Distribution of light in the human retina under natural viewing conditions

Age-related macular degeneration (AMD) is the leading cause of blindness inAmerica. The fact that AMD wreaks most of the damage in the center of the retina raises the question of whether light, integrated over long periods, is more concentrated in the macula. A method, based on eye-tracking, was developed to measure the distribution of light in the retina under natural viewing conditions. The hypothesis was that integrated over time, retinal illumination peaked in the macula. Additionally a possible relationship between age and retinal illumination was investigated. The eye tracker superimposed the subject's gaze position on a video recorded by a scene camera. Five informed subjects were employed in feasibility tests, and 58 naïve subjects participated in 5 phases. In phase 1 the subjects viewed a gray-scale image. In phase 2, they observed a sequence of photographic images. In phase 3 they viewed a video. In phase 4, they worked on a computer; in phase 5, the subjects walked around freely. The informed subjects were instructed to gaze at bright objects in the field of view and then at dark objects. Naïve subjects were allowed to gaze freely for all phases. Using the subject's gaze coordinates, and the video provided by the scene camera, the cumulative light distribution on the retina was calculated for ∼15° around the fovea. As expected for control subjects, cumulative retinal light distributions peaked and dipped in the fovea when they gazed at bright or dark objects respectively. The light distribution maps obtained from the naïve subjects presented a tendency to peak in the macula for phases 1, 2, and 3, a consistent tendency in phase 4 and a variable tendency in phase 5. The feasibility of using an eye-tracker system to measure the distribution of light in the retina was demonstrated, thus helping to understand the role played by light exposure in the etiology of AMD. Results showed that a tendency for light to peak in the macula is a characteristic of some individuals and of certain tasks. In these situations, risk of AMD could be increased. No significant difference was observed based on age.

Eyetracking: analisi della user interface di una pagina web

Negli ultimi vent'anni con lo sviluppo di Internet, il modo di comunicare tra le persone �è totalmente cambiato. Grazie a Internet si sono ridotte le distanze e soprattutto tramite i siti web le aziende hanno una propria vetrina sul mondo sempre accessibile. Tutto ci�ò ha portato a nuovi comportamenti da parte dei consumatori che divengono sempre pi�u esigenti nella vastità di informazioni presenti sul Web. Perciò è necessario che le web companies riescano a produrre website efficienti e usabili per favorire l'interazione con l'utente. Inoltre il web ha avuto una rapida espansione per quanto concerne le metodologie di sviluppo e analisi del comportamento del consumatore. Si cercano sempre nuovi spunti per poter acquisire quello che �è il percorso di un utente affinché porti a termine una determinata azione nel proprio dominio. Per questo motivo, oltre agli strumenti gi�à consolidati come il riempimento di questionari o il tracking per mezzo di piattaforme come Google Analytics, si �è pensato di andare oltre e cercare di analizzare ancora pi�u a fondo il "consumAttore". Grazie ad un eye-tracker �è possibile riconoscere quelli che sono i modelli cognitivi che riguardano il percorso di ricerca, valutazione e acquisto di un prodotto o una call to action, e come i contenuti di una web application influenzano l'attenzione e la user experience. Pertanto l'obiettivo che si pone questo studio �è quello di poter misurare l'engagement della navigazione utente di una web application e, nel caso fosse necessario, ottimizzare i contenuti al suo interno. Per il rilevamento delle informazioni necessarie durante l'esperimento, mi sono servito di uno strumento a supporto delle decisioni, ovvero un eye-tracker e della successiva somministrazione di questionari.

Young toddlers' word comprehension is flexible and efficient.

