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ABSTRACT
In serial memory for spatial information, performance is impaired when distractors are interpolated between to-be-remembered (TBR) stimuli (Tremblay, Nicholls, Parmentier, & Jones, 2005). The so-called sandwich effect, combined with the use of eye tracking, served as a tool for examining the role of the oculomotor system in serial memory for spatial information. Participants had to recall the order in which sequences of TBR locations were presented. In some trials, to-be-ignored blue dots were presented after each TBR location. Our results show that response locations shift toward the location of the distractors, and this deviation is related to the eye movement deviation toward the distractor location. These results suggest that TBR and to-be-ignored locations are encoded onto a common map that could lie within the oculomotor system. Interference in memory for spatial information is interpreted in light of a model of oculomotor behavior (Godijn & Theeuwes, 2002b).

Canada 2010 opthalmology vision science Tobii eye tracking 1750 serial memory spatial information distraction performance oculomotor behavior

in list: Ophthalmology & Vision science

ABSTRACT
An eye tracker makes it possible to record the gaze point of a person looking at for example a computer monitor. Modern techniques are very flexible and allow the user to behave naturally without the need of cumbersome equipment such as special contact lenses or electrical probes. This is valuable in psychological research, marketing research and Human Computer Interaction. Eye trackers also give people who are severely paralyzed and unable to type and speak means to communicate using their eyes.
Measurement noise makes the use of digital filters necessary. An example is an eye-controlled cursor for a desktop environment such as Windows. The cursor has to be stable enough to allow the user to select folders, icons or other items of interest. While this type of application requires a fast real-time filter, others are less sensitive to processing time but demand an even higher level of accuracy. This work explores three areas of eye tracking filtration and aims at enhancing the performance of the filters used in the eye tracking systems built by Tobii Technology, Sweden. First, a post-processing algorithm to find fixations in raw gaze data is detailed. Second, modifications to an existing reading detection algorithm are described to make it more robust to natural irregularities in reading patterns. Third, a real-time filter for an eye-controlled cursor to be used in a desktop environment is designed using a low-pass filter in parallel with a change detector.
The fixation filter produced fewer false fixations and was also able to detect fixations lying spatially closer together than the previously used filter. The reading detection algorithm was shown to be robust to natural irregularities in reading such as revisits to previously read text or skipped paragraphs. The eye-cursor filter proved to respond quicker than the previously used moving average filter while maintaining a high level of noise attenuation.

Sweden 2007 Tobii eye tracking Clearview Studio 1750 fixation filter accuracy performance raw gaze data

in list: Eye Tracking Technology

ABSTRACT
Web sites need fast and effective navigation systems. An eye tracking laboratory study with n = 120 participants was conducted to compare the influence of different navigation designs (vertical versus dynamic menus) and task complexity (simple versus complex navigation tasks) on user performance, navigation strategy, and subjective preference. With vertical menus, users needed less eye fixations, were faster and more successful. We conclude that, firstly, vertical menus fit better to perception and cognition than dynamic menus, where the navigation items are hidden and must be accessed by an additional mouse click. Secondly, navigation systems should be extended with different kinds of navigation items adapted to the complexity of the users’ navigation tasks, because users tend to switch their navigation strategy when confronted with complex tasks.

Switzerland 2010 HCI Usability Tobii eye tracking effective navigation vertical dynamic menus complexity performance preference strategy

in list: HCI & Usability

ABSTRACT
Delivering digitally a realistic appearance of materials is one of the most difficult tasks of computer vision. Accurate representation of surface texture can be obtained by means of view- and illumination-dependent textures. However, this kind of appearance representation produces massive datasets so their compression is inevitable. For optimal visual performance of compression methods, their parameters should be tuned to a specific material. We propose a set of statistical descriptors motivated by textural features, and psychophysically evaluate their performance on three subtle artificial degradations of textures appearance. We tested five types of descriptors on five different textures and combination of thirteen surface shapes and two illuminations. We found that descriptors based on a two-dimensional causal auto-regressive model, have the highest correlation with the psychophysical results, and so can be used for automatic detection of subtle changes in rendered textured surfaces in accordance with human vision.

Czech Republic 2010 HCI Usability Tobii eye tracking X50 material texture parameter specific performance surface illumination degradation

in list: HCI & Usability

ABSTRACT
In most coordinated multiple view geovisualization systems a visual effect is used to mark observations across views when a user brushes with a mouse or other input device. This transient visual effect is called highlighting and is the focus of our recent research efforts. Current geovisualization systems make use of colored outlines or fills to mark highlighted observations, but there remain a wide range of alternatives to color that have yet to be implemented or compared in terms of user performance.
This paper describes the results of an experiment we developed to compare the performance of two highlighting methods (color and leader lines). Our approach makes use of an eye-tracking system to capture users’ gaze patterns while they answer questions that require attention to highlighted observations. The overall goal of our research is to explore whether or not there are good alternatives to color-based methods for highlighting in multiple views. In the following sections we briefly describe the motivation behind our work, the methodology we developed to compare highlighting methods, and preliminary results from our first experiments.

