There is evidence to suggest that people from different cultures have different cognitive processing styles. For example, by measuring the eye movements of American and Chinese students when viewing pictures, Chua, Boland, and Nisbett (2005) found that American students fixated more on the focal object, whereas Chinese students fixated more on the background. In a subsequent object-recognition task, the Chinese students were less likely to correctly recognize old objects presented in new backgrounds than Americans did. This study used a similar scene-viewing task to investigate whether aging modulates these cultural differences in cognitive processing style. Like Chua et al., we found that young Chinese students spent longer fixating the background than did their Western counterparts. However, we failed to replicate the accompanying memory bias observed by Chua et al. Our strongest finding was that maintaining the original background facilitated memory for objects in young participants of both cultures but not for older participants. This result suggests that older adults had poorer memory for background details and/or had poorer integration of object and background.

The ability of the human eye to change its overall refractive power so that people can focus on objects both far and near is termed accommodation. Research into how the eye automatically changes its accommodation, demands an instrument capable of tracking the accommodation with fine resolution and adequate corner frequency. An instrument capable of tracking the ocular accommodation is called an optometer. Reports of earlier optometers show that optometers using the older Scheiner principlecan have the required precision and dynamics required to track the micro fluctuations accommodation. However optometers using the Scheiner principle require precise alignment to the patient’s pupil to be maintained throughout the measurement time. Previous optometers have used the radiation reflected from the patient’s cornea (calledthe corneal reflection) to initially align the optical axis of the optometer to the centre of the patient’s pupil. Since the Scheiner principle optometer uses radiant energy reflected from the patient’s retina to make a refractive measurement, the idea of using this same radiant energy for patient alignment is investigated. Earlier optometers have blocked the corneal reflection from reaching the photodetectors for the retinal reflection using a small fixed light stop. Since it is not possible to use a fixed light stop if the retinal reflection is used for alignment, the feasibility of using crossed linear polarizers is experimentally evaluated. The results showed that about78% of the radiant energy reflected from the front lens of an artificial eye could be eliminated using crossed linear polarizers. Whether the Scheiner principle measurement of refraction of an artificial eye could be done with 78% of the front lens (corneal) reflection removed was investigated. The results were not conclusive. There was not a measureable indication of when the refraction of the experimental optometer matched that of the artificial eye. The experimental optometer system attempts to use a servo controlled mirror system to move the optical axis of the optometer so that it coincides with the optical axis of an artificial eye. The design, development and testing of the mirror system is described. The mirror system enables the optometer to perform a two dimensional scan over the pupil plane of the patient’s eye or an artificial eye. During the scanning, the total radiant power reflected can be measured. For the optometer to be aligned using radiation reflected from the retina, a scan of the pupil plane of should reveal the pupil boundaries. This was experimentally demonstrated to work. Unfortunately time limitations did not permit further development of an automatic eye alignment and tracking system.

The ability of the human eye to change its overall refractive power so that people can focus on objects both far and near is termed accommodation. Research into how the eye automatically changes its accommodation, demands an instrument capable of tracking the accommodation with fine resolution and adequate corner frequency. An instrument capable of tracking the ocular accommodation is called an optometer. Reports of earlier optometers show that optometers using the older Scheiner principlecan have the required precision and dynamics required to track the micro fluctuations accommodation. However optometers using the Scheiner principle require precise alignment to the patient’s pupil to be maintained throughout the measurement time. Previous optometers have used the radiation reflected from the patient’s cornea (calledthe corneal reflection) to initially align the optical axis of the optometer to the centre of the patient’s pupil. Since the Scheiner principle optometer uses radiant energy reflected from the patient’s retina to make a refractive measurement, the idea of using this same radiant energy for patient alignment is investigated. Earlier optometers have blocked the corneal reflection from reaching the photodetectors for the retinal reflection using a small fixed light stop. Since it is not possible to use a fixed light stop if the retinal reflection is used for alignment, the feasibility of using crossed linear polarizers is experimentally evaluated. The results showed that about78% of the radiant energy reflected from the front lens of an artificial eye could be eliminated using crossed linear polarizers. Whether the Scheiner principle measurement of refraction of an artificial eye could be done with 78% of the front lens (corneal) reflection removed was investigated. The results were not conclusive. There was not a measureable indication of when the refraction of the experimental optometer matched that of the artificial eye. The experimental optometer system attempts to use a servo controlled mirror system to move the optical axis of the optometer so that it coincides with the optical axis of an artificial eye. The design, development and testing of the mirror system is described. The mirror system enables the optometer to perform a two dimensional scan over the pupil plane of the patient’s eye or an artificial eye. During the scanning, the total radiant power reflected can be measured. For the optometer to be aligned using radiation reflected from the retina, a scan of the pupil plane of should reveal the pupil boundaries. This was experimentally demonstrated to work. Unfortunately time limitations did not permit further development of an automatic eye alignment and tracking system.

