An investigation of the distribution of gaze estimation errors in head mounted gaze trackers using polynomial functions

Second order polynomials are commonly used for estimating the point-of-gaze in head-mounted eye trackers. Studies in remote (desktop) eye trackers show that although some non-standard 3rd order polynomial models could provide better accuracy, high-order polynomials do not necessarily provide better results. Different than remote setups though, where gaze is estimated over a relatively narrow field-of-view surface (e.g. less than 30x20 degrees on typical computer displays), head-mounted gaze trackers (HMGT) are often desired to cover a relatively wider field-of-view to make sure that the gaze is detected in the scene image even for extreme eye angles. In this paper we investigate the behavior of the gaze estimation error distribution throughout the image of the scene camera when using polynomial functions. Using simulated scenarios, we describe effects of four different sources of error: interpolation, extrapolation, parallax, and radial distortion. We show that the use of third order polynomials result in more accurate gaze estimates in HMGT, and that the use of wide angle lenses might be beneficial in terms of error reduction

LIMBUSTRACK: STABLE EYE-TRACKING IN IMPERFECT LIGHT CONDITIONS

We are aware of only one serious effort at development of a cheap, accurate, wearable eye tracker: the open source openEyes project. However, its method of ocular feature detection is such that it is prone to failure in variable lighting conditions. To address this deficiency, we have developed a cheap wearable eye tracker. At the heart of our development are novel techniques that allow operation under variable illumination

Understanding minds in real-world environments : toward a mobile cognition approach

This work is supported by a scholarship from the University of Stirling and a research grant from SINAPSE (Scottish Imaging Network: A Platform for Scientific Excellence).There is a growing body of evidence that important aspects of human cognition have been marginalized, or overlooked, by traditional cognitive science. In particular, the use of laboratory-based experiments in which stimuli are artificial, and response options are fixed, inevitably results in findings that are less ecologically valid in relation to real-world behavior. In the present review we highlight the opportunities provided by a range of new mobile technologies that allow traditionally lab-bound measurements to now be collected during natural interactions with the world. We begin by outlining the theoretical support that mobile approaches receive from the development of embodied accounts of cognition, and we review the widening evidence that illustrates the importance of examining cognitive processes in their context. As we acknowledge, in practice, the development of mobile approaches brings with it fresh challenges, and will undoubtedly require innovation in paradigm design and analysis. If successful, however, the mobile cognition approach will offer novel insights in a range of areas, including understanding the cognitive processes underlying navigation through space and the role of attention during natural behavior. We argue that the development of real-world mobile cognition offers both increased ecological validity, and the opportunity to examine the interactions between perception, cognition and action—rather than examining each in isolation.Publisher PDFPeer reviewe

Understanding Minds in Real-World Environments: Toward a Mobile Cognition Approach

There is a growing body of evidence that important aspects of human cognition have been marginalized, or overlooked, by traditional cognitive science. In particular, the use of laboratory-based experiments in which stimuli are artificial, and response options are fixed, inevitably results in findings that are less ecologically valid in relation to real-world behavior. In the present review we highlight the opportunities provided by a range of new mobile technologies that allow traditionally lab-bound measurements to now be collected during natural interactions with the world. We begin by outlining the theoretical support that mobile approaches receive from the development of embodied accounts of cognition, and we review the widening evidence that illustrates the importance of examining cognitive processes in their context. As we acknowledge, in practice, the development of mobile approaches brings with it fresh challenges, and will undoubtedly require innovation in paradigm design and analysis. If successful, however, the mobile cognition approach will offer novel insights in a range of areas, including understanding the cognitive processes underlying navigation through space and the role of attention during natural behavior. We argue that the development of real-world mobile cognition offers both increased ecological validity, and the opportunity to examine the interactions between perception, cognition and action—rather than examining each in isolation

Classroom Interpreting and Visual Information Processing in Mainstream Education for Deaf Students: Live or Memorex?

