Quintessential Solutions to Existential Problems: How Human Factors and Ergonomics Can and Should Address the Imminent Challenges of Our Times

OBJECTIVE

To examine and evaluate ways in which an understanding of the quintessential element of Human Factors/Ergonomics can address the spectrum of existential threats that confront contemporary civilization.

BACKGROUND

HF/E is dedicated to improving quality of life. Paradoxically, many processes which sustain contemporary civilization act to reduce that overall quality. Some technological developments themselves now even present existential threats to the fragile skein of civilization itself. Many disciplines address these diverse threats, and each may be advised and facilitated by HF/E knowledge and methods. It is a moral imperative of our science to contribute what we can to proposed resolutions.

METHOD

A primary conduit, by the established strengths of HF/E can contribute to potential solutions is identified. The present work advocates for specific, practical interventions using a direct-perception mediated, panopticon principle, that derives from the corpus of our science.

RESULT

Limitations upon a general, social understanding of imminent global concerns, which are largely ignorable when not actually present, are brought to immediate consciousness via an HF/E principle emphasizing the direct-perception of threat. It is argued that this, and allied HF/E insights can generate practical steps toward problem resolution at both macroscopic and localized levels of implementation.

APPLICATIONS

The primary, practical application of the proposed panopticon principle is to use our science to save global civilization. It is postulated that this represents useful employment of the knowledge we have adduced and accumulated across our discipline's existence.

Considerations for first field trials of low-threshold gene drive for malaria vector control

Sustainable reductions in African malaria transmission require innovative tools for mosquito control. One proposal involves the use of low-threshold gene drive in Anopheles vector species, where a 'causal pathway' would be initiated by (i) the release of a gene drive system in target mosquito vector species, leading to (ii) its transmission to subsequent generations, (iii) its increase in frequency and spread in target mosquito populations, (iv) its simultaneous propagation of a linked genetic trait aimed at reducing vectorial capacity for Plasmodium, and (v) reduced vectorial capacity for parasites in target mosquito populations as the gene drive system reaches fixation in target mosquito populations, causing (vi) decreased malaria incidence and prevalence. Here the scope, objectives, trial design elements, and approaches to monitoring for initial field releases of such gene dive systems are considered, informed by the successful implementation of field trials of biological control agents, as well as other vector control tools, including insecticides, Wolbachia, larvicides, and attractive-toxic sugar bait systems. Specific research questions to be addressed in initial gene drive field trials are identified, and adaptive trial design is explored as a potentially constructive and flexible approach to facilitate testing of the causal pathway. A fundamental question for decision-makers for the first field trials will be whether there should be a selective focus on earlier points of the pathway, such as genetic efficacy via measurement of the increase in frequency and spread of the gene drive system in target populations, or on wider interrogation of the entire pathway including entomological and epidemiological efficacy. How and when epidemiological efficacy will eventually be assessed will be an essential consideration before decisions on any field trial protocols are finalized and implemented, regardless of whether initial field trials focus exclusively on the measurement of genetic efficacy, or on broader aspects of the causal pathway. Statistical and modelling tools are currently under active development and will inform such decisions on initial trial design, locations, and endpoints. Collectively, the considerations here advance the realization of developer ambitions for the first field trials of low-threshold gene drive for malaria vector control within the next 5 years.

Genetic surveillance of insecticide resistance in African Anopheles populations to inform malaria vector control

Insecticide resistance in malaria vector populations poses a major threat to malaria control, which relies largely on insecticidal interventions. Contemporary vector-control strategies focus on combatting resistance using multiple insecticides with differing modes of action within the mosquito. However, diverse genetic resistance mechanisms are present in vector populations, and continue to evolve. Knowledge of the spatial distribution of these genetic mechanisms, and how they impact the efficacy of different insecticidal products, is critical to inform intervention deployment decisions. We developed a catalogue of genetic-resistance mechanisms in African malaria vectors that could guide molecular surveillance. We highlight situations where intervention deployment has led to resistance evolution and spread, and identify challenges in understanding and mitigating the epidemiological impacts of resistance.

Are humans still necessary?

Our long accepted and historically-persistent human narrative almost exclusively places us at the motivational centre of events. The wellspring of this anthropocentric fable arises from the unitary and bounded nature of personal consciousness. Such immediate conscious experience frames the heroic vision we have told to, and subsequently sold to ourselves. But need this centrality necessarily be a given? The following work challenges this, oft unquestioned, foundational assumption, especially in light of developments in automated, autonomous, and artificially-intelligent systems. For, in these latter technologies, human contributions are becoming ever more peripheral and arguably unnecessary. The removal of the human operator from the inner loops of momentary control has progressed to now an ever more remote function as some form of supervisory monitor. The natural progression of that line of evolution is the eventual excision of humans from access to any form of control loop at all. This may even include system maintenance and then, prospectively, even initial design. The present argument features a 'unit of analysis' provocation which explores the proposition that socially, and even ergonomically, the human individual no longer occupies priority or any degree of pre-eminent centrality. Rather, we are witnessing a transitional phase of development in which socio-technical collectives are evolving as the principle sources of what, may well be profoundly unhuman motivation. These developing proclivities occupy our landscape of technological innovations that daily act to magnify, rather than diminish, such progressive inhumanities. Where this leaves a science focused on work as a human-centred enterprise serves to occupy the culminating consideration of the present discourse.

Attribution Errors by People and Intelligent Machines

OBJECTIVE

To explore the ramifications of attribution errors (AEs), initially in the context of vehicle collisions and then to extend this understanding into the broader and diverse realms of all forms of human-machine interaction.

BACKGROUND

This work focuses upon a particular topic that John Senders was examining at the time of his death. He was using the lens of attribution, and its associated errors, to seek to further understand and explore dyadic forms of driver collision.

METHOD

We evaluated the utility of the set of Senders' final observations on conjoint AE in two-vehicle collisions. We extended this evaluation to errors of attribution generally, as applicable to all human-human, human-technology, and prospectively technology-technology interactions.

RESULTS

As with Senders and his many other contributions, we find evident value in this perspective on how humans react to each other and how they react to emerging forms of technology, such as autonomous systems. We illustrate this value through contemporary examples and prospective analyses.

APPLICATIONS

The comprehension and mitigation of AEs can help improve all interactions between people, between intelligent machines and between humans and the machines they work with.

Isometric Arm Forces Exerted by Females at Different Levels of Physical Comfort and Their EEG Signatures

A variety of subjective measures have traditionally been used to assess the perception of physical exertion at work and related body responses. However, the current understanding of physical comfort experienced at work is very limited. The main objective of this study was first to investigate the magnitude of isometric arm forces exerted by females at different levels of physical comfort measured on a new comfort scale and, second, to assess their corresponding neural signatures expressed in terms of power spectral density (PSD). The study assessed PSDs of four major electroencephalography (EEG) frequency bands, focusing on the brain regions controlling motor and perceptual processing. The results showed statistically significant differences in exerted arm forces and the rate of perceived exertion at the various levels of comfort. Significant differences in power spectrum density at different physical comfort levels were found for the beta EEG band. Such knowledge can be useful in incorporating female users' force requirements in the design of consumer products, including tablets, laptops, and other hand-held information technology devices, as well as various industrial processes and work systems.