Much of what is known about word recognition in toddlers comes from eyetracking studies. Here we show that the speed and facility with which children recognize words, as revealed in such studies, cannot be attributed to a task-specific, closed-set strategy; rather, children's gaze to referents of spoken nouns reflects successful search of the lexicon. Toddlers' spoken word comprehension was examined in the context of pictures that had two possible names (such as a cup of juice which could be called "cup" or "juice") and pictures that had only one likely name for toddlers (such as "apple"), using a visual world eye-tracking task and a picture-labeling task (n = 77, mean age, 21 months). Toddlers were just as fast and accurate in fixating named pictures with two likely names as pictures with one. If toddlers do name pictures to themselves, the name provides no apparent benefit in word recognition, because there is no cost to understanding an alternative lexical construal of the picture. In toddlers, as in adults, spoken words rapidly evoke their referents.

Item and task difficulty in a B2 reading examination: perceptions of test-takers and CEFR alignment experts compared with psychometric measurements

The article presents a study of a CEFR B2-level reading subtest that is part of the Slovenian national secondary school leaving examination in English as a foreign language, and compares the test-taker actual performance (objective difficulty) with the test-taker and expert perceptions of item difficulty (subjective difficulty). The study also analyses the test-takers’ comments on item difficulty obtained from a while-reading questionnaire. The results are discussed in the framework of the existing research in the fields of (the assessment of) reading comprehension, and are addressed with regard to their implications for item-writing, FL teaching and curriculum development.

Answering questions after initial study guides attention during restudy

Though the testing-effect can be boosted by including a restudy phase after answering test questions, we do not know precisely why it does so. One possible explanation is being tested here. The present study measured attention allocation during initial reading and rereading with a remote eye tracker to gain information on the cognitive processes during restudy, with and without prior testing. The results show that at the final study moment, students in the study-test-condition attended longer to information pertaining to the initial test questions as compared to students in the study-only condition (i.e., who did not take the test). No differences in attention allocation were found for information only questioned on a posttest 1 week later. In addition, it was found that performance on the initial test questions heavily affected which information students restudy; students in the study-test-condition paid namely more attention to the answers of questions they answered incorrectly during the initial test than to the answers of the questions they answered correctly on the initial test

Bilingual Lexical Access in Reading : Analyzing the Effect of Semantic Context on Non-Selective Access in Bilingual Memory

Recent empirical studies about the neurological executive nature of reading in bilinguals differ in their evaluations of the degree of selective manifestation in lexical access as implicated by data from early and late reading measures in the eye-tracking paradigm. Currently two scenarios are plausible: (1) Lexical access in reading is fundamentally language non-selective and top-down effects from semantic context can influence the degree of selectivity in lexical access; (2) Cross-lingual lexical activation is actuated via bottom-up processes without being affected by top-down effects from sentence context. In an attempt to test these hypotheses empirically, this study analyzed reader-text events arising when cognate facilitation and semantic constraint interact in a 22 factorially designed experiment tracking the eye movements of 26 Swedish-English bilinguals reading in their L2. Stimulus conditions consisted of high- and low-constraint sentences embedded with either a cognate or a non-cognate control word. The results showed clear signs of cognate facilitation in both early and late reading measures and in either sentence conditions. This evidence in favour of the non-selective hypothesis indicates that the manifestation of non-selective lexical access in reading is not constrained by top-down effects from semantic context.

Online Alpha Wave detector: an Embedded hardware-software implementation

The recent trend on embedded system development opens a new prospect for applications that in the past were not possible. The eye tracking for sleep and fatigue detection has become an important and useful application in industrial and automotive scenarios since fatigue is one of the most prevalent causes of earth-moving equipment accidents. Typical applications such as cameras, accelerometers and dermal analyzers are present on the market but have some inconvenient. This thesis project has used EEG signal, particularly, alpha waves, to overcome them by using an embedded software-hardware implementation to detect these signals in real time

Quantitative and Qualitative Trade-Off Analysis of Drowsy Driver Detection Methods: Single Electrode Wearable EEG Device, Multi-Electrode Wearable EEG Device, and Head-Mounted Gyroscope

