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Objective: To provide an evaluative overview of the life and contributions of Raja Parasuraman. Background: From his earliest contributions in clarifying and explaining the problematic area of vigilance to his most recent interdisciplinary advances in understanding how genotype relates to behavior in complex technical environments, Raja Parasuraman was a giant of human factors and ergonomics. Our present exposition articulates and recounts his many contributions to our science and to science in general beyond the confines of our own discipline. Method: We use the history of scientific contributions, biographical analysis, and reported personal experience to accomplish our overall assessment of the man and his work. Results: We conclude that Parasuraman’s contributions were unique, substantive, and seminal, and will continue to influence our science for many years to come. Application: This work will serve as a record for those to come who look to make significant contributions to the goals, aims, and aspirations that we set ourselves in human factors and ergonomics in seeking to improve the human condition.

As semiautonomous driving systems are becoming prevalent in late model vehicles, it is important to understand how such systems affect driver attention. This study investigated whether measures from low-cost devices monitoring peripheral physiological state were comparable to standard EEG in predicting lapses in attention to system failures. Twenty-five participants were equipped with a low-fidelity eye-tracker and heart rate monitor and with a high-fidelity NuAmps 32-channel quick-gel EEG system and asked to detect the presence of potential system failure while engaged in a fully autonomous lane changing driving task. To encourage participant attention to the road and to assess engagement in the lane changing task, participants were required to: (a) answer questions about that task; and (b) keep a running count of the type and number of billboards presented throughout the driving task. Linear mixed effects analyses were conducted to model the latency of responses reaction time (RT) to automation signals using the physiological metrics and time period. Alpha-band activity at the midline parietal region in conjunction with heart rate variability (HRV) was important in modeling RT over time. Results suggest that current low-fidelity technologies are not sensitive enough by themselves to reliably model RT to critical signals. However, that HRV interacted with EEG to significantly model RT points to the importance of further developing heart rate metrics for use in environments where it is not practical to use EEG.

Objective: The goal for this study was to develop an English translation of the Attention-Related Driving Errors Scale (ARDES-US) and to determine its potential relationship with driver history and other demographic variables. Background: Individual differences in performance on vigilance and cognitive tasks are well documented, but less is known about susceptibility to attention-related errors while driving. The ARDES has been developed and administered in both Spanish and Chinese but to our knowledge has never been administered or examined in an English-speaking population. Method: Two hundred ninety-six English-speaking individuals completed a series of self-report measures, including the ARDES-US, Attention-Related Cognitive Errors Scale, Mindful Attention Awareness Scale, and Cognitive Failures Questionnaire. Results: A confirmatory factor analysis using maximum-likelihood estimates with robust standard errors revealed results largely consistent with previous versions of the ARDES, namely, the ARDES-Spain and ARDES-Argentina. Additionally, a number of new results emerged. Specifically, women, drivers who received traffic tickets within the previous 2 years, and those with a lower level of education all had a greater propensity toward self-reported driver inattention as measured by the ARDES-US. Further analyses revealed that these findings were independent of age, years of driving experience, and driving frequency. Conclusion: These results suggest that the ARDES-US is a valid and reliable measure of driver inattention with an English-speaking American sample. Application: Potential applications of the ARDES-US include identifying individuals who are at greater risk of attention-related errors while driving and suggesting individually tailored training and safety countermeasures.

Objective We investigated performance, workload, and stress in groups of paired observers who performed a vigilance task in a coactive (independent) manner. Background Previous studies have demonstrated that groups of coactive observers detect more signals in a vigilance task than observers working alone. Therefore, the use of such groups might be effective in enhancing signal detection in operational situations. However, concern over appearing less competent than one’s cohort might induce elevated levels of workload and stress in coactive group members and thereby undermine group performance benefits. Accordingly, we performed the initial experiment comparing workload and stress in observers who performed a vigilance task coactively with those of observers who performed the vigilance task alone. Method Observers monitored a video display for collision flight paths in a simulated unmanned aerial vehicle control task. Self-reports of workload and stress were secured via the NASA-Task Load Index and the Dundee Stress State Questionnaire, respectively. Results Groups of coactive observers detected significantly more signals than did single observers. Coacting observers did not differ significantly from those operating by themselves in terms of workload but did in regard to stress; posttask distress was significantly lower for coacting than for single observers. Conclusion Performing a visual vigilance task in a coactive manner with another observer does not elevate workload above that of observers working alone and serves to attenuate the stress associated with vigilance task performance. Application The use of coacting observers could be an effective vehicle for enhancing performance efficiency in operational vigilance.