Reacting and responding to rare, uncertain and unprecedented events

This work examines how we may be able to anticipate, respond to, and train for the occurrence of rare, uncertain, and unexpected events in human-machine systems operations. In particular, it uses a foundational matrix which describes the combinations of the state-of-the-world and the state-of-the-respondent, to formulate preferred response strategies, contingent upon what is knowable and actionable in each circumstance. It employs the dichotomy of System I and System II forms of cognitive response and augments these perspectives with a further form of decision-making, namely Systems III. The latter is predicated upon reactions to novel, unprecedented, and even 'unthinkable' events. The degree to which any human operator, the associated automation and/or the autonomy of a system, or each of these acting in concert, can best deal with these 'blue swan' events is explored. Potential forms of remediation, especially featuring training, are discussed, and evaluated in light of the skills needed to respond to even prohibitive degrees of situational uncertainty.Practitioners summary: Practitioners are liable to witness a growing spectrum of unusual and, on occasion, even unprecedented events in the operation of systems for which they are responsible. They will be required to account for their response to these circumstances to a spectrum of involved constituencies to whom they answer. This work aids them in succeeding to bring clarity to such difficult and challenging processes.Abbreviations: K: Known; Unk: Unknown; AI: Artificial Intelligence; ML: Machine Learning; CHARM: Cockpit Human-Automation Resource Management; SDT: signal detection theory; ASRS: Aviation Safety Reporting System.

Trust in Artificial Intelligence: Meta-Analytic Findings

OBJECTIVE

The present meta-analysis sought to determine significant factors that predict trust in artificial intelligence (AI). Such factors were divided into those relating to (a) the human trustor, (b) the AI trustee, and (c) the shared context of their interaction.

BACKGROUND

There are many factors influencing trust in robots, automation, and technology in general, and there have been several meta-analytic attempts to understand the antecedents of trust in these areas. However, no targeted meta-analysis has been performed examining the antecedents of trust in AI.

METHOD

Data from 65 articles examined the three predicted categories, as well as the subcategories of human characteristics and abilities, AI performance and attributes, and contextual tasking. Lastly, four common uses for AI (i.e., chatbots, robots, automated vehicles, and nonembodied, plain algorithms) were examined as further potential moderating factors.

RESULTS

Results showed that all of the examined categories were significant predictors of trust in AI as well as many individual antecedents such as AI reliability and anthropomorphism, among many others.

CONCLUSION

Overall, the results of this meta-analysis determined several factors that influence trust, including some that have no bearing on AI performance. Additionally, we highlight the areas where there is currently no empirical research.

APPLICATION

Findings from this analysis will allow designers to build systems that elicit higher or lower levels of trust, as they require.

Development of the Smart Tools Proneness Questionnaire (STP-Q): an instrument to assess the individual propensity to use smart tools

Humans have developed a prolonged and special relationship with their tools, which themselves exhibit the propensity to become ever more intelligent across the years. A 'smart tool' is defined as to representing any entity, machine, or device that can complete an informational, mechanical, or electronic work. This work explains the development of the Smart Tool Proneness Questionnaire (STP-Q), which is designed to measure an individual's propensity to use smart tools. Data collection was designed to (1) identify the psychological dimensions underlying smart tool use (2) establish the questionnaire's reliability (3) validity, (4) propose a normalisation, and (5) provide an English translation of the French original. The work therefore implements a reliable and valid questionnaire, sensitive to inter-individual differences regarding the propensity to use smart tools. Statistical analysis reveals that the individual self-reported propensity for smart tool use rests on three factors (1) utilitarian use, (2) hedonic and social use, and (3) proneness to delegate. From a theoretical perspective, this individual propensity to use smart tools might be considered key to our species development. In practical terms, measuring an individual's propensity to use smart tools can be of considerable benefit to the design of future smart tools in both professional and non-professional settings. Practitioner summary: The STP-Q, a self-reported measure of an individual's propensity to use smart tools, was developed. STP-Q offers practitioners a measure of individual propensity to use smart tools along three dimensions: utilitarian use, hedonic and social use, and proneness to task delegate. Individual results can easily be interpreted from normalizations that STP-Q provides. Abbreviations: CFI: comparative fit index; GFI: goodness of fit index; IFI: incremental fit index; ISO: International Standardization Organization; IRB: institutional review board of the university of central Florida; IT: information technology; MATB: multi-attribute task battery; NMP-Q: no more phone phobia; RMSEA: root mean square error of approximation; STP-Q: smart tools proneness questionnaire; TAM: technology acceptance model; TRI: technology readiness index; UTAUT: unified theory of acceptance and use of technology; WAIS IV: Wechsler adult intelligence scale.

Modelling spatiotemporal trends in the frequency of genetic mutations conferring insecticide target-site resistance in African mosquito malaria vector species

Background

Resistance in malaria vectors to pyrethroids, the most widely used class of insecticides for malaria vector control, threatens the continued efficacy of vector control tools. Target-site resistance is an important genetic resistance mechanism caused by mutations in the voltage-gated sodium channel (Vgsc) gene that encodes the pyrethroid target-site. Understanding the geographic distribution of target-site resistance, and temporal trends across different vector species, can inform strategic deployment of vector control tools.

Results

We develop a Bayesian statistical spatiotemporal model to interpret species-specific trends in the frequency of the most common resistance mutations, Vgsc-995S and Vgsc-995F, in three major malaria vector species Anopheles gambiae, An. coluzzii, and An. arabiensis over the period 2005–2017. The models are informed by 2418 observations of the frequency of each mutation in field sampled mosquitoes collected from 27 countries spanning western and eastern regions of Africa. For nine selected countries, we develop annual predictive maps which reveal geographically structured patterns of spread of each mutation at regional and continental scales. The results show associations, as well as stark differences, in spread dynamics of the two mutations across the three vector species. The coverage of ITNs was an influential predictor of Vgsc allele frequencies, with modelled relationships between ITN coverage and allele frequencies varying across species and geographic regions. We found that our mapped Vgsc allele frequencies are a significant partial predictor of phenotypic resistance to the pyrethroid deltamethrin in An. gambiae complex populations.

Conclusions

Our predictive maps show how spatiotemporal trends in insecticide target-site resistance mechanisms in African An. gambiae vary across individual vector species and geographic regions. Molecular surveillance of resistance mechanisms will help to predict resistance phenotypes and track their spread.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01242-1.