Australia 2010 HCI Usability Tobii eye tracking X120 60Hz geovisualization highlighting compare performance Visual

in list: HCI & Usability

ABSTRACT
To enable people with motor impairments to use gaze control to play online games and take part in virtual communities, new interaction techniques are needed that overcome the limitations of dwell clicking on icons in the games interface. We have investigated gaze gestures as a means of achieving this. We report the results of an experiment with 24 participants that examined performance differences between different gestures. We were able to predict the effect on performance of the numbers of legs in the gesture and the primary direction of eye movement in a gesture. We also report the outcomes of user trials in which 12 experienced gamers used the gaze gesture interface to play World of Warcraft. All participants were able to move around and engage other characters in fighting episodes successfully. Gestures were good for issuing specific commands such as spell casting, and less good for continuous control of movement compared with other gaze interaction techniques we have developed.

Finland X120 2010 Tobii eye tracking control games gaming gaze gesture HCI performance

in list: Eye Control

ABSTRACT
Previous studies have suggested that signaling enhances multimedia learning. However, there is not enough evidence showing why signaling leads to better performance. The goal of this study was to examine the effects of signaling on learning outcomes and to reveal the underlying reasons for this effect by using eye movement measures. The participants were 40 undergraduate students who were presented with either signaled or nonsignaled multimedia materials. Labels in the illustration were signaled by temporarily changing the color of the items. The results suggest that the signaled group outperformed the nonsignaled group on transfer and matching tests. Eye movement data shows that signaling guided attention to relevant information and improved the efficiency and effectiveness of finding necessary information.

Turkey 2010 Tobii eye tracking 1750 signaling effect performance learning multimedia attention cognitive Behavioral psychology

in list: Cognitive & Behavioural Psychology

ABSTRACT
Product listing pages, where information on multiple products are displayed, represent a vital point of an E-commerce website on which consumer decisions are made. Prior research has shown that the design of product listing pages has an impact on users’ performance and their recall of brand names. The aim of this study was to examine effects of presentation on cognitive load and consumer decisions. An online study was conducted comparing presentation type (matrix versus list presentation). List presentation was associated with lower cognitive load and more economic product selections. Eye-tracking data from an additional laboratory experiment suggest that list presentation triggers comparison processes which could account for the differences found.

Switzerland 2010 Tobii eye tracking 1750 product listing cognitive workload e-commerce design evaluation performance decision layout HCI Usability

in list: HCI & Usability

ABSTRACT
We report on the results of a study in which pairs of subjects were involved in spoken dialogues and one of the subjects also operated a simulated vehicle. We estimated the driver's cognitive load based on pupil size measurements from a remote eye tracker. We compared the cognitive load estimates based on the physiological pupillometric data and driving performance data. The physiological and performance measures show high correspondence suggesting that remote eye tracking might provide reliable driver cognitive load estimation, especially in simulators. We also introduced a new pupillometric cognitive load measure that shows promise in tracking cognitive load changes on time scales of several seconds.

USA 2010 Tobii eye tracking 1750 conversation driving simulation cognitive load performance evaluation Behavioral psychology

in list: Cognitive & Behavioural Psychology

ABSTRACT
The World Wide Web (Web) is changing. The much vaunted Web 2.0 sees once static pages evolving into hybrid applications. Content that was once simple is now becoming increasingly complicated due to the many updating components located throughout the page. The information overload and visual complexity of such components is significant. This increased complexity can produce lower performance and higher levels of stress and frustration which negatively effect the user. In previous work we have shown how galvanic skin response (GSR) measurements, collected in tandem with eye-tracking data, can be used as a method for determining how stressed users become when interacting with content. The results of that study demonstrated that when used appropriately, the presence of Web 2.0 content can reduce GSR measurements and be of benefit to users. In this work, the previous study was repeated with twenty-three older Web users to establish if similar patterns of interaction could be established. The results reveal that while older participants made use of dynamic content, unlike previous participants, they were a non-homogenous group with a large variance in the GSR measurements. We assert that a cause of this is hesitancy and therefore developing techniques to reduce hesitancy will benefit older users when interacting with Web 2.0 content.

