Search

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.

An experiment utilizing an auditory-spatial Stroop paradigm was created to assess whether participants are better able to attend to spatial or semantic information across near and far regions of space. Participants were instructed to attend to either the semantic information of a stimulus or identify the location of where the stimulus came from, depending on the condition. The sounds came from speakers that were physically located in either near space (peripersonal region of space) or far space (extrapersonal region of space) and the words were either “near” or “far.” Results indicate that participants in general were quicker at responding to the semantic condition than the location condition. Furthermore, consistent with findings of many other Stroop-like experiments, there was a significant difference between congruent and incongruent trials in both task conditions. The results of this investigation provide additional insight into how people process different types of information across near and far regions of space.

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.

Tactile displays hold promise as an effective and efficient means of presenting a wide range of information to the driver. This study examined the subjective perceptions of urgency and annoyance for tactile signals of different pulse duration, interpulse interval (IPI), and pulse pattern from devices called tactors located on the wrist, on the waist belt, or in the seat pan. Results revealed significant utility (steep increases in urgency without similarly steep increases in annoyance) for signals presented in pulse durations from 10 to 150 ms with decreasing utility beyond this range (200 ms or greater). Perceived urgency showed a decreasing trend as the IPI increased. Strikingly similar magnitude estimation functions were obtained across the three tactor locations. Results are discussed in terms of their implications for tactile display design in vehicles.

We examined performance and preference for tactile route guidance formats. Participants drove a simulated vehicle through counterbalanced pairings of four distinct cities using one of four navigation systems (three tactile and one auditory control). One tactile system used only the pulse rate, the second system used only tactor location, and the third used both pulse rate and location to convey guidance instructions. All navigation systems provided both a preliminary and an immediate cue indicating to take the next most immediate turn. The pulse-rate route guidance system was the most commonly preferred system. Results also indicate that participants’ ability to accurately retrace their route and identify landmarks did not differ across navigation systems. All four systems resulted in equivalent wayfinding performance and support previous literature indicating that tactile guidance systems can effectively support navigation in unfamiliar environments.

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.

Music sometimes improves performance in sustained attention tasks. But the type of music employed in previous investigations has varied considerably, which can account for equivocal results. Progress has been hampered by lack of a systematic database of music varying in key characteristics like tempo and valence. The aims of this study were to establish a database of popular music varying along the dimensions of tempo and valence and to examine the impact of music varying along these dimensions on restoring attentional resources following performance of a sustained attention to response task (SART) vigil. Sixty-nine participants rated popular musical selections that varied in valence and tempo to establish a database of four musical types: fast tempo positive valence, fast tempo negative valence, slow tempo positive valence, and slow tempo negative valence. A second group of 89 participants performed two blocks of the SART task interspersed with either no break or a rest break consisting of 1 of the 4 types of music or silence. Presenting positive valence music (particularly of slow tempo) during an intermission between two successive blocks of the SART significantly decreased miss rates relative to negative valence music or silence. Results support an attentional restoration theory of the impact of music on sustained attention, rather than arousal theory and demonstrate a means of restoring sustained attention. Further, the results establish the validity of a music database that will facilitate further investigations of the impact of music on performance.

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.

Driver distraction is a persistent threat to traffic safety. External distraction has been examined extensively, but few studies have focused on internal distraction such as mind wandering. Equivocal results from the few existing studies are likely due, at least in part, to different experimental methods. Mind wandering is commonly assessed using either a self-caught or probe-caught method. The current investigation sought to better understand the effects of mind wandering on driving performance using the self-caught method and the probecaught method. In the Self-Caught Experiment, lateral control measures such as, lateral position variability and steering reversal rate were greater when drivers reported on-task thoughts versus mind wandering. In the Probe-Caught Experiment, these results were not replicated using the traditional probe-caught analysis. Instead, when analyzing the results of the Probe-Caught Experiment in a similar manner as the Self-Caught Experiment, the results were replicated. These results highlight methodological concerns in detecting mind wandering while driving. Additional research is needed to determine which method should be employed in future studies.

