pour cela, une série desept expériences visant à tester quelle description apparaît la plus optimale pourdétecter le suspect a été conçue. Les études ont montré que plus la descriptioncontient d’indices sur le suspect, plus elle aide les enquêteurs à affiner la liste desuspects (expérience 1 ). Néanmoins, contrairement aux théories sur la recherchevisuelle indicée, il semblerait que l’ajout de nouvelles informations concernant leportrait du suspect n’améliore pas la détection de la cible recherchée ; certainsdescripteurs physiques n’étant pas utiles pour détecter la cible (expérience 2 )etce quel que soit leur ordre d’apparition dans la description physique (expérience3 ). En outre, l’ajout d’indices invalides sur le portrait physique du suspect a unimpact variable sur la détection selon le type de descripteurs (généraux, faciauxessentiels ou faciaux secondaires)(expérience 4 ). Par ailleurs, l’ajout d’indices nonphysiquesn’aide pas forcément les enquêteurs à détecter plus facilement leur cible(expériences 5 et 6 ). Enfin, nous avons montré que des facteurs contextuels et lescaractéristiques personnelles pouvaient modifier la prise de décision des enquêteurs(expérience 7 et 7 bis). Les analyses montrent que si les descriptions physiques lesplus complètes aident les enquêteurs à affiner la liste de suspects potentiels, elle n’améliore pas forcément la détection du criminel. Le système cognitif étant limité,toutes les informations de la description ne sont pas utilisées, l’individu va chercherà sélectionner l’information en se focalisant sur certains descripteurs physiquesjugés plus efficaces pour retrouver le suspect. / This thesis focuses on the efficiency of suspects’ verbal description to detect himin hit and run or obvious offense contexts. This approach allows agents to know thesuspect’s identity when the officer does not detains any other available evidences.Description is the most commonly applied technique used by professionals in thefield, so it seems necessary to understand its use and impact on suspects’ detection.To achieve this goal, we designed a set of seven studies in order to test the mostefficient description to detect suspects. Our studies revealed that the more physicalclues of the criminal is given in the description, the more it helps officers to narrowsuspects (experiment 1 ). However, unlike theories of visual search, it seems thatadding information about suspect’s portrait does not improve detection ; somephysical descriptors are not useful to detect the target (experiment 2 ) regardlessof their rank order in the description’s list (experiment 3 ). Furthermore, adding"invalid clues" modulates detection depending on their properties (general, facialprimary, facial secondary experiment 4 ). In addition, inserting non-physical cluesin the description list do not necessarily help investigators to ease target detection(experiments 5 and 6 ). Finally, we showed that contextual factors and personalcharacteristics could change the officer’s decision (experiments 7 and 7bis). Ouranalyzes emphasised that the richer or the longer the list might not always be thebetter to reduce the number of suspects. In other words, while the most completeand detailled physicial descriptions help officers to narrow potential suspect’s list,it does not necessarily improve the criminal detection. As our cognitive systemis limited,the indivual must select information by focusing on specific physicaldescriptors thought to be more efficient to find the suspect.

The independent style of scanning and payment at self-service checkouts (SCOs) has resulted in areas for concern. The reduction of employee involvement may reduce the social presence perceived at a SCO. Social presence is when a user experiences the perception that there is another intelligence or entity within their environment (Short, William & Christie, 1976). If customers are not influenced by the social presence of the employees at a SCO then it may affect their behaviour. Using a mixed methods approach, with a combination of qualitative and quantitative data gathering, this thesis investigated dishonest behaviours at self-service checkouts and the effects of a social presence on consumer behaviour. The overreaching research question then guiding this dissertation is: What effect does a social presence have on thefts at self-service checkouts and can social presence be effectively implemented via technology? Three exploratory qualitative (Studies 1-3) and two empirical studies (Studies 4-5) were conducted to investigate issues surrounding thefts at SCO with reference to social presence. Study 1 consisted of in-depth observations of customers within supermarkets to gain an understanding of everyday behaviours associated with self-service checkouts. Both customers and staff seemed to be frustrated at the amount of times the technology did not work properly and the customer would appear disadvantaged when they required assistance. With an understanding of the salient factors and behaviours associated with self-service checkouts, Study 2 then explored SCO staff perceptions of thefts at self-service checkouts (Creighton et al., 2015). Qualitative semi-structured interviews were used to investigate the perceived influence of social presence at self-service checkouts by staff and its perceived effect on dishonest customer behaviour. Twenty-six self-service checkout staff took part in a series of semi-structured interviews to describe customer behaviours with self-service. With respect to actual physical social presence, such as the recognised presence of an employee, staff reported that more customer thefts occurred when the self-service checkouts were busy and their social presence was reduced. To further explore social presence within a retail environment and validate the perceptions from SCO Staff, Study 3 investigated the role of the security guard in terms of their social presence and explored their perceptions of thefts at self-service checkouts. Interviews with 6 security guards were conducted to determine factors surrounding theft as their role is to monitor this type of dishonest behavior. There was an overall agreement from security guards that there were more thefts at self-service checkouts when the store was busy and that there were more thefts at self-service checkouts overall, compared to traditional manned checkouts. The first empirical study (Study 4), consisting of 2 Experiments, considered the effects of a social presence within a self-service checkout interface on user behaviour. This study examined whether a social presence in the form of a computer designed onscreen agent at a simulated SCO, with design features varying in ‘humanness’, i.e. agents that displayed more or less-human-like features (eyes in Experiment 1, and human shapes in Experiment 2), would have an effect on opportunistic behaviour (cheating) in a simulated checkout scenario. Ninety-one participants interacted with a simulated SCO while their eye movements were tracked via a Tobii TX300 eye-tracker. Hypotheses that predicted a social presence would receive attention and result in fewer instances of theft when integrated within an interface were supported, suggesting that implementing an agent designed to suggest some level of humanness e.g. with eyes, within a SCO interface may reduce levels of theft as customers are likely to notice it. However, Study 4 showed mixed results for the effects of varying agent appearance alone. Research has shown that social presence can also be induced by varying agent behaviour (Burgoon et al., 2000). Study 5 thus varied interactivity (i.e. personal vs impersonal nature) of the agent via voice implementation on the SCO, using the same agent as in Study 4 (Experiment 2). The research highlights the need for the current designs of SCO to be updated to reduce operational issues which could be contributing to thefts occurring at SCOs. It is also concluded that further research is needed on the effects of interactivity and agent presence during a SCO interaction to explore dimensions of social presence and how they are being experienced by the user, which may ultimately lead to a reduction in thefts at SCOs.