In our rapidly diversifying society the needs of sometimes vastly different populations must be considered. The current population is made up of a greater number of older adults, “Baby Boomers” and younger adults “Millenials” than the current middle aged-adult population. These two generations have consistently forced change on many fronts, and will continue to do so, particularly in the area of transportation. This panel is intended to address transportation research and design needs in our ever-diversifying society, from driver-interface (DVI) design to public transportation needs, from increased safety systems to the integration of technology for our navigation of various forms of transportation. Specifically, needs that might require researchers to consider the design of systems to address the sometimes conflicting abilities, desires, cultural and demographic factors, and personal goals related to age groups separated by anywhere from 20 to 60 years in age. Panelists included have a broad range of expertise working with technology, transportation, and both older and younger adult population groups.

Vibrotactile navigation systems can provide drivers with directional information while reducing annoyance from a voice that interrupts on-going music and conversations. However, little is currently known regarding the working memory processes involved in utilizing vibrotactile navigation. Prior research has demonstrated that individuals differ in their sense of direction and ability to navigate and the working memory resources used to carry out the navigation task. Recent research has shown that vibrotactile cues can be used effectively to facilitate navigation while potentially reducing workload. The aim of this study is to examine impact of vibrotactile navigation systems on working memory. Specifically, the aim is to examine how they may differentially impact individuals based upon their sense of direction. It is predicted that the location based information provided by the vibrotactile navigation system may facilitate performance among individuals with a poor sense of direction – because it is not expected to rely on their verbal working memory. Conversely, vibrotactile systems are expected to hinder the performance of individuals with a good sense of direction since they may overload the visuospatial working memory processes. The results of this research will help in better understanding the differences between these individuals and help improve navigation system design to better navigational performance.

Auditory displays are currently used in many medical, automotive and aviation settings. Although there are many existing guidelines for developing effective auditory signals, there is a need for more research considering the interaction between signals within a display, especially when sounds originate from conceptually distinct referent systems. Identifying the parameters that are most relevant to auditory similarity can facilitate acoustic branding and the development of guidelines that ensure signals for different systems are distinct without requiring standardisation. Twenty-seven undergraduate students judged the similarity of a set of abstract sounds varying in tempo, or pulse rate, fundamental frequency and burst density. Results indicate that no single parameter is entirely responsible for determining auditory similarity, but temporal characteristics are most salient. These findings have implications for acoustic branding and suggest that designers intending to ensure perceptual similarity and sep...

Driving research has recently seen a surge in the collection and use of physiological measurements. This use of physiological data is often part of an attempt to either measure cognitive load or detect affective states. While these methods are becoming more popular it seems that many driving researchers are still unsure of the best methods of data collection and analysis. This discussion panel will center around a question and answer session between the audience and experts in techniques for the collection and analysis of physiological measures in the driving research fields to help researchers increase their productivity in this space and provide a forum for frank discussion on methods in the area.

Participants drove a simulated vehicle while completing an n-back task of high or low cognitive demand. Concurrently, they responded via brake press to signals presented in either a single modality (auditory, visual or tactile) or a bimodal combination. Participants were asked to indicate the perceived urgency of each signal by adjusting the force applied in their brake response. Signals were designed to be of “high” or “low” urgency based on previous research for both unimodal and bimodal combinations. Participants were capable of subjectively judging perceived urgency independent of response time and responded to bimodal (relative to unimodal) and high (relative to low) urgency stimuli with significantly greater brake force. However, both factors interacted with cognitive demand indicating that the magnitude of these differential responses was reduced under high demand. Implications for warning evaluation in an in-vehicle driving context are discussed.

In-vehicle forward collision warnings (FCWs) can be presented in visual, auditory or tactile modalities. Across several experiments, unimodal and bimodal warning combinations were compared. Audiovisual and visuotactile FCWs hold promise for improving traffic safety.

The use of machine learning algorithms to classify Mental Workload (MW) from various neurophysiological measures is a growing trend in Human Factors research. Several teams have demonstrated that artificial neural networks (ANNs) can be employed to differentiate highly-dimensional neurophysiological data from participants performing tasks at different levels of cognitive demand in many experimental paradigms. Yet, in other cases, classifier performance was found not to exceed chance levels. One inescapable aspect of neurophysiological measures is the time course associated with data collection. This study directly examined the effect of time on classifier performance. Relative classifier performance values were compared for ANNs trained with EEG data from participants performing a verbal/spatial n-back task at varying load levels. For the vast majority of participants, classifiers trained with data from one session were ineffective when tested with data from a subsequent session. Similarly, classification performance suffered when training and testing tasks were incongruent. In contrast to the very high aggregate performance when trained and tested with data from the same session and same task (M = .81), cross-classification performance was consistently much worse (M = .49 – .53). The relative magnitude of the cross-session and cross-task “costs” to classification were compared, revealing a greater effect for session than task. The authors argue that the mere passage of time causes tonic changes in MW-related features of EEG that severely confound ANNs.

