Predicting battlefield vigilance: a multivariate approach to assessment of attentional resources

The strategic allocation theory of vigilance

Despite its importance in different occupational and everyday contexts, vigilance, typically defined as the capacity to sustain attention over time, is remarkably limited. What explains these limits? Two theories have been proposed. The Overload Theory states that being vigilant consumes limited information-processing resources; when depleted, task performance degrades. The Underload Theory states that motivation to perform vigilance tasks declines over time, thereby prompting attentional shifts and hindering performance. We highlight some conceptual and empirical problems for both theories and propose an alternative: the Strategic Allocation Theory. For the Strategic Allocation Theory, performance on vigilance tasks optimizes as a function of intrinsic and extrinsic motivations, including metacognitive factors such as the expected value of effort and the expected value of planning. Limited capacities must be deployed across task sets to maximize expected reward. The observed limits of vigilance reflect changes in the perceived value of, among other things, sustaining attention to a task rather than attending to something else. Drawing from recent computational theories of cognitive control and meta-reasoning, we argue that the Strategic Allocation Theory explains more phenomena related to vigilance behavior than other theories, including self-report data. Finally, we outline some of the testable predictions the theory makes across several experimental paradigms. This article is categorized under: Philosophy > Foundations of Cognitive Science Psychology > Attention.

Application of the sustainable system-of-systems approach and econometric analysis to address China's decarbonisation problem

The Sustainable system-of-systems (SSoS) approach, complemented with econometric analysis was used to address China's decarbonisation problem, i.e. selecting fossil fuel consumption sources to be reduced in various regions to meet CO2 reduction targets with minimal effect on population and economic growth. In the SSoS, the micro-level system is represented by residents' health expenditure, the meso-level system by industry's CO2 emissions intensity, and the macro-level system by the government's achievement of economic growth. Regional panel data from 2009 to 2019 were used in an econometric analysis conducted using structural equation modelling. The results show that health expenditure was affected by CO2 emissions from the consumption of raw coal and natural gas. To support economic growth, the government should reduce raw coal consumption. For CO2 emissions reduction, industry in the eastern region should reduce raw coal consumption. The key advantage is SSoS with econometrics offers a way to reach a common goal among stakeholders.Practitioner summary: This research shows that the use of the SSoS approach, complemented with an econometric analysis of key social, economic, and natural capital data, can address a complex decarbonisation problem facing a nation (China, in the present case) while considering the goals of all stakeholders (the government, industrial communities, and residential communities).Abbreviations: CEADs: Carbon Emissions Accounts and Datasets for Emerging Countries; CEIC: CEIC Global Database; GRPS: World Economic Forum's Global Risks Perception Survey; HFE: human factors/ergonomics; ML-SEM: maximum likelihood estimation method; NDRC: National Development and Reform Commission of China; SEM: structural equation modelling; SSoS: Sustainable system-of-systems; TBL: triple bottom line.

EEG Coherence Metrics for Vigilance: Sensitivity to Workload, Time-on-Task, and Individual Differences

The vigilance decrement in performance is a significant operational issue in various applied settings. Psychophysiological methods for diagnostic monitoring of vigilance have focused on power spectral density measures from the electroencephalogram (EEG). This article addresses the diagnosticity of an alternative set of EEG measures, coherence between different electrode sites. Coherence metrics may index the functional connectivity between brain regions that supports sustained attention. Coherence was calculated for seven pre-defined brain networks. Workload and time-on-task factors primarily influenced alpha and theta coherence in anterior, central, and inter-hemispheric networks. Individual differences in coherence in inter-hemispheric, left intro-hemispheric and posterior networks correlated with performance. These findings demonstrate the potential applied utility of coherence metrics, although several methodological limitations and challenges must be overcome.

The ANT Executive Control Index: No Evidence for Temporal Decrement

OBJECTIVE

This study tested whether indices of executive control, alertness, and orienting measured with Attention Network Test (ANT) are vulnerable to temporal decrement in performance.