Robotics have advanced to include highly anthropomorphic (human-like) entities. A novel eye-tracking paradigm was developed to assess infants’ sensitivity to communicative gestures by human and robotic informants. Infants from two age groups (5-9 months, n = 25; 10-15 months, n = 9) viewed a robotic or human informant pointing to locations where events would occur during experimental trials. Trials consisted of three phases: gesture, prediction, and event. Duration of looking (ms) to two areas of interest, target location and non-target location, was extracted. A series of paired t-tests revealed that only older infants in the human condition looked significantly longer to the target location during the prediction phase (p = .036). Future research is needed to tease apart what components of the robotic hand infants respond to differentially, and whether a robotic hand can be manipulated to increase infants’ sensitivity to social communication gestures executed by said robotic hand. / Includes bibliography. / Thesis (MA)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

archives@tulane.edu / Making eye contact is one of the earliest, most important forms of communication. Newborns are sensitive to adults’ gaze direction (Farroni, Massaccesi, Pividori, & Johnson, 2004), and by 4 months infants learn more about an object that an adult has looked at (Reid & Striano, 2005). Emotional facial expressions influence infants’ scanning of adults’ eyes (Shepard & Spence, 2012), which may affect their sensitivity to eye gaze cues. In two experiments, we examined the effects of silent dynamic emotional messages on 6-month-old infants’ scanning of face features, as well as their sensitivity to and learning from eye gaze cues. In Experiment 1, infants completed a gaze cueing task in which speakers delivered silent approving, comforting, prohibition, and neutral messages and then shifted their eye gaze to a peripheral target. Although infants showed increased attention to the eyes during prohibition and comforting messages, all infants showed enhanced gaze cueing in the context of approving messages. Moreover, female infants showed trend-level gaze cueing following approving messages, whereas male infants showed trend-level gaze cueing following neutral messages. In Experiment 2, a separate group of infants completed a similar gaze cueing task that included a visual paired comparison test phase to examine learning of the gaze-cued and non-cued targets, based on the hypothesis that increased sensitivity to gaze cues would enhance learning of the cued targets. As in Experiment 1, infants showed increased attention to the eyes during comforting messages. However, we did not find any reliable gaze cueing effects. Infants spent more time looking at test targets following approving messages but did not show evidence of enhanced learning of cued targets. Overall, findings from both experiments suggest that 6-month-olds are more responsive to gaze cues in the context of approving messages, underscoring the significance of positive infant-directed interactions to the development of early joint attention. We conclude by discussing clinical implications, limitations (including a relevant error in Experiment 2), and future directions. / 1 / Claire Frances Noonan

Individuals who have Attention Deficit/Hyperactivity Disorder (ADHD) experience adverse effects relating to driving; in addition, they experience deficits in scanning ability (Barkely et.al, 1996; Fischer et al., 2007; Munoz et al., 2003; Naja-Raja et al., 2007). The present study examined the effects of ADHD on eye tracking while driving. Ten participants consisting of both ADHD and individuals who do not have ADHD were included in this study. It was hypothesized that individuals who have ADHD will make more saccadic eye movements and thus shorter fixations than individuals who do not have ADHD. Furthermore, it was hypothesized that despite the fact that individuals who have ADHD will make more saccadic eye movements than individuals without ADHD, those individuals with ADHD will commit more traffic violations including collisions compared to individuals who do not have such a diagnosis. Findings indicated that hypothesis one was not supported by the data, whereas hypothesis two was supported in that ADHD individuals had more collisions and committed more traffic violations than the Control group. Additionally, upon conducting a Chi Square test for independence, a significant difference was found in the spatial distributions of the fixations between the ADHD and Control groups. The findings of this study could help better understand the factors involved in ADHD driving and could be used to train individuals with ADHD to become more aware of their surroundings and driving habits and thus become safer drivers.