This study examined visual information processing and learning in classrooms including both deaf and hearing students. Of particular interest were the effects on deaf students’ learning of live (threedimensional) versus video-recorded (two-dimensional) sign language interpreting and the visual attention strategies of more and less experienced deaf signers exposed to simultaneous, multiple sources of visual information. Results from three experiments consistently indicated no differences in learning between three-dimensional and two-dimensional presentations among hearing or deaf students. Analyses of students’ allocation of visual attention and the influence of various demographic and experimental variables suggested considerable flexibility in deaf students’ receptive communication skills. Nevertheless, the findings also revealed a robust advantage in learning in favor of hearing students

Imaging methods for understanding and improving visual training in the geosciences

Experience in the field is a critical educational component of every student studying geology. However, it is typically difficult to ensure that every student gets the necessary experience because of monetary and scheduling limitations. Thus, we proposed to create a virtual field trip based off of an existing 10-day field trip to California taken as part of an undergraduate geology course at the University of Rochester. To assess the effectiveness of this approach, we also proposed to analyze the learning and observation processes of both students and experts during the real and virtual field trips. At sites intended for inclusion in the virtual field trip, we captured gigapixel resolution panoramas by taking hundreds of images using custom built robotic imaging systems. We gathered data to analyze the learning process by fitting each geology student and expert with a portable eye- tracking system that records a video of their eye movements and a video of the scene they are observing. An important component of analyzing the eye-tracking data requires mapping the gaze of each observer into a common reference frame. We have made progress towards developing a software tool that helps automate this procedure by using image feature tracking and registration methods to map the scene video frames from each eye-tracker onto a reference panorama for each site. For the purpose of creating a virtual field trip, we have a large scale semi-immersive display system that consists of four tiled projectors, which have been colorimetrically and photometrically calibrated, and a curved widescreen display surface. We use this system to present the previously captured panoramas, which simulates the experience of visiting the sites in person. In terms of broader geology education and outreach, we have created an interactive website that uses Google Earth as the interface for visually exploring the panoramas captured for each site

Acquisition of Verbal Aspect in L2 English by advanced learners with L1 Russian and L1 Norwegian: A web-based eye tracking study

It is well known that the similarities between L1 and L2 (also L3, etc.) facilitate language acquisition, whereas significant differences between them result in non-facilitating effects. These effects are known as Cross-Linguistic Influence (CLI). The main objective of the current study is to investigate the CLI, experienced by high proficient L2 English speakers when the grammatical aspect is being acquired. In order to investigate and compare different L2 processing patterns, I tested L1 speakers of a language with an obligatory contrast between perfective and imperfective aspect (Russian) and a language without such distinction (Norwegian). The participants recruited for this experiment were university students with advanced level of proficiency in English, and the groups were closely matched by proficiency. From the perspective of grammatical aspect, none of these languages bears complete similarity to English. Moreover, these languages differ dramatically in how they encode aspectual semantics in their grammar, hence we hoped to find substantial differences in processing and acquisition of the English system due to CLI. In Russian, with its perfective/imperfective contrast, aspectual information is obligatorily encoded in the verb form. Speakers of Russian link imperfective aspect with ongoing events and perfective aspect with completed events. In Norwegian, on the other hand, there is no grammatical way of encoding aspectual differences, i.e., the same verbal forms are employed to refer to either ongoing or completed events. As for English, there exist specialized forms that encode progressive meaning (e.g., Present and Past Progressive), but the jury is still out as to whether the Simple Past forms encode perfectivity or should be treated as neutral aspect. The goal of this thesis is thus to investigate semantic acquisition and processing of the English Past Progressive and Simple Past forms by studying online changes in gaze patterns by L2 listeners with L1 Russian and L1 Norwegian. The thesis aims to answer the following research questions: RQ 1: Do native speakers of Russian have strong opposition between Simple Past and Progressive Past in L2 English due to the transfer of similar opposition from their L1 on the processing level? RQ 2: How will Norwegian L1 speakers behave in the online eye-tracking Picture-Sentence Matching task? RQ 3: Is there any difference between online and offline results in the L1 Norwegian or the L1 Russian group? The methodology used to answer these research questions was web-based eye tracking. The experiment was implemented on JATOS platform using Webgazer.js software. The participants were asked to perform a sentence-picture matching task: they viewed visual displays with two pictures on the screen and listened to pre-recorded audio stimuli while their eye movements were tracked. This setup allowed for collecting both processing and conscious choice data performed after each sentence. The task contained audio stimuli of sentences with the Past Simple and Past Progressive verbal forms, and visual stimuli, depicting ongoing and completed events. The results of the experiment show that: 1) Both groups have a strong preference for an ongoing event picture when they listen to sentences involving the verb in the Past Progressive form. The offline responses also reflect this preference. This corresponds to the pattern exhibited by L1 speakers of English. 2) L1 speakers of Russian have a strong preference for a completed event picture when they listen to sentences involving the verb in the Past Simple form. The offline responses also reflect this preference. This doesn’t correspond to the pattern exhibited by L1 speakers of English, who had no preference for either completed or ongoing event picture in this condition. 3) L1 speakers of Norwegian have a weaker, but still sunstantial preference for an ongoing event picture when they listen to sentences involving the verb in the Past Simple form. The offline responses also reflect this preference. This doesn’t correspond to the pattern exhibited by L1 speakers of English, who had no preference for either completed or ongoing event picture in this condition. Taken together, the results indicate that while learners from both L1s converge on target-like interpretation of the Past Progressive form, their interpretation of the Past Simple form is deviant from that of the native speakers even at advanced levels of proficiency. We argue that this is likely due to CLI, with L1 Russian speakers mapping the semantic opposition between imperfective and perfective aspect onto English, and L1 Norwegians making a link between the English and the Norwegian Simple Past tense forms