UK 2010 Tobii eye tracking 1750 age user stress frustration web 2.0 performance decrease HCI Usability

in list: HCI & Usability

ABSTRACT
This paper presents a set of qualitative and quantitative scores designed to assess performance of any eye movement classification algorithm. The scores are designed to provide a foundation for the eye tracking researchers to communicate about the performance validity of various eye movement classification algorithms. The paper concentrates on the five algorithms in particular: Velocity Threshold Identification (I-VT), Dispersion Threshold Identification (I-DT), Minimum Spanning Tree Identification (MST), Hidden Markov Model Identification (I-HMM) and Kalman Filter Identification (I-KF). The paper presents an evaluation of the classification performance of each algorithm in the case when values of the input parameters are varied. Advantages provided by the new scores are discussed. Discussion on what is the "best" classification algorithm is provided for several applications. General recommendations for the selection of the input parameters for each algorithm are provided.

USA 2010 Tobii eye tracking X120 algorithm analysis classification metrics scoring performance evaluation

in list: Eye Tracking Technology

ABSTRACT
In this paper we propose an implicit relevance feedback method with the aim to improve the performance of known Content Based Image Retrieval (CBIR) systems by re-ranking the retrieved images according to users' eye gaze data. This represents a new mechanism for implicit relevance feedback, in fact usually the sources taken into account for image retrieval are based on the natural behavior of the user in his/her environment estimated by analyzing mouse and keyboard interactions. In detail, after the retrieval of the images by querying CBIRs with a keyword, our system computes the most salient regions (where users look with a greater interest) of the retrieved images by gathering data from an unobtrusive eye tracker, such as Tobii T60. According to the features, in terms of color, texture, of these relevant regions our system is able to re-rank the images, initially, retrieved by the CBIR. Performance evaluation, carried out on a set of 30 users by using Google Images and "pyramid" like keyword, shows that about the 87% of the users is more satisfied of the output images when the re-raking is applied.

Italy 2010 Tobii eye tracking T60 visual attention feedback image retrieval rank performance evaluation HCI Usability

in list: HCI & Usability

ABSTRACT
The main aim of this study was to investigate the effects on performance and workload of the shifting between levels of automation: from manual to automatic (forward shift) and from automatic to manual (backward shift). Three levels of difficulty of the Tetris game were implemented as task load conditions. Two versions of the game were also implemented: automated and manual. The automated version provided the participants a projection of the falling block on the lowest layer for making its placement easier. Results showed that the commonsense consideration that only shifts toward a lower level of automation should reflect poor performance and higher workload is unsupported. Forward shifts may affect performance as well, particularly when workload is moderate.

Italy 2007 Cognitive Behavioral Tobii eye tracking effects performance workload shifting automation manual automatic

in list: Cognitive & Behavioural Psychology

ABSTRACT
The Restricted Focus Viewer (RFV) relates a small part of an otherwise blurred display to the focus of visual attention. A user controls which part of the screen is in focus by using a computer mouse. The RFV tool records these movements. Recently, some studies used the RFV to investigate the cognitive behavior of users and some others have even enhanced the tool for research of usability issues.We report on an eye-tracking study where the effects of RFV's display blurring on the visual attention allocation of 18 novice and expert programmers were investigated. We replicated a previous RFV-based study and analyzed attention switching and fixation durations reported by an eye tracker. Our results indicate that the blurring interferes with the strategies possessed by experts and has an effect on fixation duration: however, we found that debugging performance was preserved. We discuss possible reasons and implications.

Finland 2005 HCI Usability Tobii eye tracking 1750 Restricted Focus Viewer visual attention blur focus switching fixation duration debugging performance

in list: HCI & Usability

ABSTRACT
In this study, we aim to conduct usability tests on different WebMap sites with eye movement analysis. Overall task performance, the effects of iconic representation of information, and the efficiency of pop-up usage were evaluated. The eye tracking technology is used for this study in order to follow the position of the users’ eye-gaze. The results show that there are remarkable differences in task performance between WebMaps. Addition, they also differ in the use of iconic representations according to results of users’ evaluation. It is also found that efficiency of pop-up windows’ usage has an effect on task performance.

Turkey 2009 HCI Usability Tobii eye tracking 1750 Studio webmap map sites performance icons pop-up evaluation representation

in list: HCI & Usability

ABSTRACT
This report results from a contract tasking University of Rome 'La Sapienza' as follows: The Grantee investigated the relation between scan path (ocular activity) and mental workload on the basis of the consideration that high workload should produce fixations grouping (because the operator needs to focus on some specific feature of the interface/task) whereas low workload should be associated with regular patterns, indicating a regular check of the interface space. According to this hypothesis, indexes providing information about the dispersion of point patterns should indicate regularity in the case of low workload and grouping in the case of high workload. The results suggest that nearest neighbor index used here is sensitive for investigating the processes underlying shifts in the level of automation, and their consequences on operator performance. On the costs of switching between levels of automation (LOA), a simple visuo-motor task employed in this study suggests that switching LOA affected individual's performance because of the cost associated with engagement/disengagement process. These findings suggest that when individuals perform a task, their cognitive systems are set to a particular level and no costs are observed until the level (or rule) is changed. Under some circumstances the results suggest that no shift can even lead to a better performance.