Drowsy driving impairs motorists’ ability to operate vehicles safely, endangering both the drivers and other people on the road. The purpose of the project is to find the most effective wearable device to detect drowsiness. Existing research has demonstrated several options for drowsiness detection, such as electroencephalogram (EEG) brain wave measurement, eye tracking, head motions, and lane deviations. However, there are no detailed trade-off analyses for the cost, accuracy, detection time, and ergonomics of these methods. We chose to use two different EEG headsets: NeuroSky Mindwave Mobile (single-electrode) and Emotiv EPOC (14- electrode). We also tested a camera and gyroscope-accelerometer device. We can successfully determine drowsiness after five minutes of training using both single and multi-electrode EEGs. Devices were evaluated using the following criteria: time needed to achieve accurate reading, accuracy of prediction, rate of false positives vs. false negatives, and ergonomics and portability. This research will help improve detection devices, and reduce the number of future accidents due to drowsy driving.

Desenvolvimento de produtos à base de anchoíta e comportamento do mercado consumidor

Anchoíta (Engraulis anchoita) é uma espécie pelágica encontrada no Sudoeste do Oceano Atlântico. Estima-se que 135000 toneladas/ano desse peixe possam ser exploradas ao longo do litoral sul do Brasil. Entretanto, os recursos pesqueiros do país são ainda inexplorados, o que torna esta matéria prima candidata em potencial para a fabricação de novos produtos a base desse pescado. Com o apoio de programas governamentais sociais, a tendência para o Brasil é para o desenvolvimento de produtos de anchoíta alternativos e que sejam capazes de suprir as necessidades específicas de cada grupo de consumo alvo. Dentro desse cenário, um estudo de novos produtos de pescado frente ao mercado se faz necessário, na tentativa de compreender as variáveis influentes do setor. Para tanto, na presente tese teve objetivou-se desenvolver produtos à base de anchoíta e estudar o comportamento do mercado consumidor frente a esses novos produtos de pescado. Um total de seis artigos foi gerado. O primeiro artigo intitulou-se: “Potencial de inserção de empanados de pescado na merenda escolar mediante determinantes individuais”. Neste objetivou-se detectar os determinantes individuais do consumo de pescado com adolescentes em idade de 12 a 17 anos, visando à inserção de empanados de pescado na merenda escolar. Foi verificado que as variáveis que melhor discriminaram a frequência de consumo foram “gosta de pescado” e “grau de escolaridade dos pais”. Os resultados indicaram um potencial de consumo de empanados de pescado por adolescentes, associado à necessidade de educação alimentar. O segundo artigo “Elaboração de hambúrguer a partir de base proteica de anchoíta (Engraulis anchoita)” no qual se objetivou avaliar o efeito de diferentes combinações de solventes para a obtenção de base proteica de anchoíta visando à elaboração de hambúrguer de pescado. As lavagens com ácido fosfórico e mais dois ciclos de água foram as que apresentaram os melhores valores para a obtenção da base proteica, baseando-se na remoção de nitrogenados e respostas sensoriais. No terceiro artigo “Aceitação de empanados de pescado (Engraulis anchoita) na merenda escolar no extremo sul do Brasil” o objetivo foi avaliar a aceitação de empanados de pescado (Engraulis anchoita) com alunos (n = 830) da rede pública de ensino, em idades entre 5 e 18 anos, de duas cidades do estado do Rio Grande do Sul, Brasil. Os resultados indicaram relação inversa entre a aceitação de empanados de pescado e o aumento da idade das crianças. O quarto artigo estudou “Razões subjacentes ao baixo consumo de pescado pelo consumidor brasileiro.” Neste objetivou-se investigar o comportamento referente ao consumo de pescado de uma população com baixo consumo de pescado (Brasil), aplicando a Teoria do Comportamento Planejado (TCP). Os resultados indicaram que tanto a intenção como a atitude provou serem determinantes significativos na frequência de comer pescado, sendo a atitude inversamente correlacionada com o consumo de pescado. Hábito apareceu como uma importante variável discriminante para o consumo de pescado. O quinto artigo intitula-se “Modelagem de equações estruturais e associação de palavras como ferramentas para melhor compreensão do baixo consumo de pescado”. O objetivo foi desenvolver um modelo e explicar o conjunto das relações entre os construtos do consumo de pescado em uma população com baixo consumo de pescado (Brasil) através da aplicação da TCP e pelo Questionário das Escolhas dos Alimentos. Além disso, a percepção cognitiva de produtos de pescado (Engraulis anchoíta) foi avaliada pela mesma população. Os resultados indicaram um bom ajuste para o modelo proposto e mostraram que os construtos “saúde” e “controle de peso” são bons preditores da intenção. A técnica associação de palavras provou ser um método útil para a análise de percepção de um novo produto de pescado, além de ajudar a explicar os resultados obtidos pelas equações estruturais. O sexto e último artigo “Percepção de saudável em produtos de pescado em uma população com alto consumo de pescado. Uma investigação por eye tracking” em que se objetivou explorar o uso do método eye tracking para estudar a percepção de saudável em diferentes produtos de pescado. Dois pontos importantes podem ser salientados como influentes na percepção de saudável: produtos de pescado processados e alimentos fritos.

