A USER’S COGNITIVE WORKLOAD PERSPECTIVE IN NEGOTIATION SUPPORT SYSTEMS: AN EYE-TRACKING EXPERIMENT

Replying to several research calls, I report promising results from an initial experiment which com-pares different negotiation support system approaches concerning their potential to reduce a user’s cognitive workload. Using a novel laboratory-based non-intrusive objective measurement technique which derives the user’s cognitive workload from pupillary responses and eye-movements, I experi-mentally evaluated a standard, a chat-based, and an argumentation-based negotiation support system and found that a higher assistance level of negotiation support systems actually leads to a lower user’s cognitive workload. In more detail, I found that an argumentation-based system which fully automates the generation of the user’s arguments significantly decreases the user’s cognitive workload compared to a standard system. In addition I found that a negotiation support system implementing an additional chat function significantly causes higher cognitive workload for users compared to a standard system

Vision-Based Eye Image Classification for Ophthalmic Measurement Systems

: The accuracy and the overall performances of ophthalmic instrumentation, where specific analysis of eye images is involved, can be negatively influenced by invalid or incorrect frames acquired during everyday measurements of unaware or non-collaborative human patients and non-technical operators. Therefore, in this paper, we investigate and compare the adoption of several vision-based classification algorithms belonging to different fields, i.e., Machine Learning, Deep Learning, and Expert Systems, in order to improve the performance of an ophthalmic instrument designed for the Pupillary Light Reflex measurement. To test the implemented solutions, we collected and publicly released PopEYE as one of the first datasets consisting of 15 k eye images belonging to 22 different subjects acquired through the aforementioned specialized ophthalmic device. Finally, we discuss the experimental results in terms of classification accuracy of the eye status, as well as computational load analysis, since the proposed solution is designed to be implemented in embedded boards, which have limited hardware resources in computational power and memory size

Psychophysiological Responses to Data Visualization and Visualization Effects on Auditors’ Judgments and Audit Quality

We conduct experiments with practicing Big 4 auditors and business students in order to investigate the psychophysiological responses to Big Data visualizations and the effects of different visualization techniques on auditor judgment and ultimately audit quality. More specifically, the first experiment with students examines whether visualizations can be designed to increase the level of a users’ arousal. Such increases in arousal have the capacity to yield significant benefits to the audit profession by drawing auditors’ attention to important patterns in data and promoting the evaluation of these patterns during evidence evaluation. Results of the first experiment using cognitive pupillometry and eye gaze measurement indicate that different visualization techniques produce significant differences in the level of arousal without interfering with information evaluation efficiency. The second experiment then investigates whether visualizations that were shown to promote higher and lower levels of arousal have differential effects on auditor judgments and audit quality. In addition, the second experiment investigates whether the reliability of the data sources underlying visualizations affect auditors’ judgments. Results from the second experiment indicate that visualizations that increase arousal enhance auditors’ ability to recognize disconfirming evidence and incorporate this evidence into their decisions. That is, auditors who view visualizations of disconfirming evidence that are designed to promote arousal recommend greater reductions to management estimates of reported revenue and increase their budgeted audit hours more than auditors who view visualizations that promote less arousal. In addition, auditors who view visualizations that increase arousal are more likely to attend to the reliability of data used to create the visualizations. Overall, the experiments reveal that understanding the root causes of different visualization techniques on arousal and auditor judgment present multiple opportunities to enhance audit quality

Eye Movement and Pupil Measures: A Review

Our subjective visual experiences involve complex interaction between our eyes, our brain, and the surrounding world. It gives us the sense of sight, color, stereopsis, distance, pattern recognition, motor coordination, and more. The increasing ubiquity of gaze-aware technology brings with it the ability to track gaze and pupil measures with varying degrees of fidelity. With this in mind, a review that considers the various gaze measures becomes increasingly relevant, especially considering our ability to make sense of these signals given different spatio-temporal sampling capacities. In this paper, we selectively review prior work on eye movements and pupil measures. We first describe the main oculomotor events studied in the literature, and their characteristics exploited by different measures. Next, we review various eye movement and pupil measures from prior literature. Finally, we discuss our observations based on applications of these measures, the benefits and practical challenges involving these measures, and our recommendations on future eye-tracking research directions

