304 research outputs found

    An Exploration of the Feasibility of Functional Near-Infrared Spectroscopy as a Neurofeedback Cueing System for the Mitigation of the Vigilance Decrement

    Get PDF
    Vigilance is the capacity for observers to maintain attention over extended periods of time, and has most often been operationalized as the ability to detect rare and critical signals (Davies & Parasuraman, 1982; Parasuraman, 1979; Warm, 1984). Humans, however, have natural physical and cognitive limitations that preclude successful long-term vigilance performance and consequently, without some means of assistance, failures in operator vigilance are likely to occur. Such a decline in monitoring performance over time has been a robust finding in vigilance experiments for decades and has been called the vigilance decrement function (Davies & Parasuraman, 1982; Mackworth, 1948). One of the most effective countermeasures employed to maintain effective performance has been cueing: providing the operator with a reliable prompt concerning signal onset probability. Most protocols have based such cues on task-related or environmental factors. The present dissertation examines the efficacy of cueing when nominally based on operator state (i.e., blood oxygenation of cortical tissue) in a novel vigilance task incorporating dynamic displays over three studies. Results pertaining to performance outcomes, physiological measures (cortical blood oxygenation and heart rate variability), and perceived workload and stress are interpreted via Signal Detection Theory and the Resource Theory of vigilance

    Boredom and Distraction in Multiple Unmanned Vehicle Supervisory Control

    Get PDF
    Operators currently controlling Unmanned Aerial Vehicles report significant boredom, and such systems will likely become more automated in the future. Similar problems are found in process control, commercial aviation, and medical settings. To examine the effect of boredom in such settings, a long duration low task load experiment was conducted. Three low task load levels requiring operator input every 10, 20, or 30 minutes were tested in a our-hour study using a multiple unmanned vehicle simulation environment that leverages decentralized algorithms for sometimes imperfect vehicle scheduling. Reaction times to system-generated events generally decreased across the four hours, as did participants’ ability to maintain directed attention. Overall, participants spent almost half of the time in a distracted state. The top performer spent the majority of time in directed and divided attention states. Unexpectedly, the second-best participant, only 1% worse than the top performer, was distracted almost one third of the experiment, but exhibited a periodic switching strategy, allowing him to pay just enough attention to assist the automation when needed. Indeed, four of the five top performers were distracted more than one-third of the time. These findings suggest that distraction due to boring, low task load environments can be effectively managed through efficient attention switching. Future work is needed to determine optimal frequency and duration of attention state switches given various exogenous attributes, as well as individual variability. These findings have implications for the design of and personnel selection for supervisory control systems where operators monitor highly automated systems for long durations with only occasional or rare input.This work was supported by Aurora Flight Sciences under the ONR Science of Autonomy program as well as the Office of Naval Research (ONR) under Code 34 and MURI [grant number N00014-08-C-070]

    An evaluation of NASA's program in human factors research: Aircrew-vehicle system interaction

    Get PDF
    Research in human factors in the aircraft cockpit and a proposed program augmentation were reviewed. The dramatic growth of microprocessor technology makes it entirely feasible to automate increasingly more functions in the aircraft cockpit; the promise of improved vehicle performance, efficiency, and safety through automation makes highly automated flight inevitable. An organized data base and validated methodology for predicting the effects of automation on human performance and thus on safety are lacking and without such a data base and validated methodology for analyzing human performance, increased automation may introduce new risks. Efforts should be concentrated on developing methods and techniques for analyzing man machine interactions, including human workload and prediction of performance

    Shaped by Design "How User-Interface Design Influences Medical Decision Making: The Role of Monitoring Equipment in Anesthetic Practice"