Complex in-vehicle technology and safety systems are finding their way into many cars on the road today. These systems require alerts and warnings that appropriately convey multiple levels of urgency, but if these are deemed excessively annoying, then their implementation may be of little consequence. In this study we used a well-documented psychophysical approach to identify the relationship between specific auditory parameters, perceived urgency and perceived annoyance. In agreement with existing literature, increases in all parameters led to increases in both urgency and annoyance - although differentially. Of the parameters investigated, only pulse rate exhibited a stronger psychophysical relationship with urgency than annoyance. The tradeoff between urgency and annoyance is of practical concern and results from this study provide a potential guideline to determine the viability of future in vehicle alerts based on this relationship.

Tactile vibrations are potentially useful in a variety of environments to communicate information to visually and auditorily overloaded people. However, since vibrotactile signals must come into physical contact with the skin, they may also be perceived as highly urgent and annoying. The current study examined whether scalable levels of perceived urgency could be obtained with tactile signals by measuring the relationship between changes in vibrotactile pulse rate and ratings of urgency and annoyance. In two separate experiments, changes in pulse rate resulted in changes in ratings of perceived urgency with faster pulse rates being perceived as more urgent. Importantly, in both studies pulse rate had a greater impact on perceived urgency than it did on annoyance suggesting that scalable levels of urgency can be achieved without similarly annoying operators. Results are discussed in terms of their implications for multimodal display design.

Waypoint navigation is a critical task for dismounted soldiers, especially when navigating through novel environments with potential threats. In these dangerous environments, the soldiers should have their “eyes-up” and “ears-out” scanning the environment for critical signals. Current practices for dismounted soldiers include the use of a compass and map or small wearable computer in order to navigate. In this experiment, we compared several modalities and multiple combinations of these modalities in waypoint navigation performance. These modalities include two visual (an egocentric and a geocentric map), 3D spatialized audio, tactile, and the multimodal combinations of each. We also examined individual differences in sense of direction as a potential moderator of display usage. Results provide preliminary evidence that localized 3D audio and haptics navigation aids are an intuitive, efficient, and effective means of waypoint navigation, regardless of sense of direction.

Determining the most effective modality to use to draw an operator’s attention to a specific situation has been a topic of recent interest. Making this determination requires ensuring that the signals being compared have been equated for saliency and perceived urgency. We conducted an experiment to examine how perceptions of urgency and annoyance change with changes in physical parameters across auditory, visual, and tactile modalities. While urgency ratings in the low, medium, and high range were found in each modality, parameters such as interpulse interval had a greater impact on perceived urgency than annoyance in the auditory and tactile modality, while having relatively little impact in the visual modality. Results can be used to facilitate the design of alerts and warnings with pre-specified urgency levels while minimizing annoyance and have implications for both research and interface design.

Understanding when operators are experiencing high workload is important in the design and implementation of Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) systems. Fortunately physiological metrics, such as pupillary reflexes, have been shown to correlate with increases in mental workload. This paper proposes an automated method for characterizing and identifying task evoked pupillary responses (TEPR) during various workload levels. This method captures findings and observations from previous TEPR studies in an automated algorithm. This algorithm characterizes the rate of pupil dilation and constriction into a TEPR area metric, which is then used to identify times of increased operator workload. Independent trial analysis shows the benefits of using the TEPR area for distinguishing different workload responses but additional investigation is needed to make the algorithm more robust to individual variability.

Operator vigilance is a vital concern to the Human Factors/Ergonomic community in regard to cockpit monitoring, air-traffic control, border security, baggage inspection, the supervisory control of unmanned aerial vehicles, and the monitoring of anesthesia gauges, among others. Of key interest is the performance of teams of observers because of the reliance of modern operations on good teamwork. Previous literature has examined the efficacy of team vigilance performance by comparing the frequency of target detections by teams in comparison to those obtained by operators working alone. Team performance has consistently exceeded singleoperator performance. The present study replicates this effect and provides the initial experimental investigation of the cost of being a team member. Results indicated that team members worked harder in terms of theta band activity, but reported similar subjective workload values when compared to that of single operators in the performance of a simulated UAV monitoring task. Language: en