Determining the most effective modality or combination of modalities for presenting time sensitive information to operators in complex environments is critical to effective display design. This panel of display design experts will briefly review the most important empirical research regarding the key issues to be considered including the temporal demands of the situation, the complexity of the information to be presented, and issues of information reliability and trust. Included in the discussion will be a focus on the relative benefits and potential costs of providing information in one modality versus another and under what conditions it may be preferable to use a multisensory display. Key issues to be discussed among panelists and audience members will be the implications of the existing knowledge for facilitating the design of alerts and warnings in complex environments such as aviation, driving, medicine and educational settings. Copyright 2012 by Human Factors and Ergonomics Society, Inc. All rights reserved.

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.

Through a series of investigations involving different levels of contextual fidelity we devel- oped scales of perceived urgency for several dimensions of the auditory, visual, and tactile modalities. Psychophysical ratings of perceived urgency, annoyance, and acceptability as well as behavioral re- sponses to signals in each modality were obtained and analyzed using Steven's Power Law to allow comparison across modalities. Obtained results and their implications for use as in-vehicle alerts and warnings are discussed.

This symposium describes collaborative research on neuroergonomics, technology, and cognition being conducted at George Mason University and the US Air Force Research Laboratory (AFRL) as part of the Center of Excellence in Neuroergonomics, Technology, and Cognition (CENTEC). Six presentations describe the latest developments in neuroergonomics research conducted by CENTEC scientists. The individual papers cover studies of: (1) adaptive learning systems; (2) neurobehavioral synchronicity during team performance; (3) genetics and individual differences in decision making; (4) vigilance and mindlessness; (5) interruptions and multi-tasking; and (6) development of a simulation capability that integrates measures across these domains and levels of analysis.

Music has wide usage in many situations in everyday life, and has been shown to affect a wide range of behaviors from basic line bisection to driving performance. One hundred fourteen participants ...

Physiological assessment of cognitive processes has become a topic of increased interest. The value of understanding and measuring brain function at work has the potential to improve performance. The emphasis of this paper is to discuss how pupil diameter can be applied to learning. The link between pupil diameter and task difficulty, or cognitive load, has been repeatedly demonstrated for the past 40 years. However there has been little work to date on measuring cognitive load during training or looking at how real time metrics of cognitive load could be used to adapt training. According to Cognitive Load Theory, cognitive load should be reduced as an individual learns a task and he/she relies more on long term memory than working memory. Ten participants completed a simulated unmanned aerial vehicle task in which they had to identify targets and report their direction of movement. There were three levels of increased difficulty. As expected, pupil diameter significantly dropped within each block as participants learned the task, and then increased again at the start of the next level of difficulty. The results suggest that pupil diameter may be a useful metric for assessing when an individual has transferred information into long term memory. Implications for how pupil diameter can be used to drive an adaptive training system are discussed.

Age-related difficulties in speech processing remain a concern, especially as technology continues to depend heavily on successful speech comprehension on the part of users. Event-related potentials (ERPs) have frequently been used to assess age-related changes in the processing of language. Specifically, the amplitude of the ERP is often compared between conditions or groups of interest. In constructing ERPs, many neurophysiologic responses are averaged together to reduce the contribution of uncorrelated background activity in the electroencephalogram (EEG). However, if variability in the timing of each potential on a trial-by-trial basis (i.e., “latency jitter”) is confounded with a variable of interest, then the presence of amplitude differences observed in the average ERP might not be solely the result of genuine amplitude differences, but also timing variability. We examined the role latency jitter may play in the well-established observation of age-related changes in the processing of natural speech...

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.

Electroencephalography (EEG) has the prospect of providing a means to gauge operator workload in a manner that does not intrude on the task being performed. Specifically, it has been proposed that the technique could be used as a method to speed the learning of a task, by adjusting the task to suit the state of the learner. The present study recorded EEG while participants performed a simulated Unmanned Aerial Vehicle (UAV) reconnaissance task. Analysis of power in three EEG frequency bands of interest found differences between the types of task being performed; however more complex analysis may be necessary to discern levels of difficulty within the task.