Which way is up? Grounded mental representations of space

Processing language is postulated to involve a mental simulation, or re-enactment of perceptual, motor, and introspective states that were acquired experientially (Barsalou, 1999, 2008). One such aspect that is mentally simulated during processing of certain concepts is spatial location. For example, upon processing the word “moon” the prominent spatial location of the concept (e.g. ‘upward’) is mentally simulated. In six eye-tracking experiments, we investigate how mental simulations of spatial location affect processing. We first address a conflict in previous literature whereby processing is shown to be impacted in both a facilitatory and inhibitory way. Two of our experiments showed that mental simulations of spatial association facilitate saccades launched toward compatible locations; however, a third experiment showed an inhibitory effect on saccades launched towards incompatible locations. We investigated these differences with further experiments, which led us to conclude that the nature of the effect (facilitatory or inhibitory) is dependent on the demands of the task and, in fitting with the theory of Grounded Cognition (Barsalou, 2008), that mental simulations impact processing in a dynamic way. Three further experiments explored the nature of verticality – specifically, whether ‘up’ is perceived as away from gravity, or above our head. Using similar eye-tracking methods, and by manipulating the position of participants, we were able to dissociate these two possible standpoints. The results showed that mental simulations of spatial location facilitated saccades to compatible locations, but only when verticality was dissociated from gravity (i.e. ‘up’ was above the participant’s head). We conclude that this is not due to an ‘embodied’ mental simulation, but rather a result of heavily ingrained visuo-motor association between vertical space and eye movements.

Welchen Grad an visueller Aufmerksamkeit widmen Lernende den Abbildungen in Geographieschulbüchern?

Dieser Beitrag widmet sich der Erforschung des Grades visueller Aufmerksamkeit, mit dem Lernende Abbildungen auf Geographieschulbuchseiten betrachten. In einer explorativen Stichprobe wurden die Blickbewegungen von 20 Probanden/Probandinnen (Gymnasium 15-17 Jahre, Studierende 20-24 Jahre) mithilfe von Eye Tracking beim Betrachten verschiedener Geographieschulbuchseiten aufgezeichnet. Ein visueller Fokus auf Text und geringe visuelle Aufmerksamkeit für Fotos wurde festgestellt. Anhand der Eye-Tracking-Aufzeichnungen werden mögliche Herausforderungen im Lernprozess mit Abbildungen im Geographieschulbuch erläutert, die aus der Gestaltung der Abbildungen resultieren könnten. Hierfür werden Erkenntnisse aus pädagogischer Psychologie, Visueller Kommunikation und Schulbuchforschung herangezogen. (DIPF/Orig.)

Padrões de ratreamento na visualização de faces próprias e não próprias

Dissertação (mestrado)—Universidade de Brasília, Instituto de Psicologia, Departamento de Processos Psicológicos Básicos, Programa de Pós-Graduação em Ciências do Comportamento, 2016.