This study examined the impact of semantic and acoustics parameters of in-vehicle collision warning system (CWS) alarms on driver response. Thirty participants drove a simulated vehicle through scenarios containing five different unexpected hazard events. As drivers approached the hazard event one of four CWS alarms, counter balanced with the hazard event type, or no alarm (control) was presented. Alarms consisted of the signal word "Notice" or "Danger" presented at either 70 or 85 dBA. Rear-end collision events resulted in the highest crash rate, accounting for 45.4% of all crashes. In these scenarios, CWSs significantly reduced crash rates. CWS alarms with an intermediate urgency level achieved through an interaction of semantics and acoustics ("Danger" at 70 dB and "Notice" at 85 dB) resulted in significant reductions in crash probability. Providing an extremely urgent signal word, "Danger" at a high acoustically urgent presentation level - 85 dB was not effective in reducing crashes, nor was a low urgency signal word, "Notice" presented at a low acoustical urgency level - 70 dB. Implications of these results for the design and implementation of CWS systems and auditory alarms in general, are discussed.

Collision warnings aid drivers in responding to a collision threat. They have been identified as one solution to mitigate the effects of distractions by helping distracted drivers respond to a hazardous situation. In addition to hazard response, collision warnings have been shown to benefit general driving performance (i.e., headway distance) and may also influence how drivers engage in distracting activities. In this study, participants completed 9 driving scenarios over the course of 3 days while performing a visual-manual secondary task. Participants responded to a total of 9 forward collision events in the presence of a collision warning system. Driving and secondary task performance before and after participants' first and fourth exposure to the collision warning were examined. Results indicate that drivers were less willing to engage in the secondary task and were more conservative in their interactions following a collision warning and that adoption of this safer dual-task strategy increased over time.

The use of eye metrics to predict the state of one's mental workload involves reliable and accurate modeling techniques. This study assessed the workload classification accuracy of three data mining techniques; artificial neural network (ANN), logistic regression, and classification tree. The results showed that the selection of model technique and the interaction between model type and time segmentation have significant effects on the ability to predict an individual's mental workload during a recall task. The ANN and classification tree both performed much better than logistic regression with 1-s incremented data. The classification tree also performed much better with data averaged over the full recall task. In addition, the transparency of the classification tree showed that pupil diameter and divergence are significantly more important predictors than fixation when modeling 1-s incremented data.

An auditory spatial Stroop paradigm was used to examine the effects of semantic and spatial audio cue conflict on accuracy and response time. Participants responded to either the semantic meaning or the spatial location of a directional word, which was either congruent (i.e. the word “right” being presented from the right) or incongruent (i.e. the word “right” being presented from the left). Contrary to our predictions, people responded more accurately to the semantic meaning of the directional words relative to spatial audio cues. An interaction between task type and congruency indicated people found it more difficult to ignore the semantic content of the word when performing the location version of this task relative to ignoring the location in the semantic task. Implications of these results for use in driver collision-avoidance warning systems are discussed. The current results indicate that performance benefits gained by the use of directional words in combination with spatial audio may be offset by greater detriment to performance when the warning system presents unreliable or incongruent semantic information.

Driver fatigue is an ill-defined term in the literature. It has been broadly used to refer to a wide range of driver states, each with different causal mechanisms. Technologies currently exist which enable detection of driver fatigue and interventions that have the potential to dramatically reduce crash probability. The successful implementation of these technologies depends on the cause and type of fatigue experienced. Sleep-related (SR) forms of driver fatigue result from accumulated sleep debt, prolonged wakefulness or troughs in the circadian rhythms. SR fatigue is resistant to most intervention strategies. Conversely, technologies for detecting and countering task-related (TR) fatigue (caused by mental overload or underload) are proving to be effective tools for improving transportation safety. Methods of detecting and counteracting the various forms of driver fatigue are discussed. Emphasis is placed on examining the effectiveness of existing and emerging technologies for combating TR forms of driver fatigue.

Visual flight rules flight into instrument meteorological conditions (IMC) account for over 10% of the fatalities in general aviation. Evidence suggests that pilots' assessments of weather conditions are related to their decision to continue. This study investigated pilots' ability to assess ceiling and visibility in a flight simulator. Assessment accuracy did not differ between instrument- and non-instrument-rated pilots for ceiling accuracy, but visibility accuracy was better for non-instrument-rated pilots. The data indicated pilots allowed their estimates of ceiling and visibility to influence each other. That is, pilots tended to judge a ceiling to be higher than it actually was when it was paired with a high visibility. This interaction may play a significant role in pilots' decisions to continue into IMC.