Aerospace Medicine and Biology. A continuing bibliography with indexes

This bibliography lists 244 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1981. Aerospace medicine and aerobiology topics are included. Listings for physiological factors, astronaut performance, control theory, artificial intelligence, and cybernetics are included

Measuring gaze and pupil in the real world: object-based attention,3D eye tracking and applications

This dissertation contains studies on visual attention, as measured by gaze orientation, and the use of mobile eye-tracking and pupillometry in applications. It combines the development of methods for mobile eye-tracking (studies II and III) with experimental studies on gaze guidance and pupillary responses in patients (studies IV and VI) and healthy observers (studies I and V). Object based attention / Study I What is the main factor of fixation guidance in natural scenes? Low-level features or objects? We developed a fixation-predicting model, which regards preferred viewing locations (PVL) per object and combines these distributions over the entirety of existing objects in the scene. Object-based fixation predictions for natural scene viewing perform at par with the best early salience model, that are based on low-level features. However, when stimuli are manipulated so that low-level features and objects are dissociated, the greater prediction power of saliency models diminishes. Thus, we dare to claim, that highly developed saliency models implicitly obtain object-hood and that fixation selection is mainly influenced by objects and much less by low-level features. Consequently, attention guidance in natural scenes is object-based. 3D tracking / Study II The second study focussed on improving calibration procedures for eye-in-head positions with a mobile eye-tracker.We used a mobile eye-tracker prototype, the EyeSeeCam with a high video-oculography (VOG) sampling rate and the technical gadget to follow the users gaze direction instantaneously with a rotatable camera. For a better accuracy in eye-positioning, we explored a refinement in the implementation of the eye-in-head calibration that yields a measure for fixation distance, which led to a mobile eye-tracker 3D calibration. Additionally, by developing the analytical mechanics for parametrically reorienting the gaze-centred camera, the 3D calibration could be applied to reliably record gaze-centred videos. Such videos are suitable as stimuli for investigating gaze-behaviour during object manipulation or object recognition in real worlds point-of-view (PoV) perspective. In fact, the 3D calibration produces a higher accuracy in positioning the gaze-centred camera over the whole 3D visual range. Study III, eye-tracking methods With a further development on the EyeSeeCam we achieved to record gaze-in-world data, by superposing eye-in-head and head-in-world coordinates. This novel approach uses a combination of few absolute head-positions extracted manually from the PoV video and of relative head-shifts integrated over angular velocities and translational accelerations, both given by an inertia measurement unit (IMU) synchronized to the VOG data. Gaze-in-world data consist of room-referenced gaze directions and their origins within the environment. They easily allow to assign fixation targets by using a 3D model of the measuring environment – a strong rationalisation regarding fixation analysis. Applications Study III Daylight is an important perceptual factor for visual comfort, but can also create discomfort glare situations during office work, so we developed to measure its behavioural influences. We achieve to compare luminance distributions and fixations in a real-world setting, by also recording indoor luminance variations time-resolved using luminance maps of a scenery spanning over a 3pi sr. Luminance evaluations in the workplace environment yield a well controlled categorisation of different lighting conditions and a localisation as well as a brightness measure of glare sources.We used common tasks like reading, typing on a computer, a phone call and thinking about a subject. The 3D model gives the possibility to test for gaze distribution shifts in the presence of glare patches and for variations between lighting conditions. Here, a low contrast lighting condition with no sun inside and a high contrast lighting condition with direct sunlight inside were compared. When the participants are not engaged in any visually focused task and the presence of the task support is minimal, the dominant view directions are inclined towards the view outside the window under the low contrast lighting conditions, but this tendency is less apparent