BACKGROUND

Developing the resource theory of sustained attention requires identifying neurocognitive processes vulnerable to decrement. Executive control processes may be prone to impairment in fatigue states. Such processes are also highlighted in alternative theories. Determining the role of executive control in vigilance can both advance theory and contribute to practical countermeasures for decrement in human factors contexts.

METHOD

In Study 1, 80 participants performed the standard ANT for an extended duration of about 55 to 60 min. Study 2 (160 participants) introduced manipulations of trial blocking and stimulus degradation intended to increase resource depletion. Reaction time and accuracy measures were analyzed. Subjective stress and workload were assessed in both studies.

RESULTS

In both studies, the ANT induced levels of subjective workload and task disengagement consistent with previous sustained attention studies. No systematic decrement in any performance measure was observed.

CONCLUSION

Executive control assessed by the ANT is not highly vulnerable to temporal decrement, even when task demands are elevated. Future work should differentiate executive control processes; proactive control may be more implicated in sustained attention decrement than in reactive control.

APPLICATION

Designing systems and interfaces to reduce executive control demands may be generally beneficial but will not directly mitigate temporal performance decrement. Enhancing design guidelines and neuroergonomic methods for monitoring operator attention requires further work to identify key neurocognitive processes for decrement.

A Possible World-Based Fusion Estimation Model for Uncertain Data Clustering in WBNs

In data clustering, the measured data are usually regarded as uncertain data. As a probability-based clustering technique, possible world can easily cluster the uncertain data. However, the method of possible world needs to satisfy two conditions: determine the data of different possible worlds and determine the corresponding probability of occurrence. The existing methods mostly make multiple measurements and treat each measurement as deterministic data of a possible world. In this paper, a possible world-based fusion estimation model is proposed, which changes the deterministic data into probability distribution according to the estimation algorithm, and the corresponding probability can be confirmed naturally. Further, in the clustering stage, the Kullback–Leibler divergence is introduced to describe the relationships of probability distributions among different possible worlds. Then, an application in wearable body networks (WBNs) is given, and some interesting conclusions are shown. Finally, simulations show better performance when the relationships between features in measured data are more complex.

Effects of state motivation in overload and underload vigilance task scenarios

Vigilance, or sustained attention, is the ability to maintain attention for prolonged periods of time. Interestingly, to date, few studies on vigilance have focused on the role of state motivation in sustaining attention. To address this disparity in the literature, the present study examined the effect of two types of state motivation on vigilance performance across task types (cognitive or sensory) and across the number of displays (one, two, or four). A sample of 105 participants completed a 24-min overload or underload vigilance task in a research laboratory. Participants were randomly assigned to either a cognitive or sensory vigilance task, and were randomly assigned to monitor one, two, or four displays for target stimuli. The results indicated that intrinsic state motivation predicted correct detection performance and state success motivation predicted sensitivity, but not false alarm performance, response bias, or global workload. We conclude with a discussion of the theoretical and practical applications of this research.

Task Engagement and the Vigilance Decrement Revisited: Expanding Upon the Work of Joel S. Warm Using a Semantic Vigilance Paradigm

OBJECTIVE

The goal of the present study is twofold: (1) demonstrate the importance of measuring and understanding the relationship between task engagement and vigilance performance, and (2) celebrate the work of Joel S. Warm and expand upon his previous research in two semantic vigilance paradigms.

BACKGROUND

The importance of measuring task engagement in cognitive and sensory vigilance tasks has been well documented. But to date, our understanding of the effects of task engagement on semantic vigilance performance is limited.

METHOD

Seventy-three participants completed either a standard semantic vigilance task or a lure semantic vigilance task. Participants also completed subjective measures of workload and stress.

RESULTS

The results indicated that changes in task engagement are associated with correct detection performance. Changes in task engagement may be related to individual differences in the distress associated with performing semantic vigilance tasks.

