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Security surveillance entails many cognitive challenges (e.g., task interruption, vigilance decrements, cognitive overload). To help surveillance operators overcome these difficulties and perform more efficient visual search, gaze-based intelligent systems can be developed. The present study aimed at testing the impact of the Scantracker system—which pinpointed neglected cameras while detecting and correcting attentional tunneling and vigilance decrease—on human scanning behavior and surveillance performance. Participants took part in a surveillance simulation, monitoring cameras and searching for ongoing incidents, and half of them was supported by the Scantracker. Although behavioral surveillance performance was not improved, participants supported by the Scantracker showed more efficient gaze-based measures of surveillance. Moreover, some of these measures were associated with performance, suggesting that scan pattern improvements might lead indirectly to more efficient incident detection. Overall, these results speak to the potential of using gaze- aware intelligent systems to support surveillance operators.

Closed-circuit television (CCTV) is increasingly used as a means to ensure the safety and security of critical infrastructure and public spaces. Operators in control rooms are responsible for monitoring multiple camera feeds that generally exceed the number of screens available. Using a realistic video surveillance simulation, the current study investigates strategies that untrained operators use to deal with this visual overload. The majority of participants adopted a priority strategy by fixating some scenes more than others, as opposed to a parity strategy of devoting roughly equal time across all screens—although participants were largely unaware of the strategy they had used. A parity approach led to better detection performance, perhaps because less time elapsed between viewing each available camera feed thus reducing the probability that an incident could pass unnoticed. The identification of successful scanning strategies can be used to inform operator training.

The failure to notice critical changes in both visual and auditory scenes may have important consequences for performance in complex dynamic environments, especially those related to security, such as aviation, surveillance during major events, and command and control of emergency response. Previous work has shown that a significant number of situation changes remain undetected by operators in such environments. In the current study, we examined the impact of using auditory warning messages to support the detection of critical situation changes and to a broader extent the decision making required by the environment. Twenty-two participants performed a radar operator task involving multiple subtasks while detecting critical task-related events that were cued by a specific type of audio message. Results showed that about 22% of the critical changes remained undetected by participants, a percentage similar to that found in previous work using visual cues to support change detection. However, we found that audio messages tended to bias threat evaluation toward perceiving objects as more threatening than they were in reality. Such findings revealed both benefits and costs associated with using audio messages to support change detection in complex dynamic environments.

Providing decision support to operators in command and control contexts requires careful assessment of its impacts on task performance. Here we describe a human-in-the-loop experiment using a naval air defense testbed to compare three conditions: 1) a baseline interface (DSSBASE; 2) one that displays the temporal proximity of radar aircraft (DSSTEMP); and 3) one which adds a change history panel (DSSCHEX). Threatevaluation accuracy and cognitive models of participants’ judgments did not significantly differ across conditions. Eye-tracking data showed that DSSTEMP lead to a reduced verification of track attributes. Confusion matrices also differed across conditions: DSSTEMP lead to more errors that are “two-categoriesaway” when erroneously classifying hostile aircraft as non-hostile or uncertain. We conclude that in addition to looking at standard metrics of task accuracy and response times, critical insights can be obtained by assessing how different designs for decision support may alter strategies and cognitive processes.

The CSSS microworld simulates the task of a closed-circuit television (CCTV) operator responsible for monitoring multiple CCTV feeds in the context of security surveillance. Operators must manage the display of multiple CCTV feeds, monitor the feeds for critical incidents, and then report detected incidents. The microworld can be used for human factors research, interface design, training and personnel selection, and systems engineering. We present a use case of the CSSS microworld to identify the best predictors of CCTV performance. Our results show that the Automated Operation Span and inattentional blindness tests can predict both CSSS detection rate and false alarms, suggesting that these instruments have the potential for quickly assessing the surveillance competency of candidates. This use case illustrates how the CSSS platform may prove to be useful in the selection of personnel for CCTV operator roles.

Dynamic and complex command and control situations often require the timely recognition of changes in the environment in order to detect potentially malicious actions. Change detection can be challenging within a continually evolving scene, and particularly under multitasking conditions whereby attention is necessarily divided between several subtasks. On-screen tools can assist with detection (e.g., providing a visual record of changes, ensuring that none are overlooked), however, in a high workload environment, this may result in information overload to the detriment of the primary task. One alternative is to exploit the auditory modality as a means to support visual change detection. In the current study, we use a naval air-warfare simulation, and introduce an auditory alarm to coincide with critical visual changes (in aircraft speed/direction) on the radar. We found that participants detected a greater percentage of visual changes and were significantly quicker to detect these changes when they were accompanied by an auditory alarm than when they were not. Furthermore, participants reported that mental demand was lower in the auditory alarm condition, and this was reflected in reduced classification omissions on the primary task. Results are discussed in relation to Wickens’ multiple resource theory of attention and indicate the potential for using the auditory modality to facilitate visual change detection.