Distribution of Light in the Human Retina under Natural Viewing Conditions

Age-related macular degeneration (AMD) is the leading cause of blindness inAmerica. The fact that AMD wreaks most of the damage in the center of the retina raises the question of whether light, integrated over long periods, is more concentrated in the macula. A method, based on eye-tracking, was developed to measure the distribution of light in the retina under natural viewing conditions. The hypothesis was that integrated over time, retinal illumination peaked in the macula. Additionally a possible relationship between age and retinal illumination was investigated. The eye tracker superimposed the subject’s gaze position on a video recorded by a scene camera. Five informed subjects were employed in feasibility tests, and 58 naïve subjects participated in 5 phases. In phase 1 the subjects viewed a gray-scale image. In phase 2, they observed a sequence of photographic images. In phase 3 they viewed a video. In phase 4, they worked on a computer; in phase 5, the subjects walked around freely. The informed subjects were instructed to gaze at bright objects in the field of view and then at dark objects. Naïve subjects were allowed to gaze freely for all phases. Using the subject’s gaze coordinates, and the video provided by the scene camera, the cumulative light distribution on the retina was calculated for ~15° around the fovea. As expected for control subjects, cumulative retinal light distributions peaked and dipped in the fovea when they gazed at bright or dark objects respectively. The light distribution maps obtained from the naïve subjects presented a tendency to peak in the macula for phases 1, 2, and 3, a consistent tendency in phase 4 and a variable tendency in phase 5. The feasibility of using an eye-tracker system to measure the distribution of light in the retina was demonstrated, thus helping to understand the role played by light exposure in the etiology of AMD. Results showed that a tendency for light to peak in the macula is a characteristic of some individuals and of certain tasks. In these situations, risk of AMD could be increased. No significant difference was observed based on age.

How textbook design may influence learning with geography textbooks

This paper investigates how textbook design may influence students’ visual attention to graphics, photos and text in current geography textbooks. Eye tracking, a visual method of data collection and analysis, was utilised to precisely monitor students’ eye movements while observing geography textbook spreads. In an exploratory study utilising random sampling, the eye movements of 20 students (secondary school students 15–17 years of age and university students 20–24 years of age) were recorded. The research entities were double-page spreads of current German geography textbooks covering an identical topic, taken from five separate textbooks. A two-stage test was developed. Each participant was given the task of first looking at the entire textbook spread to determine what was being explained on the pages. In the second stage, participants solved one of the tasks from the exercise section. Overall, each participant studied five different textbook spreads and completed five set tasks. After the eye tracking study, each participant completed a questionnaire. The results may verify textbook design as one crucial factor for successful knowledge acquisition from textbooks. Based on the eye tracking documentation, learning-related challenges posed by images and complex image-text structures in textbooks are elucidated and related to educational psychology insights and findings from visual communication and textbook analysis.

Neural Dynamics of Saccadic and Smooth Pursuit Eye Movement Coordination during Visual Tracking of Unpredictably Moving Targets

How does the brain use eye movements to track objects that move in unpredictable directions and speeds? Saccadic eye movements rapidly foveate peripheral visual or auditory targets and smooth pursuit eye movements keep the fovea pointed toward an attended moving target. Analyses of tracking data in monkeys and humans reveal systematic deviations from predictions of the simplest model of saccade-pursuit interactions, which would use no interactions other than common target selection and recruitment of shared motoneurons. Instead, saccadic and smooth pursuit movements cooperate to cancel errors of gaze position and velocity, and thus to maximize target visibility through time. How are these two systems coordinated to promote visual localization and identification of moving targets? How are saccades calibrated to correctly foveate a target despite its continued motion during the saccade? A neural model proposes answers to such questions. The modeled interactions encompass motion processing areas MT, MST, FPA, DLPN and NRTP; saccade planning and execution areas FEF and SC; the saccadic generator in the brain stem; and the cerebellum. Simulations illustrate the model’s ability to functionally explain and quantitatively simulate anatomical, neurophysiological and behavioral data about SAC-SPEM tracking.