CONCLUSION

In line with the work of Warm and his colleagues (Dember, Warm, Bowers, & Lanzetta, 1984), participants who reported increased task engagement after the vigil outperformed their peers who noted decreased task engagement upon conclusion of the task. Participants reporting increases in engagement with the semantic vigilance tasks also reported significantly greater distress pretask, but not posttask. Instead, increases in postvigil distress were driven by the task to which participants were assigned, not task engagement.

APPLICATION

The present study has several implications for applied settings that involve long duration semantic processing or semantic target identification. Such real-world tasks include aviation, cyber threat detection and analysis, driving, and reading.

Does Depleting Self-Control Result in Poorer Vigilance Performance?

OBJECTIVE

To investigate whether depleting self-control prior to vigilance results in a steeper vigilance decrement.

BACKGROUND

The resource-control theory of vigilance asserts that an inherent bias toward self-generated mind-wandering draws attentional resources away from the primary task. This study seeks to test whether depleting self-control, the potential mechanism of self-generated mind-wandering, results in poorer vigilance performance.

METHOD

This study featured a between-subjects design where participants either completed a typing task that depleted self-control resources or a standard typing task that did not require self-control before performing a vigilance task. In the self-control depletion condition, participants typed a passage while omitting any "e" and "space" keys. In the standard typing task, participants typed the same passage without skipping any keys. Following both typing tasks, participants in both conditions completed an identical 12-min vigilance task.

RESULTS

Results demonstrated decreased accuracy and increased reaction times over time for both groups. Depleting self-control did not result in significant differences in accuracy, reaction time, nor a steeper vigilance decrement.

CONCLUSION

These results provide evidence against resource-control theory and self-control as an explanation for vigilance, and provide further support for cognitive resource theory as the predominant explanation for vigilance impairments.

APPLICATION

It is still unclear exactly what constitutes a "resource." A better understanding of the nature of these resources can help researchers and practitioners identify how they can be replenished, which could enhance human performance in situations requiring vigilance such as baggage screening.

Vigilance Tasks: Unpleasant, Mentally Demanding, and Stressful Even When Time Flies

OBJECTIVE

To determine whether perceived time progression (PTP) moderates participants' negative reactions to vigilance tasks.

BACKGROUND

Vigilance tasks are rated by participants to be unenjoyable and as having high levels of workload and stress. Based on the adage, "You are having fun when time flies," we tested the possibility that accelerating PTP might reduce these negative experiences.

METHOD

Two studies were performed, involving a long 30-min and a short 12-min vigil. We manipulated participants' PTP by creating a mismatch between their expectations about how long they would perform the task and the actual time that they were engaged.

RESULTS

PTP was significantly faster for participants who were led to expect that the vigilance task would last longer than it did relative to those led to expect that task duration would be shorter than it actually was and for controls for whom task duration was equal to the expected duration. However, accelerating PTP had no effect in either experiment on undesirable reactions to the vigilance tasks. Participants uniformly rated both tasks as unenjoyable, as having a high level of workload, and as stressful. Apparently, vigilance isn't fun even when time flies.

CONCLUSION

Our findings greatly underscore the depth to which negative subjective reactions are embedded in the nature of vigilance tasks and therefore that these tasks can have potentially serious costs to participants in terms of health, safety, and productivity.

APPLICATION

These costs must be considered at the operational level.

Evaluating non-technical skills and mission essential competencies of pilots in military aviation environments

To develop and validate a classification of non-technical skills (NTS) in military aviation, a study was conducted, using data from real operations of F16 aircraft formations. Phase 1 developed a NTS classification based on the literature review (e.g. NOTECHS) and a workshop with pilots. The Non-TEChnical-MILitary-Skills (NOTEMILS) scheme was tested in Phase 2 in a series of Principal Component Analysis with data from After-Action-Review sessions (i.e. 900 records from a wide range of operations). The NTS were found to make a good prediction of Mission Essential Components (R² > 0.80) above the effect of experience. Phase 3 undertook a reliability analysis where three raters assessed the NOTEMILS scheme with good results (i.e. all r_wg > 0.80). To look into the consistency of classifications, another test indicated that, at least, two out of three raters were in agreement in over 70% of the assessed flight segments. Practitioner Summary: A classification scheme of Non-Technical Skills (NTS) was developed and tested for reliability in military aviation operations. The NTS scheme is a valuable tool for assessing individual and team skills of F-16 pilots in combat. It is noteworthy that the tool had a good capability of predicting Mission Essential Competencies.