    Get PDF
    abstract: Objective: The aim of this research is to uncover, via a comprehensive cross study analysis, data patterns that could potentially point to a positive correlation between two main variables: anesthetic monitoring equipment and anesthetic decision making. Of particular interest is the equipment's monitor screen and the extent to which its user interface design influences anesthetic situation awareness (SA) and hence, decision making. It is hypothesized that poor anesthetic diagnosis from inadequate SA may be largely attributable to patient data displays lacking in human factors design considerations. Methods: A systematic search was conducted of existing empirical studies pertaining to patient physiologic monitoring that spanned across interrelated domains, namely, ergonomics, medical informatics, visual computing, cognitive psychology, human factors, clinical monitoring, intensive care medicine, and intelligent systems etc. all published in scholarly research journals between 1970 to August 2012. Anesthetic-related keywords were queried i.e. anesthetic mishaps, patient physiological data displays, anesthetic vigilance etc. (found in Appendix A). This approach yielded a few thousand results, of which 65 empirical studies were pulled. Further extraction of articles having direct connection to the use of data displays within the anesthetic context produced a total of 20 empirical studies. These studies were grouped under two broad categories of Monitoring and Monitors whereby factors directly contributing to the studies' results were identified with the aim to find emerging themes that provide insights involving interface design and medical decision making. Results: There is a direct correlation between user-interface design and decision making. The situation awareness (SA) required for decision making heavily relies upon data displays oriented towards information extraction and integration. In the systematic assessment of empirical studies, it is undeniable how strikingly prominent visual attributes show up as contributing factors to subjects' enhanced performance in the studies. Conclusions: How and to what users direct their perceptual and cognitive resources necessarily influence their perception of the environment, and by extension, their development of situation awareness (SA). Although patient monitoring equipment employed in anesthetic practice has proven to be indispensable in quality patient care, graphical representations of patient data is still far from optimal in the clinical setting. User-interfaces that lend decision support to facilitate SA and subsequent decision making is critical in crisis management.Dissertation/ThesisM.S.D. Design 201

    Hysteresis Effects In Driving

    Get PDF
    This dissertation presents two studies examining the interaction between workload history and driver mental workload. The first experiment focuses on testing for the presence of a hysteresis effect in the driving task. The second experiment examines the proposition that cueing impending periods of higher task demand can reduce the impact of any such potential hysteresis effects. Thirty-two licensed drivers served as participants and all served in both studies. Using the directions provided by a Heads-Up-Display navigation system, participants followed a pre-set route in the simulated environment. At specified points within the drive, the navigation system would purposefully fail which required drivers to relay a ten digit alphanumeric error code to a remote operator in order to reset the system. Results indicated that this increase in task demand from the navigation system\u27s failure leads to a significant increase in perceived mental workload as compared to pre-failure periods. This increase in driver mental workload was not significantly reduced by the time the drive ended, indicating the presence of a hysteresis effect. In the second experiment, the navigation system provided a completely reliable visual warning before failure. Results indicate that cueing had neither an effect on perceived mental workload, nor any ameliorating effect on the hysteretic type effect seen in mental workload recovery. The conclusion of these findings being that the overall safety and efficiency of the surface transportation system would likely improve by designs which accommodate the periods immediately following a reduction in stress. Whether from leaving high demand areas such as work zones or in the period immediately after using a in-car information device such as a GPS or a cell phone, these post-high workload periods are associated with increased variability in driver inputs and levels of mental workload

    Physiological Investigation of Localized Temperature Effects on Vigilance Performance

    Get PDF
    Despite a long history of vigilance research, the relationship between the vigilance decrement and a broad range of physiology measures has not been fully documented. In an attempt to address this gap, an experiment was designed in which participants detected critical signals displayed at random during a 40-minute simulated air traffic control vigilance task. Three localized temperature condition changes, a positive, negative, or no change, were randomly assigned to participants and administered at the halfway point of the task. In addition to collecting performance data, cerebral oximetry, electrocardiography (ECG), and electrooculography (EOG) were utilized to collect a range of physiological signals from participants including cerebral oxygenation levels, heart rate, heart rate variability, blink rate, and interblink intervals. The physiology data when correlated with the decrement indicated by the performance data demonstrated a potential relationship between these measures. By identifying a vigilance decrement in individuals, one or more physiology measures may aid the design of interactive vigilance displays and compensatory measures for overcoming the vigilance decrement

    Remotely Piloted Aircraft: The impact of audiovisual feedback and workload on operator performance

