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High Cognitive Load Assessment in Drivers Through Wireless Electroencephalography and the Validation of a Modified

This paper explores the influence of high cognitive load on vehicle driver's electroencephalography (EEG) signals collected from two channels (Fp1, Fp2) using a wireless consumer-grade system. Although EEG has been used in driving-related research to assess cognitive load, only a few studies focused on high load, and they used research-grade systems. Recent advancements allow for less intrusive and more affordable systems. As an exploration, we tested the feasibility of one such system to differentiate among three levels of cognitive taskload in a simulator study. Thirty-seven participants completed a baseline drive with no secondary task and two drives with a modified version of the n-back task (1-back and 2-back). The modification removed the verbal response required during task presentation to prevent EEG-signal degradation, with the 2-back task expected to impose higher load than that by the 1-back task. Another objective of this study is to validate that this modified task increased the cognitive load in the expected manner. The modified task led to significant trends from baseline to 1-back, and from 1-back to 2-back in participants' heart rate, galvanic skin response, respiration, horizontal gaze position variability, and pupil diameter, all in line with the previous driving-related studies on cognitive load. Furthermore, the EEG system was observed to be sensitive to the modified task, with the power of alpha band decreasing significantly with increasing n-back levels (baseline versus 1-back: 0.092 Bels on Fp1, 0.179 on Fp2; 1-back versus 2-back: 0.209 on Fp1, 0.147 on Fp2). Thus, a consumer-grade EEG system has the potential to capture high levels of cognitive load experienced by drivers.

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Influence of driving experience on distraction engagement in automated vehicles

State-of-the-art vehicle automation requires drivers to visually monitor the driving environment and the automation (through interfaces and vehicle’s actions) and intervene when necessary. However, as evidenced by recent automated vehicle crashes and laboratory studies, drivers are not always able to step in when the automation fails. Research points to the increase in distraction or secondary-task engagement in the presence of automation as a potential reason. However, previous research on secondary-task engagement in automated vehicles mainly focused on experienced drivers. This issue may be amplified for novice drivers with less driving skill. In this paper, we compared secondary-task engagement behaviors of novice and experienced drivers both in manual (non-automated) and automated driving settings in a driving simulator. A self-paced visual-manual secondary task presented on an in-vehicle display was utilized. Phase 1 of the study included 32 drivers (16 novice) who drove the simulator manually. In Phase 2, another set of 32 drivers (16 novice) drove with SAE-level-2 automation. In manual driving, there were no differences between novice and experienced drivers’ rate of manual interactions with the secondary task (i.e., taps on the display). However, with automation, novice drivers had a higher manual interaction rate with the task than experienced drivers. Further, experienced drivers had shorter average glance durations toward the task than novice drivers in general, but the difference was larger with automation compared with manual driving. It appears that with automation, experienced drivers are more conservative in their secondary-task engagement behaviors compared with novice drivers.

8 versions available

Interaction options for wearables and smart-devices while walking

Using smartphones and wearables in parallel activities, e.g. while walking, is a widespread phenomenon. In different individuals we furthermore find different interaction styles which involve one or both hands. To study the effects of different interaction styles, we carried out a study involving three different interaction styles for touch-sensitive devices compared to a HMD operated by an additional controller providing passive haptic feedback. The experimental task was carried out while walking on a treadmill. In addition to the primary task of using the interaction device, a secondary task was administered which competed for the participants’ visual attention. We found an impact of the different interaction styles on the input performance: Time on task proved to be faster with the HMD combined with a haptic input device, but error count increased significantly as well. Using the thumb for input resulted in a longer overall time during which the visual attention was focused on the interaction device.

2 versions available

Investigating driver gaze behavior during lane changes using two visual cues: ambient light and focal icons

Currently, lane change decision aid systems primarily address foveal vision and thus compete for drivers’ attention with interfaces of other assistant systems. Also, alternative modalities such as acoustic perception (Mahapatra et al., 2008), tactile perception (Löcken et al., 2015), or peripheral vision (Löcken et al., 2015), have been introduced for lane change support. We are especially interested in ambient light displays (ALD) addressing peripheral vision since they can adapt to the driver’s attention using changing saliency levels (Matthews et al., 2004). The primary objective of this research is to compare the effect of ambient light and focal icons on driving performance and gaze behavior. We conducted two driving simulator experiments. The first experiment evaluated an ambient light cue in a free driving scenario. The second one focused on the difference in gaze behavior between ALD and focal icons, called “abstract faces with emotional expressions” (FEE). The results show that drivers decide more often for safe gaps in rightward maneuvers with ambient light cues. Similarly, drivers decide to overtake more often when the gaps are big enough with both displays in the second experiment. Regarding gaze behavior, drivers looked longer towards the forward area, and less often and shorter into the side mirrors when using ALD. This effect supports the assumption that drivers perceive the ALD with peripheral vision. In contrast, FEE did not significantly affect the gaze behavior when compared to driving without assistance. These results help us to understand the effect of different modalities on performance and gaze behavior, and to explore appropriate modalities for lane change support.

