Different Methods to Detect Stress in Knowledge Workers: A Pilot Study for Long-term Monitoring.

Stress is a common part of working life, but knowledge is lacking on how to identify it early and with little effort on the part of the employee. We investigated whether simple stress reports and computer usage data could be useful tools for long-term assessment of stress in real life. 38 experts responded to a baseline questionnaire on need for recovery (NFR) and psychological distress (General Health Questionnaire, GHQ12). Their computer usage for work was recorded for 5 months, during which they filled in a 4-month simple diary and a 2-week detailed diary on, for example, stress and productivity. Salivary cortisol and heart rate variability were collected on 3 consecutive days. Generalized estimating equations models were used for the analyses. High NFR and GHQ12 predicted self-reported stress during work, and a decrease in (some) mouse usage features, but not keyboard usage features, over the following months. Some mouse usage features were associated with stress and productivity. The results provide some support for the usefulness of simple stress questions and mouse usage features in assessing long-term stress in real life.

Effects of overnight military training and acute battle stress on the cognitive performance of soldiers in simulated urban combat.

Understanding the effect of stress, fatigue, and sleep deprivation on the ability to maintain an alert and attentive state in an ecologically valid setting is of importance as lapsing attention can, in many safety-critical professions, have devastating consequences. Here we studied the effect of close-quarters battle (CQ battle) exercise combined with overnight military training with sleep deprivation on cognitive performance, namely sustained attention and response inhibition. In addition, the effect of the CQ battle and overnight training on cardiac activity [heart rate and root mean square of the successive differences (RMSSD)] during the cognitive testing and the relationship between cardiac activity and cognitive performance were examined. Cognitive performance was measured with the psychomotor vigilance task (PVT) and the sustained attention to response task (SART). Altogether 45 conscripts participated in the study. The conscripts were divided into control (CON) and experimental (EXP) groups. The CON completed the training day after a night of sleep and the EXP after the overnight military training with no sleep. Results showed that the effect of the overnight training on cognitive performance and the between-group difference in heart rate (HR) and heart rate variability (HRV) depended on the cognitive test. Surprisingly, the cognitive performance was not largely affected by the CQ battle. However, as expected, the CQ battle resulted in a significant decrease in RMSSD and an increase in HR measured during the cognitive testing. Similarly, the HR parameters were related to cognitive performance, but the relationship was found only with the PVT. In conclusion, fatigue due to the overnight training impaired the ability to maintain sufficient alertness level. However, this impairment in arousal upregulation was counteracted by the arousing nature of the SART. Hence, the conscripts' cognitive performance was mainly preserved when performing a stimulating task, despite the fatigue from the sleep loss of the preceding night and physical activity.

Annoyance, perception, and physiological effects of wind turbine infrasound.

Even though some individuals subjectively associate various symptoms with infrasound, there are very few systematic studies on the contribution of infrasound to the perception, annoyance, and physiological reactions elicited by wind turbine sound. In this study, sound samples were selected among long-term measurement data from wind power plant and residential areas, both indoors and outdoors, and used in laboratory experiments. In the experiments, the detectability and annoyance of both inaudible and audible characteristics of wind turbine noise were determined, as well as autonomic nervous system responses: heart rate, heart rate variability, and skin conductance response. The participants were divided into two groups based on whether they reported experiencing wind turbine infrasound related symptoms or not. The participants did not detect infrasonic contents of wind turbine noise. The presence of infrasound had no influence on the reported annoyance nor the measured autonomic nervous system responses. No differences were observed between the two groups. These findings suggest that the levels of infrasound in the current study did not affect perception and annoyance or autonomic nervous system responses, even though the experimental conditions corresponded acoustically to real wind power plant areas.

Implementing and evaluating novel safety training methods for construction sector workers: Results of a randomized controlled trial.

INTRODUCTION: The construction industry is regarded as one of the most unsafe occupational fields worldwide. Despite general agreement that safety training is an important factor in preventing accidents in the construction sector, more studies are needed to identify effective training methods. To address the current research gap, this study evaluated the impact of novel, participatory safety training methods on construction workers' safety competencies. Specifically, we assessed the efficacy of an immersive virtual reality (VR)-based safety training program and a participatory human factors safety training program (HFST) in construction industry workplaces. METHOD: In 2019, 119 construction sector workers from eight workplaces participated in a randomized controlled trial conducted in Finland. All the study participants were assessed using questionnaires at baseline, immediately after the intervention and at one-month follow-up. We applied generalized linear mixed modeling for statistical analysis. RESULTS: Compared to lecture-based safety training, VR-based safety training showed a stronger impact on safety motivation, self-efficacy and safety-related outcome expectancies. In addition, the construction sector workers who participated in the VR-based safety training showed a greater increase in self-reported safety performance at one-month follow-up. Contrary to our study hypotheses, we found no significant differences between the study outcomes in terms of study participants in the HFST training condition and the comparison condition without HFST training. CONCLUSION: Our study indicates that VR technology as a safety training tool has potential to increase safety competencies and foster motivational change in terms of the safety performance of construction sector workers. In the future, the efficacy of participatory human factors safety training should be studied further using a version that targets both managerial and employee levels and is implemented in a longer format. PRACTICAL IMPLICATIONS: Safety training in virtual reality provides a promising alternative to passive learning methods. Its motivating effect complements other safety training activities.