Print versus screen—presentation medium-dependent picture consumption

Part I: The use of digital technologies has forever changed how consumers are capturing, sharing, and storing their pictures. The long-term objective of Part I of this study is to obtain an overall picture of the current state of consumer photographers’ practices. While digital camera owners are taking more photos than ever before, most are not printing them. However, experiments conducted on the presentation mediumdependent differences in picture consumption showed that a majority of the participants prefer printed images to images viewed on a screen. Regardless of this preference, participants did not print images very often for a variety of reasons, including lack of time or money. In addition, results showed that the most commonly used printing tools included Kodak EasyShare Gallery, Shutterfly, and Flickr. Finally, participants cited Photoshop, Lightroom, and Picasa as the primary editing tools, with Facebook being mentioned as the main sharing tool. Parts II & III: The advent of digital print engines capable of achieving high image quality has opened up many new and exciting print product opportunities, including the short-run printing of magazines. However, content available for magazines is also readily available on-line. It is not immediately obvious that the capability of creating a short-run magazine translates into a viable business model; just because they can be printed does not necessarily mean that it makes sense to do so. The objective of this project was to take the first steps toward identifying and understanding the differences in how information is consumed from print on paper versus computer display and which characteristics of these media are particularly relevant in this comparison. Longer-term, it is intended to explore how such differences affect the efficacy of magazine advertising. This evaluation involved an assessment of differences for several metrics, including information retention, time taken to view images, preference for visually consuming information, and distribution of visual gaze as measured by eyetrackers. Experimentation was conducted that focused on the first three of these four factors (Part II). Experimentation in Part III generally confirmed the results of this study: specifically, that people preferred the hard copy rendition over a PDF when given the choice (for reasons of image accessibility and tangibility), and that neither the time used to view the photo books nor information retention as measured by image recognition and information recall were affected by the medium in which the photo book was seen. The results of this study also agreed with earlier research findings that observers tend to fixate first and most often in the central areas of images. This research also found, however, important differences between how the observers viewed the printed and screen versions of the photo book, with the screen group having more fixations per image for many of the images early in the book (though not spending more time with these images), while the print group switched more often between images. While the work conducted in Part II suggested that there were no important differences between the print and screen groups of observers, the results of Part III hint at differences that may be important with regard to individual images or image layouts. Further work involving image content with a more balanced mix of text and pictorial imagery might prove useful in exploring these findings further