How human factors and ergonomics save lives

This work is directed to an understanding as to how the knowledge of, and the application of human factors and ergonomics (HF/E) can save lives. To achieve this, the paper features an assessment of the achievements of one particular scientist, Neville Anthony Stanton, and how his body of contributions has impacted the realm of ground transportation and, in particular, driver behavior assessment. On the widest scale, it is objectively and obviously the case that Stanton is one of the most fecund scientists of our discipline ever. His impact is evident globally and results not simply from the sum total of his written and published works but through an extensive record of international scientific presentations, mutual investigative collaborations across the globe, and mentoring at all levels of the Academy and beyond. As well as mastering and elucidating the HF/E dimensions of a number of content domains, he has generated vital, and even unique tools and methods through which we can explore and understand the problem space of HF/E. Placing those attainments in context permits us a wider window upon how the discipline itself exerts practical and positive influences across the wide swath of real-world systems.

Evolving Trust in Robots: Specification Through Sequential and Comparative Meta-Analyses

OBJECTIVE

The objectives of this meta-analysis are to explore the presently available empirical findings on the antecedents of trust in robots and use this information to expand upon a previous meta-analytic review of the area.

BACKGROUND

Human-robot interaction (HRI) represents an increasingly important dimension of our everyday existence. Currently, the most important element of these interactions is proposed to be whether the human trusts the robot or not. We have identified three overarching categories that exert effects on the expression of trust. These consist of factors associated with (a) the human, (b) the robot, and (c) the context in which any specific HRI event occurs.

METHOD

The current body of literature was examined and all qualifying articles pertaining to trust in robots were included in the meta-analysis. A previous meta-analysis on HRI trust was used as the basis for this extended, updated, and evolving analysis.

RESULTS

Multiple additional factors, which have now been demonstrated to significantly influence trust, were identified. The present results, expressed as points of difference and points of commonality between the current and previous analyses, are identified, explained, and cast in the setting of the emerging wave of HRI.

CONCLUSION

The present meta-analysis expands upon previous work and validates the overarching categories of trust antecedent (human-related, robot-related, and contextual), as well as identifying the significant individual precursors to trust within each category. A new and updated model of these complex interactions is offered.

APPLICATION

The identified trust factors can be used in order to promote appropriate levels of trust in robots.

The seat of happiness? The effect of seat comfort on the achievement of psychological flow during transactional work

Psychological flow is highly pleasurable, time-limited form of engagement in a task which has been shown to produce benefits in the workplace. Flow has historically been studied in the context of the interaction between the task and the performer. However, in work settings such as an office, many other factors may contribute to or hinder the achievement of flow. This present study broadens the research on flow to test the extent to which seating comfort while executing a challenging task influences an individual's ability to achieve flow. Fifty-four participants in this study were randomly assigned to one of two seat types and given a set of tasks to perform via a computer simulation. Seat comfort, coupled with participants' perceptions of their ability to concentrate on the simulation's set of tasks, was found to predict participants' flow experiences. Implications and future directions are discussed.

Why human factors science is demonstrably necessary: historical and evolutionary foundations

We review the theoretical foundation for the need for human factors science. Over the past 2.8 million years, humans and tools have co-evolved. However, in the last century, technology is introduced at a rate that exceeds human evolution. The proliferation of computers and, more recently, robots, introduces new cognitive demands, as the human is required to be a monitor rather than a direct controller. The usage of robots and artificial intelligence is only expected to increase, and the present COVID-19 pandemic may prove to be catalytic in this regard. One way to improve overall system performance is to 'adapt the human to the machine' via task procedures, operator training, operator selection, a Procrustean mandate. Using classic research examples, we demonstrate that Procrustean methods can improve performance only to a limited extent. For a viable future, therefore, technology must adapt to the human, which underwrites the necessity of human factors science. Practitioner Summary: Various research articles have reported that the science of Human Factors is of vital importance in improving human-machine systems. However, what is lacking is a fundamental historical outline of why Human Factors is important. This article provides such a foundation, using arguments ranging from pre-history to post-COVID.

Predicting non-state terrorism worldwide

Several thousand people die every year worldwide because of terrorist attacks perpetrated by non-state actors. In this context, reliable and accurate short-term predictions of non-state terrorism at the local level are key for policy makers to target preventative measures. Using only publicly available data, we show that predictive models that include structural and procedural predictors can accurately predict the occurrence of non-state terrorism locally and a week ahead in regions affected by a relatively high prevalence of terrorism. In these regions, theoretically informed models systematically outperform models using predictors built on past terrorist events only. We further identify and interpret the local effects of major global and regional terrorism drivers. Our study demonstrates the potential of theoretically informed models to predict and explain complex forms of political violence at policy-relevant scales.

The Effects of Virtual Reality, Augmented Reality, and Mixed Reality as Training Enhancement Methods: A Meta-Analysis

OBJECTIVE

The objective of this meta-analysis is to explore the presently available, empirical findings on transfer of training from virtual (VR), augmented (AR), and mixed reality (MR) and determine whether such extended reality (XR)-based training is as effective as traditional training methods.

BACKGROUND

MR, VR, and AR have already been used as training tools in a variety of domains. However, the question of whether or not these manipulations are effective for training has not been quantitatively and conclusively answered. Evidence shows that, while extended realities can often be time-saving and cost-saving training mechanisms, their efficacy as training tools has been debated.

METHOD

The current body of literature was examined and all qualifying articles pertaining to transfer of training from MR, VR, and AR were included in the meta-analysis. Effect sizes were calculated to determine the effects that XR-based factors, trainee-based factors, and task-based factors had on performance measures after XR-based training.

RESULTS

Results showed that training in XR does not express a different outcome than training in a nonsimulated, control environment. It is equally effective at enhancing performance.

CONCLUSION

Across numerous studies in multiple fields, extended realities are as effective of a training mechanism as the commonly accepted methods. The value of XR then lies in providing training in circumstances, which exclude traditional methods, such as situations when danger or cost may make traditional training impossible.

A participatory modelling approach for investigating the spread of COVID-19 in countries of the Eastern Mediterranean Region to support public health decision-making

Early on in the COVID-19 pandemic, the WHO Eastern Mediterranean Regional Office recognised the importance of epidemiological modelling to forecast the progression of the COVID-19 pandemic to support decisions guiding the implementation of response measures. We established a modelling support team to facilitate the application of epidemiological modelling analyses in the Eastern Mediterranean Region (EMR) countries. Here, we present an innovative, stepwise approach to participatory modelling of the COVID-19 pandemic that engaged decision-makers and public health professionals from countries throughout all stages of the modelling process. Our approach consisted of first identifying the relevant policy questions, collecting country-specific data and interpreting model findings from a decision-maker's perspective, as well as communicating model uncertainty. We used a simple modelling methodology that was adaptable to the shortage of epidemiological data, and the limited modelling capacity, in our region. We discuss the benefits of using models to produce rapid decision-making guidance for COVID-19 control in the WHO EMR, as well as challenges that we have experienced regarding conveying uncertainty associated with model results, synthesising and comparing results across multiple modelling approaches, and modelling fragile and conflict-affected states.