Italy 2007 Cognitive Behavioral Tobii eye tracking scan path mental workload fixations patterns automation performance switching engagement

in list: Cognitive & Behavioural Psychology

ABSTRACT
To evaluate the potential of gaze input for game interaction, we used two tasks commonly found in video game control, target acquisition and target tracking, in a set of two experiments. In the first experiment, we compared the target acquisition and target tracking performance of two eye trackers with four other input devices. Gaze input had a similar performance to the mouse for big targets, and better performance than a joystick, a device often used in gaming. In the second experiment, we compared target acquisition performance using either gaze or mouse for pointing, and either a mouse button or an EMG switch for clicking. The hands-free gaze-EMG input combination was faster than the mouse while maintaining a similar error rate. Our results suggest that there is a potential for gaze input in game interaction, given a sufficiently accurate and responsive eye tracker and a well-designed interface.

HCI Usability interaction Gaze input video games electromyography pointing devices performance evaluation Fitts’ Law eye tracking Denmark 2008 Tobii 1750

in list: HCI & Usability , Eye Control

ABSTRACT
This study aims to explore the possibility of using machine learning techniques to build predictive models of performance in collaborative induction tasks. More specifically, we explored how signal-level data, like eye-gaze data and raw speech may be used to build such models. The results show that such low level features have effectively some potential to predict performance in such tasks. Implications for future applications design are shortly discussed.

2009 Switzerland HCI Usability Tobii eye tracking 1750 models predict performance Computer learning Collaborative

in list: HCI & Usability

ABSTRACT
Recent advancements in computer graphics hardware have made it possible to develop hardware-accelerated real-time imaging displays. This poster presents technical details of an OpenGL multitexturing approach for real-time simulation of arbitrary visual fields over a still image. Mipmapping facilitates in-hardware dyadic (power-of-two) degradation of the image to serve as the low-resolution periphery. Multitexture compositing provides a mechanism to combine the image's high-resolution pixels within a window (of arbitrary shape). The poster presents code examples to achieve gaze-contingent movement of the high-resolution window over a smoothly or coarsely degraded version of the image background as shown in Figure 1.To test the display rate of the multitexturing approach, the "runway" image (1024 × 512) of Figure 1 was shown in a 1280 × 1024 display window (sufficient to fill a 17'' flat panel). Image rendering was timed in code as the foveal Region Of Interest (ROI) was made to move continuously over the image (diagonally from the top-right corner to the bottom-left, maintaining the full ROI within the window). Sustained display rates (in frames per second) reported by the timer averaged 120 fps on three different platforms.The multitexturing display was successfully adapted to a gaze-contingent application using the Tobii eye tracker for real-time gaze measurement. The Tobii eye tracker can be configured in several ways, one of which is acting as a server for a (possibly remote) eye tracking client application. Communication between client and server occurs over TCP/IP. A Linux PC, used for most of the eye tracker code testing, was set up with dual monitors, as shown in Figure 1, with the Tobii server running on a Windows 2000 PC.

Poster:
http://andrewd.ces.clemson.edu/research/vislab/docs/etra04-poster.pdf

Design Experimentation Performance Hardware-accelerated real-time simulation arbitrary visual fields eye tracking USA 2004 Tobii ET-17

in list: HCI & Usability

Abstract
This study examined the influence of cognitive styles on navigation patterns in hypertext environment. 20 undergraduate students from the Foreign Language Department were pre-tested on their cognitive styles, computer use and ability and prior knowledge about content presented in hypertext environment. All participants completed the Group-Embedded Figures Test (GEFT), Internet Influence and prior knowledge tests. Then they were asked to complete 6 tasks and navigate on a hypertext material on the planet Neptune. While they were reading the material, their eye movements were recorded by on eye-tracker device. The results were analyzed by measuring the fixation duration and eye-gaze points of the participants with regard to visited, revisited page numbers and navigation complexity. At the end of the study a recall performance test was applied. Results showed that cognitive style has no effect on recall performance, and navigational pattern while eye-fixation number on relevant information has significant effect on retention.

Linguistics eye tracking cognition navigation patterns hypertext recall Performance Turkey 2008 Tobii

in list: Linguistics