3 versions available

Investigating Temporal Changes of Behavioral Adaptation and User Experience During Highly Automated Driving

Sleepiness and micro-sleep as a consequence of the monotony of moving in queues as well as a very stressful daily routine of truck drivers put a serious risk on traffic safety (National Transportation Safety Board 1995). The automation of heavy traffic provides an opportunity to enhance traffic safety and drivers’ convenience and allows the safe use of integrated infotainment and communication systems. The research project TANGO (German abbreviation for ‘Technologie für automatisiertes Fahren nutzergerecht optimiert’, English equivalent ‘Technology for autonomous driving, optimized to user needs’) is funded by the German Federal Ministry of Economic Affairs and Energy. It takes place in cooperation with Robert Bosch GmbH, Volkswagen Aktiengesellschaft, MAN Truck & Bus, University of Stuttgart and Stuttgart Media University. The project aims at improving user experience and acceptance of (highly) automated driving functions for trucks. The project focuses the user-centered development of an Attention and Activity Assistance system (AAA) which provides the truck driver with a variance of non-driving-related activities based on current traffic situation, automation level up to SAE level 3 (SAE international 2018), and the driver’s current attentional state. While behavioral adaptation of drivers to the first use of highly automated systems has already been considered in a number of studies, little is known about the development of these behavioral changes over time, when familiarity with the system increases. In order to address these issues, a long term static driving simulator study will be conducted in spring 2019. The central research subject is the adaptation of drivers’ behavior in take-over scenarios with low time budgets, which require an immediate reaction by the driver. The study will run from March to June, 2019. First research results will be presented at the HCI International Conference in July.

2 versions available

Is the level of eye-hand coordination and executive functioning related to performance in para table tennis players?–An explorative study

The goal of this explorative study was to explore whether eye-hand coordination and executive functions (i.e. cognitive flexibility, attention control and information processing) are related to the performance level in para table tennis players. The data of 11 elite (age 15-54) and 11 non-elite para table tennis players (age 13-49) were analyzed. The results showed that the elite players performed better than the median norm values for cognitive flexibility and attention control while the non-elite players demonstrated slower information processing than the median norm values (p<0.05). The players’ competition rating correlated significantly with the eye-hand coordination, cognitive flexibility and information processing measures (p < 0.05). Players with a competition rating > 1000 points scored ≥ 24 catches per 30 s in the eye hand coordination task, whereas the players with < 1000 rating points score ≤ 18 catches per 30 s. In contrast, there was a clear overlap of scores between the players with > 1000 and < 1000 rating scores in the executive functions tests. The results present a first profile of para table tennis players regarding their eye-hand coordination and executive functions and the relationship of these constructs with the performance level. Long-term international cooperation is recommended to understand the value of the measured constructs to predict future successes.

2 versions available

Microsaccades in applied environments: Real-world applications of fixational eye movement measurements

Across a wide variety of research environments, the recording of microsaccades and other fixational eye movements has provided insight and solutions into practical problems. Here we review the literature on fixational eye movements—especially microsaccades—in applied and ecologically-valid scenarios. Recent technical advances allow noninvasive fixational eye movement recordings in real-world contexts, while observers perform a variety of tasks. Thus, fixational eye movement measures have been obtained in a host of real-world scenarios, such as in connection with driver fatigue, vestibular sensory deprivation in astronauts, and elite athletic training, among others. Here we present the state of the art in the practical applications of fixational eye movement research, examine its potential future uses, and discuss the benefits of including microsaccade measures in existing eye movement detection technologies. Current evidence supports the inclusion of fixational eye movement measures in real-world contexts, as part of the development of new or improved oculomotor assessment tools. The real-world applications of fixational eye movement measurements will only grow larger and wider as affordable high-speed and high-spatial resolution eye trackers become increasingly prevalent.