Where is my mind? Examining mind-wandering and vigilance performance

Vigilance is the ability to sustain attention to information for prolonged periods of time, particularly in environments where critical signals may be rare. Recent research in the domain of mind-wandering has suggested that processes associated with mind-wandering may underpin the typical decline in vigilance task performance. Current methods for measuring mind-wandering either disrupt vigils by asking probe questions throughout the task, or, require observers to reflect on how much mind-wandering occurred during the task upon conclusion of the vigil. Across three experimental studies, we treat mind-wandering as an individual difference, which was measured pre- and post-vigil. We argue this technique is a more holistic representation of mind-wandering and is less intrusive than probe measures, which serve to disrupt the vigil. The results of our first experiment challenge previous results in the literature: higher rates of mind-wandering were associated with improved correct detection performance. Interestingly, the second experiment suggests that increases in mind-wandering were not linked to vigilance performance deficits. However, significant differences in global workload emerged in the second experiment, implying individuals low in mind-wandering report greater workload. In a third experiment, wherein we manipulated event rate, mind-wandering typology had no significant effect on vigilance performance. We conclude with a discussion of the relevance of individual differences in mind-wandering in vigilance research considering the present findings.

The relationship between cell phone use and management of driver fatigue: It's complicated

INTRODUCTION

Voice communication may enhance performance during monotonous, potentially fatiguing driving conditions (Atchley & Chan, 2011); however, it is unclear whether safety benefits of conversation are outweighed by costs. The present study tested whether personalized conversations intended to simulate hands-free cell phone conversation may counter objective and subjective fatigue effects elicited by vehicle automation.

METHOD

A passive fatigue state (Desmond & Hancock, 2001), characterized by disengagement from the task, was induced using full vehicle automation prior to drivers resuming full control over the driving simulator. A conversation was initiated shortly after reversion to manual control. During the conversation an emergency event occurred.

RESULTS

The fatigue manipulation produced greater task disengagement and slower response to the emergency event, relative to a control condition. Conversation did not mitigate passive fatigue effects; rather, it added worry about matters unrelated to the driving task. Conversation moderately improved vehicle control, as measured by SDLP, but it failed to counter fatigue-induced slowing of braking in response to an emergency event. Finally, conversation appeared to have a hidden danger in that it reduced drivers' insights into performance impairments when in a state of passive fatigue.

CONCLUSIONS

Automation induced passive fatigue, indicated by loss of task engagement; yet, simulated cell phone conversation did not counter the subjective automation-induced fatigue. Conversation also failed to counter objective loss of performance (slower braking speed) resulting from automation. Cell phone conversation in passive fatigue states may impair drivers' awareness of their performance deficits. Practical applications: Results suggest that conversation, even using a hands-free device, may not be a safe way to reduce fatigue and increase alertness during transitions from automated to manual vehicle control.

Impact of three task demand factors on simulated unmanned system intelligence, surveillance, and reconnaissance operations

The present study investigated how three task demand factors influenced performance, subjective workload and stress of novice intelligence, surveillance, and reconnaissance operators within a simulation of an unmanned ground vehicle. Manipulations were task type, dual-tasking and event rate. Participants were required to discriminate human targets within a street scene from a direct video feed (threat detection [TD] task) and detect changes in symbols presented in a map display (change detection [CD] task). Dual-tasking elevated workload and distress, and impaired performance for both tasks. However, with increasing event rate, CD task deteriorated, but TD improved. Thus, standard workload models provide a better guide to evaluating the demands of abstract symbols than to processing realistic human characters. Assessment of stress and workload may be especially important in the design and evaluation of systems in which human character critical signals must be detected in video images. Practitioner Summary: This experiment assessed subjective workload and stress during threat and CD tasks performed alone and in combination. Results indicated an increase in event rate led to significant improvements in performance during TD, but decrements during CD, yet both had associated increases in workload and engagement.