Driver fatigue is associated with increased lane position variability, decreased response time and increased crash rate. Collision avoidance systems (CASs), which are currently installed in many vehicles, have been shown to reduce the crash rates of alert drivers. The current investigation examined the effectiveness of two auditory CAS warnings for reducing crash rates in fatigued young and older drivers faced with a potential rear-end collision. Relative to a no-warning condition, auditory CAS warnings reduced overall crash probability. The presence of a CAS warning was particularly beneficial to reducing crashes in older drivers. Results of this study indicate that auditory CAS warnings may help reduce fatigue-related rearend crashes, particularly among older drivers. Fatigue and sleepiness account for

The current experiment examined the role of working memory components during route-learning as a function of Sense of Direction. Individuals with good or poor sense of direction (GSD/PSD) were selected a priori. Participants learned routes while performing working memory tasks consisting of spatial interference (SI) or verbal interference (VI). Previous empirical research indicates that GSDs rely on visual-spatial strategies while PSDs rely on verbal strategies for navigation. Based on Baddeley's (1992) working memory model we therefore expected route learning performance to be differentially disrupted by SI in GSDs and VI in PSDs. Providing partial support for our prediction, GSDs took more time and made more errors in routes learned during SI relative to VI, and PSDs were slower when traversing routes learned under VI relative to SI. Our findings show strong individual differences in route-learning performance and provide support for tailoring navigation systems and training programs to reflect these differences.

Datalink is a text system used to send messages between ATC and pilots. There are concerns related to changes in information processing demands and responses associated with executing speech and text ATC commands. The timing of interference and the acknowledgement response on command execution performance were examined during the processing of simulated ATC commands. Verbal and central executive (CE) interference tasks were presented before or after the acknowledgement. Participants received both speech and text commands, responded by a verbal or manual acknowledgement, and set the controls in a flight simulator. Results demonstrated an advantage for a manual acknowledgement with longer messages. CE as opposed to verbal interference prior to an acknowledgement had a greater negative effect that was exacerbated in the text condition. The findings are interpreted within the context of a working memory and multiple-resource perspective and implications are discussed with regard to communication processes in aviation.

Auditory route guidance systems (RGSs), relative to electronic maps, facilitate wayfinding and reduce mental workload while having the important safety advantage of allowing drivers to keep their eyes on the road. This interface characteristic is particularly important for novice and older drivers. However, existing auditory RGS instructions may fail to facilitate rapid development of route memory and other forms of spatial knowledge. We sought to determine whether adding salient spatial cues to standard auditory RGS instructions could facilitate route memory. Participants were instructed to learn specific routes while driving a simulated vehicle using one of three auditory RGS formats: standard RGS (SRGS), landmark plus standard RGS (LRGS), or cardinal heading plus standard (CRGS). Participants required significantly fewer trials to learn novel routes and reported lower overall workload when using the LRGS format relative to the SRGS. Further, the LRGS resulted in significantly fewer navigational errors during memory trials relative to both the CRGS and the SRGS. Based on measures of driving performance and workload ratings, supplementing the standard RGS with landmark or cardinal heading information did not appear to excessively increase instruction complexity. Actual or potential applications of this research include designing improved auditory RGS interfaces that facilitate both wayfinding and route memory.

VFR flight into IMC conditions accounts for over 10% of general aviation fatalities each year. Recent research suggests that pilots may not properly assess weather conditions. New graphical weather information systems (GWISs) may positively or negatively influence pilot weather-related judgments. Since GWIS information is not always current it may not be veridical. In the current investigation twenty-four GA pilots made visibility and ceiling estimates of simulated weather conditions either with or without a GWIS display. Pilots generally overestimated weather conditions and their judgments were influenced by the GWIS. The results revealed an interaction between ceiling and visibility that suggests a new model for understanding VFR flight into IMC. The current results suggest an important area for future research into understanding pilots' decisions to continue into deteriorating weather conditions. Results are discussed in terms of advancing aviation decision making models for understanding VFR into IMC flight, and the design of GWIS symbology to foster accurate assessments.

Use of in-vehicle routing and navigational systems (IRANS) is on the rise. IRANS may place additional informational processing demands on drivers thus compromising safety. Driving requires extensive visual processing and therefore auditory route guidance (ARG) systems have important safety advantages. However, relative to visual guidance formats, little attention has been focused on the design components of ARG formats. The current investigation examined the relative impact of three different ARG formats (traditional, cardinal, and landmark) on drivers' ability to learn novel routes through unfamiliar areas in a driving simulator. Results indicated that the inclusion of salient landmark information in ARG instructions facilitated route learning ability for a majority of drivers, relative to traditional ARG information and the inclusion of cardinal directions. Application of these results has the potential to increase transportation safety by decreasing the attentional processing requirements and distraction cost of existing IRANS displays.