11 versions available

mobEYEle: an embedded eye tracking platform for industrial assistance

The eyes are a particularly interesting modality for cognitive industrial assistance systems, as gaze analysis can reveal cognition- and task-related aspects, while gaze interaction depicts a lightweight and fast method for hands-free machine control. In this paper, we present mobEYEle, a body-worn eye tracking platform that performs the entire computation directly on the user, as opposed to primarily streaming the data to a centralized unit for online processing and hence restricting its pervasiveness. The applicability of the platform is demonstrated throughout extensive performance and battery runtime tests. Moreover, a self-contained calibration method is outlined that enables the usage of mobEYEle without any supervisor nor digital screen.

2 versions available

Objective measures of pilot workload

This project was an engineering feasibility study to determine the value of using physiological based workload assessment technology in the USAF test and evaluation process at the Air Force Test Center, Edwards AFB. The feasibility study was requested by the 412 Test Wing, Air Force Test Center, Edwards AFB, California. The responsible test organization was the 418th Flight Test Squadron at Edwards AFB. Testing was conducted by the 418th Flight Test Squadron with the Operator Performance Laboratory (OPL) from the University of Iowa. The OPL provided, operated and collected data with test equipment called the Cognitive Assessment Tool Set (CATS) kit. Testing was conducted from 28 August 2018 to 12 February 2019 and consisted of four sorties totaling 18.5 flight test hours. Testing was conducted by the Combined Test Force IAW test plan, 412TW-TP-18-47, Objective Measures of Workload Feasibility Study [1]. A total of seven evaluator pilots performed takeoff, AR, normal flight operations, and landing tasks to determine the utility of the CATS system in a flight test environment. The CATS was set up inside an instrumented C-17 aircraft acting as a receiving aircraft against a legacy KC-135 tanker. Alongside CATS, OPL used the Dikablis Professional eye-tracking glasses in conjunction withD-Lab software from Ergoneers. Each pilot was fitted with electrocardiogram (ECG or EKG) electrodes prior to flight. The eye-tracker was used exclusively in the right seat, and only on the August flights. During the course of these flights, ECG data was successfully obtained with little-to-no complications. Flight One produced useful eye-tracking data, but Flight Two did not result in successful eye tracking from the Dikablis glasses due to inproper fit. For the final two flights in February, due to technical infeasibility of the current eye tracking setup, OPL made the decision to forego additional eye tracking data and instead focus on the CATS workload data collection. In addition to live flights, workload data was gathered from simulator tasks in Simulator B at the Test Pilot School. Pilots flew through 4 scenarios of varying difficulty in which they were tasked with following an aircraft while keeping it within a set of horizontal bars in the HUD, all while performing a secondary auditory response task. OPL gathered data from seven pilots total, but only five of these seven participated in the live flights, with the two additional pilots only instrumented with OPL’s ECG amplifier. Results indicated the pilots subjectively rated the ECG as comfortable and non-evasive. The utility of the ECG was reliable for the most part, there were a few instances of leads disconnecting resulting momentary data drop-outs, but were quickly detected and corrected by the pilot. The Dikablis glasses eye-tracker was generally uncomfortable and compatable with head-sets for only short durations. The eye-tracker could be better implemented if integrated into a helmet. Using the ECG and workload data, the difficulty level of each task (and even levels for distinct aspects of each task) was able to be determined. ECG data was sensitive to both low and high workload flight conditions and consistent across users. When combined with eye-tracker and aircraft data, the measure showed good diagnostisity. ECG data were unique to each pilot, but of the various tasks performed, station keeping on-boom during a turn generally produced the highest workload, followed by boom limits operations. Comparatively, takeoff and landing tasks seemed fairly straightforward and low-workload. Post-task pilot questionnaires (TLX and Bedford) backed up the ECG workload scores. Eye-tracking data showed that during aerial refueling tasks, the singular point that attracted the attention of the pilot was the KC-135 pilot director lights (PDL’s), and could be delineated down to the “captain’s bars”, which were used as a visual reference point to maintain formation. Regardless of the presence of the HUD, the captain’s bars held each pilot’s attention exclusively during refueling, with only occasional glances to their instruments or the tanker wing. Unsurprisingly, pilots maintained good situational awareness with a robust scan-pattern as they shifted their gaze much more during Landing and Takeoff tasks, alternating between the HUD, instruments, and forward and right-side windows. This study has shown that OPL’s methods and instrumentation can reliably provide physiological data including workload and eye-tracking that can help better evaluate the effort and attention required by the flight crew to successfully complete aerial refueling operations. The ECG based workload assessment system was deployed in minutes and required no training or special skills from the pilot. The system provides a relative workload number in real-time from the second the ECG amplifier was turned on and no further, calibration, modification, or refinement was needed to generate the figures shown in this report. Other than commercial power for the laptops, there was zero integration with the aircraft and was acceptably nonintruisive as the pilots were not tethered in any way. Unique flight events were conviently tagged by the test team to eliminate the need for aircraft systems integration. The ECG system could easily be deployed simultaneously on the boom operator and on a pilot in a single seat cockpit at the same time and get the total team workload picture established with relative ease.