Driving Into the Future

This work considers the future of driving in terms of both its short- and long-term horizons. It conjectures that human-controlled driving will follow in the footsteps of a wide swath of other, now either residual or abandoned human occupations. Pursuits that have preceded it into oblivion. In this way, driving will dwindle down into only a few niche locales wherein enthusiasts will still persist, much in the way that steam train hobbyists now continue their own aspirational inclinations. Of course, the value of any such prognostication is in direct proportion to the degree that information is conveyed, and prospective uncertainty reduced. In more colloquial terms: the devil is in the details of these coming transitions. It is anticipated that we will see a progressive transformation of the composition of on-road traffic that will be registered most immediately in the realm of professional transportation in which the imperative for optimization exceeds that in virtually all other user segments. The transition from manual control to full automation will be more punctate than gradualist in its evolutionary development. As performance optimization slowly exhausts the commercial sector, it will progressively transition more into the discretionary realm by dint of simple technology transfer alone. The hedonic dimension of everyday driving will be dispersed and pursued by progressively fewer individuals. The traveling window of generational expectation will soon mean that human driving will be largely “forgotten,” as each sequential generation matures without this, still presently common experience. Indications of this stage of progress are beginning to be witnessed in the demographic profile of vehicle usage and ownership rates. The purpose of the exposition which follows is to consider and support each of these stated propositions.

On Senders's Models of Visual Sampling Behavior

OBJECTIVE

We review the sampling models described in John Senders's doctoral thesis on "visual sampling processes" via a ready and accessible exposition.

BACKGROUND

John Senders left a significant imprint on human factors/ergonomics (HF/E). Here, we focus on one preeminent aspect of his career, namely visual attention.

METHODS

We present, clarify, and expand the models in his thesis through computer simulation and associated visual illustrations.

RESULTS

One of the key findings of Senders's work on visual sampling concerns the linear relationship between signal bandwidth and visual sampling rate. The models that are used to describe this relationship are the periodic sampling model (PSM), the random constrained sampling model (RCM), and the conditional sampling model (CSM). A recent replication study that used results from modern eye-tracking equipment showed that Senders's original findings are manifestly replicable.

CONCLUSIONS

Senders's insights and findings withstand the test of time and his models continue to be both relevant and useful to the present and promise continued impact in the future.

APPLICATION

The present paper is directed to stimulate a broad spectrum of researchers and practitioners in HF/E and beyond to use these important and insightful models.

Specifying advantages of multi-modal cueing: Quantifying improvements with augmented tactile information

This work examines how tactile cues, encoded with azimuth and distance information, compare with visual and speech cues on performance and mental workload in a target detection task. Two experiments are reported using a simulated environment in which targets were presented at varying azimuth and distance locations. In the first experiment, participants engaged targets both while stationary and while in motion using tactile, visual, or speech cues. A no cueing control was included. In the second multi-modal experiment, participants completed the same task using cue pairings. Performance metrics consisted of hits, misses due to non-detection, misses due to inaccurate engagement, false alarms, response time, navigation errors as well as subjective ratings of mental workload scores were also collected. Results demonstrate the superiority of tactile cues as a means to communicate target location information either as a single modality or when paired with the two other cue types.

A Distracted Scientist: The Life and Contributions of John Senders

OBJECTIVE

To provide an evaluative and personal overview of the life and contributions of Professor John Senders and to introduce this Special Issue dedicated to his memory.

BACKGROUND

John Senders made many profound contributions to HF/E. These various topics are exemplified by the range of papers which compose the Special Issue. Collectively, these works document and demonstrate the impact of his many valuable research works.

METHOD

The Special Issue serves to summarize Senders' collective body of work as can be extracted from archival sources. This introductory paper recounts a series of remembrances derived from personal relationships, as well as the products of cooperative investigative research.

RESULTS

This collective evaluative process documents Senders' evident and deserved status in the highest pantheon of HF/E pioneers. It records his extraordinary life, replete with accounts of his insights and joie de vivre in exploring and explaining the world which surrounded him.

APPLICATIONS

Senders' record of critical contributions provides the example, par excellence, of the successful and fulfilling life in science. It encourages all, both researchers and practitioners alike, in their own individual search for excellence.

Specifying and Mitigating Thermal Stress Effects on Cognition During Personal Protective Equipment Use

OBJECTIVE

To report present understanding concerning selected task and environmental factors influencing the changing performance capacity associated with use of personal protective equipment (PPE).

BACKGROUND

Much knowledge is available concerning change in complex cognitive capacities under the effects of thermal stress. Our science can inform critical care facilities as to remediation strategies such as work-rest schedules to minimize performance error in highly cognitively demanding circumstances such as intensive care units.

METHOD

The present exposition draws from the state-of-the-art understanding concerning thermal stress effects on cognition and workload in complex and demanding tasks.

RESULTS

The summation and synthesis of HF/E findings provides important insights into combinatorial effects of forms of stress, typically dealt with only as discrete sources in traditional standards and regulations. The identified interaction between ascending thermal stress and cognitive task demand provides an instance of the plurality of ways HF/E can specify performance limitations in safety-critical circumstances, as witnessed in the current pandemic.

CONCLUSION

Accumulated HF/E insights provide systematic ways in which to address and ameliorate the combined forces of physical and cognitive stress on medical personnel constrained to use varying forms of PPE. These principles extend beyond this specific domain to all who are required to work in differential and isolated microclimates.

APPLICATION

To minimize the possibility of critical and life-threatening error in intensive care facilities which necessitate PPE use, we need principled work-rest ratio and heat stress mitigation guidance. To promote health, we need to champion healthy work practices in our health workers. HF/E insights can help achieve this important goal.

Mapping trends in insecticide resistance phenotypes in African malaria vectors

Mitigating the threat of insecticide resistance in African malaria vector populations requires comprehensive information about where resistance occurs, to what degree, and how this has changed over time. Estimating these trends is complicated by the sparse, heterogeneous distribution of observations of resistance phenotypes in field populations. We use 6,423 observations of the prevalence of resistance to the most important vector control insecticides to inform a Bayesian geostatistical ensemble modelling approach, generating fine-scale predictive maps of resistance phenotypes in mosquitoes from the Anopheles gambiae complex across Africa. Our models are informed by a suite of 111 predictor variables describing potential drivers of selection for resistance. Our maps show alarming increases in the prevalence of resistance to pyrethroids and DDT across sub-Saharan Africa from 2005 to 2017, with mean mortality following insecticide exposure declining from almost 100% to less than 30% in some areas, as well as substantial spatial variation in resistance trends.