Advanced in-vehicle technologies (IVTs) are rapidly being introduced. Methods of assessing the mental workload required by the driving situation are imperative to the safe implementation of these advanced systems. The current investigation compared the sensitivity of an array of assessment techniques to changes in simulated driving task demand. P300 amplitude was sensitive to increased driving task demand due to reduced visibility (presence of fog) but was not sensitive to changes in road type (urban versus freeway). Conversely, RT and accuracy to a secondary task were sensitive to changes in road type but were not sensitive to the visibility manipulation. Subjective workload ratings were not sensitive to either manipulation. Results are discussed in terms of their implications for assessing the impact of environmental factors on the mental workload demands of the driving task and for the design and implementation of adaptive driver interfaces.

It is well acknowledged in the literature that the set of audible alarms supporting a global standard for medical devices (IEC 60601-1-8) is in need of updating. Developments in sound design, computer technology and sound reproduction now make it possible to develop a wider range of possible alarm sounds producing both new challenges and opportunities. In this symposium we discuss and present progress in developing both new audible alarms for IEC 60601-1-8 and a framework for evaluation, covering the processes of design, usability in middleware, testing sounds in realistic work environment, and masking.

Drivers over the age of 65 are increasing rapidly in numbers and are driving more frequently. It is well recognized that older driver safety may be compromised due to age-related changes in cognitive functioning. Less well appreciated, however, is that sensory loss may interact with cognitive changes to compound the threat to safety. A sensory-cognitive interaction theory of ageing is described and its implications are discussed for the design of in-vehicle technologies. A particular area of focus is the difficulties of older drivers in carrying out navigational tasks while simultaneously maintaining safe control of the motor vehicle. Advanced automotive technologies including in-vehicle route guidance and navigational displays have the potential to improve safety and mobility if designed in accordance with the sensory/cognitive abilities of older drivers.

Twenty-two participants drove a simulated vehicle while engaged in a low or high working memory load task and responded to signals presented in auditory, visual and tactile modalities or their bimodal combinations by pressing on the brake. Signals were designed to be of low or high urgency in both unimodal and bimodal combinations. High urgency and bimodal signals were responded to faster than their low urgency and unimodal counterparts. Fewer bimodal signals were missed overall. This bimodal advantage was particularly significant relative to unimodal signals of low urgency in the high working memory load condition. Together these results indicate that hazard mapping can most effectively be obtained by designing with both the perceived urgency level of the signal and modal plurality in mind.

Older drivers constitute the fastest growing segment of the driving population, in terms of both number of drivers and number of miles driven. Accident analyses reveal that older drivers are not able to fully compensate for emerging reductions in perceptual/cognitive capacity. Establishment of a method of assessing older drivers with perceptual/cognitive impairments which place them at risk of accidents is imperative. In this investigation, a subsidiary task of mental arithmetic was demonstrated to be sensitive to age differences in relative mental workload resulting from increased steering task complexity in a simulated driving task. As steering task difficulty increased, verbal response latency to concurrent mental arithmetic problems increased for older, but not younger, participants. Steering error remained stable across single and dual task conditions indicating that the secondary mental arithmetic task did not interfere with steering (primary task) performance. These results provide preliminary support for the use of this assessment technique outside of the laboratory in actual driving situations.

Point to point navigation is a critical and demanding task for dismounted operators, especially while traversing hostile terrains. Visual displays such as a compass, maps, and global positioning systems have been the ubiquitous means of navigation and have proven to be effective; however, these tools require visual attention in an already visually demanding environment. Multiple resource theory proposes that time-sharing between two tasks with the same sensory modality can produce interference and the use of separate perceptual channels can be more effective. Since the dismounted operator's visual attention is already engaged in examining their environment for potential threats, the use of auditory and/or tactile displays could supplement the visual display to provide enhanced waypoint information. The reduction of the operator's visual load to allow for undivided attention to their environment could allow for more efficient and secure navigations through novel environments. The study investigated the effectiveness of waypoint navigation with the use of a visual map, spatialized auditory and tactile displays in a virtual environment. In addition to performance data, as measured by root mean squared error and time of completion, the participants completed usability and perceived mental workload questionnaires pertaining to the utility of the different displays.