Operators working in extreme environments are often confronted with task interruptions. These interruptions tend to impair performance, which can represent a threat to public safety. Most of the tools designed to aid task resumption in such dynamic contexts are post-interruption solutions consisting of providing information about missed events once the interruption is over. The goal of the present study is to test whether a pre-interruption solution consisting of warning operators of an impending interruption can also facilitate interruption recovery. We employed a microworld simulating above-water warfare and compared primary task recovery following an interruption that could either be notified (8 s before it takes place) or not. Results revealed enhanced post-interruption decision accuracy and speed when providing foreknowledge of the imminent interruption. These findings suggest that a pre-interruption warning, which has already proven effective in static contexts, can also support interruption recovery in dynamic settings.

Policy capturing is a judgment analysis method that typically uses linear statistical modeling to estimate expert judgments. A variant to this technique is to capture decision policies using data-mining algorithms designed to handle nonlinear decision rules, missing attributes, and noisy data. In the current study, we tested the effectiveness of a decision-tree induction algorithm and an instance-based classification method for policy capturing in comparison to the standard linear approach. Decision trees are relevant in naturalistic decision-making contexts since they can be used to represent “fast-and-frugal” judgment heuristics, which are well suited to describe human cognition under time pressure. We examined human classification behavior using a simulated naval air defense task in order to empirically compare the C4.5 decision-tree algorithm, the k-nearest neighbors algorithm, and linear regression on their ability to capture individual decision policies. Results show that C4.5 outperformed the other methods in terms of goodness of fit and cross-validation accuracy. Decision-tree models of individuals’ judgment policies actually classified contacts more accurately than their human counterparts, resulting in a threefold reduction in error rates. We conclude that a decision-tree induction algorithm can yield useful models for training and decision support applications, and we discuss the application of judgmental bootstrapping in real time in dynamic environments.

In dynamic environments such as air-traffic control, emergency response and security surveillance, there are severe constraints to information processing and decision-making. Human operators must constantly monitor, assess, and integrate incoming information in order to make optimal decisions in such complex environments. In order to maximize operators’ performance, there is a need for effective technological support for dynamic decision-making. Eye tracking is one promising avenue that can provide online, non-obtrusive indices of cognitive functioning. Using a simulated maritime decision-making environment, we evaluated whether oculometry may be exploited to foretell the decision made by the operator beforehand. Our results showed that pupil dilation and fixation transitions can reveal the upcoming judgment of the human operator by about half a second before the decision. This finding can be useful to design adaptive support tools for dynamic decision-making by integrating the operator’s cognitive state.

Policy capturing is a decision analysis method that typically uses linear statistical modeling to estimate the basis of expert judgments. Using more flexible data mining algorithms may yield more accurate models or instead result in poor functional estimations. The objective of this study is to test the effectiveness of a decision tree induction algorithm for policy capturing in comparison to the standard linear approach. We examined human classification behavior using a simulated naval air-defense task in order to empirically compare the C4.5 decision tree algorithm to linear regression on their ability to capture individual decision policies. The pattern of results shows that C4.5 outperformed linear regression in terms of goodness-of-fit and cross-validation accuracy. Results also show that the decision tree models of individuals’ judgment policies actually classified contacts more accurately than their human counterparts. We conclude that non-linear policy capturing can yield useful models for training and decision support applications.

The LABY microworld, a functional simulation of Air Traffic Control (ATC), captures the underlying processes involved in electronic air traffic management with a simplified version of the operational human-machine interface. LABY is a computer-based human-in-the-loop dynamic environment whereby a controller must issue directional commands to guide aircraft along a predetermined route, while avoiding potential conflicts and dealing concurrently with other incoming information. It can be used for human factors research or system engineering purposes, or configured specifically for use with expert controllers for the training of non-technical skills in ATC. We present a use case of LABY, comparing the efficiency of input devices for ATC: Input times using the mouse were quicker than with the stylus, but error was not greater. We discuss the potential of LABY for system engineering, training and research purposes.

Cardiff University, Cardiff, UK Change detection is required in monitoring and managing complex situations such as air traffic control. Considering that change blindness—the incapacity to detect changes in a visual scene—is a considerable source of human errors and that most studies on change detection have involved static visual scenes, it is crucial to evaluate existing tools designed to help this cognitive function in complex dynamic situations. The goal of the present study was to determine the efficacy of the Change History Explicit (CHEX)—a tool already proven effective when explicit change detection is the only task to execute—when change detection is implicit and intrinsic to a more complex task. Results revealed that the CHEX failed to improve implicit change detection when this task was embedded in a threat-evaluation and weapon-assignment (TEWA) task. Moreover, TEWA performance was hindered and mental workload was perceived as higher when the CHEX was available. Even when the information load imposed by the CHEX was reduced, the tool remained ineffective. This suggests that the nature of the change detection task should be taken into account when designing a decision support system.