    Full text link
    Remotely piloted aircraft systems (RPAS) offer new possibilities to a growing civilian field. However, unlike pilots of conventionally piloted aircraft, the remote pilot operates in a sensory deprived environment. A reduction in available sensory cues present unique human factors challenges, hence the aim of the present study was to understand the impact of real-time auditory feedback from the RPA on operator performance. Experiment 1 tested conventional pilots manually flying a small multi-rotor RPA under two visual operating conditions. Experiment 2 introduced a non-pilot participant group in an automated configuration. Experiment 3 retained the methodology of the second, but presented an adaptable auditory feedback component, with incremental volumes above and below a comfortable sound level. Key findings revealed transitional instances of auditory feedback being perceived as either sound (i.e., useful information, and/or arousing) or noise (i.e., sound that is unwanted), with results broadly aligned with predicted values associated with behavioural models of performance such as the Maximal Adaptability Model. In addition, no statistical significant differences in task performance (automated flight conditions) between the pilot and non-pilot participants were evident. Together, these findings suggest the ability to include or remove the availability of sensory cueing for remote pilots should be dependent on the stage of flight and associated workload. In addition, they raise questions about the restrictions imposed on who is permitted to operate an RPA. Practically, this gives credence to the inclusion of adaptable sensory cueing in future systems. Furthermore, consideration should be given to licensing operators without conventional flying experience for more complex, automated RPAS operations

    Directly Comparing Handoff Protocols for Pediatric Hospitalists

    Get PDF
    BACKGROUND AND OBJECTIVES: Handoff protocols are often developed by brainstorming and consensus, and few are directly compared. We hypothesized that a handoff protocol (Flex 11) developed using a rigorous methodology would be more favorable in terms of clinicians’ attitudes, behaviors, cognitions, or time-on-task when performing handoffs compared with a prevalent protocol (Situation Background Assessment Recommendation [SBAR]). METHODS: Using a between-groups, randomized control trial design (Flex 11 versus SBAR) during a pilot study in a simulated environment, 20 clinicians (13 attending physicians and 7 residents) received 3 patient handoffs from a standardized physician, managed the patients, and handed off the patients to the same standardized physician. Participants completed surveys assessing their attitudes and cognitions, and behaviors and handoff duration were assessed through observations. RESULTS: All data were analyzed using independent samples t tests. For attitudes, “ease of use” ratings were lower for SBAR participants than Flex 11 participants (P , .01), and “being helpful” ratings were lower for SBAR participants than Flex 11 participants (P 5 .02). For behaviors, results indicate no significant difference in the information acquired between the SBAR and Flex 11 protocols. However, SBAR participants gave significantly less information than Flex 11 participants (P , .01). For cognitions, SBAR and Flex 11 participants reported similar workload except for frustration. For handoff duration, there were no significant differences between the protocols (P 5 .36). CONCLUSIONS: The results suggest that Flex 11 is an efficient, beneficial tool in a simulated environment with pediatric clinicians. Future studies should evaluate this protocol in the inpatient setting

    The Underpinnings of Workload in Unmanned Vehicle Systems

    Get PDF
    This paper identifies and characterizes factors that contribute to operator workload in unmanned vehicle systems. Our objective is to provide a basis for developing models of workload for use in design and operation of complex human-machine systems. In 1986, Hart developed a foundational conceptual model of workload, which formed the basis for arguably the most widely used workload measurement techniquethe NASA Task Load Index. Since that time, however, there have been many advances in models and factor identification as well as workload control measures. Additionally, there is a need to further inventory and describe factors that contribute to human workload in light of technological advances, including automation and autonomy. Thus, we propose a conceptual framework for the workload construct and present a taxonomy of factors that can contribute to operator workload. These factors, referred to as workload drivers, are associated with a variety of system elements including the environment, task, equipment and operator. In addition, we discuss how workload moderators, such as automation and interface design, can be manipulated in order to influence operator workload. We contend that workload drivers, workload moderators, and the interactions among drivers and moderators all need to be accounted for when building complex, human-machine systems
    • …
    corecore