Understanding individualistic response patterns when assessing expert operators on nuclear power plant control tasks

We evaluated the performance of three highly practiced participants on three task types that comprised a simulated nuclear power plant control operation. Multiple subjective, physiological, and objective performance measures were collected on these three highly-practiced individuals. Results indicated ceiling effects in terms of performance accuracy, yet each individual adopted a unique response strategy across the respective sub-tasks. Their maximised accuracy was achieved at the expense of longer response times across differing sub-tasks. The measures which proved diagnostic and predictive of performance capacity were explored. The current conclusion presents us with an invidious problem in that performance and workload associations, insensitivities, and dissociations may be unique to each individual operator, and may well depend also upon the overall task in context. Such findings push our science away from seeking nomothetic assertions and toward individuated concerns. In consequence, the age of the idiographic may well be upon us. Practitioner summary: The importance and relevance of nuclear power control is self-evident. Concerns here have centred around the safety of the technology and its operators. Our work informs practitioners in this industry, and in Ergonomics in general, of the response of highly trained individuals in these safety-critical, operational domains. We show that even experts engage in personal and individual strategies, an observation critical to the assessment of this specific workplace, and potentially all others. Abbreviations: NPP: nuclear power plant; ROs: reactor operators; MCR: main control room; LOA: levels of automation; EOP: emergency operating procedure; OP: operating procedures; ISA: instantaneous self-assessment; DSSQ: Dundee stres state questionnaire.

Challenges to Human Drivers in Increasingly Automated Vehicles

OBJECTIVE

We examine the relationships between contemporary progress in on-road vehicle automation and its coherence with an envisioned "autopia" (automobile utopia) whereby the vehicle operation task is removed from all direct human control.

BACKGROUND

The progressive automation of on-road vehicles toward a completely driverless state is determined by the integration of technological advances into the private automobile market; improvements in transportation infrastructure and systems efficiencies; and the vision of future driving as a crash-free enterprise. While there are many challenges to address with respect to automated vehicles concerning the remaining driver role, a considerable amount of technology is already present in vehicles and is advancing rapidly.

METHODS

A multidisciplinary team of experts met to discuss the most critical challenges in the changing role of the driver, and associated safety issues, during the transitional phase of vehicle automation where human drivers continue to have an important but truncated role in monitoring and supervising vehicle operations.

RESULTS

The group endorsed that vehicle automation is an important application of information technology, not only because of its impact on transportation efficiency, but also because road transport is a life critical system in which failures result in deaths and injuries. Five critical challenges were identified: driver independence and mobility, driver acceptance and trust, failure management, third-party testing, and political support.

CONCLUSION

Vehicle automation is not technical innovation alone, but is a social as much as a technological revolution consisting of both attendant costs and concomitant benefits.

How and why the brain evolves time

The present work evaluates the proposition that the dimension of time is iatrogenically created. That is, time is a property that necessarily emerges alongside the genesis of living systems. Humans, as the most complex known expression of such living creatures, exhibit the most intricate and sophisticated incarnation of this fabricated temporality. Evidence is considered to support this contention; most pointedly, the problem concerning the vacuity of a temporal foundation in the brain. I argue that one can 'force' processes, that are intrinsic to brain operations, to demonstrate such a temporal base; and even necessarily confirm this synchrony. However, this insistence is a categorical error. It conflates processes in time, with time itself. I also consider the observation of the psychophysical exponent at unity represents one that indicates support for the proposition I advance. I anticipate that the fundamental proposition of temporal iatrogenesis, that founds the present work, will be rejected 'out-of-hand.' Such vehement visceral rejections, alongside an even instinctive revulsion to the fracture of the idea known as the 'phenomenological constraint,' can also be taken as one essential form of validation for this observed delusion of time.

Diminishing Cognitive Capacities in an Ever Hotter World: Evidence From an Applicable Power-Law Description

OBJECTIVE

Modeling and evaluating a series of power law descriptions for boundary conditions of undiminished cognitive capacities under thermal stress.

BACKGROUND

Thermal stress degrades cognition, but precisely which components are affected, and to what degree, has yet to be fully determined. With increasing global temperatures, this need is becoming urgent. Power-law distributions have proven their utility in describing differing natural mechanisms, including certain orders of human performance, but never as a rationalization of stress-altered states of attention.

METHOD

From a survey of extant empirical data, absolute thresholds for thermal tolerance for varying forms of cognition were identified. These thresholds were then modeled using a rational power-law description. The implications of the veracity of that description were then identified and analyzed.

RESULTS

Cognitive performance thresholds under thermal stress are advanced as power-law relationships, t = f(T) = c[(T - T_ref)/T_ref]^-α. Coherent scaling parameters for diverse cognitive functionalities are specified that are consistent with increases in deep (core) body temperature. Therefore, scale invariance provides a "universal constant," viz, 20% detriment in mental performance per 10% increase in T deviation, from a comfortable reference temperature T_ref.

CONCLUSION

We know the thermal range within which humans can survive is quite narrow. The presented power-law descriptions imply that if making correct decisions is critical for our future existence, then our functional thermal limits could be much more restricted than previously thought.

APPLICATION

We provide our present findings, such that others can both assess and mitigate the effects of adverse thermal loads on cognition, in whatever human scenario they occur.

The humane use of human beings?

The closing of loops exerts magical effects. This powerful act sculpts both the structural form and the functional expression of the systems which accrue from this ultimate connection. Systems and societies are each erected upon, and composed of, such intricate webs of self-correcting and self-shaping influences. However, without appropriate feedback regulation, these loops can become, in a utilitarian sense, dysfunctional. This is as true for social architectures as it is for any intentionally designed technological system. Here, a sequence of examples are used to expose an evident divergence between what is espoused for our social systems and what is actually enacted therein. Failure of regulation and associated diminution or even disconnection of such regulatory loops leads to an evident and growing dissonance between aspiration and reality. The first two of these examples used here are rather facile and even trivial while the third example is much more serious. All examples provide insight concerning, and expose the ways in which, a fuller understanding of cybernetic principles may rectify such discordant circumstances, at least in principle if not in practice.

On the Dynamics of Conspicuity

OBJECTIVE

To examine the influences of dynamic conspicuity on object recognition and to evaluate the real-world implications of these processes.

BACKGROUND

Conspicuity is the major influence on persons' abilities to recognize the presence of entities within their environment. Shortfalls in sensory and cognitive conspicuity are implicated in many, if not most, real-world systemic failures.

METHOD

The present observations derive from an overview of relevant empirical research allied to a synthetic integration. From these foundations, I articulate a proposed taxonomy through which to parse the essential dimensions of conspicuity.

RESULTS

The taxonomy features three axes related to (a) modality (e.g., visual vs. auditory, etc.), (b) processing directionality (e.g., top-down vs. bottom-up information flow), and finally (c) temporality (i.e., the differences between static vs. dynamic presentations).

CONCLUSION

Existing conspicuity studies have primarily featured static, sensory comparisons. Exploration of the other quadrants of the proposed taxonomy can serve to frame future conspicuity research. This taxonomic description also provides the basis from which to understand failure etiology in a wide spectrum of human-machine systems.

APPLICATION

Improvements in the understanding of conspicuity can help in all domains of HF/E and can serve to reduce failure in a wide variety of operational contexts.

Social Conformity Effects on Trust in Simulation-Based Human-Robot Interaction

OBJECTIVE

We investigated the co-acting influences of communication and social conformity on trust in human-robot interaction.

BACKGROUND

Previous work has investigated aspects of the robot, the human, and the environment as influential factors in the human-robot relationship. Little work has examined the conjoint effects of social conformity and communication on this relationship. As social conformity and communication have been shown to affect human-human trust, there are a priori reasons to believe that they will play an influential role in human-robot trust also.