Objective: We employed a computer-controlled command-and-control (C2) simulation and recorded eye movements to examine the extent and nature of the inability to detect critical changes in dynamic displays when change detection is implicit (i.e., requires no explicit report) to the operator’s task. Background: Change blindness—the failure to notice significant changes to a visual scene—may have dire consequences on performance in C2 and surveillance operations. Method: Participants performed a radar-based risk-assessment task involving multiple subtasks. Although participants were not required to explicitly report critical changes to the operational display, change detection was critical in informing decision making. Participants’ eye movements were used as an index of visual attention across the display. Results: Nonfixated (i.e., unattended) changes were more likely to be missed than were fixated (i.e., attended) changes, supporting the idea that focused attention is necessary for conscious change detection. The finding of significant pupil dilation for changes undetected but fixated suggests that attended changes can nonetheless be missed because of a failure of attentional processes. Conclusion: Change blindness in complex dynamic displays takes the form of failures in establishing task-appropriate patterns of attentional allocation. Application: These findings have implications in the design of change-detection support tools for dynamic displays and work procedure in C2 and surveillance.

The rate at which technology continues to develop and permeate our lives is such that it has become increasingly easier, and thus more likely, for information to be presented to us via different modalities simultaneously. But to what extent does this confluence of information affect our subsequent judgment and performance? Furthermore, what are the implications for system design when this information is critical to saving our lives and others? This study uses a visual ‘microworld’ simulation of a naval anti-air warfare to investigate whether the content and priority of audio messages that accompany changes in the visual modality assist or hinder performance in the task (identification of change and evaluation of threats). Results indicate that although helping critical change detection, a critical warning in the auditory modality is not as efficient as its visual counterpart. Moreover, audio messages tended to bias threat evaluation towards perceiving objects as more hostile than they were in reality. Such findings have clear implications in regard to the costs and benefits of further exploiting the auditory modality in dynamic visual environments.

Omnipresent in everyday multitasking environments task interruptions are usually detrimental to individual performance. Here, we examined whether teaming up renders an individual less vulnerable to interruptions in complex and dynamic situations. We employed a microworld to simulate command and control in a crisis management situation and to examine the relative impact of interruptions on operators working in a functional dyad versus operators working alone. While task interruption was detrimental to efficacy in supervisory control of both single and team interrupted operators, the latter were less vulnerable than the former. However, teaming up did not translate into faster resumption time, a consequence of the overhead attributable to coordination and communication requirements of collaborative work. These findings suggest that in complex and dynamic environments working in a small team confers more resistance to task interruption than working alone and speed of interruption recovery is no guarantee of quality of recovery.

Temporal awareness is key to successful decision making in a wide range of command and control situations, yet little explicit support to maintaining temporal awareness is provided by Decision Support Systems (DSS) for time-critical decisions. In the context of simulated weapon-target scheduling, the present study compared the decision support gained from two display formats: typical geospatial display and temporal display. The results demonstrated that the temporal display facilitates scheduling performance though its beneficial impact seems to require greater familiarization.

The consensus among influential AIDS experts that heterosexual transmission accounts for 90% of HIV infections in African adults emerged no later than 1988. We examine evidence available through 1988, including risk measures associating HIV with sexual behaviour, health care, and socioeconomic variables, HIV in children, and risks for HIV in prostitutes and STD patients. Evidence permits the interpretation that health care exposures caused more HIV than sexual transmission. In general population studies, crude risk measures associate more than half of HIV infections in adults with health care exposures. Early studies did not resolve questions about direction of causation (between injections and HIV) and confound (between injections and STD). Preconceptions about African sexuality and a desire to maintain public trust in health care may have encouraged discounting of evidence. We urge renewed, evidence-based, investigations into the proportion of African HIV from non-sexual exposures.

Objective: The aim of this study was to test whether inattentional deafness to critical alarms would be observed in a simulated cockpit. Background: The inability of pilots to detect unexpected changes in their auditory environment (e.g., alarms) is a major safety problem in aeronautics. In aviation, the lack of response to alarms is usually not attributed to attentional limitations, but rather to pilots choosing to ignore such warnings due to decision biases, hearing issues, or conscious risk taking. Method: Twenty-eight general aviation pilots performed two landings in a flight simulator. In one scenario an auditory alert was triggered alone, whereas in the other the auditory alert occurred while the pilots dealt with a critical windshear. Results: In the windshear scenario, 11 pilots (39.3%) did not report or react appropriately to the alarm whereas all the pilots perceived the auditory warning in the no-windshear scenario. Also, of those pilots who were first exposed to the no-windshear scenario and detected the alarm, only three suffered from inattentional deafness in the subsequent windshear scenario. Conclusion: These findings establish inattentional deafness as a cognitive phenomenon that is critical for air safety. Pre-exposure to a critical event triggering an auditory alarm can enhance alarm detection when a similar event is encountered subsequently. Application: Case-based learning is a solution to mitigate auditory alarm misperception.