Las dificultades del aprendizaje se cuentan entre las principales razones de la deserción escolar, siendo éste un problema a nivel global. El diagnóstico temprano de estas dificultades es primordial para abordar un tratamiento de manera temprana y un acompañamiento adecuado. Hoy en día el diagnóstico de estas dificultades se lleva a cabo por psicopedagogos y/o psicólogos evaluando la resolución de una batería de tests. La relación 1 a 1 entre una persona a diagnosticar y el profesional dificulta la tarea de estudios masivos para detectar tempranamente a niños en edad escolar que sufran alguna dificultad específica del aprendizaje. Un síntoma estudiado para detectar procesos cognitivos anómalos son comportamientos atípicos en los movimientos oculares. Con la tecnología de acceso masivo se pueden registrar los movimientos oculares, de manera sencilla y económica, con dispositivos de seguimiento ocular llamados por su nombre en inglés eye trackers. En esta tesis se desarrollaron herramientas para el estudio de las señales de los dispositivos mencionados. Una de estas herramientas es clave para estudiar los movimientos oculares y es la clasificación de estos en dos grandes grupos llama- dos fijaciones y sacadas. Las características estadísticas que poseen estos movimientos están íntimamente relacionados con procesos cognitivos. Otra herramienta desarrolla- da es el cálculo de diferentes cantidades de carácter estadístico que permiten describir en pocos números múltiples propiedades de señales obtenidas con los eye trackers. Una dificultad específica del aprendizaje que padece alrededor del 10 % de la población es la dislexia. Ésta es un trastorno con el que, aún hoy, hay controversia al momento de definirlo, pero que es una dificultad que afecta el desarrollo el desarrollo de la alfabetización y las habilidades relacionadas con el lenguaje. En esta tesis se estudiaron los movimientos oculares de niños que fueron diagnosticados con dislexia y de niños de un grupo control que han tenido un desarrollo típico. Describimos la dinámica de la trayectoria de la mirada de los niños al leer con un modelo estocástico basado en lo que se conoce como Continuous Time Random Walk (CTRW). Con dicho modelo fuimos capaces de generar señales sintéticas con iguales características que las señales reales. La generación de señales sintéticas es una técnica clave en el aprendizaje automático, o aprendizaje de máquina (machine learning) y es importante porque ayuda a mejorar el rendimiento de los modelos, combatir el sobre-ajuste y manejar la escasez de datos. Con datos reales hemos probado una serie de clasificadores de disléxicos y no disléxicos utilizando herramientas de machine learning. Dos de estos métodos tuvieron una alta precisión. Tener herramientas para analizar movimientos oculares podría ayudar en el diagnóstico rápido de dificultades del aprendizaje. A su vez podría ayudar a evaluar de forma masiva a niños en sus colegios y así bajar de forma drástica la deserción escolar. / Learning difficulties are among the main reasons for school dropout, this being a global problem. The early diagnosis of these difficulties is essential to address early treatment and adequate follow-up. Today the diagnosis of these difficulties is carried out by educational psychologists and/or psychologists evaluating the resolution of a battery of tests. The 1 to 1 relationship between a person to be diagnosed and the professional makes the task of massive studies difficult to detect early school-age children who suffer from a specific learning difficulty. A symptom studied to detect abnormal cognitive processes are atypical behaviors in eye movements. With mass access technology, eye movements can be recorded easily and cheaply with eye tracking devices. In this thesis, tools were developed to study the signals of the mentioned devices. One of these tools is key to studying eye movements and it is the classification of these into two large groups called fixations and saccades. The statistical characteristics that these movements have are closely related to cognitive processes. Another tool developed is the calculation of different quantities of a statistical nature that allow multiple properties of signals obtained with eye trackers to be described in a few numbers. A specific learning difficulty that about 10 % of the population suffers from is dyslexia. This is a disorder with which, even today, there is controversy when defining it, but it is a difficulty that affects the development of literacy and language-related skills. In this thesis, the eye movements of children who were diagnosed with dyslexia and of children from a control group who have had a typical development were studied. We describe the dynamics of children’s gaze trajectory when reading with a stochastic model based on what is known as Continuous Time Random Walk (CTRW). With this model we were able to generate synthetic signals with the same characteristics as the real signals. The generation of synthetic signals is a key technique in machine learning, or machine learning, and is important because it helps improve model performance, combat overfitting, and handle data sparseness. With real data we have tested a series of dyslexic and non-dyslexic classifiers using machine learning tools. Two of these methods had high precision. Having tools to analyze eye movements could help in the rapid diagnosis of learning difficulties. In turn, it could help to massively evaluate children in their schools and thus drastically reduce school dropouts, with all the benefits that this entails for society.