METHOD

The experiment examined the influences of social conformity and robot communication on trust. A 2 × 2 (communication × social group) design was implemented with each variable having two levels (communication, no communication; positive social group, negative social group).

RESULTS

We created a communication manipulation which we then demonstrated to mediate the trust level between human and robot. However, this influence on trust was overcome by social information in which the subsequent trust level, attributed to the robot, was dominated by expressed social group attitudes to that robot.

CONCLUSION

The results confirm the importance of human social assessments over direct robot communication in setting human-robot trust levels. When social opinions are expressed, observers appear to conform to the trust displayed by the group than relying on their own judgment.

APPLICATION

In human-robot teams, the perceptions of the group may exert a greater impact than even robot communication. This may be especially important when new human members are introduced into such teams.

Analysis-ready datasets for insecticide resistance phenotype and genotype frequency in African malaria vectors

The impact of insecticide resistance in malaria vectors is poorly understood and quantified. Here a series of geospatial datasets for insecticide resistance in malaria vectors are provided, so that trends in resistance in time and space can be quantified, and the impact of resistance found in wild populations on malaria transmission in Africa can be assessed. Specifically, data have been collated and geopositioned for the prevalence of insecticide resistance, as measured by standard bioassays, in representative samples of individual species or species complexes. Data are provided for the Anopheles gambiae species complex, the Anopheles funestus subgroup, and for nine individual vector species. Data are also given for common genetic markers of resistance to support analyses of whether these markers can improve the ability to monitor resistance in low resource settings. Allele frequencies for known resistance-associated markers in the Voltage-gated sodium channel (Vgsc) are provided. In total, eight analysis-ready, standardised, geopositioned datasets encompassing over 20,000 African mosquito collections between 1957 and 2017 are released.

The Relationship Between Trust and Use Choice in Human-Robot Interaction

OBJECTIVE

To understand the influence of trust on use choice in human-robot interaction via experimental investigation.

BACKGROUND

The general assumption that trusting a robot leads to using that robot has been previously identified, often by asking participants to choose between manually completing a task or using an automated aid. Our work further evaluates the relationship between trust and use choice and examines factors impacting choice.

METHOD

An experiment was conducted wherein participants rated a robot on a trust scale, then made decisions about whether to use that robotic agent or a human agent to complete a task. Participants provided explicit reasoning for their choices.

RESULTS

While we found statistical support for the "trust leads to use" relationship, qualitative results indicate other factors are important as well.

CONCLUSION

Results indicated that while trust leads to use, use is also heavily influenced by the specific task at hand. Users more often chose a robot for a dangerous task where loss of life is likely, citing safety as their primary concern. Conversely, users chose humans for the mundane warehouse task, mainly citing financial reasons, specifically fear of job and income loss for the human worker.

APPLICATION

Understanding the factors driving use choice is key to appropriate interaction in the field of human-robot teaming.

Microsaccades Distinguish Looking From Seeing

Understanding our visual world requires both looking and seeing. Dissociation of these processes can result in the phenomenon of inattentional blindness or 'looking without seeing'. Concomitant errors in applied settings can be serious, and even deadly. Current visual data analysis cannot differentiate between just 'looking' and actual processing of visual information, i.e., 'seeing'. Differentiation may be possible through the examination of microsaccades; the involuntary, smallmagnitude saccadic eye movements that occur during processed visual fixation. Recent work has suggested that microsaccades are post-attentional biosignals, potentially modulated by task. Specifically, microsaccade rates decrease with increased mental task demand, and increase with growing visual task difficulty. Such findings imply that there are fundamental differences in microsaccadic activity between visual and nonvisual tasks. To evaluate this proposition, we used a high-speed eye tracker to record participants in looking for differences between two images or, doing mental arithmetic, or both tasks in combination. Results showed that microsaccade rate was significantly increased in conditions that require high visual attention, and decreased in conditions that require less visual attention. The results support microsaccadic rate reflecting visual attention, and level of visual information processing. A measure that reflects to what extent and how an operator is processing visual information represents a critical step for the application of sophisticated visual assessment to real world tasks.

Sustained Attention to Science: A Tribute to the Life and Scholarship of Joel Warm

OBJECTIVE

To provide an evaluative synthesis of the life and scientific contributions of the late Joel Warm.

BACKGROUND

As the doyen of vigilance research, Joel Warm expanded our understanding and horizons concerning this critical response capacity. However, he also made widespread and profound contributions to many other areas of perception and applied psychology, as we elucidate here.

METHOD

Using archival sources, personal histories, and analysis of extant literature documenting Warm's own productivity, we articulate his life in science.

RESULTS

Our synthesis illustrates the continued, broad, influential, and expanding impact that one individual can exert on diverse fields of study. Whole bodies of understanding of human behavior have been illuminated by his exemplary career.

APPLICATION

By understanding his path to success in applied experimental psychology, we anticipate that others will be motivated, inspired, and guided to replicate and even outstrip a lifetime of such seminal and influential contributions. The presence of individuals such as Warm serves as a primary motive in enhancing Humans Factors/Ergonomics Science.

Workload and Performance: Associations, Insensitivities, and Dissociations

OBJECTIVE

The aim of this study was to distill and define those influences under which change in objective performance level and the linked cognitive workload reflections of subjective experience and physiological variation either associate, dissociate, or are insensitive, one to another.

BACKGROUND

Human factors/ergonomics frequently employs users' self-reports of their own conscious experience, as well as their physiological reactivity, to augment the understanding of changing performance capacity. Under some circumstances, these latter workload responses are the only available assessment information to hand. How such perceptions and physiological responses match, fail to match, or are insensitive to the change in primary-task performance can prove critical to operational success. The reasons underlying these associations, dissociations, and insensitivities are central to the success of future effective human-machine interaction.

METHOD

Using extant research on the relations between differing methods of workload assessment, factors influencing their association, dissociation, and insensitivity are identified.

RESULTS

Dissociations and insensitivities occur more frequently than extant explanatory theories imply. Methodological and conceptual reasons for these patterns of incongruity are identified and evaluated.

APPLICATION

We often seek convergence of results in order to provide coherent explanations as bases for future prediction and practical design implementation. Identifying and understanding the causes as to why different reflections of workload diverge can help practitioners toward operational success.

Some pitfalls in the promises of automated and autonomous vehicles

Differing forms of self-operating transportation are already among us and some have been in operation now for an extended period of time. From elevators and escalators to airport transit trams, we already use many fully automatic systems. Now such technologies are very publicly and prominently penetrating into the on-road environment of everyday personal vehicle usage. The present article raises and addresses a number of the specific and more general human factors/ergonomic issues associated with such an evolutionary step. One particular concern is that of identified responsibility when such systems fail to perform flawlessly. The ways in which this (r)evolution will impact the social and cultural fabric of affected societies is also considered. Further observations as to the vector of the future characteristics of these vehicular forms and how they and other autonomous systems will affect our world are examined. The very future of the human experience depends upon the ways in which such systems are designed, enacted and integrated into everyday life and these are fundamentally ergonomic endeavours.Practitioner's Summary: The prominence of practitioners working on advanced human-machine systems will increase with public concerns surrounding self-driving vehicles. Driverless cars are not only a technological step but they will also exert widespread effects throughout society. Practitioners should prepare for these broad socio-technical challenges in an evolving, autonomous world.