and sways more towards the inside of the room under the high contrast lighting condition. This result implicates an avoidance of glare sources in gaze behaviour. In a second more extensive series of experiments, the participants’ subjective assessments of the lighting conditions will be included. Thus, the influence of glare can be analysed in more detail and tested whether visual discomfort judgements are correlated in differences in gaze-behaviour. Study IV The advanced eye-tracker calibration found application in several following projects and included in this dissertation is an investigation with patients suffering either from idiopathic Parkinson’s disease or from progressive supranuclear palsy (PSP) syndrome. PSP’s key symptom is the decreased ability to carry out vertical saccades and thus the main diagnostic feature for differentiating between the two forms of Parkinson’s syndrome. By measuring ocular movements during a rapid (< 20s) procedure with a standardized fixation protocol, we could successfully differentiate pre-diagnosed patients between idiopathic Parkinson’s disease and PSP, thus between PSP patients and HCs too. In PSP patients, the EyeSeeCam detected prominent impairment of both saccade velocity and amplitude. Furthermore, we show the benefits of a mobile eye-tracking device for application in clinical practice. Study V Decision-making is one of the basic cognitive processes of human behaviours and thus, also evokes a pupil dilation. Since this dilation reflects a marker for the temporal occurrence of the decision, we wondered whether individuals can read decisions from another’s pupil and thus become a mentalist. For this purpose, a modified version of the rock-paper-scissors childhood game was played with 3 prototypical opponents, while their eyes were video taped. These videos served as stimuli for further persons, who competed in rock-paper-scissors. Our results show, that reading decisions from a competitor’s pupil can be achieved and players can raise their winning probability significantly above chance. This ability does not require training but the instruction, that the time of maximum pupil dilation was indicative of the opponent’s choice. Therefore we conclude, that people could use the pupil to detect cognitive decisions in another individual, if they get explicit knowledge of the pupil’s utility. Study VI For patients with severe motor disabilities, a robust mean of communication is a crucial factor for well-being. Locked-in-Syndrome (LiS) patients suffer from quadriplegia and lack the ability of articulating their voice, though their consciousness is fully intact. While classic and incomplete LiS allows at least voluntary vertical eye movements or blinks to be used for communication, total LiS patients are not able to perform such movements. What remains, are involuntarily evoked muscle reactions, like it is the case with the pupillary response. The pupil dilation reflects enhanced cognitive or emotional processing, which we successfully observed in LiS patients. Furthermore, we created a communication system based on yes-no questions combined with the task of solving arithmetic problems during matching answer intervals, that yet invokes the most solid pupil dilation usable on a trial-by-trial basis for decoding yes or no as answers. Applied to HCs and patients with various severe motor disabilities, we provide the proof of principle that pupil responses allow communication for all tested HCs and 4/7 typical LiS patients. Résumé Together, the methods established within this thesis are promising advances in measuring visual attention allocation with 3D eye-tracking in real world and in the use of pupillometry as on-line measurement of cognitive processes. The two most outstanding findings are the possibility to communicate with complete LiS patients and further a conclusive evidence that objects are the primary unit of fixation selection in natural scenes

High-performance Diagnosis of Sleep Disorders: A Novel, Accurate and Fast Machine Learning Approach Using Electroencephalographic Data

While diagnosing sleep disorders by physicians using electroencephalographic data is protracted and inaccurate, we report promising results from a novel, fast and reliable machine learning approach. Our approach only needs an electroencephalographic recording snippet of 10 minutes instead of eight hours to correctly classify the disorder with an accuracy of over 90 percent. The Rapid Eye Movement sleep behavior disorder can lead to secondary diseases like Parkinson or Dementia. Therefore, it is important to classify the disorder fast and with a high level of accuracy - which is now possible with our approach