Matching the perceived urgency of an alert with the relative hazard level of the situation is critical for effective alarm response. Two experiments describe the impact of acoustic and semantic parameters on ratings of perceived urgency, annoyance and alerting effectiveness and on alarm response speed. Within a simulated driving context, participants rated and responded to collision avoidance system (CAS) messages spoken by a female or male voice (experiments 1 and 2, respectively). Results indicated greater perceived urgency and faster alarm response times as intensity increased from -2 dB signal to noise (S/N) ratio to +10 dB S/N, although annoyance ratings increased as well. CAS semantic content interacted with alarm intensity, indicating that at lower intensity levels participants paid more attention to the semantic content. Results indicate that both acoustic and semantic parameters independently and interactively impact CAS alert perceptions in divided attention conditions and this work can inform auditory alarm design for effective hazard matching. Matching the perceived urgency of an alert with the relative hazard level of the situation is critical for effective alarm response. Here, both acoustic and semantic parameters independently and interactively impacted CAS alert perceptions in divided attention conditions. This work can inform auditory alarm design for effective hazard matching. STATEMENT OF RELEVANCE: Results indicate that both acoustic parameters and semantic content can be used to design collision warnings with a range of urgency levels. Further, these results indicate that verbal warnings tailored to a specific hazard situation may improve hazard-matching capabilities without substantial trade-offs in perceived annoyance.

Adaptive training using neurophysiological measures requires efficient classification of mental workload in real time as a learner encounters new and increasingly difficult levels of tasks. Previous investigations have shown that artificial neural networks (ANNs) can accurately classify workload, but only when trained on neurophysiological exemplars from experienced operators on specific tasks. The present study examined classification accuracies for ANNs trained on electroencephalographic (EEG) activity recorded while participants performed the same (within task) and different (cross) tasks for short periods of time with little or no prior exposure to the tasks. Participants performed three working memory tasks at two difficulty levels with order of task and difficulty level counterbalanced. Within-task classification accuracies were high when ANNs were trained on exemplars from the same task or a set containing the to-be-classified task, (M = 87.1% and 85.3%, respectively). Cross-task classification accuracies were significantly lower (average 44.8%) indicating consistent systematic misclassification for certain tasks in some individuals. Results are discussed in terms of their implications for developing neurophysiologically driven adaptive training platforms.

There have been a number of successes of real-time application of physiological measures in operational environments such as with the control of remotely piloted vehicles (RPV). More recently, similar techniques have been investigated within the context of improving learning. A major challenge of the learning environment is that an individual's ability to perform the task, and thus their workload experienced during the task, are constantly changing. Cognitive Load Theory provides insight into how workload interacts with learning. One aspect of this theory is that as information is learned it reduces working memory demands. This paper discusses results from an RPV training study investigating the effects of workload and learning on pupil diameter. Specifically, pupil diameter decreased overtime as the task difficulty was held constant, and increased as new information was presented. The results of these studies are discussed in terms of how they can be used in a physiologically driven adaptive training system.

Three decades after their publication, Bloom and Fischler’s (1980) sentence completion norms continue to demonstrate widespread utility. The aim of the present study was to extend this contribution by expanding the existing database of high-constraint, high cloze probability sentences. Using the criteria established by Bloom and Fischler, we constructed 398 new sentences and presented these along with 100 sentences from their original list to be normed using a sample of 400 participants. Of the 498 sentences presented, 400 met criteria for high cloze probability—that is, .67 or higher probability of being completed by a specific single word. Of these, 321 sentences were from the new set and an additional 79 were from Bloom and Fischler’s set. A high degree of correspondence was observed between responses obtained by Bloom and Fischler for their high-constraint set. A second experiment utilized an N400 event-related potential paradigm to provide further validation of the contextual constraint for the newly generated set. As expected, N400 amplitude was greater for sentences that violated contextual expectancy by ending in a word other than the newly established completion norm. Sentence completion norms are frequently used in cognitive research, and this larger database of high cloze probability sentences is expected to be of benefit to the research community for many years to come. The full set of stimuli and sentence completion norms from this study may be downloaded from http://brm.psychonomic-journals.org/ content/supplemental.

This paper discusses how the fields of augmented cognition and neuroergonomics can be expanded into training. Several classification algorithms based upon EEG data and occular data are discussed in terms of their ability to classify operator state in real time. These indices have been shown to enhance operator performance within adaptive automation paradigms. Learning is different from performing a task that one is familiar with. According to cognitive load theory (CLT), learning is essentially the act of organizing information from working memory into long term memory. However, our working memory system has a bottleneck in this process, such that when training exceeds working memory capacity, learning is hindered. This paper discusses how CLT can be combined with multiple resource theory to create a model of adaptive training. This new paradigm hypothesizes that a system that can monitor working memory capacity in real time and adjust training difficulty can improve learning.