Some promises in the pitfalls of automated and autonomous vehicles: A response to commentators

My interlocutors have offered numerous and important responses to my target article. Here, I endeavour to respond to the issues raised. Despite some contentions over specifics, the overall tenor of these commentaries is one of general agreement. One particular challenge, as noted, is how to disseminate our discipline's knowledge beyond the pages of our journals to effect the impact and change in the world to which we aspire. This is a challenge that transcends efforts solely associated with automated vehicles, but it may be in this specific realm that our science can offer its most widespread impact in the immediate, coming future.

Associated patterns of insecticide resistance in field populations of malaria vectors across Africa

The development of insecticide resistance in African malaria vectors threatens the continued efficacy of important vector control methods that rely on a limited set of insecticides. To understand the operational significance of resistance we require quantitative information about levels of resistance in field populations to the suite of vector control insecticides. Estimation of resistance is complicated by the sparsity of observations in field populations, variation in resistance over time and space at local and regional scales, and cross-resistance between different insecticide types. Using observations of the prevalence of resistance in mosquito species from the Anopheles gambiae complex sampled from 1,183 locations throughout Africa, we applied Bayesian geostatistical models to quantify patterns of covariation in resistance phenotypes across different insecticides. For resistance to the three pyrethroids tested, deltamethrin, permethrin, and λ-cyhalothrin, we found consistent forms of covariation across sub-Saharan Africa and covariation between resistance to these pyrethroids and resistance to DDT. We found no evidence of resistance interactions between carbamate and organophosphate insecticides or between these insecticides and those from other classes. For pyrethroids and DDT we found significant associations between predicted mean resistance and the observed frequency of kdr mutations in the Vgsc gene in field mosquito samples, with DDT showing the strongest association. These results improve our capacity to understand and predict resistance patterns throughout Africa and can guide the development of monitoring strategies.

Training for vigilance on the move: a video game-based paradigm for sustained attention

The capacity for superior vigilance can be trained by using knowledge of results (KR). Our present experiments demonstrate the efficacy of such training using a first-person perspective movement videogame-based platform in samples of students and Soldiers. Effectiveness was assessed by manipulating KR during a training phase and withdrawing it in a subsequent transfer phase. Relative to a no KR control condition, KR systematically improved performance for both Soldiers and students. These results build upon our previous findings that demonstrated that a video game-based platform can be used to create a movement-centred sustained attention task with important elements of traditional vigilance. The results indicate that KR effects in sustained attention extend to a first person perspective movement based paradigm, and that these effects occur in professional military as well as a more general population. Such sustained attention training can save lives and the present findings demonstrate one particular avenue to achieve this goal. Practitioner Summary: Sustained attention can be trained by means of knowledge of results using a videogame-based platform with samples of students and Soldiers. Four experiments demonstrate that a dynamic, first-person perspective video game environment can serve to support effective sustained attention training in professional military as well as a more general population.

Human interaction with robotic systems: performance and workload evaluations

We first tested the effect of differing tactile informational forms (i.e. directional cues vs. static cues vs. dynamic cues) on objective performance and perceived workload in a collaborative human-robot task. A second experiment evaluated the influence of task load and informational message type (i.e. single words vs. grouped phrases) on that same collaborative task. In both experiments, the relationship of personal characteristics (attentional control and spatial ability) to performance and workload was also measured. In addition to objective performance and self-report of cognitive load, we evaluated different physiological responses in each experiment. Results showed a performance-workload association for directional cues, message type and task load. EEG measures however, proved generally insensitive to such task load manipulations. Where significant EEG effects were observed, right hemisphere amplitude differences predominated, although unexpectedly these latter relationships were negative. Although EEG measures were partially associated with performance, they appear to possess limited utility as measures of workload in association with tactile displays. Practitioner Summary: As practitioners look to take advantage of innovative tactile displays in complex operational realms like human-robotic interaction, associated performance effects are mediated by cognitive workload. Despite some patterns of association, reliable reflections of operator state can be difficult to discern and employ as the number, complexity and sophistication of these respective measures themselves increase.

Thermal effects on cognition: a new quantitative synthesis

There is little doubt that increases in thermal load beyond the thermo-neutral state prove progressively stressful to all living organisms. Increasing temperatures across the globe represent in some locales, and especially for outdoors workers, a significant source of such chronic load increase. However, increases in thermal load affect cognition as well as physical work activities. Such human cognition has perennially been viewed as the primary conduit through which to solve many of the iatrogenic challenges we now face. Yet, thermal stress degrades the power to think. Here, we advance and refine the isothermal description of such cognitive decrements, founded upon a synthesis of extant empirical evidence. We report a series of mathematical functions which describe task-specific patterns of performance deterioration, linking such degrees of decrement to the time/temperature conditions in which they occur. Further, we provide a simple, free software tool to support such calculations so that adverse thermal loads can be monitored, assessed and (where possible) mitigated to preserve healthy cognitive functioning.

Measuring Resilience

OBJECTIVE

As human factors and ergonomics (HF/E) moves to embrace a greater systems perspective concerning human-machine technologies, new and emergent properties, such as resilience, have arisen. Our objective here is to promote discussion as to how to measure this latter, complex phenomenon.

BACKGROUND

Resilience is now a much-referenced goal for technology and work system design. It subsumes the new movement of resilience engineering. As part of a broader systems approach to HF/E, this concept requires both a definitive specification and an associated measurement methodology. Such an effort epitomizes our present work.

METHOD

Using rational analytic and synthetic methods, we offer an approach to the measurement of resilience capacity.

RESULTS

We explicate how our proposed approach can be employed to compare resilience across multiple systems and domains, and emphasize avenues for its future development and validation.

CONCLUSION

Emerging concerns for the promise and potential of resilience and associated concepts, such as adaptability, are highlighted. Arguments skeptical of these emerging dimensions must be met with quantitative answers; we advance one approach here.

APPLICATION

Robust and validated measures of resilience will enable coherent and rational discussions of complex emergent properties in macrocognitive system science.

State-of-science: situation awareness in individuals, teams and systems

Our review addresses one of the most used, but debated, topics in Ergonomics: Situation Awareness (SA). We examine and elaborate upon key SA models. These models are divided into individual SA, team SA and systems SA categories. Despite, or perhaps because of, the debates surrounding SA it remains an enduring theme for research and practice in the domain of Ergonomics, now for over two decades. A contingent approach, which seeks to match different models of SA to different types of ergonomics problem, enables the differences between positions to be revealed and reconciled, and the practitioner guided towards optimum methodological solutions. Practitioner Summary: Measuring SA in individuals, teams and systems has become a key objective in Ergonomics. One single approach to SA does not fit all problems encountered. This review shows the importance of considering all three types of models and achieving a match between them and the problem at hand.