Die Kombination von Eyetracking und fMRI in den Neurowissenschaften ist eine relativ neue Methode, die einerseits eine technische Herauforderung darstellt, andererseits neue Möglichkeiten des Zugangs zu neuronalen Prozessen darbietet. In der vorliegenden Arbeit wurden durch Kombination beider Methoden Prozesse der neuronalen und visuellen Verarbeitung von Emotionen untersucht. Zunächst wurde die Rolle von verschiedenen Gehirnregionen innerhalb des emotionalen Netzwerks sowie die Frage nach der Lateralität der emotionalen Verarbeitung untersucht. Die Ergebnisse zeigten, dass die neuronale Antwort in den unterschiedlichen Regionen in erster Linie die Anforderungen an die jeweilige funktionelle Einheit spiegelt. Im Rahmen der Untersuchungen von visueller Verarbeitung wurden die einzelnen spezifischen Blickbewegungsmuster für Emotionen Angst, Ekel und Freude erstmals charakterisiert. Es wurden auch Habituationseffekte auf die beschriebenen Blickbewegungsmuster untersucht. Die gemeinsame Analyse beider Datensätze zeigte, dass zwischen visuellen und neuronalen Prozessen eine enge qualitative Interaktion besteht. Es wurde ein Zusammenhang zwischen der Betrachtungsdauer und der tiefe der Verarbeitung nachgewiesen.

Today’s assembly operations represent about 15-70% of all manufacturing time and about 40% of all manufacturing costs, and manual assembly processes are still a significant portion of today’s assembly operations. Furthermore, today’s manufacturing environment requires a well-trained and flexible workforce that can easily adapt to changing products and processes. Unfortunately, manufacturing training is often performed using the master-apprentice model in the assembly line resulting in unsafe and expensive training conditions as this model is a slow and expensive process. Previous research has considered the use of virtual environments (VEs) for training purposes in different fields such as aviation, driving, construction, medicine, and manufacturing among many others. However, to this date, no assembly studies have been successful in providing a positive transfer of knowledge between virtual environments and real environments. On the other hand, several eye-tracking studies in radiology, air-traffic control, driving, and reading show that participants with higher levels of experience have different eye-scan patterns than participants with lower levels of experience. However, it is unknown how visual scans are affected by practice. Furthermore, several empirical visuomotor studies of task-oriented processes in real environments show that observers fixated their eyes on the areas that are crucial to the required task. However, we do not know the necessary visual elements to observe when performing and when learning how to perform an assembly task, nor the effects of following visual instructions and having visual distractors during this process. Finally, we have yet to establish what observation differences may exist between real and virtual environments with regards to these unknowns. This work presents the results of an assembly task which required participants to follow visual instructions and to select assembly objects among similar distractors. This assembly task was performed for ten cycles in real and virtual environments, and we used an eye-tracking device to register participants’ visual scans. We successfully identified the areas that are needed to observe for an assembly task in both environments and the effect of visual instructions and distractors in a visual scan. We found statistically significant differences for visual scans by assembly cycle and environment, with a p-value of <0.05. We also identified a connection between learning curves and participant eye scan, showing a significant decrease in the incidence of eye tracking metrics (visit count, visit duration, fixation count and fixation duration) between the first and the tenth cycles (ΔΜ), particularly for visual distractors ranging from 37.36% to 48.77%, and for visual instructions ranging from 35.17% to 54.82%. We found that participants’ observations became more efficient with practice, not only in terms of identifying distractors and following visual instructions but also in terms of developing an ability to observe key visual elements. For the RE we found a positive Pearson correlation between the proportion of fixation duration and assembly cycle for the key visual areas with p-values<0.002 and a negative Pearson correlation between the proportion of fixation duration for the non-key visual areas with p-values<0.046. Similar results were obtained for the VE.

Die Kombination von Eyetracking und fMRI in den Neurowissenschaften ist eine relativ neue Methode, die einerseits eine technische Herauforderung darstellt, andererseits neue Möglichkeiten des Zugangs zu neuronalen Prozessen darbietet. In der vorliegenden Arbeit wurden durch Kombination beider Methoden Prozesse der neuronalen und visuellen Verarbeitung von Emotionen untersucht. Zunächst wurde die Rolle von verschiedenen Gehirnregionen innerhalb des emotionalen Netzwerks sowie die Frage nach der Lateralität der emotionalen Verarbeitung untersucht. Die Ergebnisse zeigten, dass die neuronale Antwort in den unterschiedlichen Regionen in erster Linie die Anforderungen an die jeweilige funktionelle Einheit spiegelt. Im Rahmen der Untersuchungen von visueller Verarbeitung wurden die einzelnen spezifischen Blickbewegungsmuster für Emotionen Angst, Ekel und Freude erstmals charakterisiert. Es wurden auch Habituationseffekte auf die beschriebenen Blickbewegungsmuster untersucht. Die gemeinsame Analyse beider Datensätze zeigte, dass zwischen visuellen und neuronalen Prozessen eine enge qualitative Interaktion besteht. Es wurde ein Zusammenhang zwischen der Betrachtungsdauer und der tiefe der Verarbeitung nachgewiesen.