This experiment compared simulator sickness between males and females as a function of fixed-base versus rotating base platforms. Eight males and eight females drove through two routes in a driving simulator. One route was presented in fixed-base mode and another was presented in motion-base with a .5 to 1 ratio of motion (physical world to virtual world). Routes and fixed versus motion mode were presented in counter- balanced order. Measures of simulator sickness on the Simulator Sickness Questionnaire (Kennedy et al., 1993) were obtained after each route. As predicted, males reported lower levels of simulator sickness than females. A nonsignificant trend for this gender effect to be diminished in the rotating versus stationary condition was observed. Results warrant additional investigation into the potential for motion-based platforms to reduce the incidence and severity of simulator sickness in populations at greater risk of experiencing these negative consequences (i.e., females and older adults).

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.

Twenty-one young (M=21.3) and 19 older (M=73.1) adults completed an aurally administered test of working memory capacity presented at 5 above threshold levels (65, 60, 55, 50, and 45 dB). The test required verification of sentences and recall of sentence final words at the end of each set. Audiometric assessment as well as sentence verification ensured that all auditory stimuli were above hearing levels in both age groups. Both young and older listeners demonstrated reduced working memory capacity scores as stimuli were presented at lower dB levels. The impact of decreases in dB level was greater for older relative to younger adults. But since older adults have elevated hearing thresholds within the range investigated here, the capacity differences observed between the two groups may be negligible. Implications of the results for theories of cognitive aging and for cognitive testing among older adults with subclinical hearing loss are discussed.

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.

Three investigations that demonstrate the importance of considering individual differences when designing in-vehicle navigation systems are described. Drivers were categorised in terms of their spatial awareness and wayfinding strategies, based on brief self-report questionnaires. Experiment 1 revealed individual differences in route learning performance as a function of these categories and display modality (visual, auditory or both). Experiment 2 demonstrated that individuals within these categories use different route learning strategies that place differential demands on verbal vs. visuospatial working memory. Experiment 3 examined the navigational strategies and capabilities of older drivers and offers evidence-based design suggestions. These findings show that individual driver characteristics must be considered in order to reduce the attentional cost of extracting information from in-vehicle navigation systems. Effective displays are not a one size fits all configuration.

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.

Advanced technologies have enabled the choice of either visual or auditory formats for avionics and surface transportation displays. Methods of assessing the mental workload imposed by displays of different formats are critical to their successful implementation. Towards this end a series of investigations were conducted with the following aims: 1) developing analogous auditory and visual versions of a secondary task that could be used to compare display modalities; and 2) to compare the sensitivity of neurophysiological, behavioral and subjective indices of workload. Experiments 1 and 2 confirmed that analogous auditory and visual secondary oddball discrimination tasks were of equivalent difficulty as indicated by P300 amplitude, RT, accuracy and subjective ratings of workload. Experiments 1–3 revealed that RT and accuracy for target detections were generally more sensitive to changes in primary task difficulty than P300 responses and subjective ratings. However, Experiment 3 indicated that P300 amplitude was sensitive to increased perceptual demands (resulting from driving in heavy fog versus clear visibility) not revealed by changes in either behavioral or subjective indices. Together the results of the current investigations indicate that a battery of assessment techniques will provide the most sensitive assessment of workload in complex environments.

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.

The present study investigated the ability of individuals to correctly execute different numbers of commands presented in speech and text format (simulating voice and data link communications). These commands were executed in the presence of different sources of task interference drawing upon visual, verbal, and central executive resources. The results showed that performance decreased as the number of commands in the message set increased from two to four, regardless of presentation format. Visual interference was less disruptive than both verbal and central executive interference. These findings have implications for the design of data link systems and suggest that during periods of high workload, communications should include fewer commands within a message set particularly when there is insufficient time to request clarification.