Imposing limits on autonomous systems

Our present era is witnessing the genesis of a sea-change in the way that advanced technologies operate. Amongst this burgeoning wave of untrammelled automation there is now beginning to arise a cadre of ever-more independent, autonomous systems. The degree of interaction between these latter systems with any form of human controller is becoming progressively more diminished and remote; and this perhaps necessarily so. Here, I advocate for human-centred and human favouring constraints to be designed, programmed, promulgated and imposed upon these nascent forms of independent entity. I am not sanguine about the collective response of modern society to this call. Nevertheless, the warning must be voiced and the issue debated, especially among those who most look to mediate between people and technology. Practitioner Summary: Practitioners are witnessing the penetration of progressively more independent technical orthotics into virtually all systems' operations. This work enjoins them to advocate for sentient, rational and mindful human-centred approaches towards such innovations. Practitioners need to place user-centred concerns above either the technical or the financial imperatives which motivate this line of progress.

Detection of error-related negativity in complex visual stimuli: a new neuroergonomic arrow in the practitioner's quiver

Brain processes responsible for the error-related negativity (ERN) evoked response potential (ERP) have historically been studied in highly controlled laboratory experiments through presentation of simple visual stimuli. The present work describes the first time the ERN has been evoked and successfully detected in visual search of complex stimuli. A letter flanker task and a motorcycle conspicuity task were presented to participants during electroencephalographic (EEG) recording. Direct visual inspection and subsequent statistical analysis of the resultant time-locked ERP data clearly indicated that the ERN was detectable in both groups. Further, the ERN pattern did not differ between groups. Such results show that the ERN can be successfully elicited and detected in visual search of complex static images, opening the door to applied neuroergonomic use. Harnessing the brain's error detection system presents significant opportunities and complex challenges, and implication of such are discussed in the context of human-machine systems. Practitioner Summary: For the first time, error-related negativity (ERN) has been successfully elicited and detected in a visually complex applied search task. Brain-process-based error detection in human-machine systems presents unique challenges, but promises broad neuroergonomic applications.

Design of instructions for evacuating disabled adults

We investigated how the design of instructions can affect performance in preparing emergency stair travel devices for the evacuation of disable individuals. We had three hypotheses: 1) Design of instructions would account for a significant portion of explained performance variance, 2) Improvements in design of instructions would reduce time on task across device type and age group, and 3) There would be a performance decrement for older adults compared to younger adults based on the slowing of older adult information processing abilities. Results showed that design of instructions does indeed account for a large portion of explained variance in the operation of emergency stair travel devices, and that improvements in design of instructions can reduce time on task across device type and age group. However, encouragingly for real-world operations, results did not indicate any significant differences between older versus younger adults. We look to explore ways that individuals with disabilities can exploit these insights to enhance the performance of emergency stair travel devices for use.

Predicting Wolbachia invasion dynamics in Aedes aegypti populations using models of density-dependent demographic traits

BACKGROUND

Arbovirus transmission by the mosquito Aedes aegypti can be reduced by the introduction and establishment of the endosymbiotic bacteria Wolbachia in wild populations of the vector. Wolbachia spreads by increasing the fitness of its hosts relative to uninfected mosquitoes. However, mosquito fitness is also strongly affected by population size through density-dependent competition for limited food resources. We do not understand how this natural variation in fitness affects symbiont spread, which limits our ability to design successful control strategies.

RESULTS

We develop a mathematical model to predict A. aegypti-Wolbachia dynamics that incorporates larval density-dependent variation in important fitness components of infected and uninfected mosquitoes. Our model explains detailed features of the mosquito-Wolbachia dynamics observed in two independent experimental A. aegypti populations, allowing the combined effects on dynamics of multiple density-dependent fitness components to be characterized. We apply our model to investigate Wolbachia field release dynamics, and show how invasion outcomes can depend strongly on the severity of density-dependent competition at the release site. Specifically, the ratio of released relative to wild mosquitoes required to attain a target infection frequency (at the end of a release program) can vary by nearly an order of magnitude. The time taken for Wolbachia to become established following releases can differ by over 2 years. These effects depend on the relative fitness of field and insectary-reared mosquitoes.

CONCLUSIONS

Models of Wolbachia invasion incorporating density-dependent demographic variation in the host population explain observed dynamics in experimental A. aegypti populations. These models predict strong effects of density-dependence on Wolbachia dynamics in field populations, and can assist in the effective use of Wolbachia to control the transmission of arboviruses such as dengue, chikungunya and zika.

Factors Influencing Drivers' Left Turn Decisions

An experiment is reported which examined drivers' responses in turning left across a line of traffic as presented in a closed-loop, interactive, fixed-base driving simulator. Drivers were located near an intersection and instructed to turn left across a stream of on-coming traffic when they felt that it was safe for them to do so. The on-coming stream of traffic was varied in terms of the physical parameters of approach velocity, inter-vehicle time interval, and vehicle type. Specifically, seven velocities (10–70 mph) were crossed with seven gap sizes (3–9 sec) to yield forty-nine within-subject conditions for each of four, between-subject, vehicle types; motorcycle, compact car, large car, and delivery truck. There were ten subjects per vehicle type, giving forty total participants in the experiment. Results indicated differential acceptance of gap and velocity combinations depending upon the type of approaching vehicle. Collisions tended to occur along the boundaries where driver's decisions to reject or accept turns were ambivalent. They also occurred with greater frequency at higher velocity approach rates. Turn decisions were not dependent upon a single physical parameter such as vehicle velocity or inter-vehicle distance, although gap-size generated an arguable influence. Rather, left turn decisions appeared to result from the complex interplay of rate-of-change perceptual variables such as “time-to-contact” and the perceived characteristics of the vehicles themselves. Implications of the results are discussed with respect to the perception of vehicles and turn safety at roadway intersections.

The stress and workload of virtual reality training: the effects of presence, immersion and flow

The present investigation evaluated the effects of virtual reality (VR) training on the performance, perceived workload and stress response to a live training exercise in a sample of Soldiers. We also examined the relationship between the perceptions of that same VR as measured by engagement, immersion, presence, flow, perceived utility and ease of use with the performance, workload and stress reported on the live training task. To a degree, these latter relationships were moderated by task performance, as measured by binary (Go/No-Go) ratings. Participants who reported positive VR experiences also tended to experience lower stress and lower workload when performing the live version of the task. Thus, VR training regimens may be efficacious for mitigating the stress and workload associated with criterion tasks, thereby reducing the ultimate likelihood of real-world performance failure. Practitioner Summary: VR provides opportunities for training in artificial worlds comprised of highly realistic features. Our virtual room clearing scenario facilitated the integration of Training and Readiness objectives and satisfied training doctrine obligations in a compelling engaging experience for both novice and experienced trainees.