Evaluation of the efficacy of a virtual reality-based safety training and human factors training method: study protocol for a randomised-controlled trial.

BACKGROUND: The construction industry has a high risk of occupational accidents and injuries. More randomised controlled trials are needed to identify effective techniques for improving the occupational safety of construction sector workers. New technologies such as virtual reality (VR) offer the potential to develop engaging learning tools for safety training. Although the number of VR applications in occupational safety training is increasing, only a few studies have evaluated the learning outcomes of VR safety training. Furthermore, previous studies indicate that learning to recognise human factors at work has positive outcomes for safety skills. However, there is lack of knowledge regarding the efficacy of human factors-related training in the construction industry. OBJECTIVE: To evaluate the efficacy and the implementation process of a VR-based safety training and a human factors-related safety training. METHODS: In Finland, 8 study organisations and approximately 130 construction sector workers will participate in a randomised controlled trial. The study participants will be randomly assigned to one of four intervention arms: (1) immersive VR safety training alone, (2) lecture-based safety training alone, (3) combined immersive VR safety training and HF Tool training or (4) combined lecture-based safety training and HF Tool training. We will test the efficacy of the safety training processes in these four arms. Randomisation of study participants is stratified by work experience. Baseline assessment will take place before randomisation. The short-term follow-up measurements of all study participants will be conducted immediately after the VR safety training and lecture-based safety training. The study participants will complete second measurements immediately after the HF Tool training approximately 1 month after previous safety training. The second measurement of the intervention arms 1 and 2 study participants will be conducted during the same week as that of the intervention arms 3 and 4 participants, who will not take part in the HF Tool training. Finally, semistructured individual interviews will be conducted to evaluate the learning process. OUTCOME MEASURES: Outcome measures include safety knowledge, safety locus of control, safety self-efficacy, perceived control over safety issues, safety-related outcome expectancies, safety motivation and safety performance. DISCUSSION: Study results will provide knowledge on the efficacy of VR safety training and human factors-related safety training. Furthermore, study provides knowledge on pedagogical techniques that can be used to guide future intervention plans and development. TRIAL REGISTRATION NUMBER: ISRCTN55183871.

Probabilistic Approach to Robust Wearable Gaze Tracking.

This paper presents a method for computing the gaze point using camera data captured with a wearable gaze tracking device. The method utilizes a physical model of the human eye, advanced Bayesian computer vision algorithms, and Kalman filtering, resulting in high accuracy and low noise. Our C++ implementation can process camera streams with 30 frames per second in realtime. The performance of the system is validated in an exhaustive experimental setup with 19 participants, using a self-made device. Due to the used eye model and binocular cameras, the system is accurate for all distances and invariant to device movement. We also test our system against a best-in-class commercial device which is outperformed for spatial accuracy and precision. The software and hardware instructions as well as the experimental data are published as open source.

Forest, Trees, Dynamics: Results from a Novel Wisconsin Card Sorting Test Variant Protocol for Studying Global-Local Attention and Complex Cognitive Processes.

BACKGROUND: Recognition of objects and their context relies heavily on the integrated functioning of global and local visual processing. In a realistic setting such as work, this processing becomes a sustained activity, implying a consequent interaction with executive functions. MOTIVATION: There have been many studies of either global-local attention or executive functions; however it is relatively novel to combine these processes to study a more ecological form of attention. We aim to explore the phenomenon of global-local processing during a task requiring sustained attention and working memory. METHODS: We develop and test a novel protocol for global-local dissociation, with task structure including phases of divided ("rule search") and selective ("rule found") attention, based on the Wisconsin Card Sorting Task (WCST). We test it in a laboratory study with 25 participants, and report on behavior measures (physiological data was also gathered, but not reported here). We develop novel stimuli with more naturalistic levels of information and noise, based primarily on face photographs, with consequently more ecological validity. RESULTS: We report behavioral results indicating that sustained difficulty when participants test their hypotheses impacts matching-task performance, and diminishes the global precedence effect. RESULTS also show a dissociation between subjectively experienced difficulty and objective dimension of performance, and establish the internal validity of the protocol. Contribution: We contribute an advance in the state of the art for testing global-local attention processes in concert with complex cognition. With three results we establish a connection between global-local dissociation and aspects of complex cognition. Our protocol also improves ecological validity and opens options for testing additional interactions in future work.

A novel approach to sports concussion assessment: Computerized multilimb reaction times and balance control testing.