Transcranial Doppler Sonography Reveals Reductions in Hemispheric Asymmetry in Healthy Older Adults during Vigilance

Given that older adults are remaining longer in the workforce, their ability to perform demanding cognitive tasks such as vigilance assignments needs to be thoroughly examined, especially since many vigilance assignments affect public safety (e.g., aviation, medicine and long distance driving). Previous research exploring the relation between aging and vigilance is conflicted, with some studies finding decreased vigilance performance in older adults but others finding no effect of age. We sought a better understanding of effects of age on vigilance by assessing neurophysiological change over the course of a vigil in young (aged 18–24) and healthy older (aged 66–77) adults. To measure temporal changes in cerebral blood flow, participants underwent functional transcranial doppler (fTCD) recording during a 1 h vigilance task. Based on research showing a compensatory effect of increased left hemisphere activation during vigilance in young adults and the “hemispheric asymmetry reduction in older adults” (HAROLD) model, we predicted that during vigilance our older adults would show greater left hemisphere activation but perform at a similar level compared to young adults. While cerebral blood flow velocity (CBFV) declined over time in both groups, only young adults showed the typical right-lateralized CBFV pattern. Older adults showed greater left hemisphere activation consistent with the HAROLD model. However, the increased left hemisphere activation did not appear to be compensatory as the older adults performed at a significantly lower level compared to young adults over the vigil. Findings are discussed in terms of the HAROLD model of healthy aging and the resource theory of vigilance.

Task Engagement and Attentional Resources

OBJECTIVE

Two studies tested multivariate models of relationships between subjective task engagement and vigilance. The second study included a stress factor (cold infection). Modeling tested relationships between latent factors for task engagement and vigilance, and the role of engagement in mediating effects of cold infection.

BACKGROUND

Raja Parasuraman's research on vigilance identified several key issues, including the roles of task factors, arousal processes, and individual differences, within the framework of resource theory. Task engagement is positively correlated with performance on various attentional tasks and may serve as a marker for resource availability.

METHOD

In the first study, 229 participants performed simultaneous and successive vigilance tasks. In the second study, 204 participants performed a vigilance task and a variable-foreperiod simple reaction-time task on two separate days. On the second day, 96 participants performed while infected with a naturally occurring common cold. Task engagement was assessed in both studies.

RESULTS

In both studies, vigilance decrement in hit rate was observed, and task performance led to loss of task engagement. Cold infection also depressed both vigilance and engagement. Fitting structural equation models indicated that simultaneous and successive tasks should be represented by separate latent factors (Study 1), and task engagement fully mediated the impact of cold infection on vigilance but not reaction time (Study 2).

CONCLUSIONS

Modeling individual differences in task engagement elucidates the role of resources in vigilance and underscores the relevance of Parasuraman's vision of the field.

APPLICATION

Assessment of task engagement may support diagnostic monitoring of operators performing tasks requiring vigilance.

Individual Differences in UGV Operation

Unmanned systems operations are complex, cognitively demanding tasks that elicit highly variable workload. The ability to predict performance and workload within these complex tasks can provide a powerful tool for practitioners regarding fit-for-duty verification. Further, monitoring workload aids in diagnostic assessment of factors that impact performance. The goal for this analysis was to examine the quality of cross-task averages of both baseline and concurrent psychophysiological and subjective measures to predict task performance and perceived workload. At a theoretical level, these findings suggest the need for a multivariate conceptualization of processing ‘resources’, encompassing both implicit and explicit responses. At a practical level, both subjective and psychophysiological measures may be necessary for optimizing performance prediction, at least for certain tasks.