2 versions available

Quantitative eye gaze and movement differences in visuomotor adaptations to varying task demands among upper-extremity prosthesis users

Importance: New treatments for upper-limb amputation aim to improve movement quality and reduce visual attention to the prosthesis. However, evaluation is limited by a lack of understanding of the essential features of human-prosthesis behavior and by an absence of consistent task protocols. Objective: To evaluate whether task selection is a factor in visuomotor adaptations by prosthesis users to accomplish 2 tasks easily performed by individuals with normal arm function. Design, Setting, and Participants: This cross-sectional study was conducted in a single research center at the University of Alberta, Edmonton, Alberta, Canada. Upper-extremity prosthesis users were recruited from January 1, 2016, through December 31, 2016, and individuals with normal arm function were recruited from October 1, 2015, through November 30, 2015. Eight prosthesis users and 16 participants with normal arm function were asked to perform 2 goal-directed tasks with synchronized motion capture and eye tracking. Data analysis was performed from December 3, 2018, to April 15, 2019. Main Outcome and Measures: Movement time, eye fixation, and range of motion of the upper body during 2 object transfer tasks (cup and box) were the main outcomes. Results: A convenience sample comprised 8 male prosthesis users with acquired amputation (mean [range] age, 45 [30-64] years), along with 16 participants with normal arm function (8 [50%] of whom were men; mean [range] age, 26 [18-43] years; mean [range] height, 172.3 [158.0-186.0] cm; all right handed). Prosthesis users spent a disproportionately prolonged mean (SD) time in grasp and release phases when handling the cups (grasp: 2.0 [2.3] seconds vs 0.9 [0.8] seconds; P < .001; release: 1.1 [0.6] seconds vs 0.7 [0.4] seconds; P < .001). Prosthesis users also had increased mean (SD) visual fixations on the hand for the cup compared with the box task during reach (10.2% [12.1%] vs 2.2% [2.8%]) and transport (37.1% [9.7%] vs 22.3% [7.6%]). Fixations on the hand for both tasks were significantly greater for prosthesis users compared with normative values. Prosthesis users had significantly more trunk flexion and extension for the box task compared with the cup task (mean [SD] trunk range of motion, 32.1 [10.7] degrees vs 21.2 [3.7] degrees; P = .01), with all trunk motions greater than normative values. The box task required greater shoulder movements compared with the cup task for prosthesis users (mean [SD] flexion and extension; 51.3 [12.6] degrees vs 41.0 [9.4] degrees, P = .01; abduction and adduction: 40.5 [7.2] degrees vs 32.3 [5.1] degrees, P = .02; rotation: 50.6 [15.7] degrees vs 35.5 [10.0] degrees, P = .02). However, other than shoulder abduction and adduction for the box task, these values were less than those seen for participants with normal arm function. Conclusions and Relevance: This study suggests that prosthesis users have an inherently different way of adapting to varying task demands, therefore suggesting that task selection is crucial in evaluating visuomotor performance. The cup task required greater compensatory visual fixations and prolonged grasp and release movements, and the box task required specific kinematic compensatory strategies as well as increased visual fixation. This is the first study to date to examine visuomotor differences in prosthesis users across varying task demands, and the findings appear to highlight the advantages of quantitative assessment in understanding human-prosthesis interaction.

9 versions available

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High Cognitive Load Assessment in Drivers Through Wireless Electroencephalography and the Validation of a Modified

Influence of driving experience on distraction engagement in automated vehicles

Interaction options for wearables and smart-devices while walking

Investigating driver gaze behavior during lane changes using two visual cues: ambient light and focal icons

Investigating Temporal Changes of Behavioral Adaptation and User Experience During Highly Automated Driving

Is the level of eye-hand coordination and executive functioning related to performance in para table tennis players?–An explorative study

Microsaccades in applied environments: Real-world applications of fixational eye movement measurements

mobEYEle: an embedded eye tracking platform for industrial assistance

Objective measures of pilot workload

Quantitative eye gaze and movement differences in visuomotor adaptations to varying task demands among upper-extremity prosthesis users

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