Automated systems are increasingly being implemented in modern automobiles in an effort to increase safety. Collision avoidance warning systems are an important component of this effort. A spatial auditory Stroop paradigm was used to examine the effects of verbal-spatial cue conflict on response accuracy, reaction time, and driving performance. Participants responded to either the semantic meaning or the spatial location of a directional word, which were either congruent (i.e. the word “right” being presented from the right) or incongruent (i.e. the word “right” being presented from the left), while following a lead car in a simulated driving scenario. Accuracy was worse when participants were responding to the spatial location of a word in an incongruent trial, indicating that participants experienced significant interference when trying to ignore the semantic meaning of the word when it conflicted with the presentation location. Implications for the design of collision-avoidance warning systems are discussed.

Technological advances allow presentation of more information (e.g. alerts, warnings) than operators can process. Effective management of this information requires designing displays and warnings that scale the perceived urgency of the signal to the hazard level it represents. We reviewed existing methods of scaling and propose that determining a user-defined range of acceptable intensities prior to implementing the scaling (the CRASINS method) is most effective. Here, we used the CRASINS method to develop urgency and annoyance scales for visual, auditory, and tactile signals. Parameters examined included interpulse interval (IPI) and pulse duration in the auditory and tactile modalities as well as frequency for auditory and colour for visual stimuli. The greatest range of urgency was obtained with the auditory modality, while visual stimuli result in the lowest levels of annoyance. Manipulations of IPI yielded good utility in all modalities with the highest utility being observed for changes in colour.

Population aging, in combination with improved health care and more active lifestyles well into advanced age, have resulted in an increased number of older adults driving more miles than ever before. Unfortunately, these older drivers are over-represented in motor vehicle crashes and crash-related fatalities. Rather than the risk-tasking behaviors observed in young drivers, the collisions of older drivers frequently involve perceptual-cognitive errors. Advanced in-vehicle technologies have the potential to function as sensory-cognitive aids and may offset the negative impact of age-related changes in sensory and cognitive abilities. Collision Avoidance Systems (CASs) function as sensory aids to augment hazard detection capabilities, and therefore may be of particular benefit to older drivers. Navigation aids can offset the working memory requirements of wayfinding, and auditory guidance directions may reduce the visual demands of searching for street signs and reading maps. However, these advanced systems also have the potential to increase the information processing demands of the driving task or distract drivers, particularly if they are not designed in accordance with the sensory and perceptual capabilities of older adults. A series of experiments aimed at examining the impact of sensory-cognitive characteristics of auditory navigational aids on driver wayfinding, performance on a visual peripheral detection task, and neurophysiological, behavioral and subjective indices of driver mental workload and performance were conducted.

Collision Avoidance Systems (CASs) are increasingly being installed in motor vehicles. Concurrently, verbal warnings are increasingly utilized in aviation, surface transportation, and medical environments. The current driving simulation investigation examined crash avoidance behaviors in high risk driving situations and crash rate reduction as a function of exposure to different types of verbal CAS messages. CAS messages varied in presentation level (PL) and signal word. Post-drive ratings of perceived urgency, alerting effectiveness, and annoyance were also examined. The type of CAS warning presented resulted in significant differences in appropriate crash avoidance behaviors and crash rates. In the current paradigm, the most effective CAS warnings were those of moderate PU, specifically the low PU signal word “notice” presented at high PL and the high PU signal word “danger” presented at low PL. Results are discussed in terms of their implications for CAS warning design and hazard matching applicability.

Speech displays and verbal response technologies are increasingly being used in complex, high workload environments that require the simultaneous performance of visual and manual tasks. Examples of such environments include the flight decks of modern aircraft, advanced transport telematics systems providing invehicle route guidance and navigational information and mobile communication equipment in emergency and public safety vehicles. Previous research has established an optimum range for speech intelligibility. However, the potential for variations in presentation levels within this range to affect attentional resources and cognitive processing of speech material has not been examined previously. Results of the current experimental investigation demonstrate that as presentation level increases within this 'optimum' range, participants in high workload situations make fewer sentence-processing errors and generally respond faster. Processing errors were more sensitive to changes in presentation level than were measures of reaction time. Implications of these findings are discussed in terms of their application for the design of speech communications displays in complex multi-task environments.