Performance in Vigilance Tasks is Related to Both State and Contextual Motivation

Vigilance, or sustained attention, is the ability to maintain attention to stimuli over a prolonged period of time. Synonymous with the study of sustained attention is the vigilance decrement, which is a decline in performance as a function of time on task. In the present study, we examined the effects of state motivation (i.e., motivation measured immediately prior to the task) and context-based motivation (i.e., motivation that stems from task instructions) on vigilance performance in a sensory-based vigilance task. Forty-three participants completed a 24-minute vigilance task, as well as measures of stress and workload. The results indicated that those higher in state intrinsic motivation and motivating instructions outperformed their peers in terms of hits and false alarms. We conclude that motivation may help facilitate vigilant attention.

Multidimensional Profiling of Task Stress States for Human Factors: A Brief Review

OBJECTIVE

This article advocates multidimensional assessment of task stress in human factors and reviews the use of the Dundee Stress State Questionnaire (DSSQ) for evaluation of systems and operators.

BACKGROUND

Contemporary stress research has progressed from an exclusive focus on environmental stressors to transactional perspectives on the stress process. Performance impacts of stress reflect the operator's dynamic attempts to understand and cope with task demands. Multidimensional stress assessments are necessary to gauge the different forms of system-operator interaction.

METHOD

This review discusses the theoretical and practical use of the DSSQ in evaluating multidimensional patterns of stress response. It presents psychometric evidence for the multidimensional perspective and illustrative profiles of subjective state response to task stressors and environments. Evidence is also presented on stress state correlations with related variables, including personality, stress process measures, psychophysiological response, and objective task performance.

RESULTS

Evidence supports the validity of the DSSQ as a task stress measure. Studies of various simulated environments show that different tasks elicit different profiles of stress state response. Operator characteristics such as resilience predict individual differences in state response to stressors. Structural equation modeling may be used to understand performance impacts of stress states.

CONCLUSION

Multidimensional assessment affords insight into the stress process in a variety of human factors contexts. Integrating subjective and psychophysiological assessment is a priority for future research.

APPLICATION

Stress state measurement contributes to evaluating system design, countermeasures to stress and fatigue, and performance vulnerabilities. It may also support personnel selection and diagnostic monitoring of operators.

Boredom in the Workplace: A New Look at an Old Problem

OBJECTIVE

We review historical and more recent efforts in boredom research and related fields. A framework is presented that organizes the various facets of boredom, particularly in supervisory control settings, and research gaps and future potential areas for study are highlighted.

BACKGROUND

Given the ubiquity of boredom across a wide spectrum of work environments--exacerbated by increasingly automated systems that remove humans from direct, physical system interaction and possibly increasing tedium in the workplace--there is a need not only to better understand the multiple facets of boredom in work environments but to develop targeted mitigation strategies.

METHOD

To better understand the relationships between the various influences and outcomes of boredom, a systems-based framework, called the Boredom Influence Diagram, is proposed that describes various elements of boredom and their interrelationships.

RESULTS

Boredom is closely related to vigilance, attention management, and task performance. This review highlights the need to develop more naturalistic experiments that reflect the characteristics of a boring work environment.

CONCLUSION

With the increase in automation, boredom in the workplace will likely become a more prevalent issue for motivation and retention. In addition, developing continuous measures of boredom based on physiological signals is critical.

APPLICATION

Personnel selection and improvements in system and task design can potentially mitigate boredom. However, more work is needed to develop and evaluate other potential interventions.

Individual Differences in Facial Emotion Processing

This study tested whether trait emotional intelligence (TEI) measures of narrow bandwidth predict perception of facial emotion, using two tasks: identification of microexpressions of emotion and controlled visual search for target emotions. A total of 129 undergraduates completed multiple scales for TEI, as well as cognitive ability, personality, and stress measures. TEI was associated with a reduced stress response, but failed to predict performance on either task, contrary to the initial hypothesis. However, performance related significantly to higher cognitive intelligence, subjective task engagement, and use of task-focused coping. Individual differences in attentional resources may support processing of both emotive and non-emotive stimuli.