INTRODUCTION: Mild traumatic brain injuries (MTBI) or concussions often result in problems with attention, executive functions, and motor control. For better identification of these diverse problems, novel approaches integrating tests of cognitive and motor functioning are needed. The aim was to characterize minor changes in motor and cognitive performance after sports-related concussions with a novel test battery, including balance tests and a computerized multilimb reaction time test. The cognitive demands of the battery gradually increase from a simple stimulus response to a complex task requiring executive attention. METHOD: A total of 113 male ice hockey players (mean age = 24.6 years, SD = 5.7) were assessed before a season. During the season, nine concussed players were retested within 36 hours, four to six days after the concussion, and after the season. A control group of seven nonconcussed players from the same pool of players with comparable demographics were retested after the season. Performance was measured using a balance test and the Motor Cognitive Test battery (MotCoTe) with multilimb responses in simple reaction, choice reaction, inhibition, and conflict resolution conditions. RESULTS: The performance of the concussed group declined at the postconcussion assessment compared to both the baseline measurement and the nonconcussed controls. Significant changes were observed in the concussed group for the multilimb choice reaction and inhibition tests. Tapping and balance showed a similar trend, but no statistically significant difference in performance. CONCLUSION: In sports-related concussions, complex motor tests can be valuable additions in assessing the outcome and recovery. In the current study, using subtasks with varying cognitive demands, it was shown that while simple motor performance was largely unaffected, the more complex tasks induced impaired reaction times for the concussed subjects. The increased reaction times may reflect the disruption of complex and integrative cognitive function in concussions.

Feasibility of an electrodermal activity ring prototype as a research tool.

Electrodermal activity is an indicator of sympathetic activation and a useful tool for investigating psychological and physiological arousal. Novel wearable skin conductivity sensors offer portable low-cost solutions for long-term monitoring. In this article we compare the similarity of signals between a prototype of the wearable Moodmetric EDA Ring and a laboratory-grade skin conductance sensor in a psychophysiological experiment. The similarity of the signals was estimated by calculating the cosine distance between phasic features extracted from decomposed signals. The similarity was on average 83.3% ± 16.4%. The compound error of the decomposition process was also investigated and no systematic bias was observed towards either device. We conclude that the prototype ring is a promising device for ecologically valid field studies.

Algorithm for automatic analysis of electro-oculographic data.

BACKGROUND: Large amounts of electro-oculographic (EOG) data, recorded during electroencephalographic (EEG) measurements, go underutilized. We present an automatic, auto-calibrating algorithm that allows efficient analysis of such data sets. METHODS: The auto-calibration is based on automatic threshold value estimation. Amplitude threshold values for saccades and blinks are determined based on features in the recorded signal. The performance of the developed algorithm was tested by analyzing 4854 saccades and 213 blinks recorded in two different conditions: a task where the eye movements were controlled (saccade task) and a task with free viewing (multitask). The results were compared with results from a video-oculography (VOG) device and manually scored blinks. RESULTS: The algorithm achieved 93% detection sensitivity for blinks with 4% false positive rate. The detection sensitivity for horizontal saccades was between 98% and 100%, and for oblique saccades between 95% and 100%. The classification sensitivity for horizontal and large oblique saccades (10 deg) was larger than 89%, and for vertical saccades larger than 82%. The duration and peak velocities of the detected horizontal saccades were similar to those in the literature. In the multitask measurement the detection sensitivity for saccades was 97% with a 6% false positive rate. CONCLUSION: The developed algorithm enables reliable analysis of EOG data recorded both during EEG and as a separate metrics.

Estimating brain load from the EEG.

Modern work requires cognitively demanding multitasking and the need for sustained vigilance, which may result in work-related stress and may increase the possibility of human error. Objective methods for estimating cognitive overload and mental fatigue of the brain on-line, during work performance, are needed. We present a two-channel electroencephalography (EEG)-based index, theta Fz/alpha Pz ratio, potentially implementable into a compact wearable device. The index reacts to both acute external and cumulative internal load. The index increased with the number of tasks to be performed concurrently (p = 0.004) and with increased time awake, both after normal sleep (p = 0.002) and sleep restriction (p = 0.004). Moreover, the increase of the index was more pronounced in the afternoon after sleep restriction (p = 0.006). As a measure of brain state and its dynamics, the index can be considered equivalent to the heartbeat, an indicator of the cardiovascular state, thus inspiring the name "brainbeat".

A system for tracking gaze on handheld devices.

Many of the current gaze-tracking systems require that a subject's head be stabilized and that the interface be fixed to a table. This article describes a prototype system for tracking gaze on the screen of mobile, handheld devices. The proposed system frees the user and the interface from previous constraints, allowing natural freedom of movement within the operational envelope of the system. The method is software-based, and integrates a commercial eye-tracking device (EyeLink I) with a magnetic positional tracking device (Polhemus FASTRAK). The evaluation of the system shows that it is capable of